JP2007247381A - Ground consolidation method using plastic gel injection material - Google Patents
Ground consolidation method using plastic gel injection material Download PDFInfo
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- JP2007247381A JP2007247381A JP2006221940A JP2006221940A JP2007247381A JP 2007247381 A JP2007247381 A JP 2007247381A JP 2006221940 A JP2006221940 A JP 2006221940A JP 2006221940 A JP2006221940 A JP 2006221940A JP 2007247381 A JP2007247381 A JP 2007247381A
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- Soil Conditioners And Soil-Stabilizing Materials (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
Description
本発明は浸透性の異なる固結材を併用する地盤固結工法に係り、浸透性の悪い固結材としてシリカ系非硬化性粉状体、或はカルシウム系粉状硬化発現材、流動性調整剤から選んだ素材を有効成分とする流動性可塑状ゲル注入材を地盤中の粗い部分や空隙部分に注入して時間の経過と共に、或は加圧脱水により可塑状ゲルからなる塊状体を地盤の空隙中に填充し、或は地盤中に拡大しながら形成して地盤を拘束し、さらに浸透性の良い方の地盤固結材の注入を併用して地盤強化を図る地盤強化方法に関する。 The present invention relates to a ground consolidation method using a combination of consolidation materials having different permeability, and as a consolidation material having poor permeability, a silica-based non-curable powder, or a calcium-based powder cured material, fluidity adjustment A flowable plastic gel injection material containing the material selected from the agent as the active ingredient is injected into the rough or void area of the ground, and the mass of the plastic gel is ground over time or by pressure dehydration. The present invention relates to a ground strengthening method in which the ground is constrained by being filled in the gap of the material or being expanded in the ground, and the ground is further strengthened by using injection of a ground consolidation material having better permeability.
軟弱地盤等の対象地盤中に固結材を注入して地盤を強化する方法として、従来、以下のような一次注入として、瞬結性注入材やセメントベントナイトを注入し、二次注入として、緩結注入材を注入する工法が知られている。 As a method of strengthening the ground by injecting a solidified material into the target ground such as soft ground, conventionally, a quick setting injection material or cement bentonite is injected as a primary injection as follows, and a slow injection as a secondary injection. A method for injecting a binding material is known.
(1)セメントを主体とする注入材は瞬結注入材として用いると強度発現が早いため、一次注入材注入後に同じ注入孔から二次注入材を注入する場合、二次注入材の注入を阻害する。
また、セメントベントナイトを一次注入材として用いた場合、硬化待ちのために1日以上必要とし、工期が長くなるという問題があった。
(1) Since cement-based injecting material is used as an instantaneous injecting material, its strength develops quickly. Therefore, when the secondary injecting material is injected from the same injection hole after the primary injecting material is injected, the injection of the secondary injecting material is obstructed. To do.
Further, when cement bentonite is used as a primary injection material, it takes 1 day or more for waiting for hardening, and there is a problem that the construction period becomes long.
(2)2つの注入液流路をもつ二重管ロッドを用いて一次注入と二次注入を行う工法では、始めに一次注入材のA液(主剤)とB液(瞬結反応剤)を注入管先端部で二つの流路を経て合流し注入した後、ニ次注入材のA液(主剤)とC液(緩結反応剤)の混合液に切り替える為、注入工程が複雑になる。 (2) In the construction method in which primary injection and secondary injection are performed using a double tube rod having two injection liquid channels, first, the primary injection material A liquid (main agent) and B liquid (instantaneous reaction reagent) After joining and injecting through two flow paths at the tip of the injection tube, the injection process is complicated because it is switched to the mixed liquid of the secondary injection material A liquid (main agent) and C liquid (relaxation reaction agent).
又トンネルや立坑、護岸等地下水の水圧が高かったり水位が変動したり、地下水流がある場合、しばしば瞬結グラウトで粗い部分や空隙を填充した上で浸透性の良い注入材を注入する方法がとられるが、瞬結性グラウトはそれが懸濁型であれ溶液型であれ、大きな空隙や地盤中の粗い部分しか固結せず、しかも粗い空隙の土粒子の表面を覆って固結するのみである。即ち流動性が無いため、粗い部分の表面を薄く填充するのみであって、厚い固結層を形成できない。 Also, when the groundwater pressure is high or the water level fluctuates, such as tunnels, shafts, revetments, etc., or there is a groundwater flow, there is often a method of injecting an injectable material with good permeability after filling rough parts or voids with instantaneous grouting. However, the instant setting grout solidifies only large voids and rough parts in the ground, whether they are suspension type or solution type, and only solidifies the surface of the soil particles in the coarse voids. It is. That is, since there is no fluidity, only the surface of the rough portion is filled thinly, and a thick consolidated layer cannot be formed.
ところで護岸の裏込めのように地下水位が上下したり、地下水が海と陸地間を往復して流動したり、トンネルや立坑のように水圧がかかって長期間継続して地下水が動く条件下では、上述した瞬結グラウトによる固化物は地下水の動きによって破損したり劣化したりして比較的短期間のうちにその止水固結効果を失う。なぜならばそのような地盤は比表面積が小さいため瞬結グラウトによって互いに接着されている土粒子の表面積(単位体積当たりの表面積)が小さく、かつその固結体の厚みが薄くなっているので容易に水圧或は水流によって自由空間側にゲル化物が押し流されて固結効果を失いやすいからである。 By the way, under the condition that the groundwater level fluctuates like backfilling of the revetment, the groundwater flows back and forth between the sea and land, or the groundwater moves continuously for a long time due to water pressure like a tunnel or a shaft. The above-mentioned solidified product due to the instant grouting is damaged or deteriorated by the movement of groundwater, and loses its water-stopping consolidation effect within a relatively short period of time. Because such a ground has a small specific surface area, the surface area of the soil particles (surface area per unit volume) adhered to each other by the instantaneous grouting is small, and the thickness of the solidified body is easily reduced. This is because the gelled product is pushed away to the free space side by water pressure or water flow and easily loses the consolidation effect.
(3)一次注入において瞬結性注入材が溶液型の場合、強度が弱いため瞬結グラウトが侵入し得る粗い部分や空隙は強度の弱い溶液のゲルのみで填充されるため、やはり水圧や水流で簡単に押し出されてしまう。また、瞬結性注入材が懸濁型の場合、吐出口および注入管の周囲には大きな強度で薬液が固結するため、二次注入の浸透を阻害する。 (3) When the instantaneous setting injection material is a solution type in the primary injection, the strength and strength are so weak that rough portions and voids that can penetrate the instantaneous setting grout are filled only with the gel of the weak solution, so It will be pushed out easily. In addition, when the instantaneous setting injection material is of a suspension type, the chemical solution is solidified with high strength around the discharge port and the injection tube, so that the penetration of the secondary injection is inhibited.
(4)二重管ダブルパッカ工法の場合、通常、一次注入にセメントベントナイト(以後CB)を用いるが、CBは固結時間に1日かかり、又、二次注入はその後に注入しなければならないため、工程に時間がかかる。又、CBはゲル化時間が無いため逸脱しやすく拘束効果が不十分であり、又、地下水が流動している場合は固結する前に流出してしまう等の問題点があった。また、可塑状グラウトを大きな空隙の填充や圧入することによって地盤を強化する方法が提案されているが、小さな土粒子間には浸透しないので地盤全体の改良は困難である。 (4) In the case of the double pipe double packer method, cement bentonite (hereinafter referred to as CB) is usually used for the primary injection, but CB takes one day for the consolidation time, and the secondary injection must be injected after that. The process takes time. Moreover, since CB has no gelation time, it is easy to deviate and the restraining effect is insufficient, and when groundwater is flowing, there is a problem that it flows out before consolidation. In addition, a method has been proposed in which the ground is strengthened by filling or pressing a large amount of plastic grout. However, since it does not penetrate between small soil particles, it is difficult to improve the entire ground.
そこで、本発明は流動性の異なる固結材を併用して一体化した改良地盤を形成することを目的とし、浸透性の悪い方の固結材として可塑状ゲル注入材を用いることを特徴とする。 Therefore, the present invention aims to form an improved ground integrated with the use of consolidation materials having different fluidity, and is characterized by using a plastic gel injection material as the consolidation material with poor permeability. To do.
さらに可塑状ゲル注入材として産業副生品であるフライアッシュやスラグや焼却灰や粘土、現場発生の土砂や珪砂等を主材としこれを所定の流動特性が得られるように配合し、或は流動性をよくし或は保水性をよくすることにより脱水を低減して地盤中において固化する迄に塊状体を拡大するために粘土やベントナイト、シルト、増粘剤、解こう材、気泡材等の流動性調整材を加え、これに少量のセメント又は石灰や石膏やスラグ等のカルシウム系硬化発現材と水を所定比率で配合し、所定の条件下で地盤中に圧入し、地盤中に塊状体或は可塑状ゲルによる塊状固結体を造成して、地盤強化を図ることにある。 In addition, fly ash, slag, incinerated ash, clay, earth-generated sand and silica sand, etc., which are industrial by-products as plastic gel injection material, are blended so that the predetermined flow characteristics can be obtained, or Clay, bentonite, silt, thickener, peptizer, foam material, etc. to expand debris by increasing fluidity or water retention and solidifying in the ground In addition to this, a small amount of cement or calcium-based hardened material such as lime, gypsum and slag and water are blended at a predetermined ratio, and pressed into the ground under the prescribed conditions, then lump in the ground. The object is to build a solid solid body or plastic mass to reinforce the ground.
上述本発明の課題を解決するため、本発明の地盤固結法によれば、浸透性の異なる固結材を併用して地盤に注入する地盤固結工法であって、浸透性の悪い方の固結剤として、流動性可塑状ゲル注入材を用いることを特徴とする。この可塑状ゲル注入材は、時間とともに、或いは脱水によって流動性を失って地盤中に注入材そのものの塊状体を形成し、次の成分(1)と(2)と(4)、又は(1)と(2)と(3)と(4)、又は(2)と(3)と(4)を有効成分として含む。
(1)シリカ系非硬化性粉状体(F材)
(2)カルシウム系粉状硬化発現材(C材)
(3)流動性調整材(A材)
(4)水(W材)
In order to solve the above-mentioned problems of the present invention, according to the ground consolidation method of the present invention, it is a ground consolidation method of injecting into the ground in combination with different consolidation materials, and the one with poor permeability As a caking agent, a fluid plastic gel injection material is used. This plastic gel injection material loses its fluidity with time or due to dehydration and forms a lump of the injection material itself in the ground. The following components (1), (2), (4), or (1 ), (2), (3) and (4) or (2), (3) and (4) as active ingredients.
(1) Silica-based non-curable powder (F material)
(2) Calcium-based powder hardening material (C material)
(3) Fluidity adjusting material (A material)
(4) Water (W material)
本発明は浸透性の悪い固結材としてシリカ系非硬化性粉状体、或いはカルシウム系粉状硬化発現材、流動性調整剤から選んだ素材を有効成分とする流動性可塑状ゲル注入材を地盤中の粗い部分や空隙部分に注入して時間の経過とともに、或いは加圧脱水により流動性のある可塑状ゲルから流動性の低減した可塑状ゲルからなる塊状体を地盤の空隙中に填充し、或いは地盤中に拡大しながら形成し、粒子を周辺に押しやり、地盤中に可塑状ゲル固結体そのものの塊状体を形成して地盤を拘束し、さらに、浸透性の良い方の地盤固結材の注入を併用して地盤強化を図る。 The present invention provides a fluid plastic gel injecting material containing a material selected from a silica-based non-curable powder, a calcium-based powder curing agent, and a fluidity regulator as a caking agent having poor permeability. Fill the ground voids with a lump made of a plastic gel with reduced fluidity from a fluid plastic gel with time or by dehydration by injecting into rough or voids in the ground. Alternatively, it is formed while expanding in the ground, pushing the particles to the periphery, forming a lump of plastic gel consolidated body itself in the ground to constrain the ground, The ground will be strengthened by using joint injection.
以下、本発明を添付図面を用いて具体的に詳述する。 Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
本発明は、地盤強化のためには単なる可塑状ゲルの空隙充填と異なって、地盤中に可塑状ゲルを圧入して地盤を拘束状態にし、浸透性の良い注入液で土粒子間浸透を図って地盤を一体化して地盤改良にすることを可能にするものである。これには流動性を有する可塑状ゲルが重要になる。本発明にかかわる可塑状ゲルについて以下に説明する。 In order to strengthen the ground, the present invention is different from mere filling of the plastic gel with a void, and press-fits the plastic gel into the ground to constrain the ground so as to infiltrate the soil particles with a highly permeable injection solution. It is possible to improve the ground by integrating the ground. For this purpose, a plastic gel having fluidity is important. The plastic gel according to the present invention will be described below.
このような拘束効果を得る為には、可塑状注入材が土粒子間浸透する事なく、又注入範囲外へ逸脱する事なく、所定の受け持ち領域内の弱い部分、或いは大きな空隙に塊状に形成され、かつ塊状体が塊状を保ったまま拡大して地盤を密に拘束状態をつくることが必要である。 In order to obtain such a restraining effect, the plastic injection material does not penetrate between the soil particles and does not deviate from the injection range, and is formed in a lump in a weak portion or a large gap in a predetermined holding area. In addition, it is necessary to enlarge the lumps while maintaining the lumps to create a tightly constrained ground.
そこで本発明者は種々の研究を重ねた結果、流動性可塑性グラウトの特徴に着目し上記問題を解決して本発明を完成した。 Therefore, as a result of various studies, the present inventor completed the present invention by focusing on the characteristics of the fluid plastic grout and solving the above problems.
本発明では、可塑状ゲルとは配合後可塑状を呈するグラウトをいう。配合後可塑状を呈した時間をゲル化時間というが、可塑状ゲルはゲル化後も力が加えられれば流動する。即ち、可塑状保持時間を有する。そのまま時間が経てば、或いは脱水によって非可塑性になって、固化して力を加えても流動しなくなる、という特徴を持つ。即ちゲル状態でも流動性をもつため、本発明では「流動性可塑状ゲル」と表現した。 In the present invention, the plastic gel refers to a grout that exhibits a plastic shape after blending. The time when the plasticity is exhibited after blending is referred to as gelation time, but the plastic gel flows if force is applied after gelation. That is, it has a plastic holding time. As time passes, or it becomes non-plastic by dehydration, it has the feature that it does not flow even when solidified and applied with force. That is, since it has fluidity even in a gel state, it is expressed as “fluid plastic gel” in the present invention.
(1)流動性可塑状グラウトは経時的のみならず脱水によってその流動性が低下していく。又、地盤中に圧入されている間はそれがゲル状でありながら、流動性を有し、圧入を停止すると流動性がなくなり再度注入圧を加えると先行したゲルは再び流動し、これを繰り返すことができる。地盤中に圧入された可塑状ゲルは地盤中の空隙あるいは弱い部分で塊状体となりながら長い流動保持時間を保って大きな空隙を填充し、或いは土粒子を周辺に押しやり、地盤中に塊状体を形成し、経時的に或いは加圧脱水によって流動性が低減し、ついには非可塑性となって硬化し、地盤を強化する。 (1) Fluidity of fluid plastic grout decreases not only with time but also with dehydration. Moreover, while it is pressed into the ground, it is gel-like, but has fluidity. When the injection is stopped, the fluidity is lost, and when the injection pressure is applied again, the preceding gel flows again and repeats this. be able to. The plastic gel pressed into the ground becomes a lump in the gap or weak part of the ground while maintaining a long flow holding time to fill the large gap, or push the soil particles to the periphery, and the lump in the ground It is formed and fluidity is reduced with time or by pressure dehydration, eventually becomes non-plastic and hardens, strengthening the ground.
(2)可塑状グラウトはゲル状のまま力を加えれば流動するため、地盤中の大きな空隙のみに充填され、細かい土粒子間には入らない。 (2) Since plastic grout flows when force is applied in the form of a gel, it fills only large voids in the ground and does not enter between fine soil particles.
(3) 可塑状グラウトは脱水されないと強度発現は緩やかだが、加圧によって脱水すると、水粉対比が小さくなって非流動性となり、急激に強度を発現することができる。 (3) If the plastic grout is not dehydrated, its strength will be moderate, but if it is dehydrated by pressurization, it will become non-flowable due to the reduced water powder contrast, and can rapidly develop strength.
(4)地盤の透水性により可塑状グラウトに圧力が加わると、脱水して流動性が失われ、非可塑性ゲルとなり、力を加えても流動しなくなる。また、大きな空隙に填充されたゲルは注入圧力を加えられれば、流動性を有するゲル状のままであっても(可塑状保持時間)、地下水の流れや地下水位の上下にも流動することなく抵抗し、時間と共に硬化して流動性を失う(非可塑状となる)。 (4) If pressure is applied to the plastic grout due to the water permeability of the ground, it will dehydrate and lose its fluidity, become a non-plastic gel, and will not flow even if force is applied. In addition, if the injection pressure is applied to the gel filled in the large gap, even if it remains in the form of a fluid gel (plastic holding time), it will not flow above or below the groundwater flow or the groundwater level. Resist and harden over time to lose fluidity (become non-plastic).
(5) 可塑状グラウトは1液式も1.5ショットも、2ショットでも注入が可能であり、地上部から注入管の吐出口に至る流路の中で長時間流動性を保持することができる(注入管内では脱水されない状態なので、長い可塑状保持時間を有する)。 (5) Plastic grout can be injected in one-pack type, 1.5-shot, or 2-shot, and can maintain fluidity for a long time in the flow path from the ground to the discharge port of the injection pipe. Yes (because it is not dehydrated in the injection tube and has a long plastic hold time).
上述したように、本発明における浸透性の異なる固結材を用いる地盤固結法において、浸透性の悪い方の固結材で注入管周りの空隙を填充するシール効果、注入管周りの粗い部分や弱い部分に圧入して強化するための一次注入材としての効果、あるいは二次注入材を注入中に逸脱してきた場合に注入する逸脱防止効果を得る目的のための可塑状ゲル注入材としては、素材(1)シリカ系非硬化性粉状体(F材)、(2)カルシウム系粉状硬化発現材(C材)、(3)流動性調整材(A材)および(4)水(W材)、又は(1)と(2)と (4)、又は(2)と(3)と(4)を用いて効果的に適用し得るが、弱い部分の強化や基礎の下の大きな空隙の填充と強化、あるいは護岸等の吸出し防止部分の閉塞と強化のために可塑状ゲルの塊状体を拡大しながら大きくしていく方法や、弱い部分をそのまま押し広げて弱い部分の強化も兼ねるという目的のためには(1)と(2)と(3)と(4)又は(1)と(2)と(4)が望ましい。 As described above, in the ground consolidation method using the consolidation material having different permeability in the present invention, the sealing effect of filling the void around the injection tube with the consolidation material having the lower permeability, the rough portion around the injection tube As a plastic gel injection material for the purpose of obtaining the effect of preventing the injection when the secondary injection material deviates during the injection, or the effect as the primary injection material for press-fitting into the weak part and strengthening (1) Silica-based non-curable powder (F material), (2) Calcium-based powder cured material (C material), (3) Fluidity adjusting material (A material) and (4) Water ( W material), or (1), (2), (4), or (2), (3), and (4) can be effectively applied, Enlarging and expanding the mass of plastic gel to fill and reinforce voids or to block and reinforce suction prevention parts such as revetments (1) and (2) and (3) and (4) or (1) and (2) and (1) 4) is desirable.
この場合の注入は一本の注入管から浸透性の悪い注入材と浸透性の良い注入材の併用注入も可能であるが、別々の注入管からそれぞれ注入することもできる。 In this case, the injection material having poor permeability and the injection material having good permeability can be jointly injected from one injection tube, but can also be injected from separate injection tubes.
地盤中の土粒子を押し広げて、地盤中に逸脱する事なく塊状ゲルを拡大して地盤を強化し、かつ浸透性の優れた土粒子間での浸透によって地盤を一体化して強化することを可能にする本発明にかかわる可塑状ゲルは(1)と(2)と(3)と(4)又は(1)と(2)と(4)を用いた流動性可塑状ゲルが適している。 To spread the soil particles in the ground, expand the bulk gel without deviating into the ground and strengthen the ground, and to integrate and strengthen the ground by penetration between soil particles with excellent permeability Suitable plastic gels according to the present invention are fluid plastic gels using (1), (2), (3), (4) or (1), (2) and (4) .
流動性可塑状ゲルは細い砂の間隙には填充されないが、大きな空隙全体をゲルで填充する。更に、注入圧力をもって圧入する事によりゲルのまま流動し、その填充範囲を拡大して厚いゲルによる填充層を形成する。更に、圧入して脱水すれば、或は時間と共に流動性が低下し、非可塑性となって硬化する。このため、注入管まわりの空隙や粗い部分を填充して、短時間のうちに注入対象地盤を拘束状態にする。 The flowable plastic gel does not fill the gaps in the fine sand, but fills the entire large gaps with the gel. Further, the gel is flowed as it is by press-fitting with an injection pressure, and the filling range is expanded to form a filling layer of thick gel. Furthermore, if it press-fits and spin-dry | dehydrates, or fluidity will fall with time, or it will become nonplastic and harden | cure. For this reason, the space | gap and rough part around an injection pipe are filled, and the injection | pouring object ground is restrained in a short time.
又、このような特性から護岸等のシートが破れ、吸い出しが生じて大きな空隙ができた裏込め内の注入孔から注入した場合、自由空間方向にそのまま逸脱してしまう事がなく、可塑状グラウトはゲル状になるが(可塑状ゲル)、流動性がなくなるまで可塑状態を保つ(可塑状保持時間を持つ)ことより、丁度火山の溶岩が温度が低下すると共に少しずつ流動性を失いながら圧力を加えている間は壁状に立ったまま固結範囲を拡大していくと同様な現象が起こって、海側の置石内、並びに裏込め内に生じた大きな空隙に塊状ゲルを拡大しながら吸出し部を全体的に填充して広範囲に固化する。このため海水水位の上昇、降下や水の流動にも固結部分は崩壊されない。 In addition, if a sheet such as a revetment breaks due to such characteristics and is sucked out and injected from the injection hole in the backfill where a large gap is formed, the plastic grout does not deviate as it is in the free space direction. Is in a gel form (plastic gel) but keeps its plastic state until it loses fluidity (has plastic retention time), so the pressure of the volcanic lava just loses its fluidity gradually as the temperature drops. While adding to the wall, the same phenomenon occurs when the consolidation range is expanded while standing in the wall, expanding the massive gel into the large gap created in the seaside stone and in the backfill The suction part is totally filled and solidified over a wide area. For this reason, the consolidated portion is not destroyed even by the rise and fall of the seawater level and the flow of water.
その上で裏込土側に浸透性の良いグラウトを注入すれば、地下水が浸透し得る空隙は全て固結してしまうため、完全にかつ永続的に裏込土の吸出し防止が可能になる。同じ事はトンネルや立坑の止水においても同様である。即ち、瞬結性グラウトの瞬間的止水効果の欠点を解決できる。 If a grout with good permeability is injected into the backfill side, all the voids that can be penetrated by groundwater will consolidate, making it possible to completely and permanently prevent the backfill from being sucked out. The same is true for tunnels and shafts. That is, the shortcoming of the instantaneous water stop effect of the instantaneous setting grout can be solved.
又、以上の特徴をもって流動性可塑状グラウトを浸透性に優れた注入材を地盤中に注入するに当って生じやすい注入範囲外への逸脱、特に地表面の逸脱の防止に用いると極めて有効である事を発明者は見出した。 In addition, the fluid plastic grout having the above characteristics is extremely effective when used to prevent deviations outside the injection range that are likely to occur when an injectable material with excellent permeability is injected into the ground, especially deviation from the ground surface. The inventor found out that there was.
