JPH1088561A - Chemical grouting method - Google Patents
Chemical grouting methodInfo
- Publication number
- JPH1088561A JPH1088561A JP24308496A JP24308496A JPH1088561A JP H1088561 A JPH1088561 A JP H1088561A JP 24308496 A JP24308496 A JP 24308496A JP 24308496 A JP24308496 A JP 24308496A JP H1088561 A JPH1088561 A JP H1088561A
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- liquid
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- injected
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- 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.)
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Landscapes
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
- Soil Conditioners And Soil-Stabilizing Materials (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、特に好適には液状
化対策地盤を改良するための薬液注入工法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly preferably relates to a method for injecting a chemical solution for improving the ground against liquefaction.
【０００２】[0002]
【従来の技術】地震による地盤の液状化を防止する工法
の一つとして、液状化対策地盤に改良剤を注入して、そ
の強化を図る薬液注入工法が採用されている。2. Description of the Related Art As one of the methods for preventing the liquefaction of the ground due to an earthquake, a chemical solution injection method for injecting an improving agent into the liquefaction countermeasure ground and strengthening the same is adopted.
【０００３】液状化対策地盤の改良には、浸透性と恒久
性とを兼ね備えた地盤改良剤が必要となる。[0003] Improvement of the ground against liquefaction requires a ground improver having both permeability and durability.
【０００４】従来、恒久性に優れる注入剤として、たと
えば超微粒子セメントが知られている。しかし、この注
入剤は懸濁液であるために、液状化の可能性のある砂地
盤への浸透性に劣り、十分ではない。Heretofore, for example, an ultrafine cement has been known as an injection agent having excellent durability. However, since this injection is a suspension, its infiltration into sandy ground which may be liquefied is poor and not sufficient.
【０００５】一方、地盤の強度向上や止水性の改善のた
めに行われる薬液注入工法においては、公害防止や価格
等の点で水ガラス系の注入剤ものを用いるのが一般的で
ある。この水ガラス系注入剤の多くは、経済性のほか浸
透性に優れるものの、改良強度が低く、かつ止水性が必
ずしも十分でないことに鑑み、本出願人は、特公平２−
３６１５５号公報として、「シリカまたはケイ酸アルカ
リに水酸化アルカリを添加して１〜14日放置・熟成させ
た第１液と、カルシウム系塩溶液からなる第２液とを、
前記添加後１〜14日の間に、注入管内で合流させること
なく地盤内において合流させて、その地盤にxCaO・ySiO
2 ・zH2Oなる結晶を生成させる薬液注入工法」を提案し
た。On the other hand, in the chemical liquid injection method for improving the strength of the ground and the water stoppage, it is common to use a water glass type injection agent in terms of prevention of pollution and cost. Although many of the water glass-based injectables have excellent permeability in addition to economical efficiency, in view of their low improvement strength and insufficient water stopping properties, the applicant of the present invention has reported that
Japanese Patent No. 36155 discloses that "a first solution prepared by adding an alkali hydroxide to silica or alkali silicate and allowed to stand and mature for 1 to 14 days, and a second solution comprising a calcium salt solution,
Between 1 and 14 days after the addition, they are merged in the ground without being merged in the injection pipe, and xCaO.ySiO
2 · zH 2 O becomes liquid injection method to produce a crystal "proposed.
【０００６】[0006]
【発明が解決しようとする課題】この工法は、水ガラス
系改良剤自体が有する経済性、良浸透性等の利点を生か
しつつ地盤の強度を増加させることができるとともに、
セメントと同様の恒久性を確保することができる。According to this method, the strength of the ground can be increased while taking advantage of the economy, good permeability, and the like of the water glass-based improver itself.
Permanence similar to cement can be ensured.
【０００７】しかし、この改良剤（以下「先行改良剤」
という）では、恒久性および強度の点で優れるものの、
均一な浸透性が得難く、初期に浸透した方向に続く改良
剤が流れる傾向があり、結果として１つの注入口から幅
広い範囲に均一に浸透させて改良することが難しい。However, this improving agent (hereinafter referred to as "preceding improving agent")
), Which is excellent in terms of durability and strength,
It is difficult to obtain a uniform permeability, and there is a tendency for the improving agent following the direction of initial penetration to flow, and as a result, it is difficult to uniformly penetrate into a wide range from one injection port to improve.
