JP4507355B2 - Ground hardening method - Google Patents

Ground hardening method Download PDF

Info

Publication number
JP4507355B2
JP4507355B2 JP2000170915A JP2000170915A JP4507355B2 JP 4507355 B2 JP4507355 B2 JP 4507355B2 JP 2000170915 A JP2000170915 A JP 2000170915A JP 2000170915 A JP2000170915 A JP 2000170915A JP 4507355 B2 JP4507355 B2 JP 4507355B2
Authority
JP
Japan
Prior art keywords
ground
amount
water glass
aqueous solution
dihydrogen phosphate
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.)
Expired - Lifetime
Application number
JP2000170915A
Other languages
Japanese (ja)
Other versions
JP2001348572A (en
Inventor
豊光 山田
洋 加藤
Original Assignee
名古屋カレット株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 名古屋カレット株式会社 filed Critical 名古屋カレット株式会社
Priority to JP2000170915A priority Critical patent/JP4507355B2/en
Publication of JP2001348572A publication Critical patent/JP2001348572A/en
Application granted granted Critical
Publication of JP4507355B2 publication Critical patent/JP4507355B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/24Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing alkyl, ammonium or metal silicates; containing silica sols
    • C04B28/26Silicates of the alkali metals
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2103/00Function or property of ingredients for mortars, concrete or artificial stone
    • C04B2103/0004Compounds chosen for the nature of their cations
    • C04B2103/0021Compounds of elements having a valency of 3
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474Uses not provided for elsewhere in C04B2111/00
    • C04B2111/00732Uses not provided for elsewhere in C04B2111/00 for soil stabilisation

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Soil Conditioners And Soil-Stabilizing Materials (AREA)
  • Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)