1)二重管注入工法への適用
二重管注入工法は複数の流路を有する二重管ロッドを用いて所定の位置まで削孔後、瞬結グラウトで注入管まわりの空隙の填充と所定の注入ステージの粗い部分を填充した後、緩結グラウトを注入して細い部分を固結する方法である。この場合、瞬結グラウトは主剤A液と瞬結用反応剤B液をそれぞれ別の流路から送液して先端部で合流して瞬結グラウトを注入した後、A液と緩結用反応剤C液を混合又は合流して緩結グラウトの注入に切りかえて注入する。以上を交互に切りかえながら注入ステージを下から上に移動して注入する工法である。
1) Application to the double pipe injection method The double pipe injection method uses a double pipe rod having a plurality of flow channels to drill holes to a predetermined position, and then fills the gap around the injection pipe with the instantaneous grouting. After filling the rough part of the injection stage, a slow grout is injected to consolidate the thin part. In this case, the quick setting grout is prepared by feeding the main agent A liquid and the quick setting reagent B liquid from different flow paths, joining them at the tip and injecting the quick setting grout, and then the liquid A and the slow setting reaction. Agent C solution is mixed or merged and switched to slow grouting injection. In this method, the injection stage is moved from the bottom to the top while switching the above alternately.
ところで、この瞬結グラウトの代わりに可塑性グラウトを注入すると極めて簡便にかつ効果的に二重管注入工法が可能になる。 By the way, if a plastic grout is injected instead of the instantaneous setting grout, a double pipe injection method can be performed very simply and effectively.
(1)二重管ロッドの一方の管路を一次注入材として可塑ゲルの送液管路とし、一方の管路を緩結性の二次注入材とする。まず可塑状ゲルが圧入されると注入管まわりの所定注入ステージを中心として削孔空間が可塑状ゲルで填充される。又粗い部分や弱い部分を中心として可塑状ゲルが圧入される。そして、二重管の吐出口の付近は脱水され非可塑状ゲルとなる。圧力が伝達されにくい空隙では可塑状ゲル状態を保持している。その後注入された二次注入材はゲルを破って可塑状ゲルの入らない細かい部分に注入される。 (1) One pipe line of the double tube rod is used as a primary injection material and a plastic gel liquid supply line, and one pipe line is used as a slow-binding secondary injection material. First, when the plastic gel is press-fitted, the drilling space is filled with the plastic gel around a predetermined injection stage around the injection tube. In addition, the plastic gel is press-fitted around a rough portion or a weak portion. And the vicinity of the discharge port of the double tube is dehydrated to become a non-plastic gel. In the space where pressure is not easily transmitted, the plastic gel state is maintained. Thereafter, the injected secondary injection material breaks the gel and is injected into fine portions where the plastic gel does not enter.
(2)次の注入ステージに注入管を引き上げると、注入管内は脱水されていないため可塑状グラウト送液流路内では可塑状をたもったままである。注入管吐出口付近では注入材が脱水して硬化しているが、後続する管内の可塑状ゲルの圧入によって押し出され、可塑状ゲルは注入管まわりのまだ流動性のある可塑状ゲルを押しやって填充される。 (2) When the injection tube is pulled up to the next injection stage, since the inside of the injection tube is not dehydrated, it remains plastic in the plastic grout liquid flow path. The injection material is dehydrated and hardened in the vicinity of the injection tube outlet, but it is pushed out by the press-fitting of the plastic gel in the subsequent tube, and the plastic gel pushes the still fluid plastic gel around the injection tube. To be filled.
(3)注入圧力によって可塑状ゲルの脱水により管周辺にパッカが形成されるため、その後注入された二次注入材は上部に逸脱することなく、その注入ステージでの地盤細部に注入することができる。 (3) Since a packer is formed around the tube due to the dehydration of the plastic gel due to the injection pressure, the secondary injection material injected thereafter can be injected into the ground details at the injection stage without deviating upward. it can.
(4)一次注入材となる可塑状グラウトは注入管流路内では数時間の流動性を保持できるので、二次注入材と共にそれぞれの注入管内流路から送液する事で一次注入と二次注入を交互に注入すればよく、作業性に優れ、かつ注入工程が短縮される。 (4) Since the plastic grout used as the primary injection material can maintain fluidity for several hours in the injection pipe flow path, the primary injection and the secondary injection can be performed by feeding the liquid from the respective injection pipe flow paths together with the secondary injection material. What is necessary is just to inject | pour alternately, it is excellent in workability | operativity and an injection | pouring process is shortened.
このようにして一次注入の可塑状グラウトは、地盤中の粗い空隙を埋め、或は地盤が弱ければゲルで押し広げて塊状固結体を形成して強化し、二次注入材が細かい部分に浸透することで、大きな改良効果が得られる。又、二次注入材を中に地表面からの逸脱が生じたら直ちに可塑状ゲルを送液して容易に二次注入材の逸脱経路を塞いで逸脱を防止することができる。 In this way, the primary injection plastic grout fills the rough voids in the ground or, if the ground is weak, spreads with a gel to form a massive solid body and strengthens it, so that the secondary injection material is finely divided. By penetrating, a great improvement effect is obtained. Further, when a deviation from the ground surface occurs in the secondary injection material, the plastic gel is fed immediately to easily block the deviation path of the secondary injection material and prevent the deviation.
2)ダブルパッカ工法(マルチパッカ工法)への適用
流動性可塑状グラウトをダブルパッカ工法のシールグラウトや一次注入材として使用する事ができる。可塑状グラウトの場合CBと違って、シールグラウトや一次注入材の硬化待ちする必要がないため直ちに二次注入材を注入できるので、工程を短縮させることができる。
2) Application to the double packer method (multi-packer method) The fluid plastic grout can be used as a seal grout or a primary injection material for the double packer method. In the case of a plastic grout, unlike the CB, since there is no need to wait for the seal grout or the primary injecting material to cure, the secondary injecting material can be immediately injected, so the process can be shortened.
従来のダブルパッカ工法では、注入管まわりと一次注入にはCBを注入していた。しかしCBは固結に時間がかかり、ほぼ1日は固化待ちしてから二次注入をする必要がある。又それ自体ゲル化する機能がないから地表面に逸脱したら地盤の拘束効果がなくなり、二次注入材は前述と同じく地表面や注入領域範囲外へ逸脱しやすくなる。 In the conventional double packer method, CB is injected around the injection tube and in the primary injection. However, CB takes time to consolidate, and it is necessary to wait for solidification for about one day before performing secondary injection. In addition, since it does not have a gelling function itself, if it deviates to the ground surface, the effect of restraining the ground is lost, and the secondary injection material tends to deviate from the ground surface or out of the injection area as described above.
それに対して流動性可塑状グラウトはそれ自体流動性がありながら、地盤中に注入されている間に脱水して流動性が低下して逸脱しやすい部分に填充されて地盤を拘束する。しかも脱水によって急速に硬化発現し、かつ、ゲルであるからブリージングを生じにくく、可塑状ゲルの固化物と地盤の間にすき間を生じないので、二次注入材に対する拘束効果に優れている。それに対してCBは注入液全体が均等にゲル化して固化するのではなく、固形分が沈降して固化するので二次注入材の拘束効果が少ない。 On the other hand, the fluid plastic grout itself has fluidity, but dehydrates while being injected into the ground, and is filled to a portion where the fluidity is lowered and easily deviates to restrain the ground. In addition, it rapidly cures by dehydration, and since it is a gel, it is difficult to cause breathing, and no gap is formed between the solidified product of the plastic gel and the ground, so that it has an excellent restraining effect on the secondary injection material. CB, on the other hand, does not gel and solidify the entire injected solution evenly, but solids settle and solidify, so the secondary injection material has little restraining effect.
又、実施例6,7のマルチパッカ注入管を用いて、所定の注入ステージ毎に注入内管の2つの注入液流路の一方から流動性可塑状グラウトを注入して一次注入を行って注入外管まわりの空隙とその注入ステージにおける粗い部分の粗詰め注入を行い、続いて一方の流路から長いゲル化時間の浸透注入を二次注入として行う工程を各注入ステージに移動しながら行えば、通常のCBによるシールグラウトの注入と硬化待ちを行う必要がないため、極めて工程を短縮できる。しかも一方の管路からの二次注入材の地表面への逸脱が生じたら、直ちに他方の注入流路から流動性可塑状グラウトを注入する事により、簡単に逸脱を防ぎ、地盤を拘束する事が出来る。 In addition, using the multipacker injection pipes of Examples 6 and 7, the flowable plastic grout is injected from one of the two injection liquid channels of the injection inner pipe at each predetermined injection stage, and the primary injection is performed. If the process of performing coarse filling injection of the gap around the outer tube and the rough part in the injection stage and then performing osmotic injection with a long gelation time as a secondary injection from one channel is performed while moving to each injection stage Since there is no need to perform sealing grouting with a normal CB and waiting for curing, the process can be greatly shortened. In addition, if a deviation from the secondary injection material from one pipe line to the ground surface occurs, the flowable plastic grout is immediately injected from the other injection flow path to easily prevent the deviation and restrain the ground. I can do it.
近年、液状化防止注入工法において、注入孔の間隔(2〜4m)を大きくして1孔から十数時間の長いゲル化時間の注入液を数時間から十時間以上送り続けて2〜4mの大きな径の固結体を形成する方法がとられているが、この場合、当然ゲル化時間の長い注入液は地表面や注入範囲外に逸脱しやすくなり、逸脱し始めたら全く注入効果は期待出来なくなる。 In recent years, in the liquefaction prevention injection method, the interval between injection holes (2 to 4 m) is increased, and an injection solution with a long gelation time of 1 to 10 hours is continuously fed for several hours to 10 hours or more. A method of forming a large-diameter solid body is used, but in this case, naturally the injection solution with a long gelation time tends to deviate outside the ground surface or the injection range, and if it begins to deviate, the injection effect is expected at all. It becomes impossible.
ところで、このように浸透性注入液が逸脱し始めたら直ちに一方の管路から可塑性グラウトを注入すれば、その注入液はその逸脱経路に沿って地盤中を流動しながら脱水によって急激に流動性を失い、その逸脱経路を填充してしまうと共に、強度発現するため、その後直ちに浸透性グラウトを注入しても逸脱する事なく所定注入領域に浸透固結するという優れた逸脱防止効果を生ずる。 By the way, as soon as the osmotic infusion solution begins to deviate, if plastic grout is injected from one of the pipes, the infusion solution rapidly flows through the ground along the deviating route and dehydrates rapidly. Since the loss path is lost and the deviation path is filled and strength is developed, an excellent deviation prevention effect is achieved in that the permeable grout is immediately injected into the predetermined injection region without deviating immediately after injection.
本発明にかかわる流動性可塑状ゲルは、注入液が地盤に注入されるまでの流動性と地盤中における流動性の保持と土粒子間浸透することなく空洞充填や塊状固結体の形成と大経への成長という効果を有するため、次に浸透性の優れた注入液で改良する地盤に拘束効果を与えるのに有効である。本発明者はシリカ系非硬化性粉状体と水の混合物が、あるいはシリカ系非硬化性粒状体とカルシウム系硬化発現材と流動性調整材と水の混合物が地盤中における脱水という工程で流動性を保持しながらゲル化物の塊状体が拡大し、脱水の進行に伴い低減して、地盤中で塊状体を形成し、地盤を強化することに着目した。そして地盤中における注入液の以上の流動特性を示す指標として
(1)流動性を示すフロー(テーブルフロー及び/又はシリンダーフロー)とスランプ値
(2)可塑状ゲルによるゲル化時間
(3)可塑状保持時間
(4)非可塑状になる固化時間
に着目した。
The flowable plastic gel according to the present invention has a large fluidity until the injection solution is injected into the ground, the fluidity in the ground, and the formation of large cavities and massive solids without penetration between soil particles. Since it has the effect of growth to warp, it is effective to give a restraining effect to the ground to be improved with an injection solution having excellent permeability. The present inventor found that a mixture of silica-based non-curable powder and water, or a mixture of silica-based non-curable granular material, calcium-based cured material, fluidity adjusting material, and water flows in a process of dehydration in the ground. We focused on strengthening the ground by expanding the gelled mass while maintaining the properties and reducing it as the dehydration progresses, forming a mass in the ground. And, as an indicator of the above flow characteristics of the injected liquid in the ground, (1) Flow (table flow and / or cylinder flow) showing fluidity and slump value (2) Gelation time by plastic gel (3) Plastic state Retention time (4) Focused on the solidification time to become non-plastic.
このうちゲル化時間とは配合後テーブルフローが20cmになる時間とし、可塑状保持時間とはゲル化後、外力を加えても流動しなくなる時間、即ち貫入抵抗値が0.01MN/m2を超えた時点迄の時間としてそれを硬化時間とした。そしてこれらが地盤中における圧入脱水という現象による水粉体比の変化によって大きな影響をうける事に着目した。 Of these, the gelation time is the time when the table flow is 20 cm after blending, and the plasticity retention time is the time after gelation that does not flow even when external force is applied, that is, the penetration resistance value is 0.01 MN / m 2 . It was set as the curing time as the time up to the point in time. We paid attention to the fact that these are greatly influenced by the change of water powder ratio due to the phenomenon of press-fitting dehydration in the ground.
又、更に硬化発現材の量が少なければ強度が低いため、土中で流動性を保ちながら割裂注入される事なく塊状に大きく拡大して注入材自体による塊状固結体が形成されることを見出した。 In addition, since the strength is low if the amount of the hardening developing material is small, it is greatly expanded into a lump without being split injected while maintaining fluidity in the soil, and a lump solid body is formed by the injecting material itself. I found it.
この場合、硬化物の強度が比較的低いため、施工後地盤中にセメント固結体のような高強度の杭を形成する事がない。このため地震による振動にも応力集中による破壊を生じにくく、周辺地盤と一体化を保つことが出来ることに着目した。 In this case, since the strength of the cured product is relatively low, a high-strength pile such as a cement consolidated body is not formed in the ground after construction. For this reason, we focused on the fact that vibrations caused by earthquakes are less likely to break due to stress concentration and can be integrated with the surrounding ground.
本発明者は、上記課題を解決するために種々の研究を行った結果、以下のことが判った。
1)シリカ系非硬化性粉状体、特にスラグやフライアッシュや焼却灰等の焼却過程を経たシリカ粉状体は、セメントや石灰等のCa組成物の少量と反応して、ポラゾン化反応によって初期の段階で表面にCaを吸着して電気的化学的反応を起こし、バインダーとなって擬似的な流動性の低下を生じ、更に脱水をともない水粉体比が小さくなると可塑状ゲルを形成し、更に非可塑状ゲル化物を経て固化する。
As a result of various studies to solve the above problems, the present inventor has found the following.
1) Silica-based non-curable powders, especially silica powders that have undergone incineration processes such as slag, fly ash, and incineration ash, react with a small amount of Ca composition such as cement and lime, and undergo a porazonization reaction. At the initial stage, Ca is adsorbed on the surface to cause an electrochemical reaction, and it becomes a binder, resulting in a pseudo fluidity drop. Further, when the water powder ratio decreases with dehydration, a plastic gel is formed. Further, it solidifies through a non-plasticized gelled product.
このような現象は、地盤中で脱水によって加速し、形成された塊状体が周辺地盤より強度が高ければ充分本発明効果を得る。又、硬化発現材を加えなくてもその流動特性をフロー或はスランプで特定し、或は水粉体比で水分量を特定する事により地盤中で土粒子間に浸透したり、或は脈状に拡散する事なく地盤中に塊状体を形成し、圧入を続ける事により塊状体が拡大する。そしてその地盤中における脱水した塊状体が周辺の圧縮された地盤と同じ強度或はそれよりも大きな強度を保っている限りは地盤強化の役を果たす事を本発明は見出した。 Such a phenomenon is accelerated by dehydration in the ground, and the effect of the present invention is sufficiently obtained if the formed lump is stronger than the surrounding ground. In addition, the flow characteristics can be specified by flow or slump without adding a hardening-expressing material, or the moisture content can be specified by the water / powder ratio to penetrate between soil particles in the ground. A lump is formed in the ground without diffusing into the shape, and the lump is expanded by continuing the press-fitting. The present invention has found that as long as the dehydrated mass in the ground maintains the same strength as the surrounding compressed ground or higher strength, it serves to strengthen the ground.
2)テーブルフロー、スランプ、シリンダーによるフローは、シリカ系粉状体或はそれに硬化発現材を加えた注入液の流動性を示し、テーブルフローが15cm〜25cmの範囲でスランプは10cm〜28cmの範囲、シリンダーによるフローが約10〜26cmの範囲にあり、テーブルフローが20cm付近、スランプが21cm付近、シリンダーによるフローが15cm付近で可塑状ゲルになり経時的に或は脱水による水粉体比の低下と共にフローとスランプは低下する。 2) The table flow, slump, and cylinder flow indicate the fluidity of the injection powder with silica-based powder or a hardened material added to it, the table flow is in the range of 15 to 25 cm, and the slump is in the range of 10 to 28 cm. The flow through the cylinder is in the range of about 10-26 cm, the table flow is around 20 cm, the slump is around 21 cm, and the flow through the cylinder is around 15 cm. At the same time, flow and slump decrease.
シリカ系非自硬性粉状素材と粉状のカルシウム系硬化発現材からなる粉状体の水紛体比、全紛体中の硬化発現材比を調制する事により、上記地盤注入材の地盤中における可塑状流動特性や地盤中における可塑状ゲル化物の拡大を調整して、更に、この可塑状ゲルに到る迄のゲル化時間や可塑状ゲル保持間を促進剤又は遅延剤や流動化剤、解こう剤、気泡材等の添加剤を用いる事によって調整して、作業性や可塑状ゲルの大きさを調整できる。水粉体比が小さすぎたり、硬化発現材比が大きすぎると脱水によって地盤中で塊状ゲルの拡大が阻害されるため、その比率が重要である。 By controlling the ratio of the powdered body consisting of a silica-based non-self-hardening powdered material and a powdered calcium-based hardened material, and the ratio of hardened material in the entire powder, the plasticity of the above ground injection material in the ground is controlled. The flow characteristics and expansion of the plastic gel in the ground are adjusted, and the gelation time until reaching the plastic gel and the holding time of the plastic gel are further increased. It is possible to adjust the workability and the size of the plastic gel by using additives such as a plaster and a foam material. If the water powder ratio is too small, or if the ratio of the cured material is too large, the expansion of the massive gel in the ground is inhibited by dehydration, so that ratio is important.
特に、硬化発現材比が大きいと地盤中で脱水によって急速に大きな強度となりすぎ、ゲルの拡大を防ぐのみならず、周辺土に対して大きなコンクリート体が出来たと同様になり、地盤全体の一体化が妨げられ、地震時に局部的な大きな応力を生じ破壊するため、改良地盤の耐震性が低下する。 In particular, if the ratio of hardened material is large, it becomes too strong due to dehydration in the ground, which not only prevents the gel from spreading, but is similar to the fact that a large concrete body has been created in the surrounding soil, and the entire ground is integrated. This prevents the earthquake resistance of the improved ground because it causes local stress and breaks during an earthquake.
又、地盤中で脱水により塊状体を形成するシリカ系粉状体からなる流動性注入液は、上述した人工の粉状素材のみならず掘削土砂や珪砂等を素材とし、それに粘土や増粘材や保水材を添加して流動化土として所定の流動特性、即ちテーブルフローやスランプ値とし、かつ所定の水粉体比を示すように調整し、かつ脱水してフローが20cm以下になれば可塑状ゲルとなって、土粒子間浸透せず、亀裂逸脱しないように注入する事により周辺地盤がより密になり、これにより、所定の地盤改良する事が出来る。勿論、上記素材として更に硬化発現材を加えれば強度は増加する。 In addition, the fluid injection solution made of silica-based powder that forms a lump by dehydration in the ground is made of not only the above-mentioned artificial powder material but also excavated earth and sand, etc., and clay and thickeners. Or water retaining material is added to make the fluidized soil a predetermined flow characteristic, that is, a table flow or slump value, and adjusted to show a predetermined water-powder ratio, and dehydrated and the flow is reduced to 20 cm or less. It becomes a gel, and the surrounding ground becomes denser by injecting so that it does not penetrate between the soil particles and does not deviate from the cracks, so that the predetermined ground can be improved. Needless to say, the strength increases if a curing material is further added as the material.
3)該地盤注入材の混練や圧送並びに地盤中への圧入に適したワーカビリティは、テーブルフローで12cm以上、好ましくは15cm以上、30cm以内、スランプ5cm以上、好ましくは10cm以上、28cm以内、シリンダーフローで8cmより大きく好ましくは約10cm以上、26cm以内である。スランプやフローを支配する水粉体比の決定が、ワーカビリティや土中における塊状体の形成と拡大に大きく影響する。時間と共に逐次変化するこれらの流動性を的確に判断し、フローによって水粉体比と硬化発現材比を管理して迅速に配合並びに水紛体比を調整することが地盤中に塊状の可塑状ゲルを形成しかつ拡大するために重要である。
3) Workability suitable for kneading and pumping of the ground injection material and press-fitting into the ground is 12 cm or more, preferably 15 cm or more and 30 cm or less in the table flow,
4)添加剤を添加すると添加量に応じた可塑状ゲルを形成するゲルタイムの調整ができる。促進材として水ガラスや硫酸アルミニウム塩を添加することにより容易にフローを小さくしたり、ゲル化時間を短縮する事が出来る。又、スランプを20cm付近から10cm以下に減少させる事が出来る。又地盤中における脱水と共に可塑性ゲルを形成させ、かつそのゲルが可塑状を保持する時間を長くして圧入を継続する事により、塊状ゲルが成長し地盤中に大きな塊状ゲル化物を形成し、更に非可塑状ゲルを経て硬化体に変化させる事が出来る。 4) When an additive is added, the gel time for forming a plastic gel according to the amount added can be adjusted. By adding water glass or aluminum sulfate salt as an accelerator, the flow can be easily reduced or the gelation time can be shortened. Further, the slump can be reduced from around 20 cm to 10 cm or less. Also, by forming a plastic gel together with dehydration in the ground, and continuing the press-fitting for a longer time for the gel to remain in a plastic state, the bulk gel grows and forms a large bulk gel in the ground. It can be changed into a cured product through a non-plastic gel.
この場合、シリカ系粉状体にカルシウム系硬化発現材の混合物をA液とし、水ガラス等の溶液性シリカやアルミニウム塩をB液として合流混合する事により、小さなフローや低スランプの可塑状グラウトを注入する事が出来る。しかし、空洞填充の場合は低いフロー値、低スランプの可塑状グラウトの注入は可能であるが、地盤への圧入工法の場合は地盤中で生ずる脱水によって急速に流動性が失われるため、塊状ゲルの拡大による周辺地盤の圧縮が困難になる。このため合流注入しても注入管吐出口から地盤に注入される時点では、合流液のテーブルフローは12cm以上、スランプは5cmより大きく、シリンダーによるフローは8cmより大きい事が必要である。 In this case, a small flow or low slump plastic grout can be obtained by combining and mixing silica-based powders with a mixture of calcium-based curing agent as solution A and solution silica such as water glass or aluminum salt as solution B. Can be injected. However, it is possible to inject plastic grout with a low flow value and low slump in the case of cavity filling, but in the case of press-fitting to the ground, fluidity is lost rapidly due to dehydration that occurs in the ground. It becomes difficult to compress the surrounding ground due to the expansion of the area. For this reason, it is necessary that the table flow of the merged liquid is 12 cm or more, the slump is larger than 5 cm, and the flow through the cylinder is larger than 8 cm at the time when it is injected into the ground from the injection tube discharge port even if the combined injection is performed.
5)骨材として粘土、土砂等の現場発生土、珪砂を加えることが出来る。骨材は増量材として役立つのみならず、固結強度や流動性の調整にも役立つ。一般に、粉体中の骨材の比率が多くなれば強度は小さくなり、骨材の粒径が大きくなればその流動性は低下する。 5) On-site generated soil such as clay and earth and sand can be added as aggregate. Aggregate not only serves as an extender, but also serves to adjust consolidation strength and fluidity. Generally, the strength decreases as the ratio of aggregate in the powder increases, and the fluidity decreases as the particle size of the aggregate increases.
