JP2001241031A - Sediment and ground improvement method, and grouting chemicals and its control method - Google Patents
Sediment and ground improvement method, and grouting chemicals and its control methodInfo
- Publication number
- JP2001241031A JP2001241031A JP2000053277A JP2000053277A JP2001241031A JP 2001241031 A JP2001241031 A JP 2001241031A JP 2000053277 A JP2000053277 A JP 2000053277A JP 2000053277 A JP2000053277 A JP 2000053277A JP 2001241031 A JP2001241031 A JP 2001241031A
- Authority
- JP
- Japan
- Prior art keywords
- soil
- ground
- sand
- injection
- gel state
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Soil Conditioners And Soil-Stabilizing Materials (AREA)
Abstract
Description
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【発明の属する技術分野】本発明は、土砂地盤改良工法
と注入薬液及びその施工管理方法に関し、特に、大量の
薬液を広範囲に注入することを可能にする土砂地盤改良
工法と、シリカ粒子濃度、サンドゲル状態に到るゲル化
時間と電気比抵抗値を設定した注入薬液及びこの注入薬
液を注入し、薬液注入後の電気比抵抗値を測定すること
で地盤改良域における改良効果を簡潔に確認できる施工
管理方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving soil and soil, a method for injecting a chemical and a method for managing the construction thereof, and more particularly, to a method for improving soil and soil which enables a large amount of chemical to be injected over a wide range, and a method for improving silica particle concentration. It is possible to simply confirm the improvement effect in the ground improvement area by injecting the injection liquid and the injection liquid, which are set to the gelation time and the electric resistivity value to reach the sand gel state, and measuring the electric resistivity value after the injection of the liquid medicine. Related to the construction management method.
【０００２】[0002]
【従来の技術】埋立地等の軟弱地盤に建っている構造物
の周辺や直下の液状化対策工法には、せん断変形抑制工
法、注入固化工法、間隙水圧消散工法、地下水位低下工
法等があるが、各種工法の中でも、注入固化工法が施工
性に優れており、適用範囲が広い等の特徴があることで
多くの施工実績が重ねられてきた。又、既設構造物直下
の砂質土地盤等を対象にした地盤改良には、超微粒子シ
リカを分散させたコロイド溶液を主材にした薬液を用い
て好成績を挙げている。しかして、注入固化工法は、注
入薬液の主材であるセメント、特に高価なシリカ粒子を
多量に必要とするためにコスト高を招いて経済性に劣る
という欠点が指摘されている。2. Description of the Related Art Liquefaction countermeasures around and directly below a structure built on soft ground such as a landfill include shear deformation suppression, injection solidification, pore water pressure dissipation, and groundwater level lowering. However, among the various construction methods, the injection solidification method has excellent workability and has a wide range of applications, and many construction results have been accumulated. In addition, for soil improvement for sandy ground directly under existing structures, etc., good results have been obtained using a chemical solution mainly composed of a colloid solution in which ultrafine silica particles are dispersed. However, it has been pointed out that the injection solidification method requires a large amount of cement, particularly expensive silica particles, which is the main material of the injection chemical solution, resulting in high cost and poor economic efficiency.
【０００３】このことは、従来の薬液注入工法では、
「液状化強度」を確認する地盤改良の品質評価に、一軸圧
縮強度を採用していたことから、一軸圧縮強度を大きく
することが液状化抵抗性の増大を促進して「液状化強度」
も高められると考えて来たことに大きな影響を受けてい
る。即ち、この考えに従うと、１．９〜９．８Ｎ／ｃｍ
2以上の値が必要とされる所要強度を得るためには、一
軸圧縮強度を大きくするために注入薬液の濃度を増大さ
せることが必要になり、結果として、セメントや高価な
シリカ粒子を多量に使用することになるからである。[0003] This is a problem in the conventional chemical injection method.
Since the uniaxial compression strength was used in the quality evaluation of the ground improvement to confirm the "liquefaction strength", increasing the uniaxial compression strength promoted the increase in liquefaction resistance and "liquefaction strength".
Has been greatly influenced by what we have thought to be improved. That is, according to this idea, 1.9 to 9.8 N / cm
In order to obtain the required strength where a value of 2 or more is required, it is necessary to increase the concentration of the injectable drug solution in order to increase the uniaxial compressive strength, and as a result, a large amount of cement and expensive silica particles It will be used.
【０００４】そこで、シリカ粒子の使用量を低減するこ
とでコスト低減を図る提案がなされている。例えば、特
願平１０−１４０９７３号に記載された工法では、コロ
イド溶液に分散させるシリカ粒子の平均径を１５ナノメ
ータとし、シリカコロイド溶液に分散させたシリカ粒子
の濃度を１．９重量％〜６．０重量％に配合して主材と
し、これに硬化剤を調合することによって、従来のシリ
カコロイド溶液のシリカ粒子濃度であった１０重量％よ
りもシリカ粒子の使用量を低下させたことでコスト低減
を果たしている。[0004] Therefore, a proposal has been made to reduce costs by reducing the amount of silica particles used. For example, in the method described in Japanese Patent Application No. 10-140973, the average diameter of the silica particles dispersed in the colloid solution is set to 15 nanometers, and the concentration of the silica particles dispersed in the silica colloid solution is from 1.9% by weight to 6%. 0.0% by weight as a main material, and by mixing a hardening agent with the main material, the amount of silica particles used was reduced from 10% by weight which was the silica particle concentration of the conventional silica colloid solution. It has achieved cost reduction.
【０００５】同様に、市販の注入薬剤パーマロック・Ａ
ＳＦ（旭電化工業(株)製、商品名）は、活性シリカ微粒
子のコロイド溶液の主材ＡＳＦシリカー４（旭電化工業
(株)製、商品名）に酸性塩の硬化剤ＡＳＦアクターＭ
（旭電化工業(株)製、商品名）を配合して、シリカ濃度
を３．７重量％〜７．０重量％に抑えており、シリカ粒
子の平均径を小さくすることで活性シリカ微粒子の使用
量を上記例よりもさらに少なくしている。しかし、いず
れの場合も一軸圧縮強度を品質評価の基準にしている点
で同等である。[0005] Similarly, the commercially available injectable drug Permaloc A
SF (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) is a main material of colloidal solution of activated silica fine particles, ASF Silica-4 (Asahi Denka Kogyo Co., Ltd.)
ASF Actor M, a curing agent for acidic salts
(Trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) to suppress the silica concentration to 3.7% to 7.0% by weight, and reduce the average diameter of the silica particles to reduce the active silica fine particles. The amount used is even smaller than in the above example. However, the two cases are equivalent in that the uniaxial compressive strength is used as a standard for quality evaluation.
【０００６】又、所要強度を得るために、従来の考え方
に従って一軸圧縮強度の増強を図るべく注入薬液の濃度
を増大させることは、施工面においても多くの問題点を
生じている。即ち、注入孔から離れるに従って、薬液は
地下水の影響を受けて濃度が低下し、圧縮強度が急激に
低下してしまう。従って、シリカ濃度が一定の薬液を注
入して所要強度を得ようとすると小口径の改良体に止ま
って大口径改良体の造成を不可能にしていることで、注
入のための削孔数を増大させざるを得なくなっている。
このために、地盤改良工事は、施工効率が悪くなって施
工コストの嵩高と工期の遅延化を招来する問題点を抱え
ながら、これの解消がなされてないのが現状である。[0006] In addition, increasing the concentration of the injected chemical solution in order to increase the uniaxial compressive strength in accordance with the conventional concept in order to obtain the required strength causes many problems in terms of construction. That is, as the distance from the injection hole increases, the concentration of the chemical solution is reduced by the influence of groundwater, and the compressive strength is rapidly reduced. Therefore, when trying to obtain the required strength by injecting a chemical solution with a constant silica concentration, it stops at a small-diameter improved body and makes it impossible to form a large-diameter improved body, so the number of holes for injection is reduced. We have to increase it.
For this reason, the ground improvement work has a problem that the construction efficiency is deteriorated and the construction cost is increased and the construction period is delayed. However, at present, this is not solved.
【０００７】地盤改良工事における注入効果の確認は、
注入固化工法の施工において最も重要な管理項目の１つ
である。そして、従来における地盤改良域の効果確認に
は、標準貫入試験が最も多く採用されている。標準貫入
試験が多く採用されるのは、液状化抵抗性の増大は一軸
圧縮強度の増大によるとの認識の下に、地盤改良の効果
確認に一軸圧縮強度を採用しているからであり、地盤改
良域の効果確認においてもこれらの認識を反映して、改
良土の硬軟と締まり具合をＮ値の変化で判定する標準貫
入試験を採用して地盤改良効果を判定している。しかる
に、標準貫入試験は、改良によって地盤の強度が大きく
増加することを前提にしているために、改良土における
強度の増加が小さい改良域においてはＮ値の差が僅少に
なることから、地盤改良の注入効果を明確に確認するの
は困難であった。[0007] Confirmation of the injection effect in the ground improvement work,
This is one of the most important management items in the construction of the injection solidification method. The standard penetration test is most often used for confirming the effect of the conventional ground improvement area. The reason why the standard penetration test is often adopted is that the uniaxial compressive strength is used to confirm the effect of soil improvement, recognizing that the increase in liquefaction resistance is due to the increase in uniaxial compressive strength. Reflecting these recognitions in the confirmation of the effect of the improved area, the ground improvement effect is determined by adopting a standard penetration test in which the hardness, softness, and tightness of the improved soil are determined by changes in the N value. However, since the standard penetration test presupposes that the strength of the ground is greatly increased by the improvement, the difference in N value is small in the improved area where the strength of the improved soil is small. It was difficult to clearly confirm the effect of injection.
【０００８】地盤改良域の効果確認は、標準貫入試験の
他に、透水係数試験等の間接的なものから、三成分コー
ン試験、ダイラトメータ試験等、深度方向の液状化強度
を簡易に測定する方法によっても行われている。[0008] In order to confirm the effect of the ground improvement area, in addition to the standard penetration test, a method of easily measuring the liquefaction strength in the depth direction, such as a three-component cone test or a dilatometer test, from an indirect test such as a permeability test. It is also done by.
【０００９】そして、現位置試験における上記の透水係
数試験等の間接的手法もしくは三成分コーン試験、ダイ
ラトメータ試験等の「液状化強度」を確認する手法と、
「液状化強度」を詳細に確認するために室内で試験が行な
われる繰り返し振動三軸試験や繰り返し単純せん断試験
等の手法では、標準貫入試験、三成分コーン試験、ダイ
ラトメータ試験では明確に特定できない範囲について
も、「液状化強度」の変化を明確に示すことが確認され
ている。従って、上記のような改良域においては、一軸
圧縮強度を評価基準に採用してＮ値の変化で地盤改良域
の判定をする手法と、「液状化強度」を上記試験によって
直接的に確認する手法とでは、その判定において一致を
見ることができないことになる。And an indirect method such as the above-described permeability test in the in-situ test or a method for confirming “liquefaction strength” such as a three-component cone test and a dilatometer test.