【０００８】他方、液状化対策地盤の改良に対しては、
１つの注入口から幅広い範囲に均一に浸透させて改良す
ることが特に望まれるところ、従来の先行改良剤では、
前述のとおりこれが困難である。特に、細砂地盤におい
て顕著に問題となる。On the other hand, for the improvement of the ground for liquefaction,
While it is particularly desirable to uniformly penetrate and improve a wide range from one inlet, conventional prior improvers include:
As mentioned above, this is difficult. In particular, it becomes a serious problem in fine sand ground.
【０００９】そこで、本発明の課題は、前記先行改良剤
自体が有する利点、すなわち、所要の恒久性の発現を担
保しながら、より浸透性を高め、特に均一な浸透性を確
保し、広範囲な地盤改良を図ることができるようにする
ことにある。[0009] Therefore, an object of the present invention is to improve the permeability while ensuring the required permanence of the preceding improver itself, that is, to achieve the required permanence, and in particular, to secure uniform permeability, and It is to enable ground improvement.
【００１０】[0010]
【課題を解決するための手段】上記課題を解決した本発
明の薬液注入工法は、シリカまたはケイ酸アルカリに水
酸化アルカリを添加して１〜14日放置・熟成させた第１
液と、カルシウム系塩溶液からなる第２液とを、前記添
加後１〜14日の間に、注入管内で合流させることなく地
盤内において合流させて、その地盤にxCaO・ySiO2 ・zH
2Oなる結晶を生成させる薬液注入工法において、前記第
１液のケイ酸濃度を７．５〜１５．０％とすることを特
徴とするものである。According to the chemical solution injection method of the present invention, which solves the above-mentioned problems, the first method comprises adding alkali hydroxide to silica or alkali silicate, and allowing the mixture to stand for 1 to 14 days and aged.
Liquid and a second liquid composed of a calcium salt solution are allowed to join in the ground without being joined in the injection pipe between 1 and 14 days after the addition, and xCaO.ySiO 2 .zH is added to the ground.
In a chemical liquid injection method for producing 2 O crystals, the concentration of silicic acid in the first liquid is 7.5 to 15.0%.
【００１１】本発明は、特に注入対象が液状化対策地盤
である場合において、その利点が顕著にあらわれる。The advantages of the present invention are remarkable especially when the object to be injected is a liquefaction countermeasure ground.
【００１２】＜本発明の完成に至るまでの基礎的知見＞
ここで、前記公報に開示された技術とともに、本発明の
完成に至るまで本発明者等が得た基礎的な知見を説明す
る。<Basic knowledge leading to completion of the present invention>
Here, along with the technology disclosed in the above-mentioned publication, basic knowledge obtained by the present inventors until the present invention is completed will be described.
【００１３】第１に、ケイ砂またはケイ砂化合物、たと
えば水ガラスとアルカリ金属の水酸化物または炭酸塩と
を反応させると、一般式M20 ・nSiO2( Mは一価アルカリ
金属）であらわされる水溶液であり、一価のアルカリ金
属の水酸化物を加えることによって、ケイ酸をイオン化
し活性を付加した活性化ケイ酸アルカリ（以下活性液と
もいう）が得られるが、その反応後１日以上経過する
と、ケイ酸化合物が所々で分断されてイオン化し、反応
後14日以上経過すると、イオン化したケイ酸が重合して
しまう。First, when silica sand or a silica sand compound, such as water glass, is reacted with an alkali metal hydroxide or carbonate, a general formula M 20 .nSiO 2 (M is a monovalent alkali metal) is obtained. This is an aqueous solution represented by adding a hydroxide of a monovalent alkali metal to obtain an activated alkali silicate (hereinafter also referred to as an active solution) obtained by ionizing silicic acid and adding an activity. After more than one day, the silicic acid compound is fragmented and ionized in some places, and after more than 14 days from the reaction, the ionized silicic acid polymerizes.