Description

【0001】
【発明の属する技術分野】
本発明は地盤硬化法に関する。地盤の強化及び止水を図るため、地盤中に薬液を混合注入して該地盤を硬化させることが行なわれる。本発明はかかる地盤硬化法の改良に関する。
【0002】
【従来の技術】
従来、上記のような地盤硬化法として一般に、地盤中に酸性シリカゾルとアルカリ剤の水溶液とを混合注入することが行なわれている。この場合の酸性シリカゾルは水ガラスに通常は硫酸を加えてpH2未満とした水分散液であり、またアルカリ剤として通常は水酸化マグネシウムや水酸化カルシウム等のアルカリ土類金属の水酸化物が使用されている(特公平3−24515)。しかし、この従来法には、劇物である硫酸を多量に使用するため、その取扱いが誠に厄介であり、また結果として好ましくない硫酸根を地盤中へ多量に持ち込むことになるという問題がある。しかもその上、水ガラスに硫酸を加えてpH2未満とした強酸性のシリカゾルに、水酸化マグネシウムや水酸化カルシウム等の強アルカリ剤の水溶液を混合するため、混合後における薬液全体のpHが振れ易く、地盤中に注入した水ガラスのゲル化に要する時間(ゲルタイム)が大きく乱れるという問題がある。
【0003】
水ガラスを用いる地盤硬化法では、地盤中に注入した水ガラスのゲル化を利用して該地盤を硬化させる。この場合、水ガラスのゲルタイムは、該水ガラスのSiO2濃度や硬化温度にもよるが、pHにより大きく影響されることが知られている。水ガラスに硬化剤として例えば硫酸を徐々に加え、そのpHを順次下げると、該水ガラスは概して、pH6.0〜9.0において数秒〜数十秒でゲル化する所謂瞬結状態になり、またpH4.5〜6.0未満において数分〜数十分でゲル化する所謂中結状態になり、更にpH3.0〜4.5未満において数時間〜数十時間でゲル化する所謂長結状態になり、そしてpH2未満では安定な酸性シリカゾルになる。水ガラスのゲルタイムは、pH6.0〜9.0近辺の中性領域よりも低いpH領域において、pHとの関係で対数的に長くなり、pH2未満では安定な酸性シリカゾルになるのである。
【0004】
前記した従来法のように、地盤中に注入した薬液全体のpHが振れると、地盤中に酸性シリカゾルとして注入した水ガラスのゲルタイムが大きく乱れ、地盤硬化に要する時間が乱れて、硬化作業の前後に予定されている他の作業の進行に支障をきたすのである。
【0005】
地盤中に注入した薬液全体のpHが振れるのを改善するため、アルカリ剤と共に調整剤として例えばヘキサメタリン酸アルカリ金属塩を用いることも行なわれている(特公平3−24515、特公平4−56074)。しかし、この従来法でも、単に強アルカリ剤の水溶液を用いる前記した従来法に比べれば、pHの振れを相応に改善できるものの、その改善程度が不充分という問題があり、また依然として、水ガラスに硫酸を加えてpH2未満とした強酸性のシリカゾルを用いることによる前記した従来法と同様の問題がある。
【0006】
【発明が解決しようとする課題】
本発明が解決しようとする課題は、従来法では、1)水ガラスの酸性シリカゾルを調製するのに劇物である硫酸を多量に使用するため、その取扱いが誠に厄介である点、また2)結果として好ましくない硫酸根を地盤中へ多量に持ち込むことになる点、更に3)地盤中に注入した薬液全体のpHが振れ易く、酸性シリカゾルとして注入した水ガラスのゲルタイムが乱れる点、以上の3点である。
【0007】
【課題を解決するための手段】
上記の課題を解決する本発明は、地盤中に薬液を混合注入して該地盤を硬化させる方法において、薬液として水ガラスの水溶液と硬化剤の水溶液とを用い、且つ硬化剤として、水ガラスの水溶液のpHを6.0〜9.0に調整する量の無機酸と、地盤中に注入する薬液全体のpHを4.5〜6.0未満に調整する量のリン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムとを用いることを特徴とする地盤硬化法に係る。
また本発明は、地盤中に薬液を混合注入して該地盤を硬化させる方法において、薬液として水ガラスの水溶液と硬化剤の水溶液とを用い、且つ硬化剤として、水ガラスの水溶液のpHを6.0〜9.0に調整する量の無機酸及びポリ塩化アルミニウムと、地盤中に注入する薬液全体のpHを4.5〜6.0未満に調整する量のリン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムとを用いることを特徴とする地盤硬化法に係る。
【0008】
本発明では、水ガラスの水溶液(A液)と、硬化剤の水溶液(B液)とを、地盤中に混合注入する。混合注入は、1)双方を注入直前に混合しておいてから注入する方法(1ショット法)、2)双方を途中混合しながら注入する方法(1.5ショット法)、3)双方を注入直後に混合する方法(2ショット法)のいずれによってもよい。一般に、上記1)の方法では1本の注入管を用い、また上記2)の方法では1本のY字注入管を用い、更に上記3)の方法では2本の注入管或は二重の注入管を用いる。
【0009】
A液としての水ガラスの水溶液の調製に用いる水ガラスは、市販されている任意の水ガラスを使用できる。通常はJIS3号の水ガラスを使用するが、Na2O1モルに対してSiO2を3.6〜4.5モルの割合で含有するSiO2高モル比の水ガラスも使用できる。
【0010】
B液としての硬化剤の水溶液の調製に用いる硬化剤は、1)無機酸と、緩衝用酸性剤との組合わせ、2)無機酸と、無機酸のアルミニウム塩と、緩衝用酸性剤との組合わせ、以上の2種の組合わせである。無機酸としては、塩酸、硝酸、硫酸等を使用できるが、通常は経済的な硫酸を使用する。また緩衝用酸性剤としては、リン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムを使用する。これらは優れたpH緩衝能を有する。更に無機酸のアルミニウム塩としては、ポリ塩化アルミニウムを使用する。硬化剤として無機酸と共にポリ塩化アルミニウムを用いる場合には、強固で耐久性の高いアルミニウムシリケートが形成される。
【0011】
本発明では、地盤中に注入する一方の薬液(A液)として水ガラスの水溶液を調製し、また他方の薬液(B液)として硬化剤の水溶液を調製して、これらを所定割合で地盤中に混合注入する。A液とB液の組成や濃度、更には双方の混合注入割合を調節することによって、地盤中に混合注入する薬液全体のpHを制御でき、したがって地盤中に注入した水ガラスのゲルタイムを制御できる。
【0012】
地盤硬化作業の現場では一般に、地盤硬化作業それ自体を所期の通りに行なって、前後の作業を円滑に進行させるため、地盤中に注入した水ガラスを中結させる場合が多い。地盤中に注入した水ガラスを数分〜数十分でゲル化させる中結では、前記したように、地盤中に注入する薬液全体のpHを4.5〜6.0未満に調整する必要がある。この場合、無機酸として通常用いる硫酸の使用量をできるだけ少なくし、よって地盤中に持ち込まれることとなる硫酸根の量をできるだけ少なくするため、本発明では、無機酸、或は無機酸及びポリ塩化アルミニウムの使用量は、水ガラスの水溶液のpHを6.0〜9.0に調整する量(言い替えれば水ガラスの水溶液をほぼ中和する量)とする。また地盤中に注入した水ガラスを数分〜数十分でゲル化させるため、本発明では、リン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムの使用量は、地盤中に注入する薬液全体のpHを4.5〜6.0未満に調整する量とする。
【0013】
本発明では、地盤中に注入する薬液として、従来法のように、水ガラスに硫酸を加えてpH2未満とした強酸性のシリカゾルを使用しないため、無機酸として硫酸を用いる場合においても、硫酸の使用量を著しく低減でき、また地盤中に持ち込まれることとなる硫酸根の量を著しく低減できる。その上、従来法のように、水酸化マグネシウムや水酸化カルシウム等の強アルカリ剤を使用せず、前記したようにリン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムを使用するため、そのpH緩衝能によって、資材として用いる水ガラスや硫酸に相応のバラツキがあっても、地盤中に注入する薬液全体のpHの振れを小さくでき、よって地盤中に注入した水ガラスのゲルタイムを所期の通りに制御できる。
【0014】
【発明の実施の形態】
本発明の実施形態としては、下記の1)〜7)が挙げられる。
1)JIS3号の水ガラス70リットルに、水を加えて、水ガラスの水溶液200リットルを調製する(A液)。別に、78%硫酸9リットルに、50%リン酸2水素マグネシウム18kg及び水を加えて、硬化剤の水溶液200リットルを調製する(B液)。A液とB液とを、等量割合で地盤中に混合注入する方法。この場合、硫酸の使用量は水ガラスの水溶液のpHを8.0に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.7に調整する量に相当していて、ゲルタイムは2.5分である。
【0015】
2)JIS3号の水ガラス70リットルに、水を加えて、水ガラスの水溶液200リットルを調製する(A液)。別に、78%硫酸9.5リットルに、50%リン酸2水素マグネシウム18kg及び水を加えて、硬化剤の水溶液200リットルを調製する(B液)。A液とB液とを、等量割合で地盤中に混合注入する方法。この場合、硫酸の使用量は水ガラスの水溶液のpHを7.5に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.3に調整する量に相当していて、ゲルタイムは7.5分である。
【0016】
3)JIS3号の水ガラス70リットルに、水を加えて、水ガラスの水溶液200リットルを調製する(A液)。別に、78%硫酸10リットルに、50%リン酸2水素マグネシウム10kg及び水を加えて、硬化剤の水溶液200リットルを調製する(B液)。A液とB液とを、等量割合で地盤中に混合注入する方法。この場合、硫酸の使用量は水ガラスの水溶液のpHを7.0に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを4.9に調整する量に相当していて、ゲルタイムは13分である。
【0017】
4)JIS3号の水ガラス70リットルに、水を加えて、水ガラスの水溶液200リットルを調製する(A液)。別に、78%硫酸8.5リットルに、10%ポリ塩化アルミニウム6kg、50%リン酸2水素マグネシウム15kg及び水を加えて、硬化剤の水溶液200リットルを調製する(B液)。A液とB液とを、等量割合で地盤中に混合注入する方法。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを8.0に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.7に調整する量に相当していて、ゲルタイムは2分である。
【0018】
5)JIS3号の水ガラス70リットルに、水を加えて、水ガラスの水溶液200リットルを調製する(A液)。別に、78%硫酸9リットルに、10%ポリ塩化アルミニウム6kg、50%リン酸2水素マグネシウム10kg及び水を加えて、硬化剤の水溶液200リットルを調製する(B液)。A液とB液とを、等量割合で地盤中に混合注入する方法。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを7.5に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.4に調整する量に相当していて、ゲルタイムは5分である。
【0019】
6)JIS3号の水ガラス70リットルに、水を加えて、水ガラスの水溶液200リットルを調製する(A液)。別に、78%硫酸8.5リットルに、10%ポリ塩化アルミニウム6kg、リン酸2水素ナトリウム2水和物18kg及び水を加えて、硬化剤の水溶液200リットルを調製する(B液)。A液とB液とを、等量割合で地盤中に混合注入する方法。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを8.0に調整する量に相当し、またリン酸2水素ナトリウム2水和物の使用量は地盤中に混合注入する薬液全体のpHを5.9に調整する量に相当していて、ゲルタイムは1.6分である。
【0020】
7)JIS3号の水ガラス70リットルに、水を加えて、水ガラスの水溶液200リットルを調製する(A液)。別に、78%硫酸9リットルに、10%ポリ塩化アルミニウム6kg、リン酸2水素ナトリウム2水和物15kg及び水を加えて、硬化剤の水溶液200リットルを調製する(B液)。A液とB液とを、等量割合で地盤中に混合注入する方法。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを7.5に調整する量に相当し、またリン酸2水素ナトリウム2水和物の使用量は地盤中に混合注入する薬液全体のpHを5.8に調整する量に相当していて、ゲルタイムは2.1分である。
【0021】
【実施例】
試験区分1
実施例1
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸9mlに、50%リン酸2水素マグネシウム18g及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。この場合、硫酸の使用量は水ガラスの水溶液のpHを8.0に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.7に調整する量に相当していて、ゲルタイムは2.5分であった。
【0022】
実施例2
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸9.5mlに、50%リン酸2水素マグネシウム18g及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。この場合、硫酸の使用量は水ガラスの水溶液のpHを7.5に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.3に調整する量に相当していて、ゲルタイムは7.5分であった。
【0023】
実施例3
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸10mlに、50%リン酸2水素マグネシウム10g及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。この場合、硫酸の使用量は水ガラスの水溶液のpHを7.0に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを4.9に調整する量に相当していて、ゲルタイムは13分であった。
【0024】
実施例4
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸8.5mlに、10%ポリ塩化アルミニウム6g、50%リン酸2水素マグネシウム15g及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを8.0に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.7に調整する量に相当していて、ゲルタイムは2分であった。
【0025】
実施例5
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸9mlに、10%ポリ塩化アルミニウム6g、50%リン酸2水素マグネシウム10g及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを7.5に調整する量に相当し、またリン酸2水素マグネシウムの使用量は地盤中に混合注入する薬液全体のpHを5.4に調整する量に相当していて、ゲルタイムは5分であった。
【0026】
実施例6