In a method such as a repetitive vibration triaxial test or a repetitive simple shear test in which a test is performed in a room to check the "liquefaction strength" in detail, a range that cannot be clearly specified by a standard penetration test, a three-component cone test, or a dilatometer test It has also been confirmed that the liquefaction clearly shows a change in “liquefaction strength”. Therefore, in the above-described improved region, the method of determining the ground improved region by changing the N value using the uniaxial compressive strength as an evaluation criterion and the “liquefaction strength” are directly confirmed by the above test. With the technique, no match can be seen in the determination.
【００１０】しかも、このような傾向は、地盤改良施工
のコスト低減を図るために高価なシリカ粒子の使用量を
少なくして、注入薬液の主材濃度を低下させた場合に顕
著に現れてくる。即ち、注入薬液における主材濃度の低
下は、当然に改良土における強度の増加が小さい改良域
を形成することになってＮ値の差を益々僅少にするから
である。Further, such a tendency becomes remarkable when the amount of expensive silica particles used is reduced in order to reduce the cost of the ground improvement work, and the main material concentration of the injected chemical is reduced. . That is, a decrease in the concentration of the main material in the injected chemical solution naturally forms an improved region where the increase in strength in the improved soil is small, and the difference in the N value is further reduced.
【００１１】以上の状況から、注入薬液の主材濃度を低
下させた場合には、Ｎ値の変化で判定する標準貫入試験
では、改良土における真の「液状化強度」を確認して、
改良域の品質を判定することは困難であり、他の手法に
ついても計測精度の点で問題点が残っている。しかる
に、現状は地盤改良における施工コストの低減を図るた
めに、注入薬液における主材濃度を低下させることが急
務になっている。このような状況の中で、施工された改
良土の「液状化強度」を簡便、かつ迅速に確認すること
で地盤改良された品質の判定を簡潔に実施できる管理方
法の提案が期待されている。From the above situation, when the concentration of the main material of the injection chemical solution is decreased, the true “liquefaction strength” of the improved soil is confirmed by the standard penetration test in which the N value is changed.
It is difficult to determine the quality of the improved area, and other techniques still have problems in measurement accuracy. However, at present, it is urgently necessary to reduce the concentration of the main material in the injected chemical solution in order to reduce the construction cost in ground improvement. Under such circumstances, it is expected that a proposal of a management method that can easily and quickly confirm the "liquefaction strength" of the constructed improved soil and judge the quality of the ground improvement by simply confirming it. .
【００１２】さらに、注入効果の確認における注入範囲
の測定には、ＲＩによる方法、弾性波による方法、トレ
ーサーによる方法、磁性による方法及び電気比抵抗によ
る方法が用いられてきた。しかるに、ＲＩ工法は、放射
線を用いるために取り扱いが困難であり、弾性波工法
は、剛性が大きくならない場合には適用できない。トレ
ーサー方法は、トレーサーが土粒子に吸着して適用範囲
が限定され、磁性方法は、周辺構造物の影響を受け易い
等の問題があるために、電気比抵抗方法が比較的多く用
いられている。Further, for measuring the injection range in confirming the injection effect, a method using RI, a method using elastic waves, a method using a tracer, a method using magnetism, and a method using electric resistivity have been used. However, the RI method is difficult to handle due to the use of radiation, and the elastic wave method cannot be applied if the rigidity does not increase. The tracer method has a problem that the tracer is adsorbed on the soil particles and its application range is limited, and the magnetic method has a problem that it is easily affected by surrounding structures. .
【００１３】電気比抵抗による方法は、注入前後の土中
抵抗の変化からその注入範囲を特定しようとする方法で
あるが、電気比抵抗が時間の経過で変化したり、抵抗値
の差異もあまり大きくならないことから、測定時期の設
定と注入範囲の特定が困難になり、結果的に土砂地盤改
良工法の施工管理が正確にできないという問題があっ
た。The method using electric resistivity is a method of specifying the injection range from the change in soil resistance before and after the injection, but the electric resistivity changes with the passage of time and the difference in the resistance value is too small. Since the size does not increase, it is difficult to set the measurement time and specify the injection range, and as a result, there is a problem that the construction management of the soil improvement method cannot be accurately performed.
【００１４】[0014]
【発明が解決しようとする課題】本発明は、以上の状況
に鑑みて土砂地盤改良工法における問題の解消を図るも
のであり、注入薬液のシリカ粒子濃度、サンドゲル状態
に到るゲル化時間及びサンドゲル状態における電気比抵
抗値を設定することで真の液状化強度を確保して、地盤
改良域において大量の薬液を広範囲に注入することを可
能にし、併せて注入後の電気比抵抗値を計測して注入効
果確認の視点とすることで、地盤改良域の液状化強度と
その範囲を簡潔に確認できるようにした土砂地盤改良工
法と注入薬液及びその管理方法の提供を課題にしてい
る。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and aims at solving the problems in the soil and soil improvement method. By setting the electric resistivity value in the state, the true liquefaction strength is secured, it is possible to inject a large amount of chemical solution over a wide area in the ground improvement area, and at the same time, the electric resistivity value after injection is measured It is an object of the present invention to provide a soil and soil improvement method, an injection solution, and a method for managing the liquefaction strength in the soil improvement area, which can be easily confirmed from the viewpoint of injection effect confirmation.
【００１５】[0015]
【課題を解決するための手段】請求項１、２に記載の発
明である土砂地盤改良工法は、基本的に、シリカ粒子の
コロイド溶液を主材とし主材にゲル化剤を配合した注入
薬液を土砂地盤に注入する土砂地盤改良工法において、
主材のシリカ粒子濃度、サンドゲル状態に到るゲル化時
間及びサンドゲル状態における電気比抵抗値を設定した
注入薬液を土砂地盤中に注入して土砂地盤を所定の液状
化強度の地盤に改良するものであり、注入薬液を改良す
る土砂地盤の土砂を用いて試験測定し、サンドゲル状態
に到るゲル化時間及びサンドゲル状態における電気比抵
抗値を予め確認することを特徴としており、各数値を所
定値に設定することで、低濃度の薬液を低圧、高速で注
入することによって大口径の改良体を造成することがで
きる。The earth and sand ground improvement method according to the first and second aspects of the present invention basically comprises an injectable chemical solution containing a colloidal solution of silica particles as a main material and a gelling agent mixed with the main material. In the soil and soil improvement method of injecting
Injecting an injectable chemical solution with the silica particle concentration of the main material, the gelation time to reach the sandgel state, and the electrical resistivity value in the sandgel state into the earth and sand ground to improve the earth and sand ground to the ground of the prescribed liquefaction strength It is characterized by performing test measurement using earth and sand on the earth and sand to improve the injection chemical solution, and confirming in advance the gelation time to reach the sand gel state and the electric resistivity value in the sand gel state, each value is a predetermined value With this setting, a large-diameter improved body can be formed by injecting a low-concentration chemical solution at a low pressure and at a high speed.
【００１６】請求項３に記載の発明である土砂地盤改良
工法は、請求項１又は２に記載の土砂地盤改良工法にお
いて、注入薬液を、主材を構成するコロイド溶液に対す
る粒子濃度を４．５（％）以下にし、サンドゲル状態に
到るゲル化時間を１０（ｈ）以上としてサンドゲルの状
態における電気比抵抗値を５（Ω・ｍ）以下に設定する
ことを特徴としており、上記機能を確実に達成してい
る。According to a third aspect of the present invention, there is provided the soil and soil improvement method according to the first or second aspect, wherein the injected chemical solution has a particle concentration of 4.5 with respect to the colloid solution constituting the main material. (%) Or less, the gelation time to reach the sandgel state is set to 10 (h) or more, and the electrical resistivity value in the sandgel state is set to 5 (Ω · m) or less. Has been achieved.
【００１７】請求項４、５に記載の発明である土砂地盤
改良工法に用いる注入薬液は、主材を構成するコロイド
溶液のシリカ粒子もしくは活性シリカ粒子の濃度を４．
５（％）以下にし、サンドゲル状態に到るゲル化時間を
１０（ｈ）以上としてサンドゲルの状態における電気比
抵抗値を５（Ω・ｍ）以下に設定しており、改良域の地
盤に低圧、高速で注入することを可能にして大口径の改
良体を造成することができると共に、電気比抵抗値の測
定で注入後の液状化強度を確認できる。The injection chemical solution used in the earth and sand ground improvement method according to the fourth and fifth aspects of the present invention has a concentration of silica particles or active silica particles in the colloid solution constituting the main material of 4.
5 (%) or less, the gelation time to reach the sand gel state is set to 10 (h) or more, and the electrical resistivity value in the sand gel state is set to 5 (Ω · m) or less. In addition, it is possible to perform injection at a high speed to form an improved body having a large diameter, and it is possible to confirm the liquefaction strength after injection by measuring an electric resistivity value.
【００１８】請求項６に記載の発明である土砂地盤改良
工法に用いる注入薬液は、請求項５に記載の注入薬液を
配合するのに、平均粒子径３〜６ナノメートルの活性シ
リカ粒子を０．２８〜２．２５重量％分散させてコロイ
ド溶液にした主材と０．１〜１０．０重量％の中性塩及
び０．１〜５重量％の酸性塩を混合して成るゲル化剤と
を配合することで、活性シリカ粒子の濃度を４．５
（％）以下にし、サンドゲル状態に到るゲル化時間を１
０（ｈ）以上としてサンドゲルの状態における電気比抵
抗値を５（Ω・ｍ）以下に設定している。The injection chemical solution used in the earth and sand ground improvement method according to the sixth aspect of the present invention is characterized in that active silica particles having an average particle diameter of 3 to 6 nanometers are mixed with the injection chemical solution according to the fifth aspect. A gelling agent obtained by mixing a base material dispersed in a colloidal solution by mixing 28 to 2.25% by weight with 0.1 to 10.0% by weight of a neutral salt and 0.1 to 5% by weight of an acidic salt And the concentration of the active silica particles is adjusted to 4.5.
(%) Or less, and the gelation time to reach the sand gel state is 1
The electric resistivity in the state of the sand gel is set to 5 (Ω · m) or less as 0 (h) or more.
【００１９】請求項７に記載の発明である土砂地盤改良
工法の施工管理方法は、液状化強度と電気比抵抗値との
関連を特定し、少なくとも電気比抵抗値を設定した注入
薬液を地盤改良範囲の土砂中に注入し、しかる後に深度
方向の電気比抵抗値を測定して、上記特定関連に基づい
て地盤改良範囲及び液状化強度を確認しており、改良域
における電気比抵抗を測定するだけで地盤改良域の範囲
と品質を判定できる。According to a seventh aspect of the present invention, there is provided a construction management method for a soil and soil improvement method, wherein a relation between liquefaction strength and an electric resistivity value is specified, and at least an injected chemical liquid having an electric resistivity value set therein is subjected to soil improvement. Inject into the earth and sand of the range, and then measure the electrical resistivity in the depth direction to confirm the soil improvement range and liquefaction strength based on the above specific relationship, and measure the electrical resistivity in the improved area It is possible to judge the range and quality of the ground improvement area alone.