【００１４】第２に、前述のようにイオン化された状態
のときに、M20 ・nSiO2 水溶液を地盤中に注入し、その
地盤中の土粒子間でカルシウム等を反応させると、xSiO
2 ・yM'O・zH2O（M'は金属、カルシウムを用いればM'は
Ca）なる結晶が生成し、かつこの結晶生成に伴って従来
一般に用いられている水ガラス系薬液を用いる方法に決
してない優れた恒久性、著しい強度向上および高透水係
数を示す。Second, when the M 20 .nSiO 2 aqueous solution is injected into the ground in the ionized state as described above and calcium and the like are reacted between the soil particles in the ground, xSiO
2 · yM'O · zH 2 O (M 'is a metal, and if calcium is used, M'
Crystals of Ca) are formed, and the resulting crystals exhibit excellent durability, remarkable strength improvement and high water permeability, which are never found in conventional methods using water glass-based chemicals.
【００１５】この反応過程は必ずしも明らかではないけ
れども、次の通りではないかと考えられる。たとえば、
水ガラスと水酸化ナトリウムとを反応させて得た活性溶
液と、塩化カルシウム溶液とを地盤中で反応させる場合
を考えてみると次の通りである。Although this reaction process is not always clear, it is considered that it is as follows. For example,
The following is a description of a case in which an active solution obtained by reacting water glass and sodium hydroxide is reacted with a calcium chloride solution in the ground.
【００１６】（Ｉ）水ガラスと水酸化ナトリウムとの接
触(I) Contact between water glass and sodium hydroxide
【００１７】[0017]
【化１】 Embedded image
【００１８】（II) 上記（Ｉ）による接触に伴う活性化(II) Activation associated with contact according to (I) above
【００１９】[0019]
【化２】 Embedded image
【００２０】すなわち水ガラスがNaOHと反応し、水ガラ
スの結合が所々で分断され、（II)の（Ａ）または
（Ｂ）のイオン状態になる。従来一般の水ガラスがコロ
イド性かつ非イオン性であるのに対して、本発明に係る
活性液は、非コロイド性かつイオン性であるという特別
の挙動状態にある。しかも分子が分断されているので、
分子鎖が短い。この大きさは、0.1mμ〜１μ程度であ
る。That is, the water glass reacts with NaOH, the bond of the water glass is broken at some places, and the ionic state of (II) (A) or (B) is obtained. The active liquid according to the present invention is in a special behavior state in which it is non-colloidal and ionic, whereas conventional water glass is colloidal and non-ionic. Moreover, since the molecules are separated,
The molecular chain is short. This size is about 0.1 μm to 1 μm.
【００２１】かくして得られた活性液が地盤中において
塩化カルシウムと接触すると、xCaO・ySiO2 ・zH2O（た
とえば3CaO・2SiO2 ・3H2O) なる結晶を生成させる。こ
の過程を模式的に図１および図２によって説明すると、
注入管を用いてＢ液（たとえばCaCl2)を注入すると、土
粒子１の周囲にＢ液が吸着される。その後、Ａ液を注入
すると、各土粒子に吸着したＢ液と活性水ガラスが接触
し、そのNa分とＢ液のCa分とが置換反応し、各土粒子
１，１…間において結晶が生成し、これが成長し、各土
粒子１，１間を密に埋める。これによって、薬液注入に
伴う改良効果の恒久性が得られ、さらに地盤全体の強度
向上効果が現れる。The thus obtained active liquid upon contact with calcium chloride in a ground, to produce xCaO · ySiO 2 · zH 2 O ( e.g. 3CaO · 2SiO 2 · 3H 2 O ) becomes crystalline. This process is schematically described with reference to FIGS. 1 and 2.
When the liquid B (for example, CaCl 2 ) is injected using the injection pipe, the liquid B is adsorbed around the soil particles 1. Then, when the liquid A is injected, the liquid B adsorbed on each soil particle comes into contact with the activated water glass, and the Na content and the Ca content of the liquid B undergo a substitution reaction, and crystals are formed between the soil particles 1, 1. It forms and grows, densely filling between the soil particles 1,1. Thereby, the permanent effect of the improvement effect accompanying the injection of the chemical solution is obtained, and the effect of improving the strength of the entire ground appears.