ベントナイト等の粘土や現場発生土における粘土や、シルトやローム等細粒分や、高分子剤や、増粘材等は保水性や増粘剤としてすぐれ、地盤中に圧入された圧入材の脱水を遅らせ、粉状体に対するバインダーとして作用して擬似的結合性のある流動体として作用し、分離分散することなく塊状ゲルを形成し、その拡大に役立つ。 Clay such as bentonite, clay in the soil generated in the field, fine particles such as silt and loam, polymer agents, thickeners, etc. are excellent as water retention and thickeners, and dewatering of press-fitted materials that have been pressed into the ground It acts as a binder with a pseudo-bonding property by acting as a binder for the powdery substance, and forms a lump gel without being separated and dispersed, and helps to enlarge it.
6)硫酸アルミニウム等のアルミニウム塩や水ガラス(水ガラスと酸を混合して得られた酸性水ガラスも含むものも本発明では水ガラスとしてみなすものとする)を添加するとスランプの減少、フローの減少、粘性の増大を生ずる。地盤中で地盤注入材が脈状に割裂する事なく、可塑状ゲルが地盤中に形成して塊状ゲルが大きく成長するには、硬化材発現比、水紛体比、アルミニウム比、フロー値、スランプ値の範囲、シリカ溶液からのシリカ濃度等、の選定適用方法が重要となる。 6) Addition of aluminum salt such as aluminum sulfate or water glass (including water containing acidic water glass obtained by mixing water glass and acid shall be regarded as water glass in the present invention). Decrease, increase viscosity. In order to grow a massive gel by forming a plastic gel in the ground without causing the ground injection material to split into veins in the ground, the hardened material expression ratio, water body ratio, aluminum ratio, flow value, slump It is important to select and apply the range of values and the silica concentration from the silica solution.
7) セメント系懸濁型グラウトはただでさえ粘性が大きいのにそれを可塑状にすれば地盤中に開口する注入管の注入口からの圧入抵抗並びに注入口に到る迄の送液管の送液抵抗が極めて大きく、かつ送液管やポンプの中で詰まりやすいという問題がある。このため送液を容易にするために薄い配合を用いると地盤中で脈状になる。このため先願技術では裏込め注入と同じように流動性の良いセメント系懸濁液と可塑材を注入管に送液される前の時点で合液して、瞬時に可塑状にして地盤中に圧入後スランプ5cm未満にして圧入する方法が提案された。 7) Even though cement suspension suspension grout is very viscous, if it is made plastic, the resistance to press-fitting from the injection port of the injection tube that opens into the ground and the liquid feed tube up to the injection port There is a problem that the liquid feeding resistance is extremely large and the liquid feeding pipe and the pump are easily clogged. For this reason, if a thin composition is used to facilitate liquid feeding, it becomes a vein in the ground. For this reason, in the technology of the prior application, like the backfill injection, a cement-based suspension with good fluidity and a plastic material are mixed at the time before being sent to the injection pipe, and instantly plasticized into the ground. A method for press-fitting to a slump of less than 5 cm has been proposed.
しかし、注入管の前で可塑状になったセメント系可塑状グラウトが地盤中で脱水によって直ちに高強度になるため、大きな塊状ゲルに成長するのは困難であり、又、大きな注入圧力を必要として注入不能になるか、地盤を破壊して逸脱する。 However, the cementitious plastic grout that has become plastic in front of the injection tube immediately becomes strong due to dehydration in the ground, so it is difficult to grow into a large block gel and requires a large injection pressure. It becomes impossible to inject or it destroys the ground and deviates.
本発明者は研究の結果、地盤中で圧入材が割裂によって逸脱せず、かつ大きな塊状ゲルに成長するための以下の必要条件並びに塊状ゲル化物の生成とその拡大のメカニズムを見出した。 As a result of research, the present inventor has found the following necessary conditions for the press-fit material not to deviate by splitting in the ground and grow into a large lump gel, and the mechanism of formation and expansion of the lump gel.
1.該地盤注入材は、地盤中に注入される迄は流動性があるが、地盤中に注入された後は、地盤を割裂して逸脱しない事。 1. The ground injection material is fluid until it is injected into the ground, but after it is injected into the ground, it should not break off by splitting the ground.
2.該地盤注入材は、地盤中に注入される前の段階で可塑状ゲルに到っているか、地盤中に注入されて加圧脱水によって流動性が低減して可塑状ゲルの塊状体を形成する事。 2. The ground injection material reaches the plastic gel before being injected into the ground, or is injected into the ground and reduced in fluidity by pressure dehydration to form a lump of plastic gel. Thing.
3.塊状体は地盤中で可塑状を保持し、その塊状体はその内部に後続して圧入される可塑状ゲルによって押し拡げられて、塊状体は拡大する。塊状体の外周部では押し拡げられる結果、更に脱水されて非可塑状となり流動性を失い、時間と共に外周部から固化帯を形成して大きな塊状固結体が形成されると共に、その周辺部の土砂の空隙を減少させて押し拡げて、静的に予め固める。 3. The lump retains its plastic shape in the ground, and the lump is expanded by a plastic gel that is subsequently pressed into the lump, thereby expanding the lump. As a result of being expanded at the outer peripheral part of the massive body, it is further dehydrated to become non-plastic and loses its fluidity, and with time, a solidified band is formed from the outer peripheral part to form a large massive consolidated body. It reduces the voids in the earth and sand, spreads them, and pre-sets them statically.
4.塊状体の内部は可塑状を保持している事により、更に該地盤注入材の圧入があれば塊状体の外周部の固化ゾーンがいくつか破れ、可塑状ゲルがその周辺部に押し出されて脱水して非可塑状となり、固化帯が拡大する。固化帯が或る程度以上に硬くなると通常のポンプ圧ではそれをつき破る事が困難になり、圧入不能になる。その時点が塊状固化物の大きさとなる。 4). Since the inside of the lump has a plastic shape, if there is further injection of the ground injection material, some solidification zones on the outer periphery of the lump will be broken, and the plastic gel will be pushed to the periphery to dehydrate it. As a result, it becomes non-plastic and the solidification zone expands. When the solidification zone becomes harder than a certain level, it becomes difficult to break it with normal pump pressure, and press-fit becomes impossible. The time becomes the size of the lump solidified product.
本発明者は研究の結果、送液中の送液管中の抵抗圧やポンプ中における詰まりが生ずる事なく、地盤中に設置された注入管の先端部から地盤中に圧入された後でも流動性を有し、脱水されても可塑状を呈する該地盤注入材を圧入する事によって、地盤中で可塑状保持時間(加圧されれば流動状態になる時間)を有する可塑状ゲルを形成し、更に塊状体が成長する事を見出し、本発明を完成したものである。 As a result of the research, the inventor found that the flow of fluid even after being pressed into the ground from the tip of the injection pipe installed in the ground without causing resistance pressure in the liquid feeding pipe during pumping or clogging in the pump. By press-fitting the ground injection material that has a property and exhibits a plastic shape even when dehydrated, a plastic gel having a plastic holding time (a time when it is pressurized to be in a fluid state) is formed in the ground. Further, the present inventors have found that a massive body grows and completed the present invention.
例えば、表1に示すように同一の硬化発現材比18.50%で水粉体比が35%の配合1、水粉体比が30%の配合2は配合後可塑状ゲルになる迄のゲル化時間はそれぞれ480分、300分を要する。これが水粉体比が25%になるとゲル化時間は2分になる。この事は配合時、地盤中に注入される前迄は可塑状に至っていない注入材が地盤中においては、脱水によって水紛体比が35%から30%(脱水率約15%)さらに25%(脱水率30%)に低下するにつれてゲルタイムが2分迄減少し、可塑状ゲルとなり塊状体を形成する。 For example, as shown in Table 1, blending 1 with the same cured product ratio of 18.50% and water-powder ratio of 35%, and blending 2 with a water-powder ratio of 30% will result in a plastic gel after blending. The gel times require 480 minutes and 300 minutes, respectively. When the water powder ratio is 25%, the gelation time is 2 minutes. This means that at the time of compounding, when the injected material that has not reached the plastic state before being injected into the ground is mixed in the ground, the water body ratio is reduced from 35% to 30% (dehydration rate of about 15%) and further 25% ( As the dehydration rate is reduced to 30%, the gel time is reduced to 2 minutes, forming a plastic gel and forming a lump.
しかもゲル化時では可塑状保持時間は7.5時間であるから塊状ゲルは拡大しブリージングが小さく、粘性が増大して拡散しにくくなり固化物は大きな強度となる。このような特性は従来知られていなかった。 In addition, since the plastic holding time is 7.5 hours at the time of gelation, the bulk gel expands, the breathing is small, the viscosity increases, it is difficult to diffuse, and the solidified product has high strength. Such characteristics have not been known so far.
即ち、流動性注入材は地盤中に圧入されてから水粉体比が35%から25%迄脱水する迄はゲル化に到らず、25%(脱水率約30%)になって2分後には、可塑状ゲルを形成し、その時点での可塑状保持時間は7.5時間であって、圧入が続くにつれゲル状のまま大きく生成し、更に脱水或は硬化現象の進行にともない、非流動性ゲルとなり固化する事を物語っている。 That is, the flowable injection material does not reach gelation until the water powder ratio is dehydrated from 35% to 25% after being pressed into the ground, and becomes 25% (dehydration rate of about 30%) for 2 minutes. Later, a plastic gel was formed, and the plastic holding time at that time was 7.5 hours. As the press-fitting continued, the gel-like gel was greatly formed, and as the dehydration or curing phenomenon progressed, It tells that it becomes a non-flowable gel and solidifies.
従って、このように注入時点で可塑状を呈していなくても地盤中の脱水によって可塑状になり得る。このような流動性注入液の注入においては配合液を一液のまま注入しても紛状体注入液をA液とし、アルミニウム、水ガラス等のゲル化促進材をB液とし、合流注入しようと、或はA液を可塑状ゲルとし、B液を水ガラス等のゲル化促進剤としようとその手段は問わないで施工する事が出来る。 Therefore, even if it does not exhibit plasticity at the time of injection, it can become plastic by dehydration in the ground. In the injection of such fluid injection solution, even if the compounding solution is injected as a single solution, the powder injection solution is set as A solution, and the gelation promoting material such as aluminum and water glass is set as B solution. Alternatively, the liquid A can be applied to any plastic gel and the liquid B can be used as a gelation accelerator such as water glass regardless of the means.
以上の本発明者による研究の結果、以下のようにして可塑状ゲル注入材を圧入して地盤中に大きな塊状体を形成して強度増加して、さらに浸透性の良いグラウトを注入することにより地盤を一体化して設計可能な信頼性のある地盤改良工法を可能になった。 As a result of the above research by the present inventors, the plastic gel injection material is press-fitted as follows to form a large lump in the ground to increase the strength, and by injecting grout with better permeability A reliable ground improvement method that can be designed by integrating the ground has become possible.
1.注入液そのものはポンプによる流動性があるが、地盤中に注入したものが脈状に割裂を生じて不特定に浸透して固結しないようにする。なぜならば、それぞれの注入孔の受け持ち範囲内でゲル化物による塊状固結体が形成されて初めてその受け持ち範囲における土粒子間隙が減少し、塊状固結体周辺の注入孔間の地盤の密度増加が確実に期待できるからである。 1. The infusion solution itself has fluidity by the pump, but the one injected into the ground is split into veins so that it does not penetrate and solidify. This is because the gap between the soil particles in the area of the aggregate is reduced, and the density of the ground between the injection holes around the aggregate is increased only after the aggregates are formed by the gelled material within the range of the injection holes. It is because it can be expected with certainty.
2.地盤中に注入したものが土粒子間浸透しないようにして複数の注入孔間の地盤の土粒子を塊状体で押しのけるようにする。なぜならば、土粒子間に注入液が浸透したのでは、複数の注入孔の間の地盤を圧縮することが出来ず、注入孔の受け持ち範囲における地盤の圧縮による密度増加が確実に期待できないからである。 2. The material injected into the ground is prevented from penetrating between the soil particles, and the soil particles on the ground between the plurality of injection holes are pushed away by a lump. This is because if the injection solution penetrates between the soil particles, the ground between the multiple injection holes cannot be compressed, and the increase in density due to the compression of the ground in the range of the injection holes cannot be expected with certainty. is there.
3.地盤中に圧入されたゲルが塊状に固結体を形成し、なおかつ大径の固結塊に成長するようにする。このためには(1)〜(5)のようにする。 3. The gel press-fitted into the ground forms a consolidated body in a lump shape and grows into a large-diameter consolidated lump. To do this, do (1)-(5).
(1)該注入材として非硬化性シリカ系粉状体と水の混合物をスランプ5cmより大きく、及び/又はテーブルフロー12cm以上及び/又はシリンダーによるフローが8cmよりも大きく、或は更にスランプ28cm以内及び/又はテーブルフローが30cm未満及び/又はシリンダーによるフローが28cm未満である流動性地盤注入材、又はこれにカルシウム系粉状硬化発現材とを混合した地盤注入材とを用い、これを地盤中に圧入して脱水して形成される注入材そのものからなる塊状体の拡大によって土粒子を周辺に押しやり、地盤中に塊状固結体を造成して地盤強化を図る。 (1) A mixture of non-curable silica-based powder and water as the injection material is larger than 5 cm slump, and / or the table flow is 12 cm or more and / or the flow through the cylinder is larger than 8 cm, or further within the slump of 28 cm. And / or using a fluid ground injection material having a table flow of less than 30 cm and / or a cylinder flow of less than 28 cm, or a ground injection material mixed with a calcium-based powdered hardening material, and using this in the ground The soil particles are pushed to the periphery by expanding the lump made of the injection material itself that is formed by press-fitting into the water and dewatering, and the lump is formed in the ground to strengthen the ground.
(2)該地盤注入材は脱水によってテーブルフローが20cm以下に達し得る。ここでテーブルフローが20cmになった時点を可塑状ゲルになった時点とみなす。 (2) The ground injection material can reach a table flow of 20 cm or less by dehydration. Here, the time when the table flow becomes 20 cm is regarded as the time when the plastic gel is formed.
(3)該地盤注入材は脱水が進むにつれ可塑状ゲルを経て非可塑状となって固化する。 (3) As the dehydration proceeds, the ground injection material passes through a plastic gel and becomes non-plastic and solidifies.
(4)該地盤注入材は硬化性流動化土、又は非硬化性流動化土であって、脱水によって流動性を失ってフローが20cm以下に達し、周辺地盤と同等又はそれ以上の強度を発現する配合とする。 (4) The ground injection material is curable fluidized soil or non-hardened fluidized soil, which loses fluidity due to dehydration and reaches a flow of 20 cm or less, and exhibits strength equal to or higher than the surrounding ground. The formulation is as follows.
(5)該地盤注入材は水粉体比が30%以内で可塑状ゲルになる配合とし、地盤中に圧入し続ければ可塑状ゲルとなって塊状固結体が形成される。 (5) The ground injecting material is blended to become a plastic gel when the water powder ratio is within 30%, and if it continues to be pressed into the ground, it becomes a plastic gel and a massive solid body is formed.
可塑状ゲルによる塊状体が地中で大きく成長して固結体になるには以下の条件が好ましい。
〔硬化発現材比 C/(F+C)×100(%)〕:
1重量%以上50重量%未満、好ましくは1〜40重量%、更に好ましくは1〜20重量%
〔水粉体比 W/(F+C)×100(%)〕:
20〜200重量%、好ましくは20〜100重量%、更に好ましくは20〜50重量%
〔アルミニウム比 アルミニウム塩/(F+C)×100(%)〕:
Al2O3換算で0.01〜0.52%
〔水ガラス〕:
シリカ分で0〜7.0重量%
〔スランプ(cm)〕:
注入時のスランプが5cm以上、好ましくは5〜28cm、更に好ましくは10〜28cm
〔フロー(cm)〕:
注入時のテーブルフローが12cm以上30cm未満、好ましくは15〜28cm
注入時のシリンダーフローが8cm〜28cm未満、好ましくは約10〜26cm
〔ブリージング〕:
10%以下、好ましくは5%以下
上のような条件において更に、可塑状ゲルあるいは水粉体比が30%以内の減少で可塑状ゲルすなわちテーブルフローが20cm以内になる配合を用いる。
The following conditions are preferable in order that the lump by a plastic gel grows large in the ground and becomes a consolidated body.
[Curing expression ratio C / (F + C) × 100 (%)]:
1 to 50% by weight, preferably 1 to 40% by weight, more preferably 1 to 20% by weight
[Water powder ratio W / (F + C) × 100 (%)]:
20 to 200% by weight, preferably 20 to 100% by weight, more preferably 20 to 50% by weight
[Aluminum ratio Aluminum salt / (F + C) × 100 (%)]:
0.01 to 0.52% in terms of Al 2 O 3
[Water glass]:
0 to 7.0% by weight based on silica
[Slump (cm)]:
Slump at the time of injection is 5 cm or more, preferably 5 to 28 cm, more preferably 10 to 28 cm.
[Flow (cm)]:
The table flow at the time of injection is 12 cm or more and less than 30 cm, preferably 15 to 28 cm.
Cylinder flow during injection is 8 cm to less than 28 cm, preferably about 10 to 26 cm
〔breathing〕:
10% or less, preferably 5% or less
Under the above conditions, further, a plastic gel or a blend in which the water / powders ratio is reduced by 30% or less and the plastic flow, that is, the table flow is 20 cm or less is used.
可塑状ゲルを呈する迄の時間を短縮するには、水ガラスやアルミニウム塩を加える事により調整出来る。即ち、これらはゲル化促進剤として作用する。水ガラスと硫酸等の酸を混合して水ガラスのアルカリを除去した酸性水ガラスを用いるときわめて早くゲルが形成される。本発明では酸性水ガラスも水ガラスとして扱う。この場合、重曹や炭酸ナトリウムを併用することによりゲル化時間を調整できる。又、リグニンスルフォン酸塩等のゲル化遅延剤を用いる事も出来る。 In order to shorten the time until the plastic gel is exhibited, it can be adjusted by adding water glass or aluminum salt. That is, they act as gelation accelerators. When acidic water glass obtained by mixing water glass and acid such as sulfuric acid to remove alkali of water glass is used, a gel is formed very quickly. In the present invention, acidic water glass is also treated as water glass. In this case, the gelation time can be adjusted by using sodium bicarbonate or sodium carbonate in combination. A gel retarder such as lignin sulfonate can also be used.
本発明に用いる流動性可塑状ゲルの代表的例として、懸濁液を構成する非硬化性粉体に加えるセメント又は消石灰或はスラグ或は石膏等からなる粉状の硬化発現材は使用する粉状素材中の50重量%未満、好ましくは1〜40重量%、更に好ましくは1〜20重量%、また水粉対比は20〜200重量%、好ましくは20〜100重量%である。 As a representative example of the flowable plastic gel used in the present invention, a powdery hardening material made of cement, slaked lime, slag or gypsum added to the non-hardening powder constituting the suspension is used. Less than 50% by weight, preferably 1 to 40% by weight, more preferably 1 to 20% by weight, and the water powder ratio is 20 to 200% by weight, preferably 20 to 100% by weight.
ゲル化促進材を加える場合は注入材に含まれる粉体、つまり主材と硬化発現材の総量に対してアルミニウム塩をアルミニウム比が0.1〜3.0重量%(Al2O3換算で0.01〜0.52%)練り混ぜることにより、テーブルフロー12以上30cm未満、好ましくは15〜28cm、ゲルタイムが3分以内から数100分、可塑状保持時間が数時間から10時間以上、ブリージング率が10%以内、好ましくは5%以内、スランプが5cmより大きく28cm以下、好ましくは10〜28cm、シリンダーによるフローが8cmより大きく28cm未満好ましくは約10〜26cmの注入材となる。 When adding a gelation accelerator, the aluminum ratio is 0.1 to 3.0% by weight (in terms of Al 2 O 3) with respect to the total amount of the powder contained in the injection material, that is, the main material and the curing material. 0.01 to 0.52%) By mixing, the table flow is 12 or more and less than 30 cm, preferably 15 to 28 cm, gel time is within 3 minutes to several hundred minutes, plastic holding time is several hours to 10 hours or more, breathing The rate is within 10%, preferably within 5%, the slump is greater than 5 cm and not more than 28 cm, preferably 10 to 28 cm, and the flow through the cylinder is greater than 8 cm and less than 28 cm, preferably about 10 to 26 cm.
本発明のこのような特性により、又、ゲル化促進材として水ガラスや酸性水ガラス等のシリカ分を加えるとゲルタイムも可塑状保持時間も大幅に減少させる事が出来、又、ブリージングもスランプも更にフローも小さくなる。本発明地盤注入材は地盤中に圧入されて可塑状ゲルとなり、土粒子を周辺に押しやり、地盤中で大きな塊状固結体に成長し、地盤強化を図ることが出来る。 Due to these characteristics of the present invention, addition of silica such as water glass or acidic water glass as a gelation accelerator can greatly reduce gel time and plastic holding time, and also breathing and slumping. Furthermore, the flow becomes smaller. The ground injection material of the present invention is pressed into the ground to become a plastic gel, pushes the soil particles to the periphery, grows into a large solid aggregate in the ground, and can strengthen the ground.
本発明に使用する流動性可塑状ゲルは上述のとおり、非硬化性シリカ系粉体あるいはそれより少ないカルシウム系硬化発現材を加えた懸濁液を用いるが、使用する粉粒素材の種類と組み合わせ、および特定の配合比率で配合することにより、目的に応じて流動性、固結特性を呈する所望の注入材を地盤中に圧入して、地盤中に塊状固結体を造成することにより注入孔に囲まれた地盤の土粒子を周辺に押しやり、地盤強化を図ることができる。 As described above, the fluid plastic gel used in the present invention uses a non-curable silica-based powder or a suspension to which less calcium-based cured material is added, but is combined with the type of powder material used. And by blending at a specific blending ratio, a desired infusion material exhibiting fluidity and consolidation characteristics is press-fitted into the ground according to the purpose, and an injection hole is created by forming a massive solid body in the ground. It is possible to push the soil particles of the ground surrounded by the surroundings and strengthen the ground.
地盤中に塊状に固結するには、加圧することにより流動できるものの、土粒子間には浸透せず、かつ脈状に割裂しない程度の可塑上ゲルを形成する地盤注入材であって、テーブルフローで現すと12cm以上30cm未満、好ましくは15〜28cm、スランプでは5cmより大きく、好ましくは10〜28cm、シリンダーによるフローでは8cmより大きく28cm未満、好ましくは10〜26cmの範囲を示す地盤圧入材であることが好ましい。 A ground injection material that forms a plastic gel that does not penetrate between soil particles and does not split into veins, although it can flow by pressurization to consolidate in the ground. It is a ground press-in material showing a range of 12 cm or more and less than 30 cm, preferably 15 to 28 cm, more than 5 cm, preferably 10 to 28 cm, and more than 8 cm and less than 28 cm, preferably 10 to 26 cm. Preferably there is.
又、地盤中にて加圧地盤脱水による可塑状ゲルの形成を考慮して注入前に可塑状ゲルになっているもの或いは水粉体比が30%以内減少で可塑状ゲル(テーブルフローでほぼ20cm以内)になる場合であることが好ましい。フロー値やスランプがこれ以下になると、地盤中で可塑状ゲルの塊状固結体の成長が困難になり、これ以上だと脱水しきる前に脈状や亀裂状に割裂注入され塊状体を形成されにくい。 In addition, considering the formation of a plastic gel in the ground by dehydration under pressure, the plastic gel before injection or the water-to-powder ratio is reduced by 30% or less, and the plastic gel (almost in the table flow) 20 cm or less) is preferable. If the flow value or slump is below this level, it will be difficult to grow a solid aggregate of plastic gel in the ground, and if it exceeds this value, it will be split and injected into veins and cracks before it can be dehydrated to form a lump. Hateful.
本発明の流動性可塑状ゲルは、
(1)シリカ系非硬化性粉状体(F材)、
(2)カルシウム系粉状硬化発現材(C材)、
(3)流動性調整材(A材)、
(4)水(W材)
のうち、(1)と(2)と(4)、又は(1)と(2)と(3)と(4)、又は(2)と(3)と(4)を用いる。
使用する素材の種類と組合せ、および特定の配合比率で配合することにより、目的に応じた流動特性、固結特性を呈する所望の注入材を地盤中に圧入して、注入管周りの空隙を填充し、或は地盤中に塊状固結体を造成することにより、注入孔に囲まれた地盤の土粒子を周辺に押しやり、地盤強化を図ることができる。
The flowable plastic gel of the present invention is
(1) Silica-based non-curable powder (F material),
(2) Calcium-based powdery hardening material (C material),
(3) Fluidity adjusting material (A material),
(4) Water (W material)
Of these, (1) and (2) and (4) or (1) and (2) and (3) and (4) or (2) and (3) and (4) are used.