【００２０】請求項８に記載の発明である土砂地盤改良
工法の施工管理方法は、薬液注入前に深度方向の電気比
抵抗値を地盤改良範囲において予め測定しておいて、少
なくとも電気比抵抗値を設定した注入薬液を地盤改良範
囲の土砂中に注入し、しかる後に深度方向の電気比抵抗
値を測定して、測定値と上記測定値とを比較照合するこ
とで地盤改良範囲及び液状化強度を確認しており、改良
域における注入前後の電気比抵抗値を測定、比較するだ
けで地盤改良域の範囲と品質を判定できる。[0020] The construction management method of the earth and sand ground improvement method according to the present invention is characterized in that the electric resistivity in the depth direction is measured in advance in the ground improvement range before the injection of the chemical solution, and at least the electric resistivity is measured. Inject the injected chemical solution into the soil of the ground improvement range, then measure the electrical resistivity in the depth direction, and compare and compare the measured value with the above measured value to obtain the ground improvement range and liquefaction strength The range and quality of the ground improvement area can be determined only by measuring and comparing the electrical resistivity before and after injection in the improvement area.
【００２１】[0021]
【発明の実施の形態】本発明による土砂地盤改良工法
は、シリカ粒子のコロイド溶液を主材とし主材にゲル化
剤を配合した注入薬液を土砂地盤に注入するものであっ
て、注入薬液を主材のシリカ粒子濃度、サンドゲル状態
に到るゲル化時間及びサンドゲル状態における電気比抵
抗値で以て特定することを特徴にしている。地盤改良
は、同薬液を低圧、高速で長時間に亘って改良域に注入
し、薬液を注入された土砂地盤では、所定量のシリカ粒
子が架橋してゲル化することで所望の液状化強度を発生
させている。BEST MODE FOR CARRYING OUT THE INVENTION The soil and soil improvement method according to the present invention comprises injecting an injection liquid containing a colloidal solution of silica particles as a main material and a gelling agent into the main material into the soil and soil. It is characterized by being specified by the silica particle concentration of the main material, the gelation time to reach a sand gel state, and the electrical resistivity in the sand gel state. The ground improvement is performed by injecting the chemical into the improvement area at low pressure and high speed over a long period of time, and in the earth and sand ground into which the chemical is injected, a predetermined amount of silica particles are cross-linked and gelled to achieve the desired liquefaction strength. Is occurring.
【００２２】注入薬液は、主材を構成するコロイド溶液
に対する粒子濃度を４．５（％）以下に設定しており、
ゲル化剤の配合によってサンドゲル状態に到るゲル化時
間を１０（ｈ）以上にして、サンドゲル状態における電
気比抵抗値を５（Ω・ｍ）以下に設定して、所期の目的
を達成している。そして、本発明による注入薬液の実施
の形態としては、主材として３ナノメートル乃至６ナノ
メートルの活性シリカ粒子を０．２８重量％乃至２．２
５重量％の範囲で水に分散することで粒子濃度４．５
（％）以下のコロイド溶液を構成しており、これに０．
１重量％乃至５．０重量％濃度の酸性塩と０．１重量％
乃至１０．０重量％濃度の中性塩から構成されるゲル化
剤を配合させることで、ゲル化時間１０（ｈ）以上及び
電気比抵抗値５（Ω・ｍ）以下に調整されている。The injectable drug solution has a particle concentration of 4.5 (%) or less with respect to the colloid solution constituting the main material.
The desired time is achieved by setting the gelation time to reach the sand gel state by mixing the gelling agent to 10 (h) or more and setting the electrical resistivity in the sand gel state to 5 (Ω · m) or less. ing. As an embodiment of the injection solution according to the present invention, active silica particles of 3 nm to 6 nm as the main material are 0.28% by weight to 2.2% by weight.
By dispersing in water in the range of 5% by weight, the particle concentration is 4.5.
(%) Of the following colloid solution.
1% to 5.0% by weight of acid salt and 0.1% by weight
The gelling time is adjusted to 10 (h) or more and the electric resistivity value to 5 (Ω · m) or less by blending a gelling agent composed of a neutral salt having a concentration of 1 to 10.0% by weight.
【００２３】本実施の形態では、主材としてＡＳＦシリ
カー４（旭電化工業(株)製、商品名）を用いている。改
良土砂の液状化抵抗は、上記設定によってシリカ粒子濃
度にはあまり依存せずにほぼ一定であり、液状化強度も
後述する実験結果で示すように所望の値を満たすことが
判明している。因みに、この場合の液状化防止メカニズ
ムは、セメントのように固結によるものでなく、土砂の
粒子間に存在する水が薬液のゲル化物質によって置換さ
れ、このゲル化物質が土砂の粒子同士を繋ぎ止めるもの
と推考されている。上記シリカ粒子濃度は、従来のシリ
カ粒子濃度１０重量％と比較して超微粒子を用いて低濃
度に設定されているので、薬液の浸透性が改善されてお
り低圧注入によっても、浸透距離が１０．０ｍ以上に及
ぶことが確認されている。これによって、シリカの使用
量を少なくして大口径改良体の造成を可能にしているの
で、地盤改良コストの低減を図ることができる。In this embodiment, ASF silica-4 (trade name, manufactured by Asahi Denka Kogyo KK) is used as a main material. It has been found that the liquefaction resistance of the improved earth and sand is substantially constant irrespective of the silica particle concentration by the above setting, and the liquefaction strength satisfies a desired value as shown in the experimental results described later. By the way, the liquefaction prevention mechanism in this case is not based on consolidation like cement, but the water existing between the particles of earth and sand is replaced by the gelling substance of the chemical solution, and this gelling substance separates the particles of earth and sand from each other. It is presumed to be anchored. The concentration of the silica particles is set to a low concentration by using ultrafine particles as compared with the conventional silica particle concentration of 10% by weight, so that the permeability of the chemical solution is improved, and the penetration distance can be reduced to 10 even by low-pressure injection. It has been confirmed that it extends over 0.0 m. As a result, it is possible to reduce the amount of silica used and to form a large-diameter improvement body, so that the ground improvement cost can be reduced.
【００２４】薬液のサンドゲル状態に到るゲル化時間
は、ゲル化剤の配合によって調整されている。即ち、ゲ
ル化剤中の酸性塩濃度を増大させてゆくと、酸性塩が主
剤中のアルカリ成分を中和させてゲル化時間の延長を図
ることが可能になり、１０分から数週間にも調整でき
る。そして、サンドゲル状態に到るゲル化時間を１０
（ｈ）以上にするためには、図１のようにｐＨを２以下
にする必要があるが、ｐＨを１．５以下にすると土砂中
に含まれている貝殻に起因されると推定されるガスの発
生を招くこともあることから、ｐＨを２〜１．５の範囲
に納めるようにしている。ゲル化時間の延長は薬液の浸
透距離を増加させると同時に、浸透量を増大させること
に貢献するので、重要な調整になる。尚、酸性塩として
は、クエン酸塩、燐酸塩等の弱酸性塩も使用可能である
が、本実施の形態では、酸性塩としてＡＳＦアクターＭ
（旭電化工業(株)製、商品名）を用いて、濃度を０．１
重量％乃至５．０重量％に設定している。The gelation time for the chemical solution to reach a sand gel state is adjusted by the addition of a gelling agent. That is, when the concentration of the acidic salt in the gelling agent is increased, the acidic salt neutralizes the alkali component in the main agent, thereby making it possible to extend the gelation time. it can. Then, the gelation time to reach the sand gel state is 10
(H) In order to achieve the above, it is necessary to lower the pH to 2 or less as shown in FIG. 1, but if the pH is reduced to 1.5 or less, it is estimated that the pH is caused by shells contained in the earth and sand. Since the generation of gas may be caused, the pH is set within the range of 2 to 1.5. Prolonging the gelation time is an important adjustment because it increases the penetration distance of the drug solution and at the same time contributes to increasing the penetration amount. It should be noted that weak acid salts such as citrate and phosphate can be used as the acid salt. In the present embodiment, ASF actor M is used as the acid salt.
(Made by Asahi Denka Kogyo Co., Ltd., trade name)
% By weight to 5.0% by weight.
【００２５】本発明による注入薬液には、改良域におけ
る注入効果の確認を容易にするために、サンドゲル状態
において５（Ω・ｍ）以下の電気比抵抗値を生じるよう
に調整している。上述したように、ゲル化時間を延長さ
せるために酸性塩濃度を増大させてｐＨを２〜１．５の
範囲に納めるとすると、土砂に注入する以前の液体状態
における電気伝導度は図２に示すように、４〜９（ｍＳ
／ｃｍ）のように急峻になって製品ロットによるばらつ
きを生ずることが予想される。The injection chemical solution according to the present invention is adjusted so as to have an electric resistivity of 5 (Ω · m) or less in a sand gel state in order to easily confirm the injection effect in the improved region. As described above, if the pH is kept within the range of 2 to 1.5 by increasing the acid salt concentration in order to extend the gelation time, the electric conductivity in the liquid state before injecting into earth and sand is shown in FIG. As shown, 4-9 (mS
/ Cm), and it is expected that the variation will occur depending on the product lot.
【００２６】そこで、このような状態を安定した値に設
定するために、本発明ではゲル化剤として酸性塩の他に
中性塩を加えて調整している。中性塩としては、塩化ナ
トリュウム、塩化カリュウム又は塩化アルミニュウム等
を用いることができるが、本実施の形態では、ＡＳＦア
クターＮＳ（旭電化工業(株)製、商品名）を用いてお
り、濃度を０．１重量％乃至１０．０重量％に設定する
ことで、図３に示されるように、電気伝導度４もしくは
６から１５（ｍＳ／ｃｍ）付近の大きな値に安定させた
状態で設定している。Therefore, in order to set such a state to a stable value, in the present invention, a neutralizing salt is added in addition to an acidic salt as a gelling agent. As the neutral salt, sodium chloride, calcium chloride, aluminum chloride, or the like can be used. In the present embodiment, ASF actor NS (manufactured by Asahi Denka Kogyo Co., Ltd., trade name) is used. By setting the amount to 0.1% by weight to 10.0% by weight, as shown in FIG. 3, the electric conductivity is set in a state where the electric conductivity is stabilized at 4 or 6 to a large value around 15 (mS / cm). ing.
【００２７】以上のように、所期の電気伝導度に若干の
ばらつきがあったとしても中性塩の添加量を管理するこ
とによって、目的とする所望の電気伝導度に設定できる
ものであるが、中性塩は、コロイド液状になっているシ
リカ微粒子の表面に形成されている拡散二重層を破壊し
て、コロイド粒子同士の衝突による結合を活発にしてゲ
ル化を促進する働きをすることから、中性塩の添加はサ
ンドゲル状態に到るゲル化時間を短縮する傾向に作用す
るので、管理に当たってはその点を考慮しながら設定し
てゆくことが肝要である。As described above, even if there is a slight variation in the desired electric conductivity, the desired electric conductivity can be set by controlling the amount of the neutral salt to be added. The neutral salt breaks the diffusion bilayer formed on the surface of the colloidal silica fine particles and activates the colloidal particles by colliding with each other to promote gelation. Since the addition of a neutral salt has a tendency to shorten the gelation time to reach a sand gel state, it is important to set the temperature while taking into account that point.