【００２２】＜本発明に係る知見＞しかるに、前述のと
おり、先行改良剤では、超微粒子セメント等より浸透性
に優れ、恒久性と所要の強度を発現することができるも
のの、均一な浸透性が得難く、初期に浸透した方向に続
く改良剤が流れる傾向があり、結果として１つの注入口
から幅広い範囲に均一に浸透させて改良することが難し
い。<Knowledge According to the Present Invention> As described above, the preceding improver is superior in permeability to ultrafine cement or the like, and can exhibit permanence and required strength. It is difficult to obtain, and there is a tendency for the improving agent following the direction of initial penetration to flow, and as a result, it is difficult to uniformly infiltrate a wide range from one injection port to improve.
【００２３】この理由は、先に注入する第１液は、浸透
し易い部分にまず集中的に浸透する傾向があるところ、
続いて注入される第２液と地盤中において接触すると、
瞬間的に反応し、強固に固化し、この固化部分が第２液
の浸透経路を妨げることになり、行き場がなくなった第
２液は弱い部分に向かって逸走することになると考えら
れる。The reason for this is that the first liquid to be injected first tends to permeate intensively into a portion that easily permeates.
When it comes into contact with the second liquid that is subsequently injected in the ground,
It is considered that the second liquid reacts instantaneously and solidifies firmly, and the solidified portion hinders the permeation path of the second liquid, and the second liquid having nowhere to go escapes toward the weak portion.
【００２４】そこで、本発明においては、第１液のSiO2
濃度を、７．５〜１５．０％の範囲内に調整することと
した。これにより、後述の実施例で示すように、浸透距
離を長くでき、かつ改良範囲が均一となる。他方、第１
液のSiO2濃度が低くなることにより改良強度（一軸圧縮
強度）が低下する傾向がみられるが、少なくとも第１液
のSiO2濃度が７．５％のとき０．５kg／cm2 の強度を示
すので、さほど改良強度が要求されないものの改良範囲
が広くかつ均一であることが望まれる地盤、たとえば液
状化対策地盤に対しては、きわめて有効な改良剤とな
る。Therefore, in the present invention, the first liquid SiO 2
The concentration was adjusted within the range of 7.5 to 15.0%. As a result, as shown in the examples described later, the penetration distance can be increased, and the improvement range becomes uniform. On the other hand, the first
Although improved strength by the SiO 2 concentration in the liquid decreases (uniaxial compressive strength) tends to decrease, the strength of 0.5 kg / cm 2 when SiO 2 concentration of at least the first liquid is 7.5% As shown in the figure, it is a very effective improver for a ground that does not require much improvement strength but requires a wide and uniform improvement range, for example, a liquefaction countermeasure ground.
【００２５】[0025]
【発明の実施の形態】以下、本発明の実施の形態を、図
面を参照しながら、具体的に説明する。本発明において
は、一般式M20/nSiO2(ここでM は一価アルカリ金属) の
水溶液であり、一価のアルカリ金属水酸化物を加えるこ
とによって、ケイ酸をイオン化し活性を付加した活性化
ケイ酸アルカリが基本となる。ここで、アルカリ金属と
しては、カリウム、ナトリウム、リチウム等が用いられ
る。他の高位アルカリを用いることもできるけれども、
高価であることや、放射線を発するなどの点から適当で
ない。Embodiments of the present invention will be specifically described below with reference to the drawings. In the present invention, an aqueous solution of the general formula M 20 / nSiO 2 (where M is a monovalent alkali metal) is added with a monovalent alkali metal hydroxide to ionize silicic acid and add activity. Activated alkali silicates are the basis. Here, potassium, sodium, lithium and the like are used as the alkali metal. Although other higher alkalis can be used,
It is not suitable in terms of being expensive and emitting radiation.
【００２６】活性液を得る場合、シリカをそのまま水酸
化アルカリたとえばNaOH・KOH ・LiOHに溶解するか、市
販の活性化ケイ酸アルカリ、たとえば水ガラスと水酸化
アルカリを反応させればよい。シリカとしては、熱分解
法シリカ、珪藻土、ゲーズまたはシリカエアロゲルを用
いることができる。水酸化アルカリとしては現実的なも
のは水酸化ナトリウムである。In order to obtain an active solution, silica may be dissolved as it is in an alkali hydroxide such as NaOH.KOH.LiOH, or a commercially available activated alkali silicate such as water glass may be reacted with alkali hydroxide. As the silica, pyrogenic silica, diatomaceous earth, gaze or silica airgel can be used. A practical alkali hydroxide is sodium hydroxide.