By mixing with the type and combination of the materials used and the specific mixing ratio, the desired injection material exhibiting flow characteristics and consolidation characteristics according to the purpose is pressed into the ground to fill the gap around the injection pipe. Alternatively, by creating a massive solid body in the ground, the soil particles surrounded by the injection hole can be pushed to the periphery to strengthen the ground.
地盤中で塊状に固結するには、加圧することにより流動できるものの、土粒子間には浸透せずかつ脈状に割裂しない程度の可塑状ゲルを形成する地盤注入材であって、テーブルフローで現すと12cm以上30cm未満、好ましくは15cm〜28cm、スランプでは5cmより大きく、好ましくは10〜28cm、シリンダーによるフローでは8cmより大きく28cm未満、好ましくは10〜26cmの範囲を示す地盤注入材であることが好ましい。又、地盤中にて加圧脱水による可塑状ゲルの形成を考慮して注入前に可塑状ゲルになっているもの、或いは水粉体比が30%以内減少で可塑状ゲル(テーブルフローでほぼ20cm)になる場合であることが好ましい。
In order to consolidate in the ground, it is a ground injection material that forms a plastic gel that can flow by pressurization but does not penetrate between soil particles and does not split into veins. It is a ground injection material showing a range of 12 cm or more and less than 30 cm, preferably 15 cm to 28 cm, slump greater than 5 cm, preferably 10 to 28 cm, and cylinder flow greater than 8 cm and less than 28 cm, preferably 10 to 26 cm. It is preferable. In addition, in consideration of the formation of a plastic gel by pressure dehydration in the ground, it is a plastic gel before injection, or the water-to-powder ratio is reduced within 30% and the
フロー値やスランプがこれ以下になると、地盤中で可塑状ゲルの塊状固結体の成長が困難になり、これ以上だと脱水しきる前に脈状や亀裂状に割裂注入されたり、逸脱したりして塊状体やシール状の固結を形成しにくい。 If the flow value or slump is below this level, it will be difficult to grow a lump of plastic gel in the ground, and if it exceeds this value, it will be split or injected into a vein or crack before dehydration. Therefore, it is difficult to form a lump or seal-like consolidation.
流動性可塑状ゲルの流動特性、固結特性を調節方法として以下のことが挙げられる。
(1)シリカ系非硬化性粉状体(F材)
本発明におけるシリカ系非硬化性粉状体(F材)として、粉粒素材の主材として非硬化性シリカ系粉状体、焼却灰、粘土、土砂のような現場発生土、および珪砂の1種又は複数種が挙げられる。
The following can be mentioned as a method for adjusting the flow characteristics and consolidation characteristics of the flowable plastic gel.
(1) Silica-based non-curable powder (F material)
As silica-based non-curable powder (F material) in the present invention, non-curable silica-based powder as a main material of the granular material, in-situ generated soil such as incineration ash, clay, earth and sand, and silica sand 1 Species or multiple species may be mentioned.
(2)カルシウム系粉状硬化発現材(C材)、
本発明におけるカルシウム系粉状硬化発現材(C材)として、セメント、石灰、石膏、スラグ、のいずれか又は複数の一群が挙げられる。ただし、非硬化性シリカがスラグの場合は硬化材としてのスラグは除外する。なお、上記にてスラグは通常の4000(cm2/g)のブレーン等の一般品でもよいし、それ以上6000〜15000(cm2/g)ブレーン等の超微粒子スラグでもよい。
(2) Calcium-based powdery hardening material (C material),
As a calcium type powdery hardening expression material (C material) in this invention, any one or several groups of cement, lime, gypsum, and slag are mentioned. However, when the non-curable silica is slag, slag as a curing material is excluded. In the above, the slag may be a general product such as a normal 4000 (cm 2 / g) brane, or may be an ultrafine particle slag such as 6000 to 15000 (cm 2 / g) brane.
(3)硬化発現剤比、水粉体比
硬化発現材比とはC/(F+C)×100[%]であり、また、水粉体比とはW/(F+C)×100[%]であり、F、C、Wはそれぞれ重量である。ただし、非硬化性シリカにスラグを用い硬化発現材を用いない場合は硬化発現材比はC/F×100[%],水粉体比はW/F×100[%]で示される。硬化発現材比は50重量%未満、好ましくは1〜40重量%、更に好ましくは1〜20重量%、また1〜10重量%の配合でも極めて優れた効果がある。
(3) Curing agent ratio, water powder ratio The curing material ratio is C / (F + C) × 100 [%], and the water powder ratio is W / (F + C) × 100 [%]. Yes, and F, C, and W are weights, respectively. However, when slag is used for non-curable silica and no curing material is used, the ratio of curing material is C / F × 100 [%] and the water powder ratio is W / F × 100 [%]. The ratio of the cured material is less than 50% by weight, preferably 1 to 40% by weight, more preferably 1 to 20% by weight, and even 1 to 10% by weight has a very excellent effect.
また、硬化発現材として石膏、又は石膏とセメント、石灰、スラグ、のいずれか又は複数の一群(G)と、水(W)を混合する場合は、石膏比、および石膏の混合物を用い、ここで、石膏比、石膏の混合物比とはG/(F+G)×100であり、また、水粉体比とはW/(F+G)×100である。Gは重量を表す。石膏比、石膏の混合物比は1〜40重量%、好ましくは1〜20重量%、水粉体比を20〜70重量%とする。 In addition, when mixing gypsum, or gypsum and cement, lime, slag, or a group (G) of water and water (W) as a hardening developing material, use a gypsum ratio and a mixture of gypsum, The gypsum ratio and the mixture ratio of gypsum are G / (F + G) × 100, and the water powder ratio is W / (F + G) × 100. G represents weight. The gypsum ratio and the mixture ratio of gypsum are 1 to 40% by weight, preferably 1 to 20% by weight, and the water powder ratio is 20 to 70% by weight.
硬化発現材比は50重量%未満、好ましくは1〜40重量%、更に好ましくは1〜20重量%、また1〜10重量%の配合でも極めて優れた効果がある。硬化発現材が0の場合はスランプ並びにフローが上記条件を満たすと共に脱水して地盤に圧入された塊状体が周辺地盤と同等又はそれよりも高い強度を有する事が必要である。 The ratio of the cured material is less than 50% by weight, preferably 1 to 40% by weight, more preferably 1 to 20% by weight, and even 1 to 10% by weight has a very excellent effect. When the hardening expression material is 0, it is necessary that the slump and the flow satisfy the above conditions, and the lump that is dehydrated and press-fitted into the ground has the same or higher strength than the surrounding ground.
この場合の配合や水粉体比の選定は上下にポーラスストーン又はロ紙を敷いたモールド中に注入材を填充し、想定した注入圧力相当する圧力でシリンダーにて加圧して脱水させてえられた供試体の強度を測定して注入したあとの周辺土の平均的な土の密度に対応した強度と同程度又はそれよりも大きな強度になるように設定する事が出来る。勿論、硬化発現材を少量加えた場合も同様に配合を設定できる。 In this case, the composition and water / powder ratio can be selected by filling the injection material in a mold with porous stone or paper on the top and bottom and pressurizing it with a cylinder at a pressure equivalent to the assumed injection pressure. It is possible to set the strength of the specimen to be equal to or greater than the strength corresponding to the average soil density of the surrounding soil after injection. Of course, the composition can be similarly set when a small amount of the curing material is added.
水粉体比は20〜200%、好ましくは20〜100%の配合である。ただし、非硬化性シリカがスラグの場合、水粉体比は更に好ましくは30〜80%の配合である。 The water powder ratio is 20 to 200%, preferably 20 to 100%. However, when the non-curable silica is slag, the water powder ratio is more preferably 30 to 80%.
石膏、または、石膏混合物を用いる場合は、石膏比、石膏の混合物比は1〜40重量%、好ましくは1〜20重量%、水粉体比を20〜70重量%とする。このような配合液は混合すれば、水粉体比が小さければそのままで、水粉体比が大きい場合は地盤中で脱水することにより遅かれ早かれ塊状体になる。 When gypsum or a gypsum mixture is used, the gypsum ratio and the gypsum mixture ratio are 1 to 40% by weight, preferably 1 to 20% by weight, and the water powder ratio is 20 to 70% by weight. When such a compounded liquid is mixed, it remains as it is if the water powder ratio is small, and when the water powder ratio is large, it becomes a lump sooner or later by dehydrating in the ground.
可塑状ゲルは力を加えれば流動するが静止すれば流動を停止する。可塑状ゲルとなるゲルタイムはテーブルフローがほぼ20cmになった時点とする。上記水粉体比、フロー、スランプを呈する流動性注入材はそのままで或は添加材を加えて地盤中で加圧脱水する事により水粉体比が大きい場合でも可塑性ゲルが地盤中に形成することが出来る。 The plastic gel flows when force is applied, but stops flowing when it stops. The gel time for forming a plastic gel is when the table flow is approximately 20 cm. The flowable injection material exhibiting the above water powder ratio, flow, and slump is left as it is, or by adding an additive and dehydrating under pressure in the ground, a plastic gel is formed in the ground even when the water powder ratio is large. I can do it.
地盤中において形成された塊状体は流動性が少ない状態でありながら出来るだけ広範囲に拡大されて大きな塊状固結体を形成する必要がある。このためにはフローやスランプや水粉体比(または、石膏比、石膏の混合物比)が重要であるし、更に硬化発現材比や添加材も重要である。 The lump formed in the ground needs to be enlarged over a wide range as much as possible to form a large lump consolidated body while having a low fluidity. For this purpose, the flow, slump, and water powder ratio (or gypsum ratio, gypsum mixture ratio) are important, and further, the ratio of hardening expression and the additive are also important.
硬化発現材比が過大であると、セメント等を主材とするモルタルグラウトの特性が強くなり、水が分離してブリージングが大きくなり、可塑状ゲルになりにくく、かつ脱水によって可塑状ゲルでなく、非可塑性ゲルとなって短時間のうちに固化して高強度固結体を形成する。このため割裂して逸脱するか固化して注入不能になる。 If the ratio of the cured material is excessive, the characteristics of the mortar grout mainly composed of cement, etc. will be strong, the water will separate and the breathing will increase, it will be difficult to become a plastic gel, and it will not be a plastic gel by dehydration. It becomes a non-plastic gel and solidifies in a short time to form a high strength consolidated body. For this reason, it splits and deviates or solidifies and becomes impossible to inject.
硬化発現材比が50%未満、好ましくは1〜40%、更に好ましくは1〜20%の間で、最も好ましくは1〜15%であって、地盤中で可塑性ゲルを経て大きく成長した塊状固化物が形成される。特に硬化発現材比は1〜20%、或は更に、1〜10%程度だと強度が低く、地中での可塑状ゲル保持時間が長いため拡大しやすく、又改良された地盤も均等な強度になり密度が上昇した周辺地盤と一体化して耐震性にすぐれる。 Mass solidification that has a cured material ratio of less than 50%, preferably 1 to 40%, more preferably 1 to 20%, most preferably 1 to 15%, and has grown greatly through a plastic gel in the ground Things are formed. In particular, when the ratio of cured material is 1 to 20%, or 1 to 10%, the strength is low, the plastic gel retention time in the ground is long, and it is easy to expand, and the improved ground is even. It integrates with the surrounding ground that has increased in strength and density, and has excellent earthquake resistance.
(4)流動性調整剤(A材)
a)アルミニウム塩
さらに、本発明はシリカ系粉状体と、硬化発現材としてセメント、石灰、石膏、スラグ、のいずれか又は複数の一群と、水からなる硬性懸濁液が、可塑性を発現する時間を調整するために流動性調整剤として、硫酸アルミニウムやポリ塩化アルミニウム等のアルミニウム塩を含むこともできる。
(4) Fluidity modifier (A material)
a) Aluminum salt Further, in the present invention, a silica-based powder, a hard suspension composed of one or a plurality of cement, lime, gypsum, and slag as a hardening developing material, and water express plasticity. In order to adjust time, an aluminum salt such as aluminum sulfate or polyaluminum chloride can also be included as a fluidity adjusting agent.
この場合、好ましくは硬化発現材比を2重量%以上、50重量%未満、水粉体比20〜60重量%およびアルミニウム比を2.0重量%以下、好ましくは0.1〜1.0重量%、Al2O3換算で0.01〜0.35重量%である配合グラウトとする。ここで、アルミニウム比とはアルミニウム材/(F+C)×100[%]である。アルミニウム材は重量を表す。 In this case, preferably, the ratio of cured material is 2 wt% or more and less than 50 wt%, the water powder ratio is 20 to 60 wt%, and the aluminum ratio is 2.0 wt% or less, preferably 0.1 to 1.0 wt%. %, And a blended grout of 0.01 to 0.35% by weight in terms of Al 2 O 3 . Here, the aluminum ratio is aluminum material / (F + C) × 100 [%]. Aluminum material represents weight.
なお、上記において流動性調整剤としてゲル化促進剤としてのアルミニウム塩や水ガラスは、シリカ系粉状体、硬化発現材と混合してポンプで地盤に圧入しても良いし、注入管中、或は注入管の近くで合流混合しても良いし、或はシリカ系粉状体と硬化発現材とゲル化促進剤の混合液を注入する過程で更にゲル化促進剤を合流混合して注入しても良い。 In the above, the aluminum salt or water glass as a gelling accelerator as a fluidity adjusting agent may be mixed with a silica-based powder, a hardening expression material and press-fitted into the ground with a pump, or in an injection tube, Alternatively, it may be mixed and mixed near the injection tube, or in the process of injecting a mixture of silica-based powder, curing agent and gelation accelerator, a gelation accelerator may be further mixed and injected. You may do it.
b)発泡剤、気泡剤
流動性調整剤として発泡剤や起泡剤を加えて流動性を上げ、かつ軽量化を図ることが出来る。たとえば、粘土としてベントナイトやさらに高分子系増粘剤すなわちポリビニルアルコールや、カルボキシメチルセルローズ(CMC)や、メチルセルローズ等を添加することにより水に対する分散性を抑制し、沈殿を少なくし、ワーカビリティの改善効果或は保水材として又上記主材となる粉粒素材のバインダーとしての役をし、擬似ゲル状にして流動性を保持しながら分散しにくい構造を持つ流動体を形成する。この結果地盤中における脱水を低減し、塊状性の拡大を促進する。
b) Foaming agent, foaming agent A foaming agent or a foaming agent can be added as a fluidity adjusting agent to increase fluidity and reduce the weight. For example, by adding bentonite as a clay, and further polymer thickeners such as polyvinyl alcohol, carboxymethylcellulose (CMC), methylcellulose, etc., dispersibility in water is suppressed, precipitation is reduced, and workability is improved. It serves as an improvement effect or as a water-retaining material and as a binder of the above-mentioned powder material, which is the main material, and forms a fluid having a structure that is difficult to disperse while maintaining fluidity in the form of a pseudo gel. As a result, the dehydration in the ground is reduced and the expansion of the blockiness is promoted.
本発明における二次注入材に用いられる注入材は、セメントベントナイトや、溶液型シリカ固結材を用いた水ガラス系注入材でもよいが、当然、耐久性の優れた固結材が好ましく、水ガラスからイオン交換樹脂またはイオン交換膜により脱アルカリ処理、または酸による中和処理によって得られた水溶性シリカ化合物を主成分とする注入材が好ましい。 The injection material used for the secondary injection material in the present invention may be cement bentonite or a water glass-based injection material using a solution-type silica consolidation material, but naturally, a consolidation material with excellent durability is preferable, An injection material mainly composed of a water-soluble silica compound obtained from glass by dealkalization treatment with an ion exchange resin or an ion exchange membrane or neutralization treatment with an acid is preferred.
このような水溶性シリカ化合物を主成分とする注入材としては、コロイダルシリカ系注入材(コロイダルシリカに無機塩等の硬化剤を添加してゲル化させる注入材)、活性シリカ系注入材(活性シリカまたは弱アルカリ性シリカにpH調整材および必要に応じて無機塩類を添加してゲル化させる注入材)、およびシリカゾル系注入材(弱アルカリ性〜中性、酸性)が好ましい。 As an injection material mainly composed of such a water-soluble silica compound, a colloidal silica injection material (an injection material in which a curing agent such as an inorganic salt is added to colloidal silica to be gelled), an active silica injection material (active A pH adjusting material and an injection material in which an inorganic salt is added to gel if necessary, and a silica sol-based injection material (weak alkaline to neutral, acidic) are preferable.
なお、コロイダルシリカ系注入材の場合には、少量の酸類を添加して固結体のpHを下げた方がより耐久性が良好となる。他方、酸性シリカゾルの場合、あるいはコロイダルシリカ、活性シリカ系でも同様であるが、弱アルカリ性懸濁型注入材のpHの影響によりゲル化時間が大幅に短縮することがあるので、酸性シリカゾルに燐酸化合物及び/又は金属封鎖剤を含有させたものを用いるのが望ましい。 In the case of a colloidal silica-based injection material, the durability becomes better when the pH of the solidified body is lowered by adding a small amount of acids. On the other hand, in the case of acidic silica sol, or colloidal silica or activated silica, the gelation time may be greatly shortened due to the influence of the pH of the weak alkaline suspension injection material. It is desirable to use a material containing a metal sequestering agent.
このような化合物としては、燐酸、燐酸1ソーダ、燐酸2ソーダ、燐酸3ソーダ、ピロ燐酸ソーダ、酸性ピロ燐酸ソーダ、トリポリ燐酸ソーダ、テトラポリ燐酸ソーダ、ヘキサメタ燐酸ソーダ、酸性メタ燐酸ソーダ等が挙げられる。
Examples of such compounds include phosphoric acid, phosphoric acid 1 soda, phosphoric acid 2 soda,
溶液型シリカ固結材のゲル化時間は、対象地盤が極めて粗であり、しかも一次注入材の注入量が少ない場合には、瞬結でも構わないが、通常1〜60分が好ましく、大量注入する場合には、ゲル化時間が1日以上のものも使用可能である。なお、このゲル化時間は土中ゲル化時間に相当するものであり、溶液型シリカ固結材の型により大きく異なる。例えば、活性シリカ系注入材は、配合液単位でのゲル化時間が数日程度と長くても、地盤に注入するとゲル化時間が土との接触により1日以内ともなり得る。 The gelation time of the solution-type silica consolidated material may be instantaneously set when the target ground is very rough and the injection amount of the primary injection material is small. In this case, a gelation time of one day or longer can be used. This gelation time corresponds to the gelation time in soil, and varies greatly depending on the type of solution-type silica consolidated material. For example, even if the active silica-based injecting material has a long gelation time of about several days as a blended liquid unit, when it is injected into the ground, the gelation time can be within one day due to contact with soil.
本発明の固結材を使用する場合、その注入比率は、注入する地盤の状況により異なるが、可塑状グラウト1に対し、溶液型シリカ固結材1〜5(体積比)の比率とするのが好ましい。 When using the consolidated material of the present invention, the injection ratio varies depending on the condition of the ground to be injected, but the ratio of solution-type silica consolidated material 1 to 5 (volume ratio) to the plastic grout 1 is set. Is preferred.
本発明における可塑状グラウトは単に空隙を填充するのみではなくて、空隙内或いは弱い部分を押し広げることもできる。その際、脱水を伴って非可塑状となり、ついには固化する。 The plastic grout in the present invention not only fills the voids, but can also expand the voids or weak areas. At that time, it becomes non-plastic with dehydration and finally solidifies.
そのような経過を経て、初めて注入管周りのパッカ効果を有する填充あるいは護岸の吸出し部分の填充とその後の浸透性グラウトの土粒子間浸透、或は、浸透性グラウトの逸脱時の逸脱流路の填充が可能になる。これは流動性可塑状グラウトを用いることにより可能である。以下に本発明に用いる流動性可塑状グラウトを実施例で詳述する。 After such a process, for the first time, filling with a packer effect around the injection pipe or filling of the suction part of the revetment and subsequent penetration of the permeable grout between soil particles, or the deviation flow path at the time of deviation of the permeable grout Filling becomes possible. This is possible by using a flowable plastic grout. The flowable plastic grout used in the present invention will be described in detail in the following examples.
使用材料
(1) フライアッシュ
火力発電所より排出される石炭灰:FA、シリカ系非硬化性粉状体、
密度1.9〜2.3g/cm3、粒度分布0.1mm以下が90%以上
(2) セメント
普通ポルトランドセメント:PC、硬化発現材
(3) 硫酸バンド
硫酸アルミニウム、Al2O3=17.2%、ゲル化促進剤
(4) 水ガラス
JIS3号水ガラス、SiO2=29.0%、Na2O=9.0%、モル比3.3、ゲル化促進剤
(5) 消石灰
工業用水酸化カルシウム、ゲル化促進剤および硬化発現材
(6) スラグ
スラグ8000ブレーン値、硬化発現材およびシリカ系非硬化性粉状体
(7) 石膏
半水石膏、硬化発現材
(8) 焼却灰
ごみ焼却炉より排出される焼却灰、シリカ系非硬化性粉状体
密度2.5〜2.7g/cm3
(9) ベントナイト
保水材および増粘材
(10) 起泡剤
事前発泡型エア発生剤
Materials used
(1) Fly ash Coal ash discharged from thermal power plants: FA, silica-based non-curing powder,
Density 1.9 to 2.3 g / cm 3 , particle size distribution 0.1 mm or less is 90% or more
(2) Cement Ordinary Portland cement: PC, hardened material
(3) Sulfuric acid band Aluminum sulfate, Al 2 O 3 = 17.2%, gelation accelerator
(4) Water glass
JIS No. 3 water glass, SiO 2 = 29.0%, Na 2 O = 9.0%, molar ratio 3.3, gelation accelerator
(5) Slaked lime Industrial calcium hydroxide, gelation accelerator and curing agent
(6) Slag Slag 8000 Blaine value, curing material and silica-based non-curable powder
(7) Gypsum Hemihydrate gypsum, hardening material
(8) Incineration ash Incineration ash discharged from waste incinerators, silica-based non-curable powders Density 2.5-2.7 g / cm 3
(9) Bentonite water retention and thickening material
(10) Foaming agent Pre-foaming air generating agent
配合例1〜3
フライアッシュ、セメント、水を練り混ぜる。フライアッシュとセメントの配合量は同様にして水の配合量のみを変化させた。このようにして得られた配合例1〜3の地盤注入材の調整条件および物性値を下記の表1に示す。
Formulation Examples 1-3
Mix fly ash, cement and water. The blending amount of fly ash and cement was similarly changed only in the blending amount of water. Table 1 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 1 to 3 thus obtained.
表1において、ゲル化時間とは配合後可塑性ゲルを呈するまでの時間を云い、テーブルフローがほぼ20cmとなった時点をゲルタイム(ゲル化時間)とする。又、可塑性保持時間とは静止しておけばゲル状を保持するが、力を加えると流動する状態を呈している時間を云う。配合例3に示すように水粉体比が小さくなると配合液はただちに可塑状となる。よって配合例1,2のように配合直後は流動性のある懸濁液も地盤中に注入される過程で脱水され、配合例3に示す可塑状ゲルとなる。 In Table 1, the gelation time refers to the time until the plastic gel is formed after blending, and the time when the table flow becomes approximately 20 cm is defined as the gel time (gelation time). The plastic holding time refers to the time during which a gel-like state is maintained if it is stationary, but is in a state of flowing when a force is applied. As shown in Formulation Example 3, as the water powder ratio decreases, the blended solution immediately becomes plastic. Therefore, immediately after blending as in blending examples 1 and 2, a fluid suspension is dehydrated in the process of being poured into the ground, and the plastic gel shown in blending example 3 is obtained.