【００２８】尚、電気伝導度は、土砂中においては測定
することができないので、土砂中のサンドゲル状態にお
いては電気比抵抗を測定することによって注入薬液のゲ
ル化状態と注入範囲の確認を行っている。電気比抵抗
（Ω・ｍ）は、電気伝導度（ｍＳ／ｃｍ）の逆数であ
り、電気比抵抗（Ω・ｍ）＝１０／気伝導度（ｍＳ／ｃ
ｍ）の関係にある。電気伝導度は土砂中に注入されると
周辺との関係で若干の変化が予想されることから、本発
明ではサンドゲル状態にける電気比抵抗値を設定して、
本実施の形態では５（Ω・ｍ）に設定しているものであ
り、液状状態にあるときの電気伝導度は変化を見越して
調整されている。Since the electric conductivity cannot be measured in earth and sand, the gelation state and injection range of the injection liquid are confirmed by measuring the electric resistivity in the sand gel state in the earth and sand. I have. Electric resistivity (Ω · m) is the reciprocal of electric conductivity (mS / cm), and electric resistivity (Ω · m) = 10 / air conductivity (mS / c)
m). Since the electrical conductivity is expected to slightly change in relation to the surroundings when injected into the earth and sand, in the present invention, by setting the electrical resistivity in the sand gel state,
In the present embodiment, it is set to 5 (Ω · m), and the electric conductivity in the liquid state is adjusted in anticipation of a change.
【００２９】以上の説明で明らかなように、本発明によ
る土砂地盤改良工法と注入薬液は、シリカ粒子のコロイ
ド溶液を主材とし、これにゲル化剤を配合した注入薬液
を土砂地盤に注入するものであり、注入薬液として主材
のシリカ粒子濃度を特定しサンドゲル状態に到るゲル化
時間を大きくすることによって、地盤改良域に大量の薬
液を低圧、高速で広範囲に注入することを可能にして大
口径の改良体の造成と所望の液状化強度を発生させてい
る。さらに、サンドゲル状態における電気比抵抗値を安
定状態に特定することによって、注入後の電気比抵抗値
を計測して注入効果確認の視点にすることで、地盤改良
域の液状化強度とその範囲を簡潔に確認できるようにし
ている。As is apparent from the above description, the soil and soil improvement method and the injection liquid according to the present invention are mainly composed of a colloidal solution of silica particles, and the injection liquid containing a gelling agent is injected into the soil. By specifying the silica particle concentration of the main material as the injection chemical and increasing the gelation time to reach the sand gel state, it is possible to inject a large amount of chemical into the ground improvement area at low pressure and at high speed over a wide area. Thus, a large diameter improved body is formed and a desired liquefaction strength is generated. Furthermore, by specifying the electrical resistivity in the sand gel state to a stable state, measuring the electrical resistivity after injection and using it as a viewpoint for confirming the injection effect, the liquefaction strength of the ground improvement area and its range We make it easy to confirm.
【００３０】尚、本実施の形態では、主材を構成してい
るコロイド溶液を活性シリカ微粒子の分散で形成すると
して説明してきたが、本発明は、注入薬液を主材のシリ
カ粒子濃度、サンドゲル状態に到るゲル化時間及びサン
ドゲル状態における電気比抵抗値を特定することによっ
て所期の目的を達成するものであるから、コロイド溶液
を他のシリカ微粒子の分散で形成するものであっても何
らの支障がないものである。In the present embodiment, the colloid solution constituting the main material has been described as being formed by dispersing active silica fine particles. Since the intended purpose is achieved by specifying the gelation time to reach the state and the electrical resistivity value in the sand gel state, even if the colloidal solution is formed by dispersing other silica fine particles, there is no problem. There is no hindrance.
【００３１】本発明によって造成された改良体を、室内
における繰り返し振動三軸試験と繰り返し単純せん断試
験によって「液状化強度」を確認した。The "liquefaction strength" of the improved body formed according to the present invention was confirmed by a repeated vibration triaxial test and a repeated simple shear test in a room.
【００３２】[0032]
【表１】 [Table 1]
【００３３】試験は、表１に示すように、配合シリカ濃
度２．２５％のケース１と配合シリカ濃度４．５％のケ
ース２について実施され、図４には、それぞれの試験に
供した試験体を示している。せん断試験の供試体は、三
軸試験のそれに比較して小さいのでサンプリングと供試
体の作成が比較的容易であり、試験は、１００点の供試
体を用意して液状化強度を求めている。As shown in Table 1, the tests were carried out for Case 1 having a blended silica concentration of 2.25% and Case 2 having a blended silica concentration of 4.5%. FIG. Showing body. Since the specimen in the shear test is smaller than that in the triaxial test, sampling and preparation of the specimen are relatively easy. In the test, liquefaction strength is obtained by preparing 100 specimens.
【００３４】図５は、繰り返し振動三軸試験の結果を示
している。試験は、軸ひずみの両振幅が５％になる載荷
回数をプロットし、繰り返し回数２０回の応力比を液状
化強度にしている。図示のように未改良域の液状化強度
が０．２５程度であるのに対して、ケース１の場合で
０．３２、ケース２の状態で０．５１と地盤の改良によ
って「液状化強度」の大きくなったことが判る。そし
て、未改良砂には繰り返し単純せん断試験、繰り返し振
動三軸試験を適用したが、せん断試験、三軸試験とも同
様の曲線になっているように、「液状化強度」もほぼ同
じ値が得られており、試験値の正しさを示している。FIG. 5 shows the results of a repeated vibration triaxial test. In the test, the number of loadings at which both amplitudes of the axial strain become 5% is plotted, and the stress ratio at the number of repetitions of 20 is set as the liquefaction strength. As shown in the figure, the liquefaction strength of the unimproved area is about 0.25, whereas the liquefaction strength is 0.32 in case 1 and 0.51 in case 2 due to the ground improvement. You can see that has become larger. Repeated simple shear tests and repeated vibration triaxial tests were applied to unmodified sand, but almost the same value was obtained for the liquefaction strength, as the shear test and triaxial tests had similar curves. It shows the correctness of the test value.
【００３５】図６には、未改良域（ａ）とケース１
（ｂ）の場合の応力―ひずみ曲線を示している。図６
（ａ）から明らかなように、薬液の到達していない未改
良域では繰り返し荷重によって、ある回数からせん断抵
抗力が激減するためにひずみ振幅が急激に増加する状態
を示しており、液状化破壊が発生している。これに対し
て、改良域では図６（ｂ）のようにひずみは次第に大き
くなっているが、急増することがなくせん断抵抗力を維
持しており、繰り返し載荷によっても有限のひずみ振幅
しか発生していない。FIG. 6 shows the unimproved area (a) and the case 1
3 shows a stress-strain curve in the case of (b). FIG.
As is clear from (a), in the unimproved region where the chemical solution has not reached, the shearing force is drastically reduced from a certain number of times due to the repeated load, and the strain amplitude is sharply increased. Has occurred. On the other hand, in the improved area, the strain gradually increases as shown in FIG. 6B, but the shear resistance is maintained without a sudden increase, and only a finite strain amplitude is generated even by repeated loading. Not.
【００３６】以上の各試験によって確認されたように、
本発明によって、主材を構成するコロイド溶液に対する
粒子濃度を４．５（％）以下、サンドゲル状態に到るゲ
ル化時間を１０（ｈ）以上及びサンドゲルの状態におけ
る電気比抵抗値を５（Ω・ｍ）以下に設定される注入薬
液は、これが土砂に注入されサンドゲル状態に到って改
良体を形成した場合に、充分な「液状化強度」を発揮す
ることが明らかである。As confirmed by the above tests,
According to the present invention, the particle concentration with respect to the colloid solution constituting the main material is 4.5 (%) or less, the gelation time to reach the sand gel state is 10 (h) or more, and the electrical resistivity in the sand gel state is 5 (Ω).・ M) It is clear that the injection liquid set below has a sufficient "liquefaction strength" when it is injected into earth and sand to reach a sand gel state to form an improved body.
【００３７】試験は、原位置での改良体調査でも行った
が、此処での試験は、「液状化強度」の実地試験と同時
に、改良効果の確認方法を確立することを目的にしてい
る。又、本発明による地盤改良方法はシリカ粒子濃度を
低くしていることから、標準貫入試験を採用せずに、強
度特性の変化に敏感に反応すると考えられる試験方法を
採用して実施している。The test was also conducted in-situ on the in-situ modified body, but the purpose of this test is to establish a method for confirming the effect of the improvement at the same time as the actual test of "liquefaction strength". In addition, since the ground improvement method according to the present invention has a low silica particle concentration, it does not use a standard penetration test, but uses a test method that is considered to be sensitive to changes in strength characteristics. .
【００３８】図７は、それぞれの試験用いられる先端コ
ーンを示している。図７（ａ）は三成分コーン試験のも
のであり、先端コーンを貫入させることで、貫入抵抗、
周辺摩擦力、間隙水圧を連続的に測定できる。図７
（ｂ）はダイラトメータ試験の平板状ブレードであり、
ぶれ土片側にあるメンブレンの膨張によって地盤を水平
方向に載荷している。FIG. 7 shows the tip cone used for each test. FIG. 7A shows a three-component cone test in which the tip cone is penetrated to obtain a penetration resistance.
Peripheral friction force and pore water pressure can be measured continuously. FIG.
(B) is a flat blade for a dilatometer test,
The ground is loaded horizontally by the expansion of the membrane on one side of the crushed soil.
【００３９】図７（ｃ）は電気比抵抗に試験に用いる先
端コーンであり、上端ロッドの部分に電極を取り付けて
貫入時に地盤の電気比抵抗を連続的に測定できる。本発
明では注入薬液を調合して、薬液注入によって地盤の電
気比抵抗を確実に変化させることで、改良効果の確認を
簡便に実施できるようにしていることから、電気比抵抗
を測定する試験は、地盤改良の施工管理を確実にするた
めの確認試験である。FIG. 7C shows a tip cone used for the test for the electrical resistivity. An electrode is attached to the upper end rod portion, and the electrical resistivity of the ground can be continuously measured at the time of penetration. In the present invention, a test for measuring the electrical resistivity is performed by preparing an injectable drug solution and reliably checking the improvement effect by reliably changing the electrical resistivity of the ground by injecting the drug solution. This is a confirmation test to ensure the construction management of ground improvement.