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸8.5mlに、10%ポリ塩化アルミニウム6g、リン酸2水素ナトリウム2水和物18g及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを8.0に調整する量に相当し、またリン酸2水素ナトリウム2水和物の使用量は地盤中に混合注入する薬液全体のpHを5.9に調整する量に相当していて、ゲルタイムは1.6分であった。
【0027】
実施例7
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸9mlに、10%ポリ塩化アルミニウム6g、リン酸2水素ナトリウム2水和物15g及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。この場合、硫酸及びポリ塩化アルミニウムの使用量は水ガラスの水溶液のpHを7.5に調整する量に相当し、またリン酸2水素ナトリウム2水和物の使用量は地盤中に混合注入する薬液全体のpHを5.8に調整する量に相当していて、ゲルタイムは2.1分であった。
【0028】
試験区分2
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸Xmlに、50%リン酸2水素マグネシウムYg及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。上記のXとYとを変え、そのときの薬液のpHを求めて図1に示し、またゲルタイム(分)を求めて図2に示した。
【0029】
図1は、横軸に50%リン酸2水素マグネシウムの添加量Y(g)を、また縦軸に薬液のpHを目盛り、78%硫酸の添加量X(ml)毎に、YとpHとの関係を示している。図2は、横軸に50%リン酸2水素マグネシウムの添加量Y(g)を、また縦軸にゲルタイム(分)を目盛り、78%硫酸の添加量X(ml)毎に、Yとゲルタイム(分)との関係を片対数で示している。図1及び図2中、1は78%硫酸の添加量Xが9mlの場合、2は9.5mlの場合、3は10mlの場合である。図1及び図2の結果からも明らかなように、本発明によると、地盤中に注入した水ガラスのゲルタイムを確実に制御できる。
【0030】
試験区分3
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸Xmlに、10%ポリ塩化アルミニウム水溶液6g、50%リン酸2水素マグネシウムYg及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。上記のXとYとを変え、そのときの薬液のpHを求めて図3に示し、またゲルタイム(分)を求めて図4に示した。
【0031】
図3は、横軸に50%リン酸2水素マグネシウムの添加量Y(g)を、また縦軸に薬液のpHを目盛り、78%硫酸の添加量X(ml)毎に、YとpHとの関係を示している。図4は、横軸に50%リン酸2水素マグネシウムの添加量Y(g)を、また縦軸にゲルタイム(分)を目盛り、78%硫酸の添加量X(ml)毎に、Yとゲルタイム(分)との関係を片対数で示している。図3及び図4中、4は78%硫酸の添加量Xが8mlの場合、5は8.5mlの場合、6は9mlの場合である。図3及び図4の結果からも明らかなように、本発明によると、地盤中に注入した水ガラスのゲルタイムを確実に制御できる。
【0032】
試験区分4
JIS3号の水ガラス70mlに、水を加えて、水ガラスの水溶液200mlを調製した(A液)。別に、78%硫酸Xmlに、10%ポリ塩化アルミニウム6g、リン酸2水素ナトリウム2水和物Yg及び水を加えて、硬化剤の水溶液200mlを調製した(B液)。そしてA液とB液とを、等量割合で混合した。上記のXとYとを変え、そのときの薬液のpHを求めて図3に示し、またゲルタイム(分)を求めて図4に示した。
【0033】
図5は、横軸にリン酸2水素ナトリウム2水和物の添加量Y(g)を、また縦軸に薬液のpHを目盛り、78%硫酸の添加量X(ml)毎に、YとpHとの関係を示している。図6は、横軸にリン酸2水素ナトリウム2水和物の添加量Y(g)を、また縦軸にゲルタイム(分)を目盛り、78%硫酸の添加量X(ml)毎に、Yとゲルタイム(分)との関係を片対数で示している。図5及び図6中、7は78%硫酸の添加量Xが8mlの場合、8は8.5mlの場合、9は9mlの場合である。図5及び図6の結果からも明らかなように、本発明によると、地盤中に注入した水ガラスのゲルタイムを確実に制御できる。
【0034】
【発明の効果】
既に明らかなように、以上説明した本発明には、地盤中に注入する薬液として、従来法のように、水ガラスに多量の硫酸を加えてpH2未満とした強酸性のシリカゾルを使用しないため、無機酸として硫酸を用いる場合においても、硫酸の使用量を著しく低減でき、また地盤中に持ち込まれることとなる硫酸根の量を著しく低減できるという効果がある。その上、従来法のように、水酸化マグネシウムや水酸化カルシウム等の強アルカリ剤を使用せず、リン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムを使用するため、これらのpH緩衝能によって、地盤中に注入する薬液全体のpHの振れを小さくし、よって地盤中に注入した水ガラスのゲルタイムを所期の通りに制御できるという効果がある。
【図面の簡単な説明】
【図1】 本発明の実施形態において、硫酸の添加量(ml)毎に、50%リン酸2水素マグネシウムの添加量(g)と薬液のpHとの関係を示すグラフ。
【図2】 図1と同じ実施形態において、硫酸の添加量(ml)毎に、50%リン酸2水素マグネシウムの添加量(g)とゲルタイム(分)との関係を片対数で示すグラフ。
【図3】 本発明の他の実施形態において、硫酸の添加量(ml)毎に、50%リン酸2水素マグネシウムの添加量(g)と薬液のpHとの関係を示すグラフ。
【図4】 図3と同じ実施形態において、硫酸の添加量(ml)毎に、50%リン酸2水素マグネシウムの添加量(g)とゲルタイム(分)との関係を片対数で示すグラフ。
【図5】 本発明の更に他の実施形態において、硫酸の添加量(ml)毎に、リン酸2水素ナトリウム2水和物の添加量(g)と薬液のpHとの関係を示すグラフ。
【図6】 図5と同じ実施形態において、硫酸の添加量(ml)毎に、リン酸2水素ナトリウム2水和物の添加量(g)とゲルタイム(分)との関係を片対数で示すグラフ。
[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ground hardening method. In order to strengthen and stop the ground, a chemical solution is mixed and injected into the ground to harden the ground. The present invention relates to an improvement of the ground hardening method.
[0002]
[Prior art]
Conventionally, as a ground hardening method as described above, an acidic silica sol and an aqueous solution of an alkaline agent are generally mixed and injected into the ground. The acidic silica sol in this case is an aqueous dispersion usually made of water glass with a pH of less than 2 by adding sulfuric acid, and an alkaline earth metal hydroxide such as magnesium hydroxide or calcium hydroxide is usually used as an alkaline agent. (Japanese Patent Publication No. 3-24515). However, since this conventional method uses a large amount of sulfuric acid as a deleterious substance, its handling is very troublesome, and as a result, there is a problem that a large amount of undesired sulfate radicals are brought into the ground. Moreover, since the aqueous solution of a strong alkaline agent such as magnesium hydroxide or calcium hydroxide is mixed with a strongly acidic silica sol which is made to have a pH of less than 2 by adding sulfuric acid to water glass, the pH of the whole chemical after mixing is easy to shake. There is a problem that the time (gel time) required for gelation of the water glass injected into the ground is greatly disturbed.
[0003]
In the ground hardening method using water glass, the ground is hardened by utilizing gelation of water glass injected into the ground. In this case, it is known that the gel time of the water glass is greatly influenced by the pH although it depends on the SiO 2 concentration and the curing temperature of the water glass. When, for example, sulfuric acid is gradually added to the water glass as a curing agent and the pH thereof is gradually lowered, the water glass generally becomes a so-called instantaneous state of gelation at pH 6.0 to 9.0 in several seconds to several tens of seconds, In addition, it becomes a so-called consolidated state that gels in a few minutes to several tens of minutes at a pH of 4.5 to less than 6.0, and further so-called long-lasting that gels in several hours to several tens of hours at a pH of 3.0 to less than 4.5 And becomes a stable acidic silica sol below pH 2. The gel time of water glass becomes logarithmically longer in relation to pH in a pH range lower than the neutral range near pH 6.0 to 9.0, and becomes a stable acidic silica sol below pH 2.
[0004]
When the pH of the whole chemical solution injected into the ground fluctuates as in the conventional method described above, the gel time of the water glass injected as acidic silica sol into the ground is greatly disturbed, the time required for ground hardening is disturbed, and before and after the hardening work This hinders the progress of other scheduled tasks.
[0005]
In order to improve the fluctuation of the pH of the whole chemical solution injected into the ground, for example, alkali metal hexametaphosphate is used as an adjusting agent together with an alkali agent (Japanese Patent Publication No. 3-24515, Japanese Patent Publication No. 4-56074). . However, even in this conventional method, although there is a corresponding improvement in pH fluctuation as compared with the conventional method in which an aqueous solution of a strong alkali agent is simply used, there is a problem that the degree of improvement is insufficient. There is a problem similar to that of the conventional method described above by using a strongly acidic silica sol having a pH of less than 2 by adding sulfuric acid.
[0006]
[Problems to be solved by the invention]
The problems to be solved by the present invention are as follows. In the conventional method, 1) a large amount of deleterious sulfuric acid is used to prepare an acidic silica sol of water glass, and the handling is very troublesome, and 2) As a result, a large amount of undesired sulfate radicals are brought into the ground, and 3) the pH of the whole chemical solution injected into the ground is likely to fluctuate, and the gel time of water glass injected as acidic silica sol is disturbed. Is a point.
[0007]
[Means for Solving the Problems]