表1に示すように同一の硬化発現材比8.05%で水粉体比が35%の配合1、水粉体比が30%の配合2は配合後可塑状ゲルになる迄のゲル化時間はそれぞれ480分、300分を要する。水粉体比が25%になるとゲル化時間は2分になる。この事は配合時、地盤中に注入される前迄は可塑状に到っていない注入材が地盤中においては、脱水によって水紛体比が35%から30%(脱水率約15%)さらに25%(脱水率30%)に低下するにつれてゲルタイムが2分迄減少し、可塑状ゲルとなり、塊状体を形成する。しかもゲル化時では可塑状保持時間は7.5時間であるから、塊状ゲルは拡大しブリージングが小さく、粘性が増大して拡散しにくくなり固化物は大きな強度となる。
As shown in Table 1, Formulation 1 with the same cured material ratio of 8.05% and a water powder ratio of 35% and Formulation 2 with a water powder ratio of 30% gelated until a plastic gel was formed after blending. The time takes 480 minutes and 300 minutes, respectively. When the water powder ratio is 25%, the gelation time is 2 minutes. This means that at the time of blending, when the injection material that has not reached the plastic state before being injected into the ground is mixed in the ground, the water body ratio is 35% to 30% by dehydration (dehydration rate is about 15%) and further 25 % (
このような特性は従来知られていなかった。即ち、流動性注入材は地盤中に圧入されてから水粉体比が35%から25%迄脱水する迄はゲル化に至らず、25%(脱水率約30%)になって、2分後には、可塑状ゲルを形成し、その時点での可塑状保持時間は7.5時間であって、圧入がつづくにつれゲル状のまま大きく生成し、更に脱水、或は硬化現象の進行にともない非流動性ゲルとなり、固化する事を物語っている。 Such characteristics have not been known so far. That is, the flowable injection material does not reach gelation until the water powder ratio is dehydrated from 35% to 25% after being pressed into the ground, and is 25% (dehydration rate is about 30%). Later, a plastic gel was formed, and the plastic retention time at that time was 7.5 hours. As the press-fitting continued, the gel remained large, and as the dehydration or curing proceeded, It becomes a non-flowable gel and tells it to solidify.
従って、このように注入時点で可塑状を呈していなくても地盤中の脱水によって可塑状になり得る。このような流動性注入液の注入においては配合液を一液のまま注入しても紛状体注入液をA液としアルミニウム、水ガラス等のゲル化促進材をB液とし、合流注入しようと、或はA液を可塑状ゲルとし、B液を水ガラス等のゲル化促進剤としようと、その手段は問わないで施工する事が出来る。 Therefore, even if it does not exhibit plasticity at the time of injection, it can become plastic by dehydration in the ground. In the injection of such fluid injection solution, even if the compounding solution is injected as a single solution, the powder injection solution is A solution, the gelation promoting material such as aluminum, water glass, etc. is B solution, and it is going to be combined injection Alternatively, the liquid A can be applied to any plastic gel and the liquid B can be used as a gelation accelerator such as water glass regardless of the means.
配合例4〜6
フライアッシュ、セメント、水を練り混ぜる。水の配合量は同様にしてフライアッシュとセメントの配合量を変化させた。このようにして得られた配合例4〜6の地盤注入材の調整条件および物性値を下記の表2に示す。
Formulation Examples 4-6
Mix fly ash, cement and water. The amount of water was changed in the same manner as that of fly ash and cement. Table 2 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 4 to 6 thus obtained.
表2より、硬化発現材比が大きくなるとブリージング率が大きくなり、可塑状保持時間が短くなって、初期粘性も高くなる。よって圧送において高い圧力が必要となり、又粉体と水が均等に送れず注入管内で詰まりを起こしやすい。或は、ゲル化調整剤を添加するとしても脱水によって急速に水粉体比が低下し、脈状に割裂注入されやすくなる。よって、硬化発現材比は50%より少なく、好ましくは1〜20%、さらに好ましくは1〜15%、最も好ましくは1〜10%が適している。なお本発明において、ポルトランドやセメントでなくても高炉セメント、アルミナセメント、早強セメント、スラグセメント、その他任意のセメントを用いる事が出来る。 From Table 2, when the ratio of the cured material is increased, the breathing rate is increased, the plastic holding time is shortened, and the initial viscosity is also increased. Therefore, high pressure is required for pressure feeding, and powder and water cannot be evenly fed, and clogging easily occurs in the injection tube. Alternatively, even if a gelling agent is added, the water-to-powder ratio decreases rapidly due to dehydration, and split veins are easily injected. Therefore, the ratio of cured material is less than 50%, preferably 1 to 20%, more preferably 1 to 15%, and most preferably 1 to 10%. In the present invention, blast furnace cement, alumina cement, early-strength cement, slag cement, or any other cement can be used without using Portland or cement.
配合例7,8
表1の配合例1、2に硫酸バンドを添加し、ゲル化を促進させた。ここでゲル化を促進するとは配合後可塑性を呈するまでの時間を短縮し、或はフローを小さくすることを云う。このようにして得られた配合例7、8の地盤注入材の調整条件および物性値を下記の表3に示す。
Formulation Examples 7 and 8
A sulfate band was added to Formulation Examples 1 and 2 in Table 1 to promote gelation. Here, to promote gelation means to shorten the time until the plasticity is exhibited after blending or to reduce the flow. Table 3 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 7 and 8 thus obtained.
表3より、硫酸バンドを添加することで、ゲルタイムが短縮されるが、可塑状保持時間はそれ程短縮されず、またブリージング率も減少する。表1の配合例3のようにフライアッシュ、セメント、水の配合においても直ちにゲル化させることも可能であるが、現場における作業性を考慮するとゲル化調整剤を用いた方が効率が良い。ただし、硫酸バンドには強度発現を低下させる性質のあるため、粉体に対して添加量は2.0%以内、好ましくは1.0%以内を用いる。 From Table 3, by adding a sulfuric acid band, the gel time is shortened, but the plastic holding time is not so much reduced, and the breathing rate is also reduced. Although it is possible to immediately gel in the blending of fly ash, cement, and water as shown in Formulation Example 3 in Table 1, it is more efficient to use a gelling regulator in consideration of workability in the field. However, since the sulfuric acid band has the property of reducing the strength expression, the addition amount is within 2.0%, preferably within 1.0% with respect to the powder.
可塑性グラウトとしての要因と条件
(1)硬化発現材比
グラウトに含まれる粉体、つまりフライアッシュと、セメントの含有量に対するセメントの含有量:セメント(硬化発現材)重量/{フライアッシュ(シリカ系非硬化性粉状体)重量+セメント(硬化発現材)重量}×100[%]
Factors and conditions for plastic grout (1) Ratio of hardened material: fly ash, that is, fly ash, and cement content relative to cement content: cement (hardened material) weight / {fly ash (silica type) Non-hardening powder) weight + cement (curing material) weight} × 100 [%]
セメントは硬化発現材であり、かつフライアッシュの可塑材という事も出来る。フライアッシュはセメントと混合することによりポゾラン反応を起こし固結強度を得る。しかし硬化発現材比を大きくすることにつれ、可塑状グラウトとしての特性が低下する。即ち、沈殿してブリージングが大きくなり沈殿したものは流動しにくく可塑状ゲルになりにくいため、硬化発現材比は50%未満とするが、その好ましい範囲は硫酸バンド(ゲル化促進剤)添加しない場合1〜20%、好ましくは1〜15%、さらに好ましくは1〜10%である。また硫酸バンドを添加する場合は2〜40%、好ましくは2〜20%である。 Cement is a material that develops hardening and can also be called fly ash plasticizer. When fly ash is mixed with cement, it causes a pozzolanic reaction to obtain consolidated strength. However, as the ratio of the cured material is increased, the characteristics as a plastic grout deteriorate. That is, since the precipitated and increased breathing and the precipitated are difficult to flow and hardly become a plastic gel, the ratio of the cured material is less than 50%, but the preferred range is not adding a sulfate band (gelling accelerator). In the case, it is 1 to 20%, preferably 1 to 15%, more preferably 1 to 10%. Moreover, when adding a sulfuric acid band, it is 2 to 40%, Preferably it is 2 to 20%.
(2)水粉体比
グラウト中の粉体に対する水の含有量:水重量/{フライアッシュ(シリカ系非硬化性粉状体)重量+セメント(硬化発現材)重量}×100[%]
(2) Water-powder ratio Water content with respect to the powder in the grout: water weight / {fly ash (silica-based non-curable powder) weight + cement (curing material) weight} × 100 [%]
この値が小さいと可塑状になりやすい。即ち配合後可塑状ゲルになる時間が短くなり、かつフロー値が小さくなる。しかし、水粉体比が小さすぎると作業性を損なうため、その範囲は20〜200%、好ましくは20〜100%、更に好ましくは20〜50%(重量比)とする。 When this value is small, it tends to be plastic. That is, the time for forming a plastic gel after blending is shortened, and the flow value is decreased. However, if the water powder ratio is too small, workability is impaired, so the range is 20 to 200%, preferably 20 to 100%, more preferably 20 to 50% (weight ratio).
しかし水ガラスを促進剤として用いる場合は、水粉体比は大きくとることができる。その他、混合条件、環境、また材料により、グラウトの性状は異なってくるため、後に示すブリージング率、フロー値、強度の測定が重要となる。 However, when water glass is used as an accelerator, the water powder ratio can be increased. In addition, since the properties of grout vary depending on the mixing conditions, environment, and materials, it is important to measure the breathing rate, flow value, and strength described later.
(3) 硫酸バンド添加量
グラウト中の粉体に対する硫酸バンドの添加量:硫酸バンド重量/{フライアッシュ(シリカ系非硬化性粉状体)重量+セメント(硬化発現材)重量}×100[%]
(3) Addition amount of sulfate band Addition amount of sulfate band to powder in grout: sulfate band weight / {fly ash (silica-based non-curable powder) weight + cement (hardening material) weight} × 100 [% ]
硫酸バンドはゲル化促進剤であり、フライアッシュとセメントの流動性ある状態の中に添加すると、ゲル化を促進させ、可塑状ゲルになる時間を早める。ただし、硫酸バンドには固結強度を低下させる作用もあるので、その添加量は2.0%以下、好ましくは0.1〜1.0%とする。 The sulfuric acid band is a gelation accelerator, and when added to the fluid state of fly ash and cement, it promotes gelation and accelerates the time to become a plastic gel. However, since the sulfuric acid band also has an effect of reducing the consolidation strength, its addition amount is 2.0% or less, preferably 0.1 to 1.0%.
(4)ゲルタイム
ここでは一般的な水ガラス系グラウトにみられるような固化状となる化学的ゲル化を意味するのではなく、配合後、自重による流動性がなくなり、力を加えると流動する可塑状ゲルとなるまでの物理的ゲル化時間をゲルタイムと表現する。一般の水ガラスを主材とするグラウトと違って、明確なゲル化時間を示すことはできない。よってテーブルフローを用いてその値が20cm以下になった時をゲル化とみない、これをゲルタイムとした。
(4) Gel time Here, it does not mean chemical gelation that is solidified like that found in common water glass grouts, but it loses its fluidity due to its own weight after compounding, and plastic that flows when force is applied. The physical gelation time until it becomes a gel is expressed as gel time. Unlike a grout made from a common water glass, it cannot show a clear gelation time. Therefore, when the value became 20 cm or less using the table flow, it was not regarded as gelation, and this was defined as gel time.
(5)可塑状保持時間
アスファルト針入度試験方法JIS K 2530-1961に準じて総質量230g、先端角度15度、36mmの貫入コーンを用いて静的貫入抵抗を測定し、貫入抵抗値が0.01MN/m2を越えた時非可塑状ゲルとなって、固結または硬化とみなし、ゲル化から固結に至るまでの時間を可塑状保持時間とした。
(5) Plasticity retention time Asphalt penetration test method Static penetration resistance was measured using a penetration cone with a total mass of 230 g, tip angle of 15 degrees, and 36 mm according to JIS K 2530-1961. When it exceeded 0.01 MN / m 2 , it became a non-plastic gel and was regarded as consolidated or cured, and the time from gelation to consolidation was defined as the plastic retention time.
(6)ブリージング率
配合後、グラウトを充分に混合させ、次いで、200mlメスシリンダにグラウトを入れて静止密閉し、1時間経過後にブリージング水量(上ずみ液)を測定し、次式よりブリージング率を求める。(ブリージング水量/メスシリンダ容量)×100[%]
(6) Breathing rate After blending, mix the grout thoroughly, then put the grout into a 200 ml graduated cylinder and seal it statically. After 1 hour, measure the amount of breathing water (superior liquid). Ask. (Breathing water volume / measuring cylinder capacity) x 100 [%]
ここでは1時間経過後のブリージング率を示す。1時間経過後のブリージング率が10%以上の配合では、注入液が分離しやすく脈状または亀裂状に注入されやすい。その後、時間が経過すると更にブリージング率が増大するので、従って1時間経過のブリージング率は10%以下、好ましくは5%以内の配合が好ましい。図1に、表1,3における硫酸バンドの有無による水粉体比とブリージング率の関係を示す。 Here, the breathing rate after 1 hour is shown. When the composition has a breathing rate of 10% or more after the lapse of 1 hour, the injected solution is easily separated and easily injected in the form of veins or cracks. Thereafter, the breathing rate further increases as time passes. Therefore, the blending rate after 1 hour is preferably 10% or less, preferably 5% or less. FIG. 1 shows the relationship between the water powder ratio and the breathing rate according to the presence or absence of the sulfuric acid band in Tables 1 and 3.
(7)フロー値
フロー試験(JIS R 5201テーブルフロー)に基づき、グラウトに15秒間に15回の落下運動を与え、その広がりを測定した。可塑状グラウトとしては約18〜19cmが適しているとされているが、本発明ではフロー値が20cm以下になる時点で自重による流動性がなくなったものとして、ゲルタイムとした。本発明における流動性注入材は地盤中に注入して加圧脱水によって水粉体比が低下してテーブルフローが20cm以下に至る配合が用いられる。
(7) Flow value Based on a flow test (JIS R 5201 table flow), the grout was subjected to 15 drop motions in 15 seconds, and the spread was measured. About 18-19 cm is said to be suitable as the plastic grout, but in the present invention, the fluidity due to its own weight disappeared when the flow value became 20 cm or less, and the gel time was used. The flowable injecting material in the present invention is used in such a composition that the water-to-powder ratio is lowered by pressure dehydration by pouring into the ground and the table flow reaches 20 cm or less.
またシリンダーによるフローは、高さ8cm、直径8cmの円筒にグラウトを詰め、円筒を取り除いたときのグラウトの広がりを測定するものである。その場合の適切な範囲はおよそ8〜18cmであり、さらにシリンダーを取り除いた後にテーブルフローと同様の15回の落下運動を与えた場合はおおよそ13〜22cmである。上述のテーブルフローよりも簡易に測定できるため現場などで用いられることが多いが、簡易であるため人為的な誤差が生じる可能性がある。図12にテーブルフローとシリンダーフローのおおよその関係を示す。
このような配合では、水粉体比が大きな配合でも脱水によって地盤中で水粉体比が20%以下になり可塑状ゲルから非可塑状ゲルを経て固化する。
The flow by the cylinder is to measure the spread of the grout when a cylinder having a height of 8 cm and a diameter of 8 cm is filled with the grout and the cylinder is removed. An appropriate range in that case is approximately 8 to 18 cm, and approximately 15 to 22 cm when a drop motion of 15 times similar to the table flow is given after removing the cylinder. Since it can be measured more easily than the above table flow, it is often used in the field. However, since it is simple, an artificial error may occur. FIG. 12 shows an approximate relationship between the table flow and the cylinder flow.
In such a blend, even if the water powder ratio is large, the water powder ratio becomes 20% or less in the ground due to dehydration and solidifies from a plastic gel through a non-plastic gel.
(8)初期粘性
B形粘度形を用いて配合直後の配合液の粘度を計測した。混合直後は流動性があるため計測できたが、ゲル化すると100000cps以上となり、測定不可となる。図2に、表1、3における硫酸バンドの有無による水粉体比と粘度の関係を示す。
(8) Initial viscosity The viscosity of the liquid mixture immediately after mixing was measured using a B-type viscosity type. Immediately after mixing, measurement was possible due to the fluidity, but when gelled, it becomes 100,000 cps or more, and measurement is impossible. FIG. 2 shows the relationship between the water powder ratio and the viscosity depending on the presence or absence of the sulfate band in Tables 1 and 3.
(9)一軸圧縮強度
配合後、充分に混合したグラウトを直径5cm、高さ10cmのモールドにつめ、静止した状態で1日養生し、一軸圧縮強度を測定した。図3に、表1、3における硫酸バンドの有無による水粉体比と一軸圧縮強度の関係を示す。図3によると、硫酸バンドの添加により強度が低下している。また水粉体比が多いと固結するまでの時間が長くなるため、水粉体比が小さいものよりも強度発現が遅くなる。
(9) After blending the uniaxial compressive strength, the fully mixed grout was put into a mold having a diameter of 5 cm and a height of 10 cm, cured for one day in a stationary state, and the uniaxial compressive strength was measured. FIG. 3 shows the relationship between the water powder ratio and the uniaxial compressive strength according to the presence or absence of the sulfuric acid band in Tables 1 and 3. According to FIG. 3, the strength is reduced by the addition of the sulfuric acid band. In addition, when the water powder ratio is large, the time until consolidation is prolonged, so that the strength development is slower than that when the water powder ratio is small.
配合例9〜11
フライアッシュ、セメント、消石灰、水を混合した懸濁液に水ガラスを混合する。このようにして得られた配合例9〜11の地盤注入材の調製条件および物性値を下記の表4に示す。
Formulation Examples 9-11
Mix water glass into a suspension of fly ash, cement, slaked lime, and water. Table 4 below shows the preparation conditions and physical property values of the ground injection materials of Formulation Examples 9 to 11 thus obtained.
(1)消石灰添加量
グラウト中の粉体に対する消石灰の添加量
消石灰添加量/{フライアッシュ(シリカ系非硬化性粉状体)重量+セメント(硬化発現材)重量}×100〔%〕
(1) Addition amount of slaked lime Addition amount of slaked lime to powder in grout Addition amount of slaked lime / {weight of fly ash (silica-based non-hardening powder) + weight of cement (hardening agent)} x 100 [%]
消石灰はゲル化促進剤であり、セメントと同様フライアッシュと混ぜるとポラゾン反応を起す。ただし、セメントほど固結強度は得られない。ここでは可塑状とするため、その保持時間を有するためのゲル化促進剤として用いた。その範囲はセメント添加量にもよるが3〜15%が好ましい。 Slaked lime is a gelling accelerator, and when mixed with fly ash like cement, it causes a polazone reaction. However, consolidation strength is not as good as cement. Here, in order to make it plastic, it was used as a gelation accelerator for having the retention time. The range is preferably 3 to 15%, although it depends on the amount of cement added.
(2)シリカ濃度
グラウト中のSiO2量:水ガラスのSiO2%×(水ガラス重量/グラウト重量)〔%〕
本出願人による実験によれば、グラウトを可塑状、あるいは固結させるためには、その他の材料の配合比率にもよるが、シリカ濃度は0.2〜7.0%とする。ただし3号水ガラスのモル比以下の低モル比水ガラスを用いる場合は3.0〜7.0%が好ましい。勿論、高モル比の水ガラスや粉状水ガラスを用いる事も出来る。また水ガラスと酸を混合してなる酸性水ガラスもゲル化促進剤として用いることができる。この場合も本発明では水ガラスと表現する。
(2) Silica concentration SiO 2 amount in grout: SiO 2 % of water glass × (water glass weight / grouting weight) [%]
According to the experiment by the present applicant, the silica concentration is 0.2 to 7.0% in order to plasticize or solidify the grout, depending on the blending ratio of other materials. However, when a low molar ratio water glass having a molar ratio of No. 3 water glass or less is used, 3.0 to 7.0% is preferable. Of course, a high molar ratio water glass or powdered water glass can also be used. An acidic water glass obtained by mixing water glass and acid can also be used as a gelation accelerator. This case is also expressed as water glass in the present invention.
(3)特性および比較
表4の配合の特徴としてゲルタイムの調製がしやすく、また可塑状保持時間はやや短いが早期強度の発現は顕著であることが挙げられる。よって早期強度の発現を重要視する場合に適している。可塑状グラウトをA液として、水ガラス水溶液をB液としてA液のゲルタイムを短縮させることができる。また、グラウトをゲル化後よく練り混ぜることによって、早期強度の発現は低下するが、可塑状保持時間を長くすることができる。よってゲル化後よく練り混ぜたものを注入することにより長時間の注入を要する目的やインターバル注入により、一度注入した注入ポイントに再度注入をくり返して、注入体を拡大する地盤改良に適している。
(3) Characteristics and comparison The characteristics of the formulation shown in Table 4 are that gel time can be easily prepared, and the plasticity retention time is slightly short, but the expression of early strength is remarkable. Therefore, it is suitable when importance is placed on the expression of early strength. The gel time of A liquid can be shortened by using plastic grout as A liquid and water glass aqueous solution as B liquid. Further, by mixing the grout well after gelation, the expression of the early strength decreases, but the plastic holding time can be lengthened. Therefore, it is suitable for ground improvement in which the injection body is expanded by injecting the mixture well-mixed after gelation for the purpose of requiring long-time injection or repeated injection at the injection point once injected by interval injection.
配合例12,13
フライアッシュ、セメント、水、ゲル化促進剤を配合し、経時的に可塑状となり、固結する上述の配合例7にさらゲル化促進剤を添加し、ゲルタイムを早めた。ゲル化する前の流動性がある状態の配合例7に、硫酸バンド水溶液、ならびに水ガラスを水で希釈した水溶液を添加した。配合比率は配合例7のグラウトが20に対し、可塑剤の水溶液を1とした。このようにして得られた配合例12、13の地盤注入材の調整条件および物性値を下記の表5,6に示す。
Formulation Examples 12 and 13
A fly ash, cement, water, and a gelling accelerator were blended, and the gelling accelerator was further added to the above blending example 7 which became plasticized with time and solidified, thereby speeding up the gel time. A sulfuric acid band aqueous solution and an aqueous solution obtained by diluting water glass with water were added to Formulation Example 7 having fluidity before gelation. The blending ratio was 20 for the grout of blending example 7 and 1 for the aqueous plasticizer solution. Tables 5 and 6 below show the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 12 and 13 thus obtained.
(1)配合例12、13の特性および比較
可塑状グラウトである配合例7に、水ガラスを水で希釈した水溶液を添加した場合、ゲルタイムは極めて短くなり、また可塑状保持時間も短くなり、強度発現は顕著となる。よって、早期強度の発現を重要視する場合に適している。またA液が可塑状グラウトで、B液が水ガラス水溶液の場合、A液・B液の混合注入管によって塊状ゲルの形成が容易である。
(1) Characteristics and Comparison of Formulation Examples 12 and 13 When an aqueous solution obtained by diluting water glass with water is added to Formulation Example 7 which is a plastic grout, the gel time becomes extremely short, and the plastic retention time also becomes short. Strength development becomes remarkable. Therefore, it is suitable when importance is placed on early strength development. Further, when the liquid A is a plastic grout and the liquid B is a water glass aqueous solution, it is easy to form a block gel by the mixed injection tube of the liquid A and the liquid B.
配合例14
フライアッシュ、セメントに、増粘剤としてベントナイトを混合した。その配合例14の地盤注入材の調製条件および物性値を下記の表7に示す。
Formulation Example 14
Bentonite as a thickener was mixed with fly ash and cement. The preparation conditions and physical property values of the ground injection material of Formulation Example 14 are shown in Table 7 below.
配合例15
フライアッシュ、セメントに細骨材(山砂)を混合した。その配合例15の地盤注入材の調製条件および物性値を下記の表8に示す。
Formulation Example 15
Fine aggregate (mountain sand) was mixed with fly ash and cement. The preparation conditions and physical property values of the ground injection material of Formulation Example 15 are shown in Table 8 below.