【００４０】以下に、各試験における計測結果を示すこ
とで、本発明によって設定された注入薬液の注入効果の
確認、特に、室内試験によって確認された「液状化強
度」の追認と「改良域範囲」について確認の容易性につ
いて検討し、三成分コーン試験、ダイラトメータ試験の
結果と比較して、電気比抵抗の測定による注入効果の確
認が最も効率的で精度が高いことを実証する。The measurement results in each test are shown below to confirm the injection effect of the injection liquid set according to the present invention, in particular, to confirm the “liquefaction strength” confirmed by the laboratory test and “ The results of the three-component cone test and the dilatometer test demonstrate that the confirmation of the injection effect by measuring electrical resistivity is the most efficient and accurate.
【００４１】図８は、三成分コーン試験の結果であり、
「液状化強度」の追認と併せて改良域を特定できる可能
性の確認結果を示している。図８（ａ）は、ケース１に
ついて三成分コーン試験を実施した結果を示している。
ケース１の場合は、主材のシリカ濃度が２．２５％と低
いために、貫入抵抗（ｑc）において深度３ｍの部分で
若干の向上が見られるものの、周面摩擦（ｆs）、間隙
水圧（ｕd）では、注入前後において差異を確認できる
状態にない。これに対して、主材のシリカ濃度が４．５
％のケース２については、図８（ｂ）に見られるよう
に、注入後のＧＬ−４．０〜−７．０ｍ間で明らかに貫
入抵抗（ｑc）と周面摩擦（ｆs）が大きくなっており、
間隙水圧（ｕd）が小さくなっていることで改良域を形
成している状態を正確に確認できる。FIG. 8 shows the results of a three-component cone test.
The results confirm the possibility of specifying the improved area together with the confirmation of "liquefaction strength". FIG. 8A shows the result of a three-component cone test performed on Case 1.
In case 1, since the silica concentration of the main material is as low as 2.25%, the penetration resistance (q c ) shows a slight improvement at a depth of 3 m, but the peripheral friction (f s ) and the gap in pressure (u d), not ready to check the difference in before and after injection. In contrast, the silica concentration of the main material was 4.5.
% For the case 2, as seen in FIG. 8 (b), clearly penetration resistance between GL-4.0 to-7.0 m after injection (q c) and skin friction (f s) is It's getting bigger
Can see exactly state forming the improved area by pore pressure (u d) is smaller.
【００４２】図９は、ダイラトメータ試験の結果であ
り、図８と同様に「液状化強度」の追認と併せて改良域
を特定できる可能性の確認結果を示している。図９
（ａ）は、ケース１についてダイラトメータ試験を実施
した結果を示している。この場合も、主材のシリカ濃度
が２．２５％と低いために、メンブレン膨張時の圧力
（ｐ1）、土質パラメータの（ＩD）及び変形特性を示す
（ＥD）が共に変化を見ることができず、注入前後にお
いて差異を確認できる状態にない。一方、ケース２につ
いては、図９（ｂ）に示すように、土質パラメータの
（Ｉ D）による土質の判定結果には改良効果の影響が見
られないが、メンブレン膨張時の圧力（ｐ1）、変形特
性を示す（ＥD）が共に薬液の注入後に大きくなってお
り、地盤強度の増加を推測することができると同時に、
改良域の範囲を正確に確認できる。FIG. 9 shows the results of the dilatometer test.
As with Fig. 8, together with the confirmation of "liquefaction strength",
It shows the result of confirming the possibility of identifying FIG.
(A): Dilatometer test was conducted for Case 1
The results are shown. Also in this case, the silica concentration of the main material
Is 2.25%, the pressure at the time of membrane expansion
(P1), (I)D) And deformation characteristics
(ED) Can not see any change, and before and after injection
Not be able to confirm the difference. On the other hand, case 2
Therefore, as shown in FIG.
(I DThe effect of the improvement effect is seen in the results
The pressure at the time of membrane expansion (p1), Deformation
Show the nature (ED) Both grow after the injection of the drug solution
At the same time you can estimate the increase in ground strength,
The range of the improvement area can be confirmed accurately.
【００４３】図１０乃至１６は、ケース１に関して実施
した電気比抵抗試験の実施範囲と計測結果であり、水平
方向について改良域を特定できる可能性の確認状態を示
している。図１０は、本試験を実施した調査範囲を示す
平面図であり、併せて三成分コーン試験とダイラトメー
タ試験を実施した位置についても参考的に表示してい
る。試験結果は、図示のように直交する形で、Ｎｏ．１
〜Ｎｏ．１４の位置で測定した結果を深度方向に記録し
ている。平面内に実線で示した部分は、ＧＬ−３．９ｍ
まで掘削した後に目視によって推測された改良範囲を表
示しており、電気比抵抗によって確認された改良域の範
囲と一致していることが確認できる。FIGS. 10 to 16 show an execution range and a measurement result of the electric resistivity test performed on the case 1, and show a state where the possibility of specifying an improved area in the horizontal direction is confirmed. FIG. 10 is a plan view showing an investigation range in which this test was performed, and also shows positions where the three-component cone test and the dilatometer test were performed for reference. The test results are orthogonal to each other as shown in FIG. 1
-No. The results measured at 14 positions are recorded in the depth direction. The part shown by the solid line in the plane is GL-3.9m.
The improved range estimated visually after excavation up to the excavation point is displayed, and it can be confirmed that the range matches the range of the improved region confirmed by the electric resistivity.
【００４４】図１１乃至１４は、各計測点における深度
方向の電気比抵抗値を示す計測結果であり、改良域の確
認状態を示している。試験結果について、ＧＬ−４ｍ以
深に注目すると、薬液を注入する以前は、各計測点が同
様に電気比抵抗値が１０〜２０（Ω・ｍ）の値を示して
おり、浅いほど大きくなっている。しかし、薬液の注入
後は５（Ω・ｍ）まで低下し、深さ方向にほぼ一定の値
を示す層が存在することを示している。この層が注入さ
れた薬液が浸透している範囲であり、上下の浸透してい
ない層と明確に区別することができる。FIGS. 11 to 14 show measurement results showing the electric resistivity in the depth direction at each measurement point, and show the confirmation state of the improved area. Regarding the test results, focusing on GL-4m and below, before the injection of the drug solution, each measurement point similarly shows an electric resistivity value of 10 to 20 (Ω · m). I have. However, after the injection of the chemical solution, it decreased to 5 (Ω · m), indicating that there was a layer showing a substantially constant value in the depth direction. This layer is the range where the injected chemical solution has penetrated, and can be clearly distinguished from the upper and lower non-permeated layers.
【００４５】又、その浸透状態に視点を移してみると、
注入位置を中心に浸透した深さ・層圧がほぼ対象に現れ
ており、注入の中心から離れるに従って浸透された層厚
が小さくなっていることが判る。さらに、本試験の目標
改良半径である１．５ｍよりも離れると、薬液注入前の
地盤における電気比抵抗値を示すようになり、浸透して
いないことを表示している。Turning to the permeation state,
It can be seen that the depth and the layer pressure that have penetrated around the injection position appear almost on the target, and the thickness of the permeated layer decreases as the distance from the injection center increases. Further, when the distance from the target improved radius of the test is 1.5 m, the electric resistivity value on the ground before the injection of the chemical liquid is shown, indicating that the water has not penetrated.
【００４６】図１５、１６は、本試験を実施した調査範
囲を示す断面図であり、図１０の平面図に相当させた各
計測点の深度方向における電気比抵抗値を示す計測結果
であり、深度方向について改良域を特定できる可能性の
確認状態を示している。本結果は、電気比抵抗の測定か
ら推測される改良範囲を示しているものであり、図面に
表示した破線から明らかなように、両断面とも改良域の
範囲は、ストレーナーを中心にして球状浸透した所望の
浸透範囲（半径１．５ｍの球体）とほぼ一致している。FIGS. 15 and 16 are cross-sectional views showing the investigation range in which this test was carried out, and are the measurement results showing the electric resistivity in the depth direction of each measurement point corresponding to the plan view of FIG. This shows a state of confirming the possibility of specifying an improved area in the depth direction. The results show the improvement range inferred from the measurement of the electrical resistivity, and as is clear from the broken line shown in the drawing, the range of the improvement area in both sections is spherical penetration around the strainer. Of the desired permeation range (a sphere with a radius of 1.5 m).
【００４７】従って、本発明による注入薬液を用いた地
盤改良は、理想的な注入形態である浸透注入によって、
コロイド溶液の濃度が低い場合でも所定の改良体を形成
して地盤の改良を達成しているものであり、同時に注入
後における電気比抵抗の計測によって、改良域の品質と
範囲とを簡潔に特定出来ることが確認されたことにな
る。Therefore, the ground improvement using the injection chemical solution according to the present invention can be achieved by infiltration, which is an ideal injection form.
Even if the concentration of the colloid solution is low, the ground has been improved by forming a predetermined improved body, and at the same time, the quality and range of the improved area can be simply identified by measuring the electrical resistivity after injection. It is confirmed that it can be done.
【００４８】図１７乃至１９は、ケース２に関して実施
した電気比抵抗試験の実施範囲と計測結果であり、水平
方向と深度方向についてケース１と同様に改良域を特定
できる可能性の確認状態を示している。平面内に実線で
示した部分は、ＧＬ−４．２ｍまで掘削した後に目視に
よって推測された改良範囲を表示しており、電気比抵抗
によって確認された改良域の範囲と一致していることが
確認できる。但し、改良形状は、Ｎｏ．９とＮｏ．１８
の方向に小さく、Ｎｏ．８の方向に大きくなっている
が、小さくなっている方向には、中心部に比べて細粒分
の多い砂質土層が確認されており、これによって浸透性
の良い地盤の方向に薬液が優先的に浸透したものと推測
される。FIGS. 17 to 19 show the execution range and the measurement results of the electric resistivity test performed on the case 2 and show the confirmation state of the possibility of specifying the improved area in the horizontal direction and the depth direction as in the case 1. ing. The part shown by the solid line in the plane shows the improvement range estimated visually after excavating to GL-4.2m, and it is consistent with the range of the improvement area confirmed by electrical resistivity. You can check. However, the improved shape is no. 9 and no. 18
In the direction of No. In the direction of decrease, a sandy soil layer with more fine grains than in the center was confirmed, and the chemical solution was directed toward the ground with good permeability. It is presumed that it has penetrated preferentially.
【００４９】図１８、１９は、本試験を実施した調査範
囲を示す断面図であり、コロイド溶液のシリカ濃度が高
い場合についても、各計測点の深度方向における電気比
抵抗値を示す計測結果によって、深度方向について改良
域を特定できる可能性の確認状態を示している。推測さ
れる改良範囲は、両断面とも改良範囲の上端が地下水位
ＧＬ−３ｍより低いＧＬ−４ｍ付近になっている。試掘
によると、ＧＬ−４ｍ付近には厚さ１０ｃｍ程度の薄層
の粘性土が存在していることが判明した。従って、上記
平面図に現れた浸透域の差異は、この粘性土によって薬
液の浸透が阻まれたものと推測される。実際にもそれ以
深については、浸透注入によって地盤の改良が為されて
おり、その浸透範囲は中心から２ｍに達している。FIGS. 18 and 19 are cross-sectional views showing the investigation range in which the present test was performed. Even when the silica concentration of the colloid solution was high, the measurement results showing the electrical resistivity in the depth direction at each measurement point were used. And the confirmation state of the possibility of specifying the improvement area in the depth direction. The estimated improvement range in both sections is that the upper end of the improvement range is around GL-4m, which is lower than the groundwater level GL-3m. According to the test excavation, it was found that a thin clayey soil having a thickness of about 10 cm existed in the vicinity of GL-4m. Therefore, it is presumed that the difference between the permeation areas appearing in the plan view is that the permeation of the chemical solution was prevented by the viscous soil. In fact, at deeper depths, the ground has been improved by infiltration, and the infiltration range has reached 2 m from the center.