The present invention for solving the above-mentioned problems is a method of mixing and injecting a chemical solution into the ground to cure the ground, using an aqueous solution of water glass and an aqueous solution of a curing agent as the chemical solution, and using water glass as the curing agent. An inorganic acid in an amount for adjusting the pH of the aqueous solution to 6.0 to 9.0, an amount of sodium dihydrogen phosphate in an amount for adjusting the pH of the whole chemical solution to be injected into the ground to less than 4.5 to 6.0 and / or Or it relates to the ground hardening method characterized by using magnesium dihydrogen phosphate.
According to the present invention, in the method of mixing and injecting a chemical solution into the ground and curing the ground, an aqueous solution of water glass and an aqueous solution of a curing agent are used as the chemical solution, and the pH of the aqueous solution of water glass is 6 as the curing agent. An inorganic acid and polyaluminum chloride in an amount to be adjusted to 0.0 to 9.0, and sodium dihydrogen phosphate in an amount to adjust the pH of the whole chemical solution to be injected into the ground to less than 4.5 to 6.0 and / or The present invention relates to a ground hardening method characterized by using magnesium dihydrogen phosphate.
[0008]
In the present invention, a water glass aqueous solution (A solution) and a curing agent aqueous solution (B solution) are mixed and injected into the ground. For mixed injection, 1) a method in which both are mixed immediately before injection (1 shot method), 2) a method in which both are mixed while mixing (1.5 shot method), and 3) both are injected Any of the methods of mixing immediately after (two-shot method) may be used. In general, the method 1) uses one injection tube, the method 2) uses one Y-injection tube, and the method 3) uses two injection tubes or double tubes. Use an injection tube.
[0009]
As the water glass used for preparing the aqueous solution of water glass as the liquid A, any commercially available water glass can be used. Usually, there is used water glass of No. JIS three, water glass of SiO 2 high molar ratio containing SiO 2 in a proportion of 3.6 to 4.5 mol with respect to Na 2 O1 moles can be used.
[0010]
The curing agent used for the preparation of the aqueous solution of the curing agent as the B liquid is 1) a combination of an inorganic acid and a buffering acid agent, 2) an inorganic acid, an aluminum salt of the inorganic acid, and a buffering acid agent. Combination, the above two combinations. As the inorganic acid, hydrochloric acid, nitric acid, sulfuric acid and the like can be used, but usually economical sulfuric acid is used. As the buffering acid agent, sodium dihydrogen phosphate and / or magnesium dihydrogen phosphate is used. These have an excellent pH buffering capacity. Furthermore, polyaluminum chloride is used as the aluminum salt of the inorganic acid. When polyaluminum chloride is used as a curing agent together with an inorganic acid, a strong and highly durable aluminum silicate is formed.
[0011]
In the present invention, an aqueous solution of water glass is prepared as one chemical liquid (A liquid) to be injected into the ground, and an aqueous solution of a curing agent is prepared as the other chemical liquid (B liquid), and these are added to the ground at a predetermined ratio. Inject mixed into. By adjusting the composition and concentration of liquid A and liquid B, as well as the mixture injection ratio of both, the pH of the entire chemical liquid mixed and injected into the ground can be controlled, and thus the gel time of the water glass injected into the ground can be controlled. .
[0012]
In the field of ground hardening work, in general, the ground hardening work itself is performed as expected, and the water glass injected into the ground is often joined in order to smoothly advance the work before and after. As described above, in the case of gelation in which water glass injected into the ground is gelled within a few minutes to several tens of minutes, it is necessary to adjust the pH of the whole chemical solution injected into the ground to less than 4.5 to 6.0. is there. In this case, in order to minimize the amount of sulfuric acid that is normally used as an inorganic acid, and therefore to minimize the amount of sulfate radicals that are brought into the ground, in the present invention, an inorganic acid, or an inorganic acid and a polychlorinated salt are used. The amount of aluminum used is an amount that adjusts the pH of the aqueous solution of water glass to 6.0 to 9.0 (in other words, an amount that substantially neutralizes the aqueous solution of water glass). In addition, in order to gel the water glass injected into the ground in several minutes to several tens of minutes, in the present invention, the amount of sodium dihydrogen phosphate and / or magnesium dihydrogen phosphate used is the whole chemical solution injected into the ground. The pH is adjusted to 4.5 to less than 6.0.
[0013]
In the present invention, as a chemical solution to be injected into the ground, unlike the conventional method, since a strongly acidic silica sol having a pH of less than 2 by adding sulfuric acid to water glass is not used, even when sulfuric acid is used as an inorganic acid, The amount used can be significantly reduced, and the amount of sulfate radicals that are brought into the ground can be significantly reduced. In addition, unlike the conventional method, a strong alkali agent such as magnesium hydroxide or calcium hydroxide is not used, and sodium dihydrogen phosphate and / or magnesium dihydrogen phosphate is used as described above, so that pH Due to the buffer capacity, even if the water glass or sulfuric acid used as the material varies considerably, the pH fluctuation of the whole chemical solution injected into the ground can be reduced, so the gel time of the water glass injected into the ground is as expected. Can be controlled.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the embodiment of the present invention include the following 1) to 7).
1) Water is added to 70 liters of JIS 3 water glass to prepare 200 liters of an aqueous solution of water glass (liquid A). Separately, 18 kg of 50% magnesium dihydrogen phosphate and water are added to 9 liter of 78% sulfuric acid to prepare 200 liters of an aqueous solution of a curing agent (liquid B). A method in which A liquid and B liquid are mixed and injected into the ground at an equal ratio. In this case, the amount of sulfuric acid used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 8.0, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution mixed and injected into the ground by 5.7. The gel time is 2.5 minutes.
[0015]
