JP3653305B2

JP3653305B2 - Restoration method for uneven settlement

Info

Publication number: JP3653305B2
Application number: JP12592895A
Authority: JP
Inventors: 重治有馬
Original assignee: HEISEI TECHNO'S CO., LTD.
Current assignee: HEISEI TECHNO'S CO., LTD.
Priority date: 1995-04-26
Filing date: 1995-04-26
Publication date: 2005-05-25
Anticipated expiration: 2020-05-25
Also published as: JPH08296248A

Description

【０００１】
【産業上の利用分野】
本発明は、主として不等沈下した構築物を復元させる工法に関し、詳しくは構築物の基礎部が不等沈下して構築物躯体が傾いたものを基礎下部に薬液を効果的に圧入して支持地盤を強化改良するとともに、注入薬液による押圧力で構築物躯体を持上げて正常に復帰保持させる不等沈下構築物の復元工法に関する。
【０００２】
【従来の技術】
一般に地盤が沖積層のような地層上に構築された建造物は、大地震などによる激しい衝撃を受けることによって地層の液状化現象が発生すると、支持基盤が崩れて基礎の安定が失われ、基礎から上の躯体が傾き生活環境を維持することが困難な状態となることが昨今の震災で多く見られる。
【０００３】
このような躯体が傾斜した構築物は、通常の建築設計上での躯体強度は概ね維持されているが、基礎を支える地盤が液状化現象などによって流動して躯体の支持力が失われ、その支持バランスを崩し傾斜している。そのために、この傾いた構築物（建物）を復元させることは容易でない。
【０００４】
このような傾いた構築物を復元させるために通常考えられる手段としては、傾いた構築物（建物）の下がっている側の下部に強固なビーム材などを敷き、この強固なビーム材と建物の躯体基礎要所との間にジャッキを入れて、そのジャッキで徐々に躯体を持上げて修復するような手段が考えられる。
【０００５】
【発明が解決しようとする課題】
しかしながら、このような手段は、その強固なビーム材を躯体基礎要所の下側に配置するのに地盤を掘り下げなければならないので大変危険な作業を伴い、しかも強力なジャッキを必要とするなど準備作業に多くの困難を伴う。さらに、ジャッキを使用するので、どうしても局部的に持上げ力が作用し、広い範囲を無理なく支えて復元しようとすると多大な労力と工期を要し、しかも作業性がよくない。当然、多大な工費がかかり経済性に問題がある。
【０００６】
本発明では、このような問題点を解決して、基礎部が広くて大重量の構築物（多層階の建築物など）であっても、薬液注入による地盤の改良技術を用いて、安全にかつ無理なく、短期間で復元することができる経済性の高い不等沈下構築物の復元工法を提供することを目的とする。
【０００７】
【課題を解決するための手段】
このような目的を達成するために本発明の不等沈下構築物の復元工法は、目的構築物の基礎下部に先端吐出部が位置するように所要の間隔で複数の薬液注入ロッドを設置し、これら薬液注入ロッドによってゲル化タイムの短い薬液を所要のインターバルで各薬液注入箇所に所要の順序で切替えて圧入する操作を繰り返し、各薬液注入箇所にて次回の薬液注入操作で先に注入強化された地盤及び薬液のホモゲル部を割裂させて前記薬液を注入することにより前記基礎下部に持上げ力を作用させ、この薬液注入操作の累積によって前記基礎部とともに構築物を持上げて、前記構築物を正常状態に復元させるに際し、前記薬液として複数種のゲル化タイムの異なる薬液を用い、複数種のゲル化タイムの異なる薬液を用いる場合は薬液注入箇所を巡ぐるごとにこれらゲル化タイムの異なる薬液を交互に切替えて注入操作を行ない、注入薬液で要所に強化支持地盤を順次形成させるとともに、この強化支持地盤の範囲を拡大させて広範囲で前記基礎部に持上げ力を作用させることを特徴とする。
【０００８】
本発明における前記複数種の薬液のゲル化タイムはそれぞれ、薬液注入箇所で次に注入されるまでに薬液が固結する範囲であることが好ましい。そして、前記ゲル化タイムの異なる薬液は、一方の薬液がゲル化タイムの極く短い瞬結牲のもので、他方の薬液はゲル化タイムが前者よりも長い中結性のものを用いるのがよい。なお、前記ゲル化タイムの異なる薬液の切替え注入に際しては、水洗操作を行って薬液の注入を阻害させることなく行われる。また、注入された薬液による地層の凝固が進行して最終強度が生じるまでに次の注入作業を行う際には、注入経路の水洗作業を行って後に改めて前記薬液の注入操作を実施するのがよい。
【０００９】
また、前記複数種のゲル化タイムの異なる薬液を注入するには、まず先に中結性の薬液を所要のインターバルで複数の薬液注入箇所に順次切替えて圧入し、前記薬液による各薬液注入箇所への注入操作を所要範囲で巡らせた後に、瞬結性の薬液を所要のインターバルで前記複数の薬液注入箇所に順次切替えて圧入し、以後この操作を所要回繰り返して行うようにするのが好ましい。もちろん、この操作と逆の操作で実施することもできる。