【００５０】従って、本発明による注入薬液を用いた地
盤改良は、コロイド溶液の濃度が高い場合でも理想的な
注入形態である浸透注入によって、所定の改良体を形成
して地盤の改良を達成しているものであり、同時に注入
後における電気比抵抗の計測によって、改良域の品質と
範囲とを簡潔に特定出来ることが確認されたことにな
る。Therefore, the ground improvement using the injection liquid according to the present invention achieves ground improvement by forming a predetermined improved body by infiltration injection which is an ideal injection form even when the concentration of the colloid solution is high. At the same time, by measuring the electrical resistivity after the injection, it was confirmed that the quality and range of the improved region could be simply specified.
【００５１】以上のように、室内における繰り返し振動
三軸試験と繰り返し単純せん断試験による「液状化強
度」の確認と、原位置での改良体調査で行われた三成分
コーン試験、ダイラトメータ試験と電気比抵抗試験によ
る「液状化強度」の実地試験及び改良効果を確認する方
法の確立によって、本発明による注入薬液を用いた土砂
地盤改良工法は、地盤改良域に大量の薬液を低圧、高速
で広範囲に注入することを可能にして大口径の改良体の
造成を図って所望の液状化強度を発生させ、さらに、注
入後の電気比抵抗値を計測することで地盤改良域の液状
化強度とその範囲を簡潔に確認できることが明らかにな
った。As described above, the “liquefaction strength” was confirmed by the repeated vibration triaxial test and the repeated simple shear test in the room, and the three-component cone test, the dilatometer test, and the electric By the practical test of "liquefaction strength" by the specific resistance test and the establishment of the method to confirm the improvement effect, the soil and soil improvement method using the injected chemical solution according to the present invention allows a large amount of chemical solution to be applied to the soil improvement area at low pressure, at high speed, and over a wide area. Liquefaction strength of the soil improvement area by measuring the electrical resistivity after injection to achieve the desired liquefaction strength by creating a large diameter improved body by allowing It became clear that the range could be checked briefly.
【００５２】これらの結果を踏まえて、本発明による土
砂地盤改良工法の施工管理方法は、液状化強度と電気比
抵抗値との関連を特定し、少なくとも電気比抵抗値を設
定した注入薬液を地盤改良範囲の土砂中に注入し、しか
る後に深度方向の電気比抵抗値を測定し、上記特定関連
に基づいて地盤改良範囲における液状化強度を確認して
いる。以下に、本発明による施工管理方法の実施の形態
を特定関連図に基づいて説明する。Based on these results, the construction management method of the earth and sand improvement method according to the present invention specifies the relationship between the liquefaction strength and the electric resistivity, and converts the injected chemical solution having at least the electric resistivity into the ground. It is injected into the earth and sand in the improvement area, and then the electrical resistivity in the depth direction is measured, and the liquefaction strength in the soil improvement area is confirmed based on the above specific relation. Hereinafter, an embodiment of a construction management method according to the present invention will be described based on a specific relation diagram.
【００５３】図２０は、本発明による注入薬液を用いた
試験によって予め作成した「液状化強度比」（ａ）と
「電気比抵抗値」（ｂ）の希釈倍率に対する特定関連図
である。ここで用いる希釈倍率は、以下のように定めら
れている。希釈倍率＝[（希釈によって加わる水の重
量）＋（主材の重量）]／（主材の重量）本発明による
施工管理方法は、図２０に示した両特定関連図を用いて
次のように実施することで、地盤改良域に所望の改良が
確立していることを確認できる。 注入薬液について、「液状化強度比」（ａ）と「電
気比抵抗値」とを予め求めて上記特定関連図（ａ）
（ｂ）を作成する。 注入薬液について、所定の「液状化強度比」を設定
して、主材のシリカ粒子濃度、サンドゲル状態に到るゲ
ル化時間及びサンドゲル状態における電気比抵抗値を設
定する。 注入薬液を所定の「希釈倍率」に希釈して地盤改良
域に注入する。 地盤改良域の電気比抵抗を計測する。 計測された「電気比抵抗値」を特定関連図（ｂ）に
当てはめて、曲線に従って「希釈倍率」を特定し、「希
釈倍率」を特定関連図（ａ）に当てはめて「液状化強度
比」を求める。 「液状化強度比」から改良域の「液状化強度」を確
認する。FIG. 20 is a specific relation diagram of the "liquefaction strength ratio" (a) and the "electrical resistivity" (b) prepared in advance by the test using the infused drug solution according to the present invention with respect to the dilution ratio. The dilution ratio used here is determined as follows. Dilution magnification = [(weight of water added by dilution) + (weight of main material)] / (weight of main material) The construction management method according to the present invention is as follows using the two specific relation diagrams shown in FIG. It can be confirmed that the desired improvement has been established in the ground improvement area. For the injection liquid, the “liquefaction strength ratio” (a) and the “electrical resistivity” are determined in advance and the specific relation diagram (a) is obtained.
(B) is created. A predetermined “liquefaction strength ratio” is set for the injected chemical solution, and the silica particle concentration of the main material, the gelation time to reach a sand gel state, and the electrical resistivity in the sand gel state are set. The injection liquid is diluted to a predetermined “dilution ratio” and injected into the ground improvement area. Measure the electrical resistivity in the ground improvement area. Applying the measured "electric resistivity" to the specific relation diagram (b), specifying the "dilution factor" according to the curve, and applying the "dilution factor" to the specific relation diagram (a), the "liquefaction strength ratio" Ask for. The "liquefaction strength" of the improved region is confirmed from the "liquefaction strength ratio".
【００５４】以上のように、本発明による施工管理方法
は、注入薬液に関する「液状化強度比」と「電気比抵抗
値」とを予め求めて、上記特定関連図（ａ）（ｂ）の作
成を済ましておくことで、以降の管理は、注入薬液の主
材のシリカ粒子濃度、サンドゲル状態に到るゲル化時間
及びサンドゲル状態における電気比抵抗値を設定する作
業と、注入後の電気比抵抗を計測するだけの作業だけ
で、施工管理を簡潔に実施できる。As described above, in the construction management method according to the present invention, the "liquefaction strength ratio" and the "electrical resistivity value" of the injected chemical liquid are determined in advance, and the specific relation diagrams (a) and (b) are created. After that, the subsequent management consists of the work of setting the silica particle concentration of the main material of the injection chemical solution, the gelation time to reach the sand gel state and the electric resistivity value in the sand gel state, and the electric resistivity after injection. The construction management can be carried out simply by simply measuring the measurement.
【００５５】しかして、上記管理方法では、改良域に所
望の「液状化強度」が確立しているか否かを数値的に確
認しているが、上述した試験結果でも明らかなように、
本発明による注入薬液は、所定の数値設定によって改良
域に所期の「液状化強度」を充分に形成できることが実
証されている。従って、本発明による土砂地盤改良工法
の施工管理方法は、この他に、地盤改良範囲において薬
液注入前に深度方向の電気比抵抗値を予め測定しておい
て、電気比抵抗値を設定した注入薬液を注入した後に同
様の電気比抵抗値を測定して、両方の測定値を比較照合
することで、地盤改良効果を確認することも可能であ
る。In the above management method, whether or not a desired “liquefaction strength” is established in the improved area is numerically confirmed. However, as is clear from the test results described above,
It has been demonstrated that the infused drug solution according to the present invention can sufficiently form the desired "liquefaction strength" in the improved region by setting a predetermined numerical value. Therefore, the construction management method of the earth and sand ground improvement method according to the present invention, in addition to this, the electric resistivity in the depth direction is measured in advance before the injection of the chemical solution in the soil improvement range, and the electric resistivity is set. It is also possible to confirm the ground improvement effect by measuring the same electrical resistivity after injecting the chemical solution and comparing and comparing both measured values.
【００５６】本施工管理方法は、注入薬液に関する「液
状化強度比」と「電気比抵抗値」とを予め求めることな
く、施工現場における電気比抵抗値の計測のみで地盤改
良効果を確認するもので、以下のように実施する。 薬液注入前に地盤改良範囲における深度方向の電気
比抵抗値を予め測定する。 注入薬液を地盤改良範囲の土砂中に注入した後に、
地盤改良範囲における深度方向の電気比抵抗値を再び測
定する。 両測定値を比較照合して差異が存在することを確認
する。In the present construction management method, the ground improvement effect is confirmed only by measuring the electrical resistivity at the construction site without previously obtaining the "liquefaction strength ratio" and the "electric resistivity" of the injected chemical. Then, it is carried out as follows. Before injecting the chemical, the electrical resistivity in the depth direction in the ground improvement range is measured in advance. After injecting the injected chemical into the soil improvement area,
The electrical resistivity in the depth direction in the ground improvement area is measured again. Compare and compare the two measurements to confirm that a difference exists.
【００５７】以上のように、本発明による施工管理方法
では、注入薬液にゲル化剤で設定した電気比抵抗値を改
良地盤の電気比抵抗値と比較して大きな差異を生じるよ
うに調合している特性を活用して、電気比抵抗値の変化
を観測するのみで施工管理を簡潔に実施できる。尚、本
発明による施工管理方法では、通常の地盤における電気
比抵抗が大凡の数値で確認されている場合には事前の計
測も省略して、薬液注入後の電気比抵抗値が予め設定し
た電気比抵抗値（上記実施の形態では５（Ω・ｍ））に
なっているか否かを確認するだけでも施工管理を達成で
きる。As described above, in the construction management method according to the present invention, the electrical resistivity set by the gelling agent in the injected chemical solution is compared with the electrical resistivity of the improved ground so as to produce a large difference. By utilizing the characteristics that are available, the construction management can be performed simply by observing the change in the electrical resistivity value. Note that, in the construction management method according to the present invention, when the electrical resistivity in a normal ground is confirmed by an approximate value, the advance measurement is also omitted, and the electrical resistivity after the injection of the chemical solution is set to a preset electrical resistivity. The construction management can be achieved only by checking whether or not the specific resistance value is 5 (Ω · m in the above embodiment).