2) Water is added to 70 liters of JIS3 water glass to prepare an aqueous solution of 200 liters of water glass (solution A). Separately, 18 kg of 50% magnesium dihydrogen phosphate and water are added to 9.5 liters of 78% sulfuric acid to prepare 200 liters of an aqueous solution of a curing agent (liquid B). A method in which A liquid and B liquid are mixed and injected into the ground at an equal ratio. In this case, the amount of sulfuric acid used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 7.5, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution mixed and injected into the ground by 5.3. The gel time is 7.5 minutes.
[0016]
3) Water is added to 70 liters of JIS3 water glass to prepare 200 liters of an aqueous solution of water glass (solution A). Separately, 10 kg of 50% magnesium dihydrogen phosphate and water are added to 10 liters of 78% sulfuric acid to prepare 200 liters of an aqueous solution of a curing agent (liquid B). A method in which A liquid and B liquid are mixed and injected into the ground at an equal ratio. In this case, the amount of sulfuric acid used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 7.0, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution to be mixed and injected into the ground to 4.9. The gel time is 13 minutes.
[0017]
4) Add water to 70 liters of JIS3 water glass to prepare an aqueous solution of 200 liters of water glass (solution A). Separately, 6 kg of 10% polyaluminum chloride, 15 kg of 50% magnesium dihydrogen phosphate and water are added to 8.5 liter of 78% sulfuric acid to prepare 200 liters of an aqueous solution of a curing agent (liquid B). A method in which A liquid and B liquid are mixed and injected into the ground at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 8.0, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution to be mixed and injected into the ground. Is equivalent to the amount adjusted to 5.7, and the gel time is 2 minutes.
[0018]
5) Add water to 70 liters of JIS3 water glass to prepare an aqueous solution of 200 liters of water glass (solution A). Separately, 6 kg of 10% polyaluminum chloride, 10 kg of 50% magnesium dihydrogen phosphate and water are added to 9 liter of 78% sulfuric acid to prepare 200 liters of an aqueous solution of a curing agent (liquid B). A method in which A liquid and B liquid are mixed and injected into the ground at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 7.5, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution to be mixed and injected into the ground. Is equivalent to the amount adjusted to 5.4, and the gel time is 5 minutes.
[0019]
6) Water is added to 70 liters of JIS3 water glass to prepare 200 liters of an aqueous solution of water glass (solution A). Separately, 6 kg of 10% polyaluminum chloride, 18 kg of sodium dihydrogen phosphate dihydrate and water are added to 8.5 liters of 78% sulfuric acid to prepare 200 liters of an aqueous solution of a curing agent (Liquid B). A method in which A liquid and B liquid are mixed and injected into the ground at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the water glass aqueous solution to 8.0, and the amount of sodium dihydrogen phosphate dihydrate used is mixed and injected into the ground. This corresponds to an amount for adjusting the pH of the whole drug solution to 5.9, and the gel time is 1.6 minutes.
[0020]
7) Add water to 70 liters of JIS3 water glass to prepare 200 liters of an aqueous solution of water glass (solution A). Separately, 6 kg of 10% polyaluminum chloride, 15 kg of sodium dihydrogen phosphate dihydrate and water are added to 9 liters of 78% sulfuric acid to prepare 200 liters of an aqueous solution of a curing agent (liquid B). A method in which A liquid and B liquid are mixed and injected into the ground at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the water glass aqueous solution to 7.5, and the amount of sodium dihydrogen phosphate dihydrate used is mixed and injected into the ground. This corresponds to an amount for adjusting the pH of the entire drug solution to 5.8, and the gel time is 2.1 minutes.
[0021]
【Example】
Test category 1
Example 1
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 18 g of 50% magnesium dihydrogen phosphate and water were added to 9 ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (solution B). Then, the liquid A and the liquid B were mixed at an equal ratio. In this case, the amount of sulfuric acid used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 8.0, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution mixed and injected into the ground by 5.7. The gel time was 2.5 minutes.
[0022]
Example 2
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 18 g of 50% magnesium dihydrogen phosphate and water were added to 9.5 ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (solution B). Then, the liquid A and the liquid B were mixed at an equal ratio. In this case, the amount of sulfuric acid used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 7.5, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution mixed and injected into the ground by 5.3. The gel time was 7.5 minutes.
[0023]
Example 3
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 10 g of 50% magnesium dihydrogen phosphate and water were added to 10 ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (solution B). Then, the liquid A and the liquid B were mixed at an equal ratio. In this case, the amount of sulfuric acid used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 7.0, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution to be mixed and injected into the ground to 4.9. The gel time was 13 minutes.
[0024]
Example 4
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 6 g of 10% polyaluminum chloride, 15 g of 50% magnesium dihydrogen phosphate and water were added to 8.5 ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (Liquid B). Then, the liquid A and the liquid B were mixed at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 8.0, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution to be mixed and injected into the ground. The gel time was 2 minutes.
[0025]
Example 5
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 6 g of 10% polyaluminum chloride, 10 g of 50% magnesium dihydrogen phosphate and water were added to 9 ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (solution B). Then, the liquid A and the liquid B were mixed at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the aqueous solution of water glass to 7.5, and the amount of magnesium dihydrogen phosphate used is the pH of the whole chemical solution to be mixed and injected into the ground. The gel time was 5 minutes.
[0026]
Example 6
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 6 g of 10% polyaluminum chloride, 18 g of sodium dihydrogen phosphate dihydrate and water were added to 8.5 ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (Liquid B). Then, the liquid A and the liquid B were mixed at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the water glass aqueous solution to 8.0, and the amount of sodium dihydrogen phosphate dihydrate used is mixed and injected into the ground. This corresponds to an amount for adjusting the pH of the entire drug solution to 5.9, and the gel time was 1.6 minutes.
[0027]