【００２７】現実的に、水ガラスは地盤改良用等に多く
用いられ、かつ安価で市販されているので、この市販品
と水酸化アルカリとを反応させて活性液を作るのが好適
である。In practice, water glass is widely used for ground improvement and the like and is commercially available at a low cost. Therefore, it is preferable to react this commercial product with an alkali hydroxide to prepare an active liquid.
【００２８】かくして得られる活性液は、その製造後１
〜14日の間に使用することが必要である。ここで、目標
の改良強度を得るためには、可使時間を１〜14日の間と
する必要がある。特に好ましいのは、１〜７日である。
この可使時間が規定されるのは、分子鎖の切断に最低24
時間要し、また14日を超えると、再結合が起こるためで
あると考えられる。同様のことは、水ガラスをKOH およ
びLiOHに反応させてもみられる。The active solution thus obtained is obtained after the preparation.
It is necessary to use between ~ 14 days. Here, in order to obtain the target improvement strength, the pot life needs to be between 1 and 14 days. Particularly preferred is 1 to 7 days.
This working time is defined as a minimum of 24
It is thought that it takes time, and if it exceeds 14 days, recombination occurs. The same can be seen by reacting water glass with KOH and LiOH.
【００２９】地盤内において結晶を確実に生成させるた
めには、活性液中に非コロイド性のシリカが60％、特に
80％以上含まれているのが好ましい。活性液の粘度は、
これが土粒子間に好適に浸透するためには、５〜50cps
、特に20〜30cps が望ましい。必要ならば、粘度調整
に水を用いてもよい。To ensure that crystals are formed in the ground, 60% of non-colloidal silica is contained in the active solution, especially
It is preferable that the content is 80% or more. The viscosity of the active liquid is
In order for this to penetrate properly between soil particles, 5-50 cps
In particular, 20-30 cps is desirable. If necessary, water may be used for adjusting the viscosity.
【００３０】このような活性液と反応する反応液として
は、代表的なものはカルシウム塩溶液である。このカル
シウム塩としては、塩化カルシウム、蟻酸カルシウム、
酢酸カルシウム、プロピオン酸カルシウム、あるいはこ
れらの混合物等を挙げることができる。薬液全体として
のCaO/SiO2比は、0.3 〜1.5 が望ましい。塩化カルシウ
ムはその中でも溶解性に優れ、安価であるなどの点で好
適である。A typical reaction solution that reacts with such an active solution is a calcium salt solution. This calcium salt includes calcium chloride, calcium formate,
Examples thereof include calcium acetate, calcium propionate, and mixtures thereof. The CaO / SiO 2 ratio of the whole chemical is desirably 0.3 to 1.5. Among them, calcium chloride is preferable because it has excellent solubility and is inexpensive.
【００３１】実験室的に活性液（第１液）と反応液（第
２液）とをビーカ内で反応させても結晶は生成しないか
十分に生成しない。また、注入管の手前で、あるいは注
入管内で両液を合流させても、両液の反応性が高いので
ゲル化物が生成し、これを地盤中に注入することになる
ので、結晶が生成せず、通常の水ガラス系薬液を注入す
る場合と同様で、恒久的な強度の高い固結体を造成する
ことはできない。これに対して、両液を分離的に注入
し、地盤内において初めて接触させると、目的の良好な
結晶を生成させることができる。In the laboratory, even if the active liquid (first liquid) and the reaction liquid (second liquid) are reacted in a beaker, crystals are not formed or are not sufficiently formed. Also, even if the two liquids are merged before or in the injection pipe, a gel is generated because the two liquids are highly reactive, and this is injected into the ground. In the same manner as in the case of injecting a normal water glass-based chemical, it is not possible to form a solid body having high permanent strength. On the other hand, when the two liquids are separately injected and brought into contact with each other for the first time in the ground, it is possible to generate a desired crystal.