【００５８】以上の説明で明らかなように、本発明によ
る土砂地盤改良工法の施工管理方法は、少なくとも電気
比抵抗値を設定した注入薬液を土砂地盤に注入し、しか
る後に深度方向の電気比抵抗値を測定して、地盤改良域
における液状化強度とその範囲を確認しており、注入薬
液にサンドゲル状態における電気比抵抗値を設定する作
業と、注入後の電気比抵抗を計測するだけの作業だけ
で、施工管理を簡潔に実施できるものである。As is clear from the above description, the construction management method of the earth and sand improvement method according to the present invention involves injecting at least an injectable chemical solution having an electric resistivity set into the earth and sand, and thereafter, in the depth direction, the electric resistivity in the depth direction. Measure the values to confirm the liquefaction strength and its range in the ground improvement area, work to set the electric resistivity value in the sand gel state in the injected chemical solution, and work only to measure the electric resistivity after injection In this way, construction management can be simply implemented.
【００５９】以上、本発明を実施の形態に基づいて詳細
に説明してきたが、本発明による土砂地盤改良工法と注
入薬液及びその管理方法は、上記実施の形態に何ら限定
されるものでなく、主材におけるシリカ粒子、ゲル化剤
における酸性塩や中性塩の各種態様、さらには濃度等の
配合値や注入薬液へのサンドゲル状態に到るゲル化時
間、電気比抵抗の設定値等に関して、本発明の趣旨を逸
脱しない範囲において種々の変更が可能であることは当
然のことである。As described above, the present invention has been described in detail based on the embodiments. However, the soil and soil improvement method, the injected chemical solution and the management method thereof according to the present invention are not limited to the above embodiments. Silica particles in the main material, various aspects of the acidic salt and neutral salt in the gelling agent, furthermore, the compounding value such as the concentration and the gelation time to reach the sand gel state to the injectable drug solution, the set value of the electrical resistivity, etc. Naturally, various modifications can be made without departing from the spirit of the present invention.
【００６０】[0060]
【発明の効果】請求項１、２に記載の発明である土砂地
盤改良工法は、基本的に、シリカ粒子のコロイド溶液を
主材とし主材にゲル化剤を配合した注入薬液を土砂地盤
に注入する土砂地盤改良工法において、主材のシリカ粒
子濃度、サンドゲル状態に到るゲル化時間及びサンドゲ
ル状態における電気比抵抗値を設定した注入薬液を土砂
地盤中に注入して土砂地盤を所定の液状化強度の地盤に
改良するものであり、注入薬液を改良する土砂地盤の土
砂を用いて試験測定し、サンドゲル状態に到るゲル化時
間及びサンドゲル状態における電気比抵抗値を予め確認
することを特徴としているので、低濃度のシリカ粒子か
ら成る薬液を低圧、高速で長時間に亘って注入すること
を可能にして削孔間隔を拡大した大口径の改良体を造成
することで土砂地盤改良残すとを低減し、工期を短縮で
きる効果を奏している。According to the first and second aspects of the present invention, the soil and soil improvement method is basically applied to the earth and sand ground by using an injection liquid containing a colloidal solution of silica particles as a main material and a gelling agent mixed with the main material. In the soil and soil improvement method to be injected, the injection chemical liquid that sets the silica particle concentration of the main material, the gelation time to reach the sand gel state, and the electrical resistivity value in the sand gel state is injected into the earth and sand ground, and the earth and sand ground is subjected to a predetermined liquid It is a test to measure the gelation time to reach the sandgel state and the electrical resistivity in the sandgel state in advance by performing test measurement using the earth and sand of the soil to improve the injection chemical solution. Therefore, it is possible to inject a chemical solution composed of low-concentration silica particles at a low pressure and at a high speed over a long period of time to create a large-diameter improved body with an increased drilling interval, Reduced Leave improved, and provide an advantage of shortening the work period.
【００６１】請求項３に記載の発明である土砂地盤改良
工法は、請求項１又は２に記載の土砂地盤改良工法にお
いて、注入薬液を、主材を構成するコロイド溶液に対す
る粒子濃度を４．５（％）以下にし、サンドゲル状態に
到るゲル化時間を１０（ｈ）以上としてサンドゲルの状
態における電気比抵抗値を５（Ω・ｍ）以下に設定する
ことを特徴としているので、上記機能を確実に達成して
いる効果を奏している。According to a third aspect of the present invention, there is provided the soil and soil improvement method according to the first or second aspect, wherein the injected chemical solution has a particle concentration of 4.5 with respect to the colloid solution constituting the main material. (%) Or less, the gelation time to reach the sandgel state is set to 10 (h) or more, and the electrical resistivity value in the sandgel state is set to 5 (Ω · m) or less. It has the effect that has been achieved.
【００６２】請求項４、５に記載の発明である土砂地盤
改良工法に用いる注入薬液は、主材を構成するコロイド
溶液のシリカ粒子もしくは活性シリカ粒子の濃度を４．
５（％）以下にし、サンドゲル状態に到るゲル化時間を
１０（ｈ）以上としてサンドゲルの状態における電気比
抵抗値を５（Ω・ｍ）以下に設定しているので、改良域
の地盤に低圧、高速で注入することを可能にして大口径
の改良体を造成することができると共に、電気比抵抗値
の測定で改良効果を確認できるので地盤改良の施工と管
理を低コストで簡潔に実施できる効果を奏している。The injection liquid used in the method for improving the earth and sand ground according to the fourth and fifth aspects of the present invention has a concentration of silica particles or active silica particles in the colloidal solution constituting the main material.
5 (%) or less, the gelation time to reach the sand gel state is set to 10 (h) or more, and the electrical resistivity value in the sand gel state is set to 5 (Ω · m) or less. Injection can be performed at low pressure and at high speed, and a large-diameter improved body can be created.Since the improvement effect can be confirmed by measuring the electrical resistivity, the construction and management of ground improvement can be performed simply and at low cost. It has an effect that can be done.
【００６３】請求項６に記載の発明である土砂地盤改良
工法に用いる注入薬液は、請求項５に記載の注入薬液を
配合するのに、平均粒子径３〜６ナノメートルの活性シ
リカ粒子を０．２８〜２．２５重量％分散させてコロイ
ド溶液にした主材と０．１〜１０．０重量％の中性塩及
び０．１〜５重量％の酸性塩を混合して成るゲル化剤と
を配合することで、活性シリカ粒子の濃度を４．５
（％）以下にし、サンドゲル状態に到るゲル化時間を１
０（ｈ）以上としてサンドゲルの状態における電気比抵
抗値を５（Ω・ｍ）以下に設定しているので、上記作用
効果を確実に達成する効果を奏している。The injection liquid used in the soil and soil improvement method according to the sixth aspect of the present invention is obtained by adding active silica particles having an average particle diameter of 3 to 6 nanometers to the injection liquid according to the fifth aspect. A gelling agent obtained by mixing a base material dispersed in a colloidal solution by mixing 28 to 2.25% by weight with 0.1 to 10.0% by weight of a neutral salt and 0.1 to 5% by weight of an acidic salt And the concentration of the active silica particles is adjusted to 4.5.
(%) Or less, and the gelation time to reach the sand gel state is 1
Since the electrical resistivity in the state of the sand gel is set to 5 (Ω · m) or less as 0 (h) or more, the above-described operation and effect can be surely achieved.
【００６４】請求項７に記載の発明である土砂地盤改良
工法の施工管理方法は、液状化強度と電気比抵抗値との
関連を特定し、少なくとも電気比抵抗値を設定した注入
薬液を地盤改良範囲の土砂中に注入し、しかる後に深度
方向の電気比抵抗値を測定して、上記特定関連に基づい
て地盤改良範囲及び液状化強度を確認しており、改良域
における電気比抵抗を測定するだけで地盤改良域の範囲
と品質を判定できるので、地盤改良工事の施工管理を簡
潔にできる効果を奏している。According to a seventh aspect of the present invention, there is provided a construction management method for an earth and sand ground improvement method, wherein a relation between liquefaction strength and an electric resistivity value is specified, and at least an injected chemical solution having an electric resistivity value set is used for soil improvement. Inject into the earth and sand of the range, and then measure the electrical resistivity in the depth direction to confirm the soil improvement range and liquefaction strength based on the above specific relationship, and measure the electrical resistivity in the improved area Since the range and quality of the ground improvement area can be determined only by using this method, there is an effect that the construction management of the ground improvement work can be simplified.
【００６５】請求項８に記載の発明である土砂地盤改良
工法の施工管理方法は、薬液注入前に深度方向の電気比
抵抗値を地盤改良範囲において予め測定しておいて、少
なくとも電気比抵抗値を設定した注入薬液を地盤改良範
囲の土砂中に注入し、しかる後に深度方向の電気比抵抗
値を測定して、測定値と上記測定値とを比較照合するこ
とで地盤改良範囲及び液状化強度を確認しており、改良
域における注入前後の電気比抵抗値を測定、比較するだ
けで地盤改良域の範囲と品質を判定できるので、地盤改
良工事の施工管理をさらに簡潔にできる効果を奏してい
る。In the construction management method of the earth and sand ground improvement method according to the present invention, the electric resistivity in the depth direction is measured in advance in the ground improvement range before the injection of the chemical solution, and at least the electric resistivity is measured. Inject the injected chemical solution into the soil of the ground improvement range, then measure the electrical resistivity in the depth direction, and compare and compare the measured value with the above measured value to obtain the ground improvement range and liquefaction strength It is possible to determine the range and quality of the ground improvement area just by measuring and comparing the electric resistivity value before and after injection in the improvement area, so that the effect of simplifying the construction management of the ground improvement work has been achieved. I have.
【図面の簡単な説明】[Brief description of the drawings]
【 図１】本発明による注入薬液を特定するために調整
したサンドゲル状態に到るゲル化時間とｐＨの相関図FIG. 1 is a correlation diagram between gelation time and pH to reach a sandgel state adjusted to specify an injectable drug solution according to the present invention.
【 図２】本発明による注入薬液を特定するために調整
した電気伝導度とｐＨの相関図FIG. 2 is a correlation diagram of electric conductivity and pH adjusted to specify an infusion solution according to the present invention.
【 図３】本発明による注入薬液を特定するために調整
した電気伝導度とゲル化剤の中性塩配合の相関図FIG. 3 is a correlation diagram between the electric conductivity adjusted to specify the injectable drug solution according to the present invention and the neutral salt formulation of the gelling agent.
【 図４】液状化強度試験に使用した供試体Fig. 4 Specimen used for liquefaction strength test
【 図５】液状化強度試験における載荷回数とせん断応
力比の計測値図FIG. 5 is a graph showing measured values of the number of loadings and the shear stress ratio in a liquefaction strength test.
【 図６】液状化強度試験におけるせん断ひずみとせん
断応力の計測値図FIG. 6 is a graph showing measured values of shear strain and shear stress in a liquefaction strength test.
【 図７】原位置試験に適用した各試験方法の先端コー
ン図FIG. 7: Tip cone diagram of each test method applied to the in-situ test
【 図８】低濃度シリカ粒子のケースにおける三成分コ
ーン試験の深度方向計測値図FIG. 8: Depth direction measured value diagram of the ternary cone test in the case of low concentration silica particles
【 図９】低濃度シリカ粒子のケースにおけるダイラト
メータ試験の深度方向計測値図FIG. 9 is a diagram showing measured values in the depth direction of a dilatometer test in the case of low-concentration silica particles.