配合例16
フライアッシュとセメントを泥水で混合した。その配合例16の地盤注入材の調製条件および物性値を下記の表9に示す。
Formulation Example 16
Fly ash and cement were mixed with muddy water. The preparation conditions and physical property values of the ground injection material of the blending example 16 are shown in Table 9 below.
(1)水粉体比
グラウト中の粉体に対する水の含有量:水重量/(フライアッシュ重量+セメント重量+ベントナイト重量、細骨材重量、粘土重量)×100〔%〕
ここではフライアッシュとセメント以外の粉状体にゲル化調整剤としてベントナイト、細骨材を用いた。また混合水として粘土を含む泥水を使用した。これらゲル化調整剤はグラウト中の粉状体とみなした。
(1) Water powder ratio Water content to powder in grout: water weight / (fly ash weight + cement weight + bentonite weight, fine aggregate weight, clay weight) × 100 [%]
Here, bentonite and fine aggregates were used as a gelation modifier for powders other than fly ash and cement. Moreover, the muddy water containing clay was used as mixed water. These gelation modifiers were considered as powders in the grout.
(2)配合例14の特性および比較
増粘剤としてベントナイトを添加したものは、グラウトの粘性が上がるため同量のセメントのみを用いたときよりも早く可塑状となる。しかし、ベントナイトを添加することでセメントの添加量を減らすと固結強度が低下するので、PC添加量は3%以上として、ベントナイトは増粘剤として用いることによって流動性を調整する事ができる。硬化発現材比は50%未満、好ましくは1〜20%、水粉体比は20〜150%が好ましい。
(2) Characteristics and Comparison of Formulation Example 14 Addition of bentonite as a thickener increases the viscosity of the grout, so that it becomes more plastic than when only the same amount of cement is used. However, when the addition amount of cement is reduced by adding bentonite, the consolidation strength is lowered. Therefore, the flowability can be adjusted by setting the PC addition amount to 3% or more and using bentonite as a thickener. The ratio of cured material is less than 50%, preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%.
(3)配合例15の特性および比較
フライアッシュ、セメントに増量材として細骨材(山砂)を混合することができるが、細骨材が多いとブリージング率が大きくなる傾向があるので、よって細骨材添加量80%以下が好ましい。また硬化発現材比は50%未満、好ましくは1〜20%、水粉体比は20〜150%が好ましい。
(3) Characteristics and Comparison of Formulation Example 15 Fine aggregate (mountain sand) can be mixed with fly ash and cement as an extender, but if there are many fine aggregates, the breathing rate tends to increase. The amount of fine aggregate added is preferably 80% or less. Further, the curing developing material ratio is less than 50%, preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%.
(4)配合例16の特性および比較
フライアッシュとセメントを泥水で混合したものは、泥水に含まれる粘土により増粘され、かつ流動性や保水性が向上するため、増粘材、または流動化材、または保水材としての効果があり、土中における可塑状ゲルの拡大に効果がある。よって泥水中に含まれる粘土の含有量によりグラウトの性状を調節することができる。硬化発現材比は50%未満、水粉体比は20〜150%が好ましい。
(4) Characteristics and Comparison of Formulation Example 16 Mixture of fly ash and cement with muddy water is thickened by clay contained in the muddy water, and improves fluidity and water retention. There is an effect as a material or a water retaining material, and it is effective in expanding the plastic gel in the soil. Therefore, the properties of the grout can be adjusted by the content of clay contained in the muddy water. It is preferable that the ratio of cured material is less than 50% and the water powder ratio is 20 to 150%.
配合例17、18
エア発生剤として事前発泡型の起泡剤と事後発泡型のアルミニウム粉末をフライアッシュとセメントのモルタルに混合した。その配合例17、18を表10、表11に示す。エア発生剤は固結体の密度を小さくする事の他に流動性を向上させる効果がある。
Formulation Examples 17 and 18
As an air generating agent, a prefoaming foaming agent and a post foaming aluminum powder were mixed with fly ash and cement mortar. The blending examples 17 and 18 are shown in Table 10 and Table 11. The air generating agent has the effect of improving fluidity in addition to reducing the density of the consolidated body.
(1)流動性調整材:起泡剤添加量
グラウト中に含まれるセメントに対する起泡剤の含有量を起泡剤重量/(セメント重)×100〔%〕とすると
起泡剤添加量は0.5〜1.5%(対セメント重量比)が好ましい。
(1) Fluidity modifier: foaming agent addition amount When the foaming agent content in the grout is the foaming agent weight / (cement weight) × 100 [%], the foaming agent addition amount is 0. From 0.5 to 1.5% (weight ratio of cement) is preferred.
(2)流動性調整材:アルミニウム粉末添加量
アルミニウム粉末はセメント等のアルカリに反応して水素ガス(起泡)を発生する。グラウト中に含まれる粉末に対するアルミニウム粉末の含有量をアルミニウム比:アルミニウム粉末重量/粉状体重量×100〔%〕とするとアルミニウム比0.01%程度が効果的である。
(2) Fluidity modifier: Aluminum powder addition amount Aluminum powder reacts with alkalis such as cement to generate hydrogen gas (foaming). When the aluminum powder content relative to the powder contained in the grout is aluminum ratio: aluminum powder weight / powder body weight × 100 [%], an aluminum ratio of about 0.01% is effective.
(3)配合例17、18の特性および比較
エア発生剤には固結体の密度を小さくすることの他に流動性を向上させる効果がある。
(3) Characteristics and Comparison of Formulation Examples 17 and 18 The air generating agent has an effect of improving fluidity in addition to reducing the density of the consolidated body.
配合例19、20
本発明の注入材の主材となるシリカ系非硬化性粉状体として、焼却灰、火山灰を使用した。焼却灰はフライアッシュと1対1の量で配合し、火山灰はフライアッシュと1対3の量で配合した。このようにして得られた配合例19、20の地盤注入材の調整条件および物性値を下記の表12,13に示す。
Formulation Examples 19 and 20
Incinerated ash and volcanic ash were used as the silica-based non-curable powder that is the main material of the injection material of the present invention. Incineration ash was blended with fly ash in a one-to-one amount, and volcanic ash was blended with fly ash in a one-to-three amount. Tables 12 and 13 below show the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 19 and 20 obtained as described above.
(1)水粉体比
グラウト中の粉体に対する水の含有量:水重量/(フライアッシュ、焼却灰、火山灰、(シリカ系非硬化性粉状体)重量+セメント重量)×100〔%〕
ここでは硬化発現材とフライアッシュ以外の非硬化性粉状体として焼却灰、火山灰を用いた。その他にも現場発生土や珪砂等を用いることができる。
(1) Water-powder ratio Water content with respect to the powder in the grout: water weight / (fly ash, incineration ash, volcanic ash, (silica non-curable powder) weight + cement weight) x 100 [%]
Here, incinerated ash and volcanic ash were used as non-curable powders other than the cured material and fly ash. In addition, on-site generated soil or silica sand can be used.
(2)配合例19、20の特性および比較
表12の配合例19と、表1の配合例3を比較すると、焼却灰を混合した配合例19の方がブリージング率は減少し、フロー値が小さくなった。また表13の配合例20と、表1の配合例1を比較しても同様の結果が得られた。焼却灰や火山灰を混合すると、フライアッシュのみの場合よりも流動性を失いやすく、また強度発現も低下する傾向にあると考えられる。ただし可塑状保持時間は長いため、これとゲル化調整剤を混合することで流動性や固結強度の調整が可能となる。硬化発現材比は50%未満、好ましくは1〜20%、水粉体比は20〜150%が好ましい。
(2) Characteristics and Comparison of Formulation Examples 19 and 20 When comparing Formulation Example 19 in Table 12 and Formulation Example 3 in Table 1, the blending example 19 in which incinerated ash is mixed has a reduced breathing rate and a flow value of It has become smaller. Moreover, the same result was obtained even if the combination example 20 of Table 13 and the combination example 1 of Table 1 were compared. When incinerated ash and volcanic ash are mixed, it is considered that the fluidity tends to be lost and the strength development tends to be lower than that of fly ash alone. However, since the plastic holding time is long, the fluidity and the consolidation strength can be adjusted by mixing this with a gelation modifier. The ratio of cured material is less than 50%, preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%.
配合例24
本発明の注入材の主材となるシリカ系非硬化性粉状体としてスラグを使用し、セメント、水と混合する。このようにして得られた配合例21,22の地盤注入材の調整条件および物性値を下記の表14に示す。
Formulation Example 24
Slag is used as a silica-based non-curable powder that is the main material of the injection material of the present invention, and is mixed with cement and water. Table 14 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 21 and 22 thus obtained.
(1)水粉体比
グラウト中の粉体に対する水の含有量:水重量/(スラグ(シリカ系非硬化性粉状体)重量+セメント重量)×100〔%〕
(1) Water-powder ratio Water content with respect to the powder in the grout: water weight / (slag (silica-based non-curable powder) weight + cement weight) × 100 [%]
(2)配合例21、22の特性および比較
主材として、フライアッシュを使用した場合とスラグを使用した場合を比較すると、スラグの方がセメントとの反応が良好であり、配合例2と比較すると、硬化発現材比は同様で、水粉体比が倍になっているにもかかわらず、ゲルタイムは早く、また強度発現も顕著である。これにゲル化調整剤を加えることも可能である。ただしスラグ、セメント、水のみの配合でも強度発現が急速であるため、ゲル化調整剤に促進剤を用いた場合、硬化が促進し可塑状保持時間が短くなることが考えられる。硬化発現材比は50%未満、更には1〜20%、また水粉体比は20〜150%、更には30〜80%が好ましい。
(2) Characteristics and Comparison of Formulation Examples 21 and 22 When comparing the case of using fly ash and the case of using slag as the main material, the slag has a better reaction with cement and is compared with Formulation Example 2. Then, the ratio of the cured material is the same, and the gel time is fast and the strength development is remarkable despite the fact that the water powder ratio is doubled. It is also possible to add a gelling regulator to this. However, since the development of strength is rapid even when only slag, cement, and water are blended, it is considered that when an accelerator is used as the gelation modifier, curing is promoted and the plastic holding time is shortened. The ratio of cured material is preferably less than 50%, more preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%, more preferably 30 to 80%.
配合例23,24,25
硬化発現材として消石灰、スラグ、石膏を使用し、フライアッシュ、水と混合した。このようにして得られた配合例23,24,25の地盤注入材の調整条件および物性値を下記の表15,16,17に示す。
Formulation Examples 23, 24, 25
Slaked lime, slag, and gypsum were used as the curing agent and mixed with fly ash and water. Tables 15, 16, and 17 below show the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 23, 24, and 25 thus obtained.
(1)硬化発現材比
グラウトに含まれる粉体の含有量に対する硬化発現材の含有量:硬化発現材重量/(フライアッシュ(シリカ系非硬化性粉状体)重量+硬化発現材重量)×100[%]
それぞれ硬化発現材として消石灰、スラグ、石膏を使用したので、硬化発現材重量とは消石灰添加量、スラグ添加量、石膏添加量を意味する。
(1) Curing manifestation material ratio Curing manifestation material content to powder content in grout: Curing manifestation material weight / (fly ash (silica non-curable powder) weight + curing manifestation material weight) × 100 [%]
Since slaked lime, slag, and gypsum were used as the hardening developing materials, the weight of the hardening developing material means the slaked lime addition amount, the slag addition amount, and the gypsum addition amount.
(2)配合例23の特性および比較
硬化発現材として消石灰を用いた場合、セメントと同様フライアッシュに添加するとポゾラン反応を起こすが、この反応は非常に緩慢であるため可塑状にはなるが、固結には時間がかかり、また充分な固結強度を得るためには数週間かかる。よって消石灰は硬化発現材よりも増粘材として有効である。よって配合例9,10,11のようなセメントとの併用やゲル化促進剤と混合することにより優れた効果が期待できると考える。
(2) Characteristics and Comparison of Formulation Example 23 When slaked lime is used as a hardening developing material, a pozzolanic reaction occurs when added to fly ash as with cement, but this reaction is very slow, but it becomes plastic. Consolidation takes time, and it takes several weeks to obtain sufficient consolidation strength. Therefore, slaked lime is more effective as a thickening material than a hardening developing material. Therefore, it is thought that the outstanding effect can be anticipated by using together with a cement like the blending examples 9, 10, and 11 or mixing with a gelling accelerator.
(3)配合例24の特性および比較
硬化発現材としてスラグを用いた場合、セメントよりも若干早くゲル化し、可塑状保持時間は長くなるが、セメントに類似した結果となる。よって、ゲル化調整剤を混合することでゲル化時間、流動性の調整が可能となるが、同量のセメントを混合したときよりもスラグの場合、強度発現が遅れるので強度低下作用があるゲル化調整剤を多量に混合することは好ましくない。
(3) Characteristics and Comparison of Formulation Example 24 When slag is used as a hardening developing material, it gels slightly faster than cement and the plastic holding time becomes longer, but the result is similar to cement. Therefore, it is possible to adjust the gelation time and fluidity by mixing the gelation modifier, but in the case of slag than when mixing the same amount of cement, the strength expression is delayed, so the gel has the effect of reducing the strength. It is not preferable to mix a large amount of the chemical adjusting agent.
(4)配合例25の特性および比較
硬化発現材として石膏を用いる場合、石膏は反応が早いため可塑状にもなりやすいが、
強度発現も早いため可塑状保持時間が極めて短くなる。よって遅延剤等を用いることにより、ゲル化時間を調整することが好ましい。或は早急に強度を高めたい場合、促進剤の使用も可能である。
(4) Characteristics and Comparison of Formulation Example 25 When gypsum is used as a curing agent, gypsum tends to be plastic because it reacts quickly,
Since the development of strength is fast, the plastic holding time is extremely short. Therefore, it is preferable to adjust the gelation time by using a retarder or the like. Alternatively, if it is desired to increase the strength quickly, an accelerator can be used.
本発明の特徴である塊状固結体(球状固結体)の造成について、野外注入実験を行った。配合液は表18の配合を用い、対象とした地盤はおよそN値が7、相対密度が40%、細粒分含有率が20%未満である砂質土地盤である。比較例として従来の水ガラス系懸濁型瞬結配合(以下、瞬結配合)の比較例1、3は瞬結配合(ゲル化時間10秒、可塑状保持時間なし)であり、比較例2はLW(ゲル化時間1分、可塑上保持時間なし)、比較例4はセメント系注入材(ゲル化時間数秒、可塑状保持時間なし)である。比較例1、比較例2、比較例3、比較例4の配合はそれぞれ表19、表20、表21、表22に示す。又実施例1の配合例を用いた実施例を表18に示す。配合液の混合と可塑状ゲルの生成と圧入状況についても区分をA〜Fに示す。掘削調査における固結状況をI〜VIに示す。
A field injection experiment was conducted on the formation of a massive solid body (spherical solid body), which is a feature of the present invention. The composition liquid used is the composition shown in Table 18, and the target ground is sandy ground having an N value of 7, a relative density of 40%, and a fine particle content of less than 20%. As comparative examples, Comparative Examples 1 and 3 of a conventional water glass suspension type instantaneous setting compound (hereinafter referred to as an instantaneous setting method) are instantaneous setting (
表18より区分Aによる圧入ではシリカ系非硬化性粉状体、カルシウム系粉状硬化発現材、水からなる懸濁液および可塑状ゲル、或はゲル化調整剤を混合し可塑状ゲルとしてそのまま設定圧力で圧力不能になる迄圧入した場合、可塑状ゲル化物によるほぼ球状の固結体を形成する。ゲル状塊状体の成長は可塑状保持時間が長く強度が大きくない水粉体比、硬化発現体比配合が大きな塊状体をつくる。 From Table 18, in the case of press-fitting according to Category A, a silica-based non-curable powder, a calcium-based powder-curing material, a suspension made of water and a plastic gel, or a gelling modifier are mixed and used as a plastic gel. When press-fitting until it becomes impossible to press at the set pressure, a substantially spherical solid body formed of a plastic gel is formed. The growth of the gel-like lump forms a lump having a large plastic-retaining time and a high water / powder ratio and a high ratio of the cured substance.
区分Bによる圧入では、混合後、可塑状ゲルにならないうちに注入を開始して注入過程中で可塑状ゲルに到り、そのまま設定圧力で注入不能になる迄圧入した場合、形状が不定形になるが、注入対象範囲内に塊状固結体を形成した。これは圧入初期において流動性が充分ある配合液が地盤の圧入抵抗の小さく弱い方向に圧入され脱水と共に流動性が低下し、更に可塑状になった注入材が圧入されて塊状体が拡大して固化したものと思われる。この場合、球状体でなくとも弱い部分を中心に締固めたものであるから、改良効果は充分得る事が出来る。 In the press-fitting according to section B, after mixing, the injection starts before becoming a plastic gel, reaches the plastic gel during the injection process, and press-fits until it becomes impossible to inject at the set pressure, and the shape becomes indefinite. However, a massive solid body was formed within the injection target range. This is because the liquid mixture with sufficient fluidity in the initial stage of press-fitting is pressed in the direction where the press-fitting resistance of the ground is small and weak, and the fluidity decreases with dehydration, and the plasticized injection material is pressed in and the mass is expanded. It seems to have solidified. In this case, even if it is not a spherical body, it is compacted around a weak portion, so that the improvement effect can be sufficiently obtained.
区分Cによる圧入では混合後、そのステージの圧入が完了する迄は可塑状ゲルには至らないが、圧入時間と共に圧力が上昇し最終的に注入量がゼロになって注入が不能になったもので、掘削結果の調査では注入初期では流動性が大きいため、一部受持ち範囲外迄脈状に割裂注入されるものの、地盤中で脱水によって流動性が失われ受持ち範囲内で可塑状ゲルの形成と共に塊状ゲルが大きく成長し、周辺地盤を圧縮強化する効果が得られる。 In the press-fitting according to section C, after mixing, the plastic gel does not reach until the press-fitting of the stage is completed, but the pressure increases with the press-fitting time, and finally the injection amount becomes zero and the injection becomes impossible. In the investigation of the drilling results, the fluidity is large at the beginning of the injection, so some parts are split and injected to the outside of the handling range, but the fluidity is lost due to dehydration in the ground, and a plastic gel is formed within the handling range. At the same time, massive gel grows and the effect of compressing and strengthening the surrounding ground is obtained.
区分Dによる注入では、ゲル化液可塑状保持時間のない通常の水ガラスグラウトであってゲル化と共に圧力は上昇するが、更に注入すれば脈状に割裂して受持ち範囲以外迄逸脱して脈状に固結する。このため対象地盤を高密度化する効果は殆どない。 In the injection by section D, it is a normal water glass grout with no gelling liquid plastic state retention time, and the pressure increases with gelation, but if it is further injected, it splits into a pulse shape and deviates outside the range of responsibility. Consolidate into a shape. For this reason, there is almost no effect of increasing the density of the target ground.
区分Eによる注入では、一般の可塑状を呈さない配合液であって注入中に初圧のまま圧力上昇を示さず、注入対象範囲外へ逸脱して改良効果は殆ど生じない。 The injection according to the section E is a compounded liquid that does not exhibit a general plastic state, and does not show an increase in pressure while maintaining the initial pressure during injection, and deviates outside the injection target range and hardly improves.
区分Fによる圧入では、地盤注への注入時点においてすでに流動性が殆どないから注入管吐出口から地盤に吐出されるとすぐに吐出口の外側で脱水が生じ、吐出口の内側の注入材が脱水し、更に加圧するにつけ注入管内の注入材の脱水が注入管内の上方に及び、ついには注入管全体が固化して注入不能に陥る事がわかった。 In the press-fitting according to section F, dehydration occurs immediately outside the discharge port as soon as it is discharged from the injection tube discharge port to the ground at the time of injection into the ground injection, and the injection material inside the discharge port becomes It was found that the dehydration of the injection material in the injection tube reached the upper part in the injection tube when it was dehydrated and further pressurized, and finally the entire injection tube solidified and became unable to be injected.
これが流動性の少ない可塑性グラウトを地盤中に注入すると、いくらポンプ圧を上げても注入不能になり、亀裂注入も生じないという現象が生ずる理由でもある。 This is also the reason why when a plastic grout with little fluidity is injected into the ground, no matter how much the pump pressure is raised, the injection becomes impossible and no crack injection occurs.
区分A,B,Cにおいては、注入後の掘削調査において固結体の体積と注入量を測定したところ、その脱水量はほぼ30%以内であった。これより上記流動範囲の注入材を注入不能になる迄加圧脱水して地盤注に圧入すれば、脱水率がほぼ30%以内で流動不能な塊状ゲルが地盤注に形成される事がわかった。 In sections A, B, and C, the volume of the consolidated body and the injection amount were measured in the excavation survey after injection, and the dehydration amount was within about 30%. From this, it was found that if the injection material in the above flow range was pressurized and dehydrated until it could not be injected and pressed into the ground casting, a solid gel that could not flow with a dehydration rate within about 30% was formed in the ground casting. .
これらの現象も含めて種々の野外圧入実験より、該注入液の注入時の配合液が注入時点で可塑状ゲルに至っているか、或はその時点では可塑状ゲルになっていなくても注入中に地盤に注入される前の段階で、可塑状ゲルに到るか、或は配合液から30%以内の脱水によって可塑状ゲルが注入中に形成されるように配合を設定すれば地盤中で塊状ゲルが形成されることがわかった。 From various field injection experiments including these phenomena, it is found that the compounded solution at the time of injecting the injection solution has reached a plastic gel at the time of injection, or even if it is not a plastic gel at that time, during injection. If the composition is set so that it reaches the plastic gel before it is injected into the ground, or the plastic gel is formed during the injection by dehydration within 30% of the compounded liquid, it will lump in the ground It was found that a gel was formed.
実施例2は、N値が10以下の地盤における改良効果の例である。例えば具体的には配合例3の場合、配合後5分間混合し毎分吐出量5l/min、初期圧力1.0MN/m2、最径圧力3.0MN/m2、注入速度がゼロになり不能になった。全注入量が50l圧入した掘削調査の結果、ほぼ35l(脱水率30%)の塊状ゲルが形成されている事がわかった。
Example 2 is an example of the improvement effect in the ground where the N value is 10 or less. For example, in the case of compounding example 3, for 5 minutes after mixing, the discharge rate is 5 l / min per minute, the initial pressure is 1.0 MN / m 2 , the maximum diameter pressure is 3.0 MN / m 2 , and the injection speed becomes zero. It became impossible. As a result of the excavation investigation in which the total injection amount was 50 l, it was found that a massive gel of approximately 35 l (
可塑状の圧入工法の改良効果は、地盤中で流動性の低下する可塑状ゲルの圧入であるから、ポンプ圧で圧入出来る範囲のゆるい地盤が対象となり、通常N値が15以下、最も好ましくはN値が10以下の軟弱地盤である。しかし、液状化防止や基礎の補強にあってはN値が15以上、或は20以上の地盤を更に改良する必要がある。このような地盤条件と目的では本発明者はいくつかの野外注入試験で実験2の区分B,Cによる手法がきわめて効果的である事がわかった。 The improvement effect of the plastic press-in method is the press-fit of plastic gel whose fluidity decreases in the ground, so it is intended for loose ground that can be press-fitted with pump pressure, and usually has an N value of 15 or less, most preferably It is a soft ground with an N value of 10 or less. However, in order to prevent liquefaction and strengthen the foundation, it is necessary to further improve the ground having an N value of 15 or more, or 20 or more. Under such ground conditions and purposes, the present inventor has found that the method according to the sections B and C of Experiment 2 is extremely effective in several field injection tests.