Example 7
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 6 g of 10% polyaluminum chloride, 15 g of sodium dihydrogen phosphate dihydrate and water were added to 9 ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (solution B). Then, the liquid A and the liquid B were mixed at an equal ratio. In this case, the amount of sulfuric acid and polyaluminum chloride used corresponds to the amount of adjusting the pH of the water glass aqueous solution to 7.5, and the amount of sodium dihydrogen phosphate dihydrate used is mixed and injected into the ground. This corresponds to an amount for adjusting the pH of the entire drug solution to 5.8, and the gel time was 2.1 minutes.
[0028]
Test category 2
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, Yml of 50% magnesium dihydrogen phosphate and water were added to Xml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (Liquid B). Then, the liquid A and the liquid B were mixed at an equal ratio. The above-mentioned X and Y were changed, the pH of the chemical solution at that time was determined and shown in FIG. 1, and the gel time (minute) was determined and shown in FIG.
[0029]
In FIG. 1, the horizontal axis indicates the added amount Y (g) of 50% magnesium dihydrogen phosphate, the vertical axis indicates the pH of the chemical solution, and for each added amount X (ml) of 78% sulfuric acid, Y and pH Shows the relationship. FIG. 2 shows the amount Y (g) of 50% magnesium dihydrogen phosphate on the horizontal axis, the gel time (minutes) on the vertical axis, and Y and gel time for each 78% sulfuric acid addition amount X (ml). The relationship with (minutes) is shown in semilogarithm. In FIG. 1 and FIG. 2, 1 is the case where the addition amount X of 78% sulfuric acid is 9 ml, 2 is the case of 9.5 ml, and 3 is the case of 10 ml. As is apparent from the results of FIGS. 1 and 2, according to the present invention, the gel time of the water glass injected into the ground can be reliably controlled.
[0030]
Test category 3
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 6 ml of 10% polyaluminum chloride aqueous solution, Yg of 50% magnesium dihydrogen phosphate and water were added to X ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (solution B). Then, the liquid A and the liquid B were mixed at an equal ratio. The above-mentioned X and Y were changed, the pH of the chemical solution at that time was determined and shown in FIG. 3, and the gel time (minute) was determined and shown in FIG.
[0031]
In FIG. 3, the horizontal axis indicates the addition amount Y (g) of 50% magnesium dihydrogen phosphate, the vertical axis indicates the pH of the chemical solution, and for each addition amount X (ml) of 78% sulfuric acid, Y and pH Shows the relationship. FIG. 4 shows the amount Y (g) of 50% magnesium dihydrogen phosphate added on the horizontal axis, the gel time (minutes) on the vertical axis, and Y and gel time for every 78% sulfuric acid added amount X (ml). The relationship with (minutes) is shown in semilogarithm. 3 and 4, 4 is the case where the added amount X of 78% sulfuric acid is 8 ml, 5 is the case of 8.5 ml, and 6 is the case of 9 ml. As is apparent from the results of FIGS. 3 and 4, according to the present invention, the gel time of the water glass injected into the ground can be reliably controlled.
[0032]
Test category 4
Water was added to 70 ml of JIS 3 water glass to prepare 200 ml of an aqueous solution of water glass (solution A). Separately, 6 ml of 10% polyaluminum chloride, sodium dihydrogen phosphate dihydrate Yg and water were added to X ml of 78% sulfuric acid to prepare 200 ml of an aqueous solution of a curing agent (Liquid B). Then, the liquid A and the liquid B were mixed at an equal ratio. The above-mentioned X and Y were changed, the pH of the chemical solution at that time was determined and shown in FIG. 3, and the gel time (minute) was determined and shown in FIG.
[0033]
FIG. 5 shows the addition amount Y (g) of sodium dihydrogen phosphate dihydrate on the horizontal axis, the scale of the chemical solution pH on the vertical axis, and Y for each addition amount X (ml) of 78% sulfuric acid. The relationship with pH is shown. FIG. 6 shows the amount Y (g) of sodium dihydrogen phosphate dihydrate on the horizontal axis, the gel time (minutes) on the vertical axis, and Y for each 78% sulfuric acid addition amount X (ml). And the gel time (minutes) are shown in semilogarithm. 5 and 6, 7 is the case where the added amount X of 78% sulfuric acid is 8 ml, 8 is 8.5 ml, and 9 is 9 ml. As is clear from the results of FIGS. 5 and 6, according to the present invention, the gel time of the water glass injected into the ground can be reliably controlled.
[0034]
【The invention's effect】
As is apparent, the present invention described above does not use a strongly acidic silica sol having a pH of less than 2 by adding a large amount of sulfuric acid to water glass, as in the conventional method, as a chemical solution to be injected into the ground. Even when sulfuric acid is used as the inorganic acid, the amount of sulfuric acid used can be remarkably reduced, and the amount of sulfate radicals that are brought into the ground can be remarkably reduced. In addition, unlike conventional methods, strong alkaline agents such as magnesium hydroxide and calcium hydroxide are not used, but sodium dihydrogen phosphate and / or magnesium dihydrogen phosphate are used. There is an effect that the fluctuation of the pH of the whole chemical solution injected into the ground is reduced, and thus the gel time of the water glass injected into the ground can be controlled as expected.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the addition amount (g) of 50% magnesium dihydrogen phosphate and the pH of a chemical solution for each addition amount (ml) of sulfuric acid in an embodiment of the present invention.
2 is a graph showing the relationship between the addition amount (g) of 50% magnesium dihydrogen phosphate and the gel time (min) in semilogarithm for each addition amount (ml) of sulfuric acid in the same embodiment as FIG.
FIG. 3 is a graph showing the relationship between the addition amount (g) of 50% magnesium dihydrogen phosphate and the pH of the chemical solution for each addition amount (ml) of sulfuric acid in another embodiment of the present invention.
4 is a graph showing the relationship between the addition amount (g) of 50% magnesium dihydrogen phosphate and the gel time (min) in semilogarithm for each addition amount (ml) of sulfuric acid in the same embodiment as FIG. 3;
FIG. 5 is a graph showing the relationship between the addition amount (g) of sodium dihydrogen phosphate dihydrate and the pH of the chemical solution for each addition amount (ml) of sulfuric acid in yet another embodiment of the present invention.
6 shows the relationship between the addition amount (g) of sodium dihydrogen phosphate dihydrate and the gel time (min) in semilogarithm for each addition amount (ml) of sulfuric acid in the same embodiment as FIG. Graph.