【 図１０】原位置試験を実施した低濃度シリカ粒子の
ケースにおける改良範囲の平面図FIG. 10 is a plan view of an improved range in a case of a low-concentration silica particle subjected to an in-situ test.
【 図１１】低濃度シリカ粒子のケースにおける電気比
抵抗試験の深度方向計測値図FIG. 11 is a diagram showing measured values in a depth direction of an electric resistivity test in a case of low-concentration silica particles.
【 図１２】低濃度シリカ粒子のケースにおける電気比
抵抗試験の深度方向計測値図FIG. 12 is a diagram showing measured values in a depth direction of an electric resistivity test in a case of low-concentration silica particles.
【 図１３】低濃度シリカ粒子のケースにおける電気比
抵抗試験の深度方向計測値図FIG. 13 is a diagram showing measured values in the depth direction of the electrical resistivity test in the case of low-concentration silica particles.
【 図１４】低濃度シリカ粒子のケースにおける電気比
抵抗試験の深度方向計測値図FIG. 14 is a diagram showing measured values in a depth direction of an electric resistivity test in a case of low-concentration silica particles.
【 図１５】原位置試験を実施した低濃度シリカ粒子の
ケースにおける改良範囲の断面図FIG. 15 is a cross-sectional view of an improved range in the case of a low-concentration silica particle subjected to an in-situ test.
【 図１６】原位置試験を実施した低濃度シリカ粒子の
ケースにおける改良範囲の断面図FIG. 16 is a cross-sectional view of an improved range in the case of low-concentration silica particles subjected to an in-situ test.
【 図１７】原位置試験を実施した標準濃度シリカ粒子
のケースにおける改良範囲の平面図FIG. 17 is a plan view of an improved range in the case of standard-concentration silica particles subjected to an in-situ test.
【 図１８】原位置試験を実施した標準濃度シリカ粒子
のケースにおける改良範囲の断面図FIG. 18 is a cross-sectional view of the improved range in the case of standard concentration silica particles subjected to an in-situ test.
【図１９】原位置試験を実施した標準濃度シリカ粒子の
ケースにおける改良範囲の断面図FIG. 19 is a cross-sectional view of the improved range in the case of standard-concentration silica particles subjected to an in-situ test.
【 図２０】地盤改良の施工管理に用いる特定関連図FIG. 20: Specific relation diagram used for construction management of ground improvement
───────────────────────────────────────────────────── フロントページの続き (72)発明者 高橋 一成 大阪府大阪市阿倍野区松崎町２丁目２番２ 号 株式会社奥村組内 Ｆターム(参考） 2D040 AA01 AB01 CA10 CB03 GA02 2D043 AA01 AB00 BA10 4H026 CB01 CC05 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kazunari Takahashi 2-2-2 Matsuzakicho, Abeno-ku, Osaka-shi, Osaka F-term in Okumura Gumi Co., Ltd. (Reference) 2D040 AA01 AB01 CA10 CB03 GA02 2D043 AA01 AB00 BA10 4H026 CB01 CC05
Claims (8)
該主材にゲル化剤を配合した注入薬液を土砂地盤に注入
する土砂地盤改良工法であって、主材のシリカ粒子濃
度、サンドゲル状態に到るゲル化時間及びサンドゲル状
態における電気比抵抗値を設定した注入薬液を土砂地盤
中に注入し、土砂地盤を所定の液状化強度の地盤に改良
することを特徴とする土砂地盤改良工法。1. A colloidal solution of silica particles as a main material,
A soil and soil ground improvement method for injecting an injection liquid containing a gelling agent into the main material into the earth and sand ground, wherein a silica particle concentration of the main material, a gelation time to reach a sand gel state, and an electrical resistivity value in a sand gel state are obtained. A soil and soil improvement method characterized by injecting the set injection liquid into the soil and improving the soil to a ground having a predetermined liquefaction strength.
いて試験測定し、サンドゲル状態に到るゲル化時間及び
サンドゲル状態における電気比抵抗値を予め確認するこ
とを特徴とする請求項１に記載の土砂地盤改良工法。2. The method according to claim 1, wherein a test and measurement are performed using earth and sand of the earth and sand ground for improving the injection chemical solution, and a gelation time to reach a sand gel state and an electric resistivity value in the sand gel state are confirmed in advance. The described soil and soil improvement method.
液に対する粒子濃度を４．５（％）以下、サンドゲル状
態に到るゲル化時間を１０（ｈ）以上及びサンドゲルの
状態における電気比抵抗値を５（Ω・ｍ）以下に設定さ
れることを特徴とする請求項１又は２に記載の土砂地盤
改良工法。3. The injectable drug solution has a particle concentration of 4.5 (%) or less with respect to a colloid solution constituting the main material, a gelation time to reach a sand gel state of 10 (h) or more, and an electric resistivity in a sand gel state. The soil and soil improvement method according to claim 1, wherein the value is set to 5 (Ω · m) or less.
子濃度を４．５（％）以下、サンドゲル状態に到るゲル
化時間を１０（ｈ）以上及びサンドゲルの状態における
電気比抵抗値を５（Ω・ｍ）以下に設定して成る請求項
１乃至３のいずれかに記載の土砂地盤改良工法に用いる
注入薬液。4. The colloid solution constituting the main material has a silica particle concentration of 4.5 (%) or less, a gelation time to reach a sand gel state of 10 (h) or more, and an electric resistivity value of 5 in a sand gel state. The injection chemical solution used in the soil and soil improvement method according to any one of claims 1 to 3, which is set to (Ω · m) or less.
カ粒子濃度を４．５（％）以下、サンドゲル状態に到る
ゲル化時間を１０（ｈ）以上及びサンドゲルの状態にお
ける電気比抵抗値を５（Ω・ｍ）以下に設定して成る請
求項１乃至３のいずれかに記載の土砂地盤改良工法に用
いる注入薬液。5. The colloid solution constituting the main material has an active silica particle concentration of 4.5 (%) or less, a gelation time to a sand gel state of 10 (h) or more, and an electric resistivity value in a sand gel state. The injection chemical solution used in the method for improving soil and soil ground according to any one of claims 1 to 3, wherein the injection solution is set to 5 (Ω · m) or less.
リカ粒子を０．２８〜２．２５重量％分散させてコロイ
ド溶液にした主材、０．１〜１０．０重量％の中性塩及
び０．１〜５重量％の酸性塩を混合して成るゲル化剤か
ら構成することを特徴とする請求項５に記載の注入薬
液。6. A base material in which active silica particles having an average particle diameter of 3 to 6 nanometers are dispersed in 0.28 to 2.25% by weight to form a colloidal solution, and a neutral salt of 0.1 to 10.0% by weight. 6. The injection liquid according to claim 5, comprising a gelling agent obtained by mixing 0.1 to 5% by weight of an acidic salt.
定し、少なくとも電気比抵抗値を設定した注入薬液を地
盤改良範囲の土砂中に注入し、しかる後に深度方向の電
気比抵抗値を測定して、上記特定関連に基づいて地盤改
良範囲及び液状化強度を確認する土砂地盤改良工法の施
工管理方法。7. The relationship between the liquefaction strength and the electric resistivity is specified, and an injectable liquid having at least the electric resistivity set therein is injected into the earth and soil within the ground improvement range, and then the electric resistivity in the depth direction is determined. And the soil improvement area and the liquefaction strength are measured based on the above-mentioned specific relation.
地盤改良範囲において予め測定しておいて、少なくとも
電気比抵抗値を設定した注入薬液を地盤改良範囲の土砂
中に注入し、しかる後に深度方向の電気比抵抗値を測定
して、該測定値と上記測定値とを比較照合することで地
盤改良範囲及び液状化強度を確認する土砂地盤改良工法
の施工管理方法。8. The electric resistivity in the depth direction is measured in advance in the ground improvement range before injecting the chemical solution, and the injected chemical solution having at least the electric resistivity value set is injected into the soil in the ground improvement range. A construction management method for a soil and soil improvement method in which an electric resistivity value in a depth direction is measured later, and the measured value is compared with the measured value to confirm the ground improvement range and liquefaction strength.
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|---|---|---|---|
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|---|---|---|---|
| JP2008247967A Division JP2009024493A (en) | 2008-09-26 | 2008-09-26 | Earth-and-sand soil improving method, injection chemical, and construction management method therefor |
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| Publication Number | Publication Date |
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| JP2001241031A true JP2001241031A (en) | 2001-09-04 |
| JP4376411B2 JP4376411B2 (en) | 2009-12-02 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005350961A (en) * | 2004-06-10 | 2005-12-22 | Toa Harbor Works Co Ltd | Method of determining chemical concentration for use in preventing liquefaction by injecting chemical, and method of stabilizing soil by injecting chemical |
| JP2009024493A (en) * | 2008-09-26 | 2009-02-05 | Okumura Corp | Earth-and-sand soil improving method, injection chemical, and construction management method therefor |
| JP2014005612A (en) * | 2012-06-22 | 2014-01-16 | Maeda Corp | Quality confirmation method and quality confirmation device for improved ground |
| JP2015214838A (en) * | 2014-05-12 | 2015-12-03 | 前田建設工業株式会社 | Method and device for ground improvement quality management |
| JP2021004473A (en) * | 2019-06-26 | 2021-01-14 | 戸田建設株式会社 | Method of confirming ground improvement effect and measuring device used for it |
| CN115383971A (en) * | 2022-08-29 | 2022-11-25 | 浙江科技学院 | Silica sol seepage curing sandy soil piezoresistance forming device and method |
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2000
- 2000-02-29 JP JP2000053277A patent/JP4376411B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005350961A (en) * | 2004-06-10 | 2005-12-22 | Toa Harbor Works Co Ltd | Method of determining chemical concentration for use in preventing liquefaction by injecting chemical, and method of stabilizing soil by injecting chemical |
| JP4625273B2 (en) * | 2004-06-10 | 2011-02-02 | 東亜建設工業株式会社 | Determination method of chemical concentration used to prevent liquefaction by chemical injection and stabilization treatment method of earth and sand by chemical injection |
| JP2009024493A (en) * | 2008-09-26 | 2009-02-05 | Okumura Corp | Earth-and-sand soil improving method, injection chemical, and construction management method therefor |
| JP2014005612A (en) * | 2012-06-22 | 2014-01-16 | Maeda Corp | Quality confirmation method and quality confirmation device for improved ground |
| JP2015214838A (en) * | 2014-05-12 | 2015-12-03 | 前田建設工業株式会社 | Method and device for ground improvement quality management |
| JP2021004473A (en) * | 2019-06-26 | 2021-01-14 | 戸田建設株式会社 | Method of confirming ground improvement effect and measuring device used for it |
| JP7248241B2 (en) | 2019-06-26 | 2023-03-29 | 戸田建設株式会社 | Confirmation method of ground improvement effect and measuring device used therefor |
| CN115383971A (en) * | 2022-08-29 | 2022-11-25 | 浙江科技学院 | Silica sol seepage curing sandy soil piezoresistance forming device and method |
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