このような地盤では配合3をA区分のように注入した場合、注入後1MN/m2から2分以内に注入圧を3MN/m2に上昇し圧入が困難になって、例2の配合を3時間混合後、毎分吐出量5l/minで初期圧力0.1MN/m2で注入したところ、5分後1.0MN/m2となり更に最大圧力2.0MN/m2を限界圧として全注入量が50lになるように圧入した。同塊状固化体の先行部に一部亀裂が認められ、中心部側が亀裂を中心に大きな厚さの塊状固化体が形成された。
In such a ground, when
これより注入時に可塑状ゲルの状態の圧入はN値が15以内でも地盤中で可塑状ゲルが、成長し拡大するが、地盤のN値が15以上になると可塑状ゲルのまま圧入しつづける事が困難となる。しかし、注入初期において可塑状ゲルでない状態の配合液を地盤に注入する事によりN値が15以上の大きな地盤でも脈状に亀裂を形成しながら割裂し、脱水可塑状ゲルになると、流動性が低下し亀裂中でゲルとなり、そのゲルを中心に塊状ゲルが拡大して大きな塊状ゲルに成長する。この球状体ではないが、受持ち範囲内で周辺地盤の密度を上昇させ、地盤の高強度化が可能になる。 From this, the injection of the state of the plastic gel at the time of injection is that the plastic gel grows and expands in the ground even if the N value is within 15, but if the N value of the ground becomes 15 or more, the plastic gel continues to be pressed in as the plastic gel. It becomes difficult. However, by injecting into the ground a compounded liquid that is not a plastic gel in the initial stage of injection, even when the ground has a large N value of 15 or more, it splits while forming a crack like a vein, and when it becomes a dehydrated plastic gel, the fluidity is reduced. It lowers and becomes a gel in the crack, and the massive gel expands around the gel and grows into a large massive gel. Although it is not this spherical body, the density of the surrounding ground can be increased within the range of handling and the strength of the ground can be increased.
このような結果は、注入初期において流動性のよい溶液型グラウトを注入して亀裂注入を行ってのち、可塑状ゲルの圧入にきりかえて注入する事によって可塑状ゲルを圧入するには地盤密度が高いか、地盤改良を必要とする地盤改良のためにきわめて効果的な手段である事を見出した。 These results indicate that the ground density is sufficient to inject the plastic gel by injecting the plastic gel by injecting cracks after injecting a solution type grout with good fluidity at the beginning of the injection. It was found to be an extremely effective means for ground improvement requiring high ground or ground improvement.
従来のセメントグラウトやLWグラウトのみでは単に脈状に逸脱するのみであるが、途中で可塑状ゲルに到る注入材或は可塑性ゲル状の注入材の圧入を行う事により、可塑状ゲル圧入工法の適用範囲が飛躍的に拡大する事がわかった。
野外注入実験
A conventional cement grout or LW grout only deviates in a pulse shape, but a plastic gel press-in method is performed by press-fitting an injection material that reaches the plastic gel or a plastic gel-type injection material on the way. It has been found that the scope of application has been dramatically expanded.
Field injection experiment
上記における固結状況の説明
掘削調査における固結体の形状
I 直径30〜70cmのほぼ球体の大きな塊状固結体形成
II 形状が球状でなく不定形であるが、直径20〜50cm塊状固結体形成
III 一部の先端部は注入範囲外迄脈状もみられたが、受持範囲内で直径20〜50cm塊状固結体形成
IV 厚さ1〜10cmの脈状注入範囲外へ逸脱
V 厚さ1〜5cmの脈状注入範囲外へ逸脱
VI 注入孔の大きさの固結体のみ
Explanation of consolidation status in the above Shape of consolidated body in excavation survey I Formation of large solid aggregates of approximately spherical shape with a diameter of 30 to 70 cm
II The shape is not spherical but irregular, but formed into a solid aggregate with a diameter of 20-50cm
III Some of the tip part was pulsated to the outside of the injection range.
IV Deviation outside the range of pulse injection with a thickness of 1-10cm V Deviation outside the range of pulse injection with a thickness of 1-5cm
VI Only the size of the injection hole
本発明における図4に示す試験施工による研究の結果、以下のように注入設計することにより地盤強化効果を得ることが判った。 As a result of the study by the test construction shown in FIG. 4 in the present invention, it was found that the ground strengthening effect was obtained by the injection design as follows.
図4において注入間隔は0.5〜3.0mとする。改良率は5〜40%とする。ここで改良率とは1注入孔の分担改良面積1m2当りに換算して固結塊の断面積に相当し、改良率5〜40%とは0.05〜0.4m2を意味する。又、この改良率は改良対象地盤のN値と改良目標N値から1孔当りの受持面積のうちの間隙の減少量が算出され、その減少量がゲル化物に置き換えられる面積に対応することから算出される。 In FIG. 4, the injection interval is 0.5 to 3.0 m. The improvement rate is 5 to 40%. Here it corresponds to the cross-sectional area of the conversion to consolidated mass and improved rate allocation improvement area 1 m 2 per 1 injection hole, the improvement ratio 5-40% means 0.05~0.4m 2. In addition, this improvement rate is calculated from the reduction amount of the gap in the receiving area per hole from the N value of the improvement target ground and the improvement target N value, and the reduction amount corresponds to the area to be replaced by the gelled product. Is calculated from
以下、表23に本発明における地盤強化として有効な設計例を示す。これは実施例2で砂地盤にて行った実験例に基づくものであり、注入配置は図4(ロ)に示す正方形配置、注入間隔は1m、2m、また改良率は5%、10%、15%、20%である。 Table 23 shows design examples effective as ground reinforcement in the present invention. This is based on the experimental example performed on the sand ground in Example 2, the injection arrangement is a square arrangement shown in FIG. 4 (b), the injection interval is 1 m, 2 m, and the improvement rate is 5%, 10%, 15% and 20%.
複数の流路をもつ二重管ロッドを用い、その流路から一次注入に可塑状ゲルを注入し、他方の流路から二次注入に溶液型シリカグラウトを用いる方法を図5に示す。 FIG. 5 shows a method of using a double tube rod having a plurality of flow paths, injecting plastic gel from the flow path for primary injection, and using solution-type silica grout for secondary injection from the other flow path.
本発明において、二次注入材は一次注入材よりも浸透性が良ければよく、地盤状態によって浸透出来る。例えば、溶液型シリカグラウトの外に懸濁型の可塑状を呈さないセメントグラウト、超微粒子セメントグラウトでも良い。又、可塑状グラウトであるが、一次注入材よりも浸透性の高い物ならば良い。 In the present invention, the secondary injection material only needs to have better permeability than the primary injection material, and can be penetrated depending on the ground condition. For example, in addition to the solution-type silica grout, a cement grout that does not exhibit a suspension-type plasticity or an ultrafine cement grout may be used. Moreover, although it is a plastic grout, the thing of higher permeability than a primary injection material should just be.
(1) 薬液
一次注入材には実施例の配合2を用い、二次注入材は溶液型非アルカリ性シリカグラウトを用いた。この、溶液型非アルカリ性シリカグラウトは水ガラスをイオン交換により脱アルカリして得られる活性シリカ(SiO2濃度4wt%)をベースとし、それに水ガラスと酸(リン酸)によって所定のシリカ濃度6%とpH4.0に調整した酸性シリカ溶液である。ここで、二次注入材として水ガラスと酸を加えて水ガラスのアルカリを除去して得られた酸性シリカゾルからなる酸性シリカ溶液を用いてもよい。
(1) Chemical solution Formulation 2 of the example was used as the primary injection material, and solution-type non-alkaline silica grout was used as the secondary injection material. This solution-type non-alkaline silica grout is based on active silica (SiO 2 concentration 4 wt%) obtained by dealkalizing water glass by ion exchange, and a predetermined silica concentration of 6% by water glass and acid (phosphoric acid). And acidic silica solution adjusted to pH 4.0. Here, you may use the acidic silica solution which consists of acidic silica sol obtained by adding water glass and an acid as a secondary injection material, and removing the alkali of water glass.
図5において、所定深度まで削孔した後、一次注入材として可塑状ゲルを注入管周りの空隙と地盤の粗い部分に注入する。続いて、二次注入材として溶液型シリカグラウトを注入し、地盤の細かい空隙に浸透し、地盤を強化する。注入管を引き上げ次のステップを同様に繰り返した。 In FIG. 5, after drilling to a predetermined depth, a plastic gel is injected as a primary injection material into the gap around the injection tube and the rough portion of the ground. Subsequently, solution type silica grout is injected as a secondary injection material, penetrates into the fine voids of the ground, and strengthens the ground. The injection tube was pulled up and the next step was repeated in the same manner.
1ヵ月後、掘削したところ柱状に浸透注入されており、シリカ溶液の固結体(サンドゲル)の強度を測定したところ、0.4MN/m2であった。又、可塑状ゲルの固結体を測定したところ1.23MN/m2であった。 One month later, when excavated, it was injected into a columnar shape, and the strength of the solidified body (sand gel) of the silica solution was measured and found to be 0.4 MN / m 2 . Further, when the solidified body of the plastic gel was measured, it was 1.23 MN / m 2 .
結果より、地盤中に注入した一次注入材の可塑状ゲルは、ミキサー内での配合では水粉体比が30%でゲルタイムが300分である為、ゲル化に時間を要し、また、可塑状保持時間も11時間あることから流動性を長時間保ち、ポンプからの送液が可能であるが、地盤中に注入され後続の注入材により地盤中で圧密され、脱水されることで、水粉体比が低下し、配合例3を経てゲル化する。そのため、地盤中に注入された可塑状ゲルはゲルタイム及び可塑状保持時間が短くなり、水粉体比が低下することで固結強度が上がり、可塑状ゲルの実験値での強度より高く、実際の水粉体比よりも低い配合での固結強度となる。また、二次注入材として溶液型シリカグラウトを用いることで、地盤中の細部まで注入される。 From the results, the plastic gel of the primary injection material injected into the ground has a water powder ratio of 30% and a gel time of 300 minutes when blended in the mixer. Since the state retention time is also 11 hours, the fluidity can be maintained for a long time and the liquid can be fed from the pump. However, the water is injected into the ground, consolidated in the ground by the subsequent injection material, and dehydrated. The powder ratio decreases, and gelation occurs through Formulation Example 3. Therefore, the plastic gel injected into the ground shortens the gel time and the plastic retention time, and the caking strength increases due to a decrease in the water-powder ratio, which is higher than the experimental strength of the plastic gel. The consolidation strength is lower than the water powder ratio. Moreover, by using a solution-type silica grout as a secondary injection material, details in the ground are injected.
実際の施工において、地盤の特性、及び期待強度により一次注入と二次注入の組み合わせは、上記に示した一次注入に可塑状グラウト、二次注入に溶液型グラウトの組み合わせの他に、一次注入に可塑状グラウト、二次注入にスラグ、セメントベントナイト等を配合した懸濁型グラウトを用いてもよい。 In actual construction, depending on the characteristics of the ground and the expected strength, the combination of primary injection and secondary injection is not limited to the combination of plastic grout for primary injection and solution-type grout for secondary injection, as shown above. A plastic grout or a suspension grout in which slag, cement bentonite or the like is blended in the secondary injection may be used.
また、地盤に粗い空隙が多く、地盤を強固に改良する場合、一次注入に可塑状グラウトを用い、二次注入には一次注入より流動性の高い可塑状グラウトを用いることもできる。このとき、一次注入材、二次注入材の流動性の調整には、流動性調整剤として硫酸アルミニウム、水ガラス、スラグ、ベントナイト、石膏、等を用い、ゲル化時間及び可塑状保持時間を調整することで、地盤への浸透性を変化させることができる。尚、上記において可塑状ゲルは配合例2をA液として、流動性調整剤をB液として合流した上で、一次注入の注入管経路に相液してもよい。 Moreover, when there are many rough voids in the ground and the ground is strongly improved, a plastic grout can be used for the primary injection, and a plastic grout having higher fluidity than the primary injection can be used for the secondary injection. At this time, in order to adjust the fluidity of the primary injection material and the secondary injection material, aluminum sulfate, water glass, slag, bentonite, gypsum, etc. are used as the fluidity adjusting agent, and the gelation time and plasticity retention time are adjusted. By doing so, the permeability to the ground can be changed. In the above, the plastic gel may be mixed in the injection pipe path of the primary injection after combining the blending example 2 as the A liquid and the fluidity adjusting agent as the B liquid.
地盤中に圧入し、土粒子を周辺に押しやって塊状に固結しながら周辺土砂を押しやって地盤強化を図る、重ね合わせて注入方法を示す。このような可塑性注入材の注入に当たり、初期注入圧力を低くして先行注入物の脱水を図りながら注入圧力を段階的に高め、或は、最初流動性の大きな可塑状グラウトを注入し、続いて流動性の低い可塑状グラウトを圧入することにより、流動性の大きな可塑状グラウトを細かい空隙に押し込むことにより、水流や水圧に耐える厚い固化層を形成し得る。 The injection method is shown in a superimposed manner by pressing into the ground, pushing the soil particles around and solidifying them in a lump while pushing the surrounding soil and strengthening the ground. In injecting such a plastic injection material, the initial injection pressure is lowered to increase the injection pressure step by step while dehydrating the preceding injection, or first, a plastic grout having a high fluidity is injected, followed by By press-fitting a plastic grout having low fluidity, a thick solidified layer that can withstand water flow and water pressure can be formed by pushing the plastic grout having high fluidity into a fine gap.
あるいは、注入と中断を繰り返して間欠的に加圧しながら注入し、これにより可塑性を呈するゲル化物の土粒子間浸透と地盤の割裂による逸脱を防ぎながら土粒子を周辺に押し広げて、地盤の密度を増大させながら固結してもよい。或は、矢板や、護岸の欠損部に流動性の低い可塑状グラウトを少しずつ押し広げながら圧入して脱水と共に非可塑状を経て固化に至らしめることができる。(図6(a)、(b)、(c))
しかも、この注入は複数の注入ポイントからの同時注入方式、別の注入ポイントへの切り替え注入、即ち図6(b)のような連続注入方式、1つの注入ポイントから他の注入ポイントに移行して注入してから再び戻ってきて繰り返し注入するインターバル注入方式、またはこれら方式の組み合わせで行われる。
Alternatively, it is injected while intermittently pressurizing by repeatedly injecting and interrupting, thereby spreading the soil particles to the periphery while preventing deviation due to interpenetration of the soiled gel particles and cracking of the ground, and the density of the ground It may be consolidated while increasing. Alternatively, a plastic grout having low fluidity can be pressed into a sheet pile or a breakage part of the revetment while being gradually pushed in, and then solidified through dehydration and non-plasticization. (Fig. 6 (a), (b), (c))
In addition, this injection is performed by simultaneous injection from a plurality of injection points, switching injection to another injection point, that is, a continuous injection method as shown in FIG. 6B, and a transition from one injection point to another injection point. The injection is performed by the interval injection method in which the injection is performed again after returning to the injection, or a combination of these methods.
さらに、本発明にかかる地盤注入材は複数の注入ポイントから注入して注入ポイント間の地盤を拘束し、注入管間の地盤密度を増大して地盤を固結することもできる。このような効果を期待出来るのは複数の注入管を0.5m以上3m以内の間隔で地盤に設置するのが望ましい。この上で、同一注入孔から或は別の注入孔から浸透性注入材を注入して、全体を一体化した注入を行うことができる。 Furthermore, the ground injection material according to the present invention can be injected from a plurality of injection points to constrain the ground between the injection points, and the ground density between the injection pipes can be increased to consolidate the ground. In order to expect such an effect, it is desirable to install a plurality of injection pipes on the ground at intervals of 0.5 m or more and 3 m or less. On this, the permeable injecting material can be injected from the same injection hole or from another injection hole, and the whole injection can be performed.
上述の注入は例えば次の(a)、(b)、(c)に示す注入管を用いて行われる。
(a)先端部に削孔部又は吐出口がある注入管。
(b)軸方向に複数の吐出口を有する注入管を用いて注入する。
(c)外管に少なくとも一つの袋体パッカを備えた注入管。
The above-described injection is performed using, for example, the following injection pipes (a), (b), and (c).
(A) An injection tube having a drilled portion or a discharge port at the tip.
(B) Injection is performed using an injection tube having a plurality of discharge ports in the axial direction.
(C) An injection tube having at least one bag packer in the outer tube.
軟弱地盤等の強度を大幅に向上させるために、多量の可塑性ゲルを一度に過大の量を地盤中に形成すると、地盤表面に***が生じたり、側方向に地盤を破壊し、逸脱して当該地盤の強度が設定通りに向上しない事態が生じやすい。このため本地盤注入材の特性を生かし、注入初期には低吐出量で注入し、徐々に注入圧力を上げて所定の注入圧の範囲で圧入しつづけて注入量の増大をはかるのが望ましい。注入前の地盤の強度(N値等)注入深度(上載圧)注入圧力、注入量、1本当りの受け持ち面積から注入後の改良強度を把握出来る。 If an excessive amount of plastic gel is formed in the ground at the same time in order to greatly improve the strength of soft ground, etc., the ground surface will be raised, the ground will be destroyed in the lateral direction, and the There is a tendency that the strength of the ground does not improve as set. For this reason, it is desirable to take advantage of the characteristics of the ground injecting material, injecting at a low discharge amount at the initial stage of injection, gradually increasing the injection pressure and continuing to press fit within a predetermined injection pressure range to increase the injection amount. The strength of the ground before the injection (N value, etc.), the injection depth (upload pressure), the injection pressure, the injection amount, and the area of the area per injection can be obtained.
或は更に、地盤変位を加味すれば更に正確となる。又注入中は流動性があり、注入を停止すると、流動性が停止してゲル化或は加圧脱水して擬固状態が現出することから、対象注入土層に少量ずつインターバル方式(時間の間隔をあけて注入する)で反復注入して擬固せしめ、注入された地盤を破壊することなく圧密し、排除された水分は周辺の土粒子間に分散させ、地盤側方に対する圧密と脱水を行い、ゲル化物による固結径を大きくし、或はこれらのグラウトを一定のタイムラグ(時間差)をもって注入する事も効果的である。 Or, more accurately, if the ground displacement is taken into account. In addition, fluidity is present during the injection, and when the injection is stopped, the fluidity stops and gelation or pressure dehydration occurs, and a pseudo-solid state appears. Injected at intervals of 2), it is repeatedly injected to make it solidify, and the injected ground is consolidated without destroying it, and the removed water is dispersed among the surrounding soil particles, compacting and dehydrating the ground side It is also effective to increase the consolidated diameter of the gelled product or to inject these grouts with a certain time lag (time difference).
例えば、縦方向の注入にあっては、インターバル方式により回を重ねて、注入を行い、先行して注入された地盤注入材に対し、重ねて、該地盤注入材を圧入して、当該地盤を割裂する事なく、地盤注入材を反復的に圧入することにより、当該地盤の側方に対する圧密脱水を行い、地盤強化が行わる。 For example, in the vertical injection, the interval method is repeated, injection is performed, and the ground injection material is pressed into the ground injection material previously injected, and the ground is By repeatedly pressing the ground injection material without splitting, the side of the ground is consolidated and dewatered, and the ground is strengthened.
或は,当該地盤の所定エリアに所定数の削孔を形成し、各削孔に対し、地盤注入材は所定タイムラグを介し、一か所で設計量を一挙に地盤注入材の注入が行われないように、設計注入量をいくつかに分割して注入することも出来る。 Alternatively, a predetermined number of holes are formed in a predetermined area of the ground, and the ground injection material is injected into the ground injection material at a single location through a predetermined time lag for each hole. In order to avoid this, it is possible to divide the design injection amount into several parts.
このようにして各削孔の可塑性グラウトを相互に所定タイムラグで各土層、又は、ステージ毎にインターバル方式により注入し、先行して注入した可塑性グラウトが周辺地盤を圧密し、又は、自ら、又は、注入液が脱水することをもって、追い討ち的に重ね注入をすることにより、当該所定数の多数の削孔内に注入する地盤注入材が各削孔の地盤に対し土層又はステージ毎に、同様に側方に圧密脱水作用を行い、強度をアップし、全体的に変位を抑制し、当該所定エリアの地盤の強度を増強する事が出来る。 In this way, the plastic grout of each drilling hole is injected by the interval method for each soil layer or each stage at a predetermined time lag, and the plastic grout injected in advance consolidates the surrounding ground, or by itself, or In addition, when the injection solution is dehydrated, the ground injection material to be injected into the predetermined number of drilling holes by the repeated injection is repeated for each soil layer or stage with respect to the ground of each drilling hole. Similarly, it is possible to perform consolidation dehydration on the side, increase the strength, suppress the displacement as a whole, and enhance the strength of the ground in the predetermined area.
例えば、所定深度まで先端に吐出口のある注入管を挿入し、注入管の引き上げステップを非可塑状ゲルになる前の可塑状ゲルの範囲内に吐出口が位置するようにステップアップしながら可塑状ゲルの塊状体を拡大せしめて圧入する。 For example, an injection tube with a discharge port at the tip is inserted to a predetermined depth, and the step of lifting the injection tube is stepped up so that the discharge port is positioned within the range of the plastic gel before becoming non-plastic gel. The mass of the gel-like gel is enlarged and press-fitted.
更には、削孔に挿入する注入管に袋体を地表面近くの領域にセットし、内部に懸濁型グラウトを圧入して袋を周辺に膨張させて周辺地盤を圧密することにより、地表面に可塑性注入材を逸脱する事なく地表面を改良し、かつ該袋体より下方から本地盤注入材を圧入する事により、該袋体硬化体に対する可塑性ゲルの乗り越えがなく、該袋体による拘束効果により地盤の***等の変位がなく、地盤脱水作用による強度が全体に、及び、強度向上が全領域的に図れるようにする事が出来る。 Furthermore, the bag body is set in an area near the ground surface in the injection tube to be inserted into the drilling hole, the suspension type grout is press-fitted inside, the bag is inflated to the periphery, and the surrounding ground is consolidated. The ground surface is improved without departing from the plastic injection material, and the ground injection material is press-fitted from the lower side of the bag body, so that the plastic gel does not get over the hardened body of the bag and is restrained by the bag body. Due to the effect, there is no displacement of the ground uplift and the like, and the strength due to the ground dewatering action can be achieved as a whole and the strength improvement can be achieved over the entire region.
この場合、袋体の設置領域は地表面に近い深度、例えば3m範囲(特に1.5m範囲)内にあるようにするのが好ましい。なぜならこの領域は可塑状ゲルといえども地表面に逸脱しやすいからである。又、同じ理由でこの地表面に近い領域には注入孔を密に設置することにより地表面の圧縮の均等化を図り、かつ地表面***を防ぐ事が出来る。なぜならば地表面に近い深度例えば3m以内(特に1.5m以内)の領域では一本の注入孔から多量の注入を行うと、土被りが少ないために地表面に逸脱しやすく、かつ地盤***を起こしやすいからである。 In this case, it is preferable that the installation area of the bag body be within a depth close to the ground surface, for example, within a 3 m range (particularly, a 1.5 m range). This is because even in a plastic gel, this region tends to deviate to the ground surface. For the same reason, it is possible to equalize the compression of the ground surface and prevent the ground surface from being raised by installing injection holes densely in a region close to the ground surface. This is because, in a region close to the ground surface, for example, within 3 m (especially within 1.5 m), if a large amount of injection is performed from a single injection hole, the earth surface tends to deviate because there is little earth covering, and the ground uplift It is easy to wake up.
従って、この領域は注入孔を深度の大きい領域よりも密にして、一本当りの注入量を少なくする事によって、地表面付近を均等に強化出来る。又、地表面の地盤改良は上載圧が少ないために地盤***を起こしやすく、地盤***は地表面数m径に及ぶ。従って、注入する注入孔を隣接する注入孔へ移行するのではなく、地盤***の影響範囲外の注入孔に移行して注入し、地盤***が治まった時点で隣接する注入孔の注入を行うのが望ましい。 Therefore, in this region, the vicinity of the ground surface can be uniformly strengthened by making the injection hole denser than the region having a large depth and reducing the injection amount per one. In addition, the ground improvement on the ground surface is likely to cause a ground uplift due to a low overlay pressure, and the ground uplift reaches a diameter of several m on the ground surface. Therefore, instead of shifting the injection hole to be injected into the adjacent injection hole, the injection hole is transferred to the injection hole outside the influence range of the ground uplift, and the injection of the adjacent injection hole is performed when the ground uplift has subsided. Is desirable.