Claims (2)

地盤中に薬液を混合注入して該地盤を硬化させる方法において、薬液として水ガラスの水溶液と硬化剤の水溶液とを用い、且つ硬化剤として、水ガラスの水溶液のpHを6.0〜9.0に調整する量の無機酸と、地盤中に注入する薬液全体のpHを4.5〜6.0未満に調整する量のリン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムとを用いることを特徴とする地盤硬化法。In the method of mixing and injecting a chemical solution into the ground to cure the ground, an aqueous solution of water glass and an aqueous solution of a curing agent are used as the chemical solution, and the pH of the aqueous solution of water glass is set to 6.0 to 9. Use an inorganic acid in an amount to be adjusted to 0 and sodium dihydrogen phosphate and / or magnesium dihydrogen phosphate in an amount to adjust the pH of the whole chemical solution to be injected into the ground to less than 4.5 to 6.0. A ground hardening method characterized by 地盤中に薬液を混合注入して該地盤を硬化させる方法において、薬液として水ガラスの水溶液と硬化剤の水溶液とを用い、且つ硬化剤として、水ガラスの水溶液のpHを6.0〜9.0に調整する量の無機酸及びポリ塩化アルミニウムと、地盤中に注入する薬液全体のpHを4.5〜6.0未満に調整する量のリン酸2水素ナトリウム及び/又はリン酸2水素マグネシウムとを用いることを特徴とする地盤硬化法。In the method of mixing and injecting a chemical solution into the ground to cure the ground, an aqueous solution of water glass and an aqueous solution of a curing agent are used as the chemical solution, and the pH of the aqueous solution of water glass is set to 6.0 to 9. An amount of inorganic acid and polyaluminum chloride to be adjusted to 0, and an amount of sodium dihydrogen phosphate and / or magnesium dihydrogen phosphate to adjust the pH of the whole chemical solution to be injected into the ground to less than 4.5 to 6.0 A ground hardening method characterized by using.
JP2000170915A 2000-06-07 2000-06-07 Ground hardening method Expired - Lifetime JP4507355B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000170915A JP4507355B2 (en) 2000-06-07 2000-06-07 Ground hardening method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000170915A JP4507355B2 (en) 2000-06-07 2000-06-07 Ground hardening method