【００３２】かかる分離注入法の具体例としては、図３
のように、注入管３を用いて、反応液（Ａ液）をあるス
テップで注入し、次いで同一ステップで、好ましくは３
０分以内に活性液（Ｂ液）を注入することにより行う。
また必要ならば、さらに同一ステップでＡ液→Ｂ液（→
Ａ液）の注入を繰り返してもよい。かかる同一ステップ
の施工が終わったならば、ステップアップしてＡ液→Ｂ
液の注入を行う。図４のように、２本の注入管３Ａ，３
Ｂを並設して両液を合流させるようにしてもよい。図５
のように、同一注入管３Ｃを用いて、異なった注入位置
の注入口から各液を注入してもよい。Ｐはパッカーであ
る。FIG. 3 shows a specific example of such a separate injection method.
The reaction solution (Solution A) is injected at a certain step by using the injection tube 3 as shown in FIG.
This is performed by injecting the active solution (solution B) within 0 minutes.
Also, if necessary, further liquid A → liquid B (→
The injection of the (A liquid) may be repeated. When the construction of the same step is completed, step up to solution A → B
Inject the liquid. As shown in FIG. 4, two injection tubes 3A, 3
B may be provided side by side to join both liquids. FIG.
As described above, each liquid may be injected from injection ports at different injection positions using the same injection tube 3C. P is a packer.
【００３３】活性液と反応液を時間差をもって注入する
場合、反応液を先行させてもよいが、一般に反応液の粘
性が低いので、続く粘度の高い活性液に押されて土粒子
間から逸失してしまうことがある。これに対して、粘度
の高い活性液を先行させると、この活性液が土粒子間に
好適に残存し、後行の反応液によって押し出されること
はない。その結果、強度の高い地盤を形成することがで
きる。When the active solution and the reaction solution are injected with a time lag, the reaction solution may precede the reaction solution. However, since the viscosity of the reaction solution is generally low, the reaction solution is pushed by the subsequent high viscosity active solution and is lost from between the soil particles. Sometimes. On the other hand, when an active liquid having a high viscosity precedes, the active liquid suitably remains between the soil particles and is not extruded by the subsequent reaction liquid. As a result, a ground with high strength can be formed.
【００３４】反応液を先行注入する場合の変形例とし
て、初めに塩化カルシウム溶液を注入した後、水酸化ナ
トリウムを注入して、土粒子間に水酸化カルシウムの沈
殿を生成させ、しかる後に活性液を注入することも有効
な方法である。反応式は（３）式、（４）式であらわさ
れる。As a modification of the case where the reaction solution is previously injected, a calcium chloride solution is first injected, and then sodium hydroxide is injected to form a precipitate of calcium hydroxide between the soil particles, and thereafter, the active solution is injected. Is also an effective method. The reaction formula is represented by formulas (3) and (4).
【００３５】[0035]
【化３】 Embedded image
【００３６】（３）式の反応はCa(OH)2 の沈殿を生じさ
せる反応であるから活性液により土粒子間から押し出さ
れることはない。この方法は、注入口のごく近傍にのみ
Ca(OH)2 の沈殿を予め生成させておくことにより、未反
応の活性液を残さない目的で、活性液とCaCl2 等の反応
液との主反応の補助的方法として有効である。Since the reaction of the formula (3) is a reaction that causes precipitation of Ca (OH) 2 , it is not pushed out from between the soil particles by the active liquid. This method should only be used near the inlet
The formation of Ca (OH) 2 precipitate in advance is effective as an auxiliary method for the main reaction between the active solution and a reaction solution such as CaCl 2 for the purpose of not leaving unreacted active solution.
【００３７】また、活性液と反応液との注入順序は、荒
い層では活性液、中砂層は反応液、地下水の多くある地
盤では活性液をそれぞれ先行させるのが好ましい。The order of injection of the active liquid and the reaction liquid is preferably such that the active liquid precedes the rough layer, the reaction liquid precedes the medium sand layer, and the active liquid precedes the ground with a lot of groundwater.
【００３８】ところで、活性液は、常温のものを使用す
る場合のほか、40℃以上に加温し、塩化カルシウム等の
反応剤の溶解量を増し、これを注入すると、地中に注入
された時点で液温が下がるので過飽和な状態が生じ、こ
れを利用して活性液と反応し易い状態をつくり出すこと
も有効な方法である。By the way, in addition to the case where the active solution is used at room temperature, the active solution is heated to 40 ° C. or higher to increase the amount of the reactant such as calcium chloride dissolved therein, and is injected into the ground when injected. Since the liquid temperature drops at that point, a supersaturated state occurs, and it is also an effective method to use this to create a state that easily reacts with the active liquid.