又、地表面に近い領域においては上部から下方に注入ステップを移行して本地盤注入材を圧入して地表面付近の地盤を圧縮してから改良地盤の最下部まで注入管を挿入し、下部から上方に注入ステップを移行して注入することにより、地表面の地盤***を低減して、或は上部の拘束効果により、それより下の確実な改良が可能になる。 In the area close to the ground surface, the injection step is shifted from the upper part to the lower part, the ground injection material is press-fitted to compress the ground near the ground surface, and then the injection pipe is inserted to the bottom of the improved ground. By shifting the injection step upward from the injection, the ground bulge on the ground surface is reduced, or the upper restraint effect allows a reliable improvement below it.
更に、本地盤注入材の当該地盤に対する注入において、土中水分が排除されるように、排水用のドレーン材を併設して、間欠的(時間をあけて注入する)な排水効果(注入を中断している間に脱水する)による地盤の側方圧密脱水効果を促進させ、或は可塑性注入材の脱水を促進する事が出来る(このドレーン材の適用は粘性土層の地盤強化に適している)。 In addition, in order to eliminate soil moisture in the injection of this ground injection material into the ground, drainage material for drainage is also provided, and intermittent drainage effect (injection is suspended) It is possible to promote the side consolidation dehydration effect of the ground by dehydrating during the operation, or to accelerate the dehydration of the plastic injection material (application of this drain material is suitable for the strengthening of the soil of the cohesive soil layer) ).
或は排水管を設置して地下水を排除し、当該圧密による速度を向上させるようにする。なお注管側面に吐出口の他に吸水口を設ける事によって吐出口から注入材を圧入しながら吸水口から注入材の過剰水や土中水を注入圧で吸い上げてドレーン効果を可能にする。 Alternatively, drainage pipes are installed to remove groundwater and increase the speed of consolidation. By providing a water inlet in addition to the outlet on the side of the pipe, the drain effect can be achieved by sucking in excess water or soil water from the inlet through the inlet while pressing the inlet from the outlet.
更に地盤の***等の変化を計測するためにレーザー等のセンサーにより、リアルタイムで当該変化を測定し、地盤の圧縮量を把握し、或は、当該変化が設計的に異常を生じた時には、即応的に可塑性グラウトの注入を調整し、或は、注入装置の制御装置を介し、注入量や注入深度の変更を行い、或は注入液の比重や注入量やインターバル時間等を自動的に切り換え的に調整して、所定変位を超えないうちに他のステージに移行し、設計通りの圧密脱水による地盤強度の向上が確実に行うことが出来、上記地盤の変位測定は地表面における地盤***の測定の他、ストレンゲージを張った計測棒を地盤中にセットして測定方向への地盤の部位の変化を知ることが出来、又、地盤中に間隙水圧計を設けて、圧密脱水状況を把握することが出来る。 Furthermore, in order to measure changes in the ground uplift, etc., a sensor such as a laser measures the change in real time and grasps the amount of compression of the ground, or responds immediately when the change causes an abnormal design. The injection of plastic grout is adjusted, or the injection volume and injection depth are changed via the controller of the injection apparatus, or the specific gravity of the injection liquid, the injection volume, and the interval time are automatically switched. It is possible to move to another stage before the predetermined displacement is exceeded and to improve the ground strength by compaction dehydration as designed, and the above ground displacement measurement is the measurement of ground uplift on the ground surface In addition, a measuring rod with a strain gauge can be set in the ground to detect changes in the ground part in the measuring direction, and a pore water pressure gauge is installed in the ground to understand the consolidation dehydration status. I can do it.
この発明は、本地盤注入材を注入管から軟弱地盤に低速で圧入すると、注入圧力を加えている間は流動性を呈する可塑性ゲルが塊状ゲルの範囲を拡げるが、地盤中の注入材の先進部では注入圧力による周辺土粒子への脱水によってグラウトの含水量が低減して流動性が失われ、可塑状ゲルから非可塑性ゲルになる。このようにして注入孔間の土の密度が増大して地盤の強度が増加し、地盤を強化する。注入孔間隔は上質や目標改良度や土かぶりの大きさに応じ0.5〜3.0mが有効である。 In this invention, when the ground injection material is pressed into the soft ground at a low speed from the injection tube, the flowable plastic gel expands the range of the bulk gel while the injection pressure is applied. In the part, the water content of the grout is reduced by dehydration to the surrounding soil particles due to the injection pressure, the fluidity is lost, and the plastic gel is changed to the non-plastic gel. In this way, the density of soil between the injection holes is increased, the strength of the ground is increased, and the ground is strengthened. The injection hole interval is effectively 0.5 to 3.0 m depending on the quality, the target improvement degree, and the size of the soil cover.
次に、本発明を図6に従って説明すれば以下の通りである。この場合の注入は図6(a)のようにロッド注入管を用いて下から上、又は上から下に順次注入する。或は二重管ダブルパッカ注入外管を設置し内管から複数の吐出口を経て注入してもよい。この場合は地盤における可塑状ゲルが非可塑状ゲルになる前の状態になっている範囲にその吐出口が位置するようにステージが移動するようにするのがゲル化物を拡大する上に好ましい。 Next, the present invention will be described with reference to FIG. In this case, as shown in FIG. 6A, the rod injection tube is used to sequentially inject from the bottom to the top or from the top to the bottom. Alternatively, a double pipe double packer injection outer pipe may be installed to inject from the inner pipe through a plurality of discharge ports. In this case, it is preferable for enlarging the gelled product to move the stage so that the discharge port is located in a range in which the plastic gel in the ground is in a state before becoming the non-plastic gel.
図6(b)、(c)はインターバル方式の基本的態様を示すものであり、所定の軟弱地盤3、同様に在来態様同様の形式により所定ピッチの横方向に介して削孔4を所定深度に形成し、注入管9を該削孔4に挿入し、地上の図示しない注入装置から懸濁型の可塑性グラウトを所定のタイムラグでインターバル方式により、注入管9の所定ステージに変換しながら、連ねながら注入し、又、所定ステップアップ、或はステップダウンを介し、反復して、注入を地盤3のゾーンごとに反復して追い討ち式に行っていく。この場合、注入管は注入管ロッドを用いてもよいし、注入外管内に注入内管を挿入して注入ステージを移向して注入してもよい。
FIGS. 6 (b) and 6 (c) show the basic mode of the interval method, in which a predetermined
この場合、各サイクルに於ける注入は注入初期にあっては逸脱しないように低圧で注入し、地盤3内の排水を行いながら、或は注入液の脱水を行いながら注入し、所定タイミングの後、圧送を停止すると、前述の如く流動性を失って経時的に固化し、後注入する地盤注入材は先行して形成されている可塑状ゲルを内側から側方向に押しやり、上側の地上方向には逸脱せず、追い討ち的に横方向に重合する方式で注入され、側方地盤の圧密脱水を図り、注入部位の外用部に於ける脱水が図られて可塑状ゲルの硬化物による硬化帯が形成され、後注入の地盤注入材による可塑状ゲル化物が重なって大きな塊に増大していく。
In this case, the injection in each cycle is performed at a low pressure so as not to deviate in the initial stage of the injection, and is performed while draining the
この場合、地盤3の所定エリアに対し、横方向所定間隔で設定数多数の削孔4を形成させ、各削孔に対し、各別個に注入管9を挿入し、所定タイムラグでバルブ5、ポンプを介し而して注入装置に接続し、本地盤注入材をコンピューターを有するコントローラー6により所定のプログラムを介して、削孔4に対する注入タイミングをコンピューターを介してずらして、横方向に並列的に形成された削孔4に対し、バルブ5、コントローラー6を介して所定タイムラグで、インターバル方式により、本地盤注入材を注入して地盤の相隣る削孔4の側方地盤の全領域的な圧密脱水を行って、結果的に全領域的な地盤の強度の向上を図ることが出来る。
In this case, a predetermined number of
すなわち、改良地盤は注入孔を介し、一度に多量の本地盤注入材を圧入すると、周辺土が充分な範囲を圧密する前に破壊したり、地盤***したりしてしまう。しかし、全注入量を分割してインターバルで圧入すると、可塑性であるがために注入の中断により流動が停止し、その位置に保持され、その周辺土は圧密脱水される時間と、可塑性グラウトの脱水の時間が与えられ、順次塊状可塑性ゲルによる固結体の大きさが成長し、柱状固結体とその柱状固結体にはさまれた密度の増加した複合地盤となる。 That is, when a large amount of the main soil injection material is pressed into the improved ground at once through the injection hole, the surrounding soil is destroyed before the sufficient range is compacted or the ground is raised. However, when the total injection volume is divided and press-fitted at intervals, because it is plastic, the flow stops due to interruption of the injection and is held in that position, and the surrounding soil is dehydrated and the plastic grout is dehydrated. Thus, the size of the solidified body by the massive plastic gel grows sequentially, and the columnar solidified body and the composite ground having an increased density sandwiched between the columnar solidified bodies are obtained.
もちろん、当該態様にあっては、所定のインターバル方式をとることにより、所定タイミングで全削孔4を一巡した後は、初期の削孔4に戻ることが可能であり、該管のインターバルの本地盤注入材の注入において、形成された可塑状ゲルの塊状体は固化し、地盤3に対する圧密状態を維持する。即ち、改良地盤は注入孔を介し、所定の領域に一度に多量の本地盤注入材を圧入すると、周辺土が充分の範囲を圧密する前に破壊してしまうが、全注入量を分割してインターバルで圧入すると、可塑性であるがため注入の中断により流動が停止し、その位置に保持され、その周辺土は圧密脱水される時間と、可塑状ゲルの脱水の時間が与えられ、順次塊状可塑性ゲルによる固結体の大きさが成長し、柱状固結体とその柱状固結体にはさまれた密度の増加した領域の複合地盤となる。
Of course, in this mode, by taking a predetermined interval method, it is possible to return to the
このため、注入圧力は地盤***に作用するよりも側方向への圧密作用が生ずる。尚、削孔4の軸方向上方向には所定タイムラグで注入する可塑状ゲルの機能により、変位が垂直方向よりも水平方向に起こり易く、従って、地盤3の上方への***は避けられる。
For this reason, the injection pressure produces a consolidation action in the lateral direction rather than acting on the ground uplift. In addition, due to the function of the plastic gel injected at a predetermined time lag in the axial direction upward of the
図7、図8は流路に一次注入材の可塑状ゲルを注入し、他方の流路から二次注入材として溶液型シリカグラウトまたは、懸濁型グルウト、またはゲル化時間、可塑状保持時間が一次注入より長い可塑状グラウトを注入することができる。一次注入材の可塑状ゲルは注入外管周りの空隙、及び注入ステージの粗い部分の粗詰めを行い、二次注入材は地盤中の細かい部分に浸透する。外管ゴムスリーブは間隔をあけて設けることで、深度の深いところから浅い部分に段階的に注入することが可能である。 7 and 8 show that a plastic gel of a primary injection material is injected into a flow path, and a solution type silica grout or suspension type grout as a secondary injection material from the other flow path, or a gelling time and a plasticity holding time. It is possible to inject a plastic grout that is longer than the primary injection. The plastic gel of the primary injection material coarsely packs the gap around the outer injection tube and the rough portion of the injection stage, and the secondary injection material penetrates into fine portions in the ground. By providing the outer sleeve rubber sleeve at an interval, it is possible to inject gradually from a deep part to a shallow part.
また、二次注入材が逸脱し、上部への逃げ道を作る場合、従来は、二次注入材の固結を待つため、一日程度注入を中止し、逃げ道の二次注入材が固結した後、注入を再開したが、本発明では一次注入材の可塑状ゲルに切り替えて注入することで、容易に逃げ道を塞ぎ二次注入の逸脱を防ぐ事ができ、一次注入材の固結を待たなくても再度注入でき、工程を短縮でき、かつ二次注入材を地盤中に確実に浸透させることができる。 Also, when the secondary injection material deviates and creates an escape route to the upper part, conventionally, in order to wait for the secondary injection material to consolidate, the injection was stopped for about a day, and the secondary injection material in the escape route solidified. After that, the injection was resumed, but in the present invention, by switching to the plastic gel of the primary injection material and injecting it, it was possible to easily block the escape path and prevent the deviation of the secondary injection, and waited for the primary injection material to solidify. Even if it is not, it can be injected again, the process can be shortened, and the secondary injection material can be reliably infiltrated into the ground.
図7においては可塑状グラウトを一次注入後、浸透性シリカグラウトを二次注入することを繰返しながら、注入内管を引き上げていく。又、二次注入材が注入中に地表面に逸脱した場合、一次注入材を注入すれば、二次注入材の逸脱流路を閉塞して逸脱を防止することができる。 In FIG. 7, after the primary injection of the plastic grout, the injection inner tube is pulled up while repeating the secondary injection of the permeable silica grout. Further, when the secondary injection material deviates to the ground surface during the injection, if the primary injection material is injected, the deviation flow path of the secondary injection material can be blocked to prevent the deviation.
図8では、一次注入材を注入後、二次注入材を注入することを、注入ステージを引き上げながら繰り返す。或いは、二次注入を注入中に地表面に逸脱したら、一次注入材を注入して二次注入材の逸脱流路を閉塞する。 In FIG. 8, the injection of the secondary injection material after the injection of the primary injection material is repeated while pulling up the injection stage. Alternatively, if the secondary injection deviates to the ground surface during the injection, the primary injection material is injected to close the deviation flow path of the secondary injection material.
流動性を変化させながら注入する方法
流動性可塑状ゲルの流動性を変化させながら、地盤条件に合わせて注入する方法として、流動性の低い可塑状ゲルを注入した後、後続の可塑状ゲルで圧入することで、先に注入した可塑状ゲルは流動性が低下しているものの、後続の注入材の圧入により、流動性が出て、地盤中の細かい部分に圧入することができる。
Method of injecting while changing the fluidity As a method of injecting according to the ground conditions while changing the fluidity of the fluid plastic gel, after injecting a plastic gel with low fluidity, Although the fluidity of the previously injected plastic gel is lowered by the press-fitting, the fluidity comes out by the press-fitting of the subsequent injection material, and can be press-fitted into a fine part in the ground.
また、先に流動性の高い可塑状ゲルを送り、その後流動性の低い可塑状ゲルを送ることで、先に注入された可塑状ゲルを細かい空隙に圧入して、圧入範囲を拡大しかつ圧入、脱水によって、流動性が低下することによって流動性の高い可塑状ゲルの逸脱を防ぐ事ができる。 Also, by sending a plastic gel with high fluidity first and then sending a plastic gel with low fluidity, the plastic gel injected earlier is press-fitted into a fine gap, expanding the press-fitting range and press-fitting. By dehydrating, the fluidity is lowered, so that the deviation of the plastic gel having high fluidity can be prevented.
図9の注入装置を使用する方法では、一方の管より成分(1)と(2)と(4)、或いは(1)と(4)、或いは(2)と(4)を注入し、もう一方の管より(2)または(3)を注入し、管内で混合することで、流動性を調整して、可塑状ゲルを注入することができる。また、いずれの流路の配合液に(3)を混合しておくことで流動性を調整することもできる。 In the method using the injection device of FIG. 9, components (1) and (2) and (4), or (1) and (4), or (2) and (4) are injected from one tube. By injecting (2) or (3) from one tube and mixing in the tube, the fluidity can be adjusted and the plastic gel can be injected. Moreover, fluidity | liquidity can also be adjusted by mixing (3) with the liquid mixture of any flow path.
さらに図9の注入装置を使用し、可塑状ゲルを一方の管よりA液として注入し、もう一方の管よりB液を注入して、管内で混合して、注入することもできる、この場合、A液とB液の送液量を調整し、配合比率を変えることで、ゲル化時間及び流動性保持時間を調整して可塑状ゲルを注入することが可能である。 Furthermore, using the injection device of FIG. 9, the plastic gel can be injected as liquid A from one tube, and liquid B can be injected from the other tube, mixed in the tube, and injected. It is possible to adjust the gelation time and fluidity retention time and to inject the plastic gel by adjusting the feeding amount of the liquid A and the liquid B and changing the blending ratio.
なお、上記にて一方の流路から可塑状ゲルを送液して地盤中に注入し、他方の流路より浸透性グラウトを同時に、或いは時間差をおいて注入することにより、異なる浸透性を有する注入材を併用して注入することができる。 In the above, the plastic gel is fed from one flow path and injected into the ground, and the permeable grout is injected from the other flow path at the same time or with a time difference, thereby having different permeability. The injection material can be used in combination.
注入領域により注入材を分け併用する方法
上記に示したような、同じ地盤において一次注入と二次注入を注入する他に、隣り合った地盤領域に可塑状ゲルと二次注入材を注入することで有効な効果を得ることができる。
Injecting the injection material according to the injection area In addition to injecting the primary injection and the secondary injection in the same ground as shown above, injecting the plastic gel and the secondary injection material into the adjacent ground area With this, an effective effect can be obtained.
図10、図11に示すような既設護岸において潮位の干満により吸出し防止の欠損部からの護岸背面土砂の吸出し現象が生じ、これに伴う護岸の沈下及び傾斜、さらに道路面の陥没現象が生じた。 In the existing revetment as shown in FIG. 10 and FIG. 11, the tide level tidal causes a suction phenomenon of the revetment backside sediment from the deficient portion of the suction prevention, resulting in the subsidence and inclination of the revetment, and the depression of the road surface. .
このとき、欠損部分の修復工事において、シートの欠損部分に一次注入材として可塑状ゲルを注入し、シート欠損部を粗くふさぎことで、その後地盤の細部を固結強化するため注入する二次注入材の海水等の周辺の流動水による希釈を防ぐ事ができ、従来の流動水による注入薬液の濃度低下を防ぐ事ができる。 At this time, in the repair work of the defective part, the secondary injection is performed by injecting plastic gel as a primary injection material into the defective part of the sheet, and then blocking the sheet defective part roughly to intensify the details of the ground. It is possible to prevent dilution of the material by surrounding water such as seawater, and to prevent a decrease in the concentration of the injected drug solution by conventional fluidized water.
このとき、一次注入材に用いる可塑状ゲルは、瞬結配合を用いると、地盤中で加圧脱水され、急速に固結され、粗い部分や置石の表面しか固結しないため、水流や地下水の上下で容易に破損してしまい、裏込により浸透型シリカ液で固めてもその強度が弱いため、地下水で自由空隙側に洗い出されて吸出し防止効果をえられない。 At this time, the plastic gel used for the primary injection material is dehydrated under pressure in the ground using a quick setting compound, and rapidly solidifies, so that only the rough part and the surface of the stone are consolidated. It easily breaks up and down, and even if it is hardened with osmotic silica liquid by backfilling, its strength is weak.
しかし、流動性可塑状グラウトを用いることにより、可塑状保持時間中は徐々に塊状ゲルの範囲を広げ脱水を伴い、流動水の多い地盤でも水粉体比を低下することができ、ゲル化時間の短縮、可塑状保持時間の低下、により非可塑状を経て固化するため、空隙を強固に埋めることができる。 However, by using a flowable plastic grout, it is possible to gradually expand the range of the bulk gel during the plastic holding time and accompany dehydration. Because of solidification through non-plasticity due to the shortening of the length and the decrease in the plastic holding time, the voids can be filled firmly.
本発明は浸透性の異なる固結材を併用して地盤に注入し、地盤を固結するに際し、浸透性の悪い方の固結材として、シリカ系非硬化性粉状体(F材)とカルシウム系粉状硬化発現材(C材)、流動性調整材(A材)、また上記F材とC材、A材に加えて水(W材)を有効成分とする流動性可塑状ゲル注入材を用い、時間とともに、あるいは脱水により流動性を失って、地盤中に注入材そのものの塊状体を形成するようにしたから、地盤中の空隙を填充し、あるいは地盤中で拡大しながら土粒子を周辺に押しやって地盤を拘束し、浸透性の良い方の地盤固結材を併用して地盤強化を図るものであり、土木建築分野において利用の可能性が高い。 In the present invention, when a solidifying material having different permeability is used in combination and injected into the ground, and when the ground is consolidated, a silica-based non-curable powder (F material) and Calcium-based powder hardening material (C material), fluidity adjusting material (A material), and fluid plastic gel injection containing water (W material) as an active ingredient in addition to the F material, C material, and A material. Since the material is used and loses fluidity over time or due to dehydration, a mass of the injected material itself is formed in the ground, so that the soil particles fill the voids in the ground or expand in the ground. It is intended to constrain the ground by pushing to the periphery and to strengthen the ground by using a ground-solidifying material with better permeability, and is highly likely to be used in the field of civil engineering and construction.
3 地盤
4 削孔
5 バルブ
6 コントローラー
7 コンピューター
8 ゴムスリーブ(逆止弁)
9 注入管
3
9 Injection tube
Claims (22)
(1)シリカ系非硬化性粉状体(F材)
(2)カルシウム系粉状硬化発現材(C材)
(3)流動性調整材(A材)
(4)水(W材) The plastic gel injection material according to claim 1, wherein the plastic gel injection material loses its fluidity with time or dehydration, and forms a lump of the injection material itself in the ground. The following components (1), (2) and (4) Or (1), (2), (3), (4), or (2), (3), and (4) as an active ingredient.
(1) Silica-based non-curable powder (F material)
(2) Calcium-based powder hardening material (C material)
(3) Fluidity adjusting material (A material)
(4) Water (W material)
1.流動性を変化させながら注入。
2.間欠注入。
3.重ね合せ注入。 22. The ground consolidation method according to claim 1, 2, 20 or 21, wherein the flowable plastic gel is consolidated by enlarging the volume of the bulk gel by any one or more of the following injection methods.
1. Injection while changing fluidity.
2. Intermittent injection.
3. Overlapping injection.
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JP2008195772A (en) * | 2007-02-09 | 2008-08-28 | Energia Eco Materia:Kk | Improving material slurry for ground improving construction method using coal ash |
JP2010132797A (en) * | 2008-12-05 | 2010-06-17 | Raito Kogyo Co Ltd | Agent for constructing impervious wall and method for constructing impervious wall |
JP2013036280A (en) * | 2011-08-10 | 2013-02-21 | Shinichi Yamashita | Method for removing earth retaining member |
JP2014001577A (en) * | 2012-06-20 | 2014-01-09 | Nittoc Constr Co Ltd | Injection method |
JP2016075096A (en) * | 2014-10-07 | 2016-05-12 | 東海旅客鉄道株式会社 | Chemical injection method and filler |
JP2016216327A (en) * | 2015-05-26 | 2016-12-22 | 信越化学工業株式会社 | Hydraulic composition |
CN108036985A (en) * | 2017-12-27 | 2018-05-15 | 刘睿洋 | A kind of fracture grouting slurry arteries and veins makes and infiltration coefficient detection device and method |
US10047270B2 (en) | 2014-02-28 | 2018-08-14 | Halliburton Energy Services, Inc. | Tunable control of pozzolan-lime cement compositions |
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JP2008195772A (en) * | 2007-02-09 | 2008-08-28 | Energia Eco Materia:Kk | Improving material slurry for ground improving construction method using coal ash |
JP2010132797A (en) * | 2008-12-05 | 2010-06-17 | Raito Kogyo Co Ltd | Agent for constructing impervious wall and method for constructing impervious wall |
JP2013036280A (en) * | 2011-08-10 | 2013-02-21 | Shinichi Yamashita | Method for removing earth retaining member |
JP2014001577A (en) * | 2012-06-20 | 2014-01-09 | Nittoc Constr Co Ltd | Injection method |
US10047270B2 (en) | 2014-02-28 | 2018-08-14 | Halliburton Energy Services, Inc. | Tunable control of pozzolan-lime cement compositions |
US10781355B2 (en) | 2014-02-28 | 2020-09-22 | Halliburton Energy Services, Inc. | Tunable control of pozzolan-lime cement compositions |
JP2016075096A (en) * | 2014-10-07 | 2016-05-12 | 東海旅客鉄道株式会社 | Chemical injection method and filler |
JP2016216327A (en) * | 2015-05-26 | 2016-12-22 | 信越化学工業株式会社 | Hydraulic composition |
CN108036985A (en) * | 2017-12-27 | 2018-05-15 | 刘睿洋 | A kind of fracture grouting slurry arteries and veins makes and infiltration coefficient detection device and method |
CN108036985B (en) * | 2017-12-27 | 2023-08-11 | 刘睿洋 | Device and method for manufacturing split grouting slurry vein and detecting permeability coefficient |
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