Publications (2)

Publication Number Publication Date
JP2001348572A JP2001348572A (en) 2001-12-18
JP4507355B2 true JP4507355B2 (en) 2010-07-21

Family

ID=18673556

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000170915A Expired - Lifetime JP4507355B2 (en) 2000-06-07 2000-06-07 Ground hardening method

Country Status (1)

Country Link
JP (1) JP4507355B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103343012A (en) * 2013-07-02 2013-10-09 内蒙古大学 Method for preparing hydrophobic sand from waste organic glass

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101386502B (en) * 2008-10-28 2011-06-22 海南大学 Method for preparing porous desert greening brick

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53125310A (en) * 1977-04-09 1978-11-01 Nitto Chemical Industry Co Ltd Method of stabilizing nature of soil
JPS5534201A (en) * 1978-08-30 1980-03-10 Mitsui Toatsu Chem Inc Improved method of construction of poor subsoil
JPS56152884A (en) * 1980-04-30 1981-11-26 Nitto Chem Ind Co Ltd Soil stabilization method
JPS60233192A (en) * 1984-05-07 1985-11-19 Kyokado Eng Co Ltd Grouting method
JPS62181387A (en) * 1986-02-04 1987-08-08 Shimoda Gijutsu Kenkyusho:Kk Group grouting chemical and construction method using said chemical
JPS62290790A (en) * 1986-06-11 1987-12-17 Kyokado Eng Co Ltd Grout for injection into ground
JPS6341588A (en) * 1986-08-08 1988-02-22 Kyokado Eng Co Ltd Liquid chemical for grouting
JP3226510B2 (en) * 1999-05-20 2001-11-05 名古屋カレット株式会社 Ground hardening method

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53122204A (en) * 1977-03-31 1978-10-25 Sanyo Chemical Ind Ltd Soil nature stabilizing agent

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53125310A (en) * 1977-04-09 1978-11-01 Nitto Chemical Industry Co Ltd Method of stabilizing nature of soil
JPS5534201A (en) * 1978-08-30 1980-03-10 Mitsui Toatsu Chem Inc Improved method of construction of poor subsoil
JPS56152884A (en) * 1980-04-30 1981-11-26 Nitto Chem Ind Co Ltd Soil stabilization method
JPS60233192A (en) * 1984-05-07 1985-11-19 Kyokado Eng Co Ltd Grouting method
JPS62181387A (en) * 1986-02-04 1987-08-08 Shimoda Gijutsu Kenkyusho:Kk Group grouting chemical and construction method using said chemical
JPS62290790A (en) * 1986-06-11 1987-12-17 Kyokado Eng Co Ltd Grout for injection into ground
JPS6341588A (en) * 1986-08-08 1988-02-22 Kyokado Eng Co Ltd Liquid chemical for grouting
JP3226510B2 (en) * 1999-05-20 2001-11-05 名古屋カレット株式会社 Ground hardening method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103343012A (en) * 2013-07-02 2013-10-09 内蒙古大学 Method for preparing hydrophobic sand from waste organic glass

Also Published As

Publication number Publication date
JP2001348572A (en) 2001-12-18

Similar Documents

Publication Publication Date Title
US4904304A (en) Chemical grout for ground injection and method for accretion
US4004428A (en) Process for stabilizing soil
JP4507355B2 (en) Ground hardening method
JP3091178B2 (en) Manufacturing method of ground consolidation agent
JP3226510B2 (en) Ground hardening method
JP2001003047A (en) Grouting consolidation material
JP4462583B2 (en) Ground stabilization chemical and ground stabilization method using the same
JP2000328056A (en) Ground hardening method
JPS5911632B2 (en) Soil stabilization method
JP3150380B2 (en) Ground injection agent and its injection method
JPH10324872A (en) Grout for ground and grout injection method
JP2003119465A (en) Liquefaction-preventing grouting chemical liquid
JPH10176326A (en) Ground hardening method
JP4164172B2 (en) Chemical solution for ground injection
JPS6312514B2 (en)
JP3932562B2 (en) Ground injection agent
JP3142325B2 (en) Ground injection agent and its injection method
JP2002155279A (en) Method for hardening ground
JPH07324188A (en) Grout for the ground and method for grouting the ground
JP4094285B2 (en) Silicate-based soil stabilization chemicals
JPH10245556A (en) Grout for ground
JP3949844B2 (en) Silicate soil chemicals
JP2000109835A (en) Chemical liquid to be injected in soil
JPH11181425A (en) Ground-grouting material
JPH06330037A (en) Grouting agent

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20070315

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20100215

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20100331

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20100426

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20100426

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130514

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

Ref document number: 4507355

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130514

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140514

Year of fee payment: 4

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term