【００３９】[0039]
【実施例】以下に実施例を示し、本発明の効果を明らか
にする。 〔実施例１〕Na20／SiO2のモル比３．４の水ガラス(SiO
2:２９．０１％、H20:６１．５２％、Na20：９．４７
％) の市販品２５０リットルと４８％のNaOHを３０％と
したもの８２リットルとを反応させ、３６時間放置し
た。その後、これをSiO2濃度調整のために、水で希釈し
て活性液を得た。他方、２水塩化カルシウム７５kgを１
０７リットルの水に溶解し反応液を得た。その後、シル
ト粘土分が１５％含有する砂を充填したカラムに両液を
１：１の割合の量で、かつ注入の順序を決めて、他方の
液を先の液の注入後１５分後に注入し、その改良浸透距
離と強度試験結果を表１および図６に示す。EXAMPLES Examples will be shown below to clarify the effects of the present invention. Example 1 Water glass (SiO 2) having a molar ratio of Na 2 0 / SiO 2 of 3.4
2: 29.01%, H 2 0 : 61.52%, Na 2 0: 9.47
%) And 82 liters of 30% 48% NaOH were allowed to react and left for 36 hours. Thereafter, this was diluted with water to adjust the concentration of SiO 2 to obtain an active solution. On the other hand, 75 kg of dihydrate calcium chloride
The reaction solution was obtained by dissolving in 07 L of water. Thereafter, both liquids were injected into a column packed with sand containing 15% silt clay in a ratio of 1: 1 and the injection order was determined, and the other liquid was injected 15 minutes after the injection of the previous liquid. The results of the improved penetration distance and the strength test are shown in Table 1 and FIG.
【００４０】[0040]
【表１】 [Table 1]
【００４１】表１から明らかなように、活性液（第１
液）のシリカ濃度が低くなるほど、浸透距離は飛躍的に
長くなる半面、強度はシリカ濃度に比例して低下するこ
とが判った。液状化対策地盤においては、改良強度とし
て０．５kg／cm2 以上あればよく、浸透距離が優先され
るので、第１液のケイ酸濃度は７．５〜１１．５％の範
囲がより好ましいことも、表１および図６により判る。As is clear from Table 1, the active solution (first
It was found that the lower the silica concentration of the liquid was, the longer the permeation distance was dramatically increased, but the lower the strength was in proportion to the silica concentration. In the liquefaction countermeasure ground, the improvement strength should be 0.5 kg / cm 2 or more, and the permeation distance is prioritized. Therefore, the silicic acid concentration of the first liquid is more preferably in the range of 7.5 to 11.5%. This can also be seen from Table 1 and FIG.
【００４２】〔実施例２〕液状化対策地盤を想定し、砂
を充填した大型モールド（直径１０００mm×長さ１００
０mm) に、SiO2濃度を数種類変えた活性液と反応液を注
入した。このときの浸透固結形状を図７に示す。図７に
よれば、活性液のSiO2濃度が１６．５％の場合は、固結
形状が歪むのに対し、SiO2濃度が１０．０％の場合は固
結形状が球状を呈する。このことは、第１液のケイ酸濃
度が低くなると、良浸透性を示すことを意味し、液状化
対策地盤には第１液のケイ酸濃度を低くする必要がある
ことが判る。Example 2 A large mold filled with sand (diameter 1000 mm × length 100
(0 mm), an active solution and a reaction solution in which several kinds of SiO 2 concentrations were changed were injected. FIG. 7 shows the penetration and consolidation shape at this time. According to FIG. 7, when the SiO 2 concentration of the active liquid is 16.5%, the consolidation shape is distorted, whereas when the SiO 2 concentration is 10.0%, the consolidation shape exhibits a spherical shape. This means that when the silicic acid concentration of the first liquid is low, good permeability is exhibited, indicating that it is necessary to lower the silicic acid concentration of the first liquid in the liquefaction countermeasure ground.
【００４３】[0043]
【発明の効果】以上のとおり、本発明によれば、先行改
良剤自体が有する利点、すなわち、所要の恒久性の発現
を担保しながら、より浸透性を高め、特に均一な浸透性
を確保し、広範囲な地盤改良を図ることができる。特に
液状化対策地盤に対して有効なものである。As described above, according to the present invention, it is possible to further increase the permeability while securing the advantage of the preceding improver itself, that is, the required permanence, and to secure particularly uniform permeability. , Wide ground improvement can be achieved. It is particularly effective for liquefaction countermeasures.
【図１】本発明に係わる結晶生成過程の説明図である。FIG. 1 is an explanatory diagram of a crystal formation process according to the present invention.
【図２】本発明に係わる結晶生成過程の説明図である。FIG. 2 is an explanatory diagram of a crystal formation process according to the present invention.
【図３】分離注入法（地盤中での合流法）を示す概略図
である。FIG. 3 is a schematic view showing a separation injection method (a merging method in the ground).
【図４】分離注入法（地盤中での合流法）を示す概略図
である。FIG. 4 is a schematic view showing a separation injection method (a merging method in the ground).
【図５】分離注入法（地盤中での合流法）を示す概略図
である。FIG. 5 is a schematic diagram showing a separation injection method (a merging method in the ground).
【図６】実施例１におけるケイ酸濃度と浸透距離および
一軸圧縮強度との相関の実験結果を示すグラフである。FIG. 6 is a graph showing an experimental result of a correlation between a silicic acid concentration, a permeation distance, and a uniaxial compressive strength in Example 1.
【図７】実施例２における改良体の形状に関する実験結
果を示す説明図である。FIG. 7 is an explanatory diagram showing an experimental result regarding a shape of an improved body in Example 2.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 飯尾 正俊 東京都千代田区九段北４丁目２番35号 ラ イト工業株式会社内 (72)発明者 柳沢 崇 東京都千代田区九段北４丁目２番35号 ラ イト工業株式会社内 (72)発明者 ダニエル グヴァノ フランス国 92110 クリシ アレガンベ ッタ １ ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masatoshi Iio 4-35, Kudankita, Chiyoda-ku, Tokyo Light Industry Co., Ltd. (72) Inventor Takashi Yanagisawa 4-35, Kudankita, Chiyoda-ku, Tokyo No. Light Industry Co., Ltd. (72) Inventor Daniel Gvano 92110 Chrissi Alleganbetta 1 France
Claims (2)
カリを添加して１〜14日放置・熟成させた第１液と、カ
ルシウム系塩溶液からなる第２液とを、前記添加後１〜
14日の間に、注入管内で合流させることなく地盤内にお
いて合流させて、その地盤にxCaO・ySiO2 ・zH2Oなる結
晶を生成させる薬液注入工法において、 前記第１液のケイ酸濃度を７．５〜１５．０％とするこ
とを特徴とする薬液注入工法。1. A first liquid which is added to an alkali hydroxide to silica or alkali silicate and left and aged for 1 to 14 days, and a second liquid composed of a calcium-based salt solution are added 1 to 3 after the addition.
During the 14 days, it is combined in the ground without merging with the injection tube, the liquid injection method to produce xCaO · ySiO 2 · zH 2 O becomes crystalline on the ground, the silicate concentration of the first liquid A chemical solution injection method characterized by being 7.5 to 15.0%.
記載の薬液注入工法。2. The liquefaction countermeasure ground to be injected.
Chemical solution injection method described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24308496A JP3431770B2 (en) | 1996-09-13 | 1996-09-13 | Chemical injection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24308496A JP3431770B2 (en) | 1996-09-13 | 1996-09-13 | Chemical injection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1088561A true JPH1088561A (en) | 1998-04-07 |
| JP3431770B2 JP3431770B2 (en) | 2003-07-28 |
Family
ID=17098550
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24308496A Expired - Fee Related JP3431770B2 (en) | 1996-09-13 | 1996-09-13 | Chemical injection method |
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| Country | Link |
|---|---|
| JP (1) | JP3431770B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010150431A (en) * | 2008-12-25 | 2010-07-08 | Denki Kagaku Kogyo Kk | Grouting material and grout work using the same |
-
1996
- 1996-09-13 JP JP24308496A patent/JP3431770B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010150431A (en) * | 2008-12-25 | 2010-07-08 | Denki Kagaku Kogyo Kk | Grouting material and grout work using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3431770B2 (en) | 2003-07-28 |
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