【００１０】
さらに本発明は、前記構築物の基礎下部の地盤に対し、所要の間隔で複数の薬液注入箇所にて、前記複数種のゲル化タイムの異なる薬液を所要のインターバルで各薬液注入箇所に順次切替て圧入する操作を所要の範囲で巡らせるごとに前記薬液を切替えて注入する操作を繰り返し、薬液注入操作により前記基礎部とともに構築物を持上げる操作に加えて、所要長さのアンカーを複数本所要深さまで挿入定着させて負荷を基礎部に掛けるか、または基礎上部に載荷物を載せて、前記構築物の基礎部に通常状態よりも上載荷重を増大させて下部地層の圧密強化を促進させるとともに、その上載荷重を調節しつつ前記基礎部とともに構築物を持上げ正常状態に復元させることにより、地盤が粘性土層のような圧縮性地層の場合に地盤強化部下の地層の早期圧密強化が捉進され、地盤の再沈下によって構築物が再び傾くなどの現象を未然に防止できる。
【００１１】
また、構築物の基礎下部地層の圧密強化を促進させるために、前記構築物の基礎上部に載せる載荷物としては所要の水槽を用いるとともに、その水槽内の水量を加減することにより載荷荷重を調節するのがよい。また、前記アンカーは構築物の基礎上部から基礎下の地盤に所要深度までボーリングして植込まれ、このアンカーの先端部を薬液によって硬化固定させ、基礎上部においてジャッキ装置によって前記構築物の基礎部に構築物の自重量以上に負荷が付加されるようにするのがよい。なお、このアンカーは目的構築物の基礎部において所要の間隔で複数箇所に設けられ、基礎下の地盤の深部に平均的に押圧力が付加されるようにするのが好ましい。
【００１２】
また、本発明の薬液注入操作は、目的構築物が広い構築面積を有するもの、あるいは構築物の基礎部形状が方形以外の形状である場合などでは、複数台の薬液注入ユニットを用いて複数系統の注入を同時進行で行うようにするのがよい。
【００１３】
【作用】
このような本発明の不等沈下構築物の復元工法によれば、傾斜している構築物の基礎部下に、所要の間隔で複数箇所に挿入された各薬液注入ロッドからゲル化タイムの短い薬液を用いて所要のインターバルで順次薬液注入箇所を切替えて注入する操作を繰り返すことにより、短い時間で基礎部下に強化支持地盤を形成させ、その後の薬液注入によって順次先に形成された強化支持地盤に対して、次回の注入薬液の注入圧力でその地盤の一部と薬液のホモゲル部を割裂させて主に強化支持地盤の上層部で薬液を拡散流入させる。この流動する薬液が自己のゲル化タイムによって流動を制止されるために液層の上下に注入圧力が広い範囲で伝播される。したがって、この薬液層の注入圧力が強化支持地盤で受け止められて、あたかも「くさび」を打込んだようになり、上向きに作用する押上げ力によって基礎部とともに構築物が徐々に持上げられ、繰り返し前記薬液を注入することで所期の目的を容易に達成できる。また、このような動作が繰り返されることによって、併せて支持地盤も強化されることになる。
【００１４】
この際、薬液に複数種の異なるゲル化タイムの短い薬液を用い、その一方の薬液と他方の薬液とを、各々所要のインターバルで順次薬液注入箇所を切替えて注入するに際し、注入操作が所要の範囲の薬液注入箇所を巡るごとに薬液を切替えて注入する操作を繰り返すことにより、ゲル化タイムの短い薬液の注入で短時間に所要の持上げ強化支持地盤が得られ、このゲル化タイムの短い薬液よりもゲル化タイムの長い薬液の注入によって、より広く薬液を浸透させて前記強化支持地盤を超える広い範囲で強化地盤を形成させることができる。そして、同一薬液注入ロッドを使用してこれらゲル化タイムの異なる薬液を交互に注入して形成される強化支持地盤の拡大によって、注入する薬液の圧入蓄圧力を構築物の基礎部広くに作用させれば、比較的低い注入圧力で大きな持上げ力が得られ、前記構築物が基礎部とともに効率良く持上げることができる。したがって、薬液の注入圧力，注入量，注入箇所の配置などを、目的構築物の基礎部の剛性，地中梁の剛性や構築物の押上げ荷重などに対応させることで、無理なく容易に短期間で構築物を正常に復元することができる。同時に、構築物の基礎部下の地盤を目的範囲全般にわたって有効に強化改良することができる。
【００１５】
本発明の工法にあって、使用する薬液のゲル化タイムは、複数の薬液注入箇所に切替えて注入操作が行われるに際し、次に注入されるまでに薬液が固結する範囲のものであるのがよい。このようなゲル化タイムの薬液であれば、所要の間隔をおいて繰り返し注入されるときに、先に注入された薬液は既に土砂と混じて固結して強化支持地盤（まだ完全に固化されていない）が形成されてあり、この強化支持地盤が新たに注入される薬液を受け止めて前述の基礎部の持上げ反力を支持することができる。また、同一の注入箇所で前述のような薬液の切替え注入操作を行えるので、１台のポンプによって広い分担範囲をまかなうことができ、必要に応じて複数台のポンプを使用すれば工期を縮めて経済性を高め得る。
【００１６】
このようにして所要のインターバルをとって複数の注入箇所で順次切替て薬液を注入する方式を採用することにより、万遍なく当該各注入箇所での反力増大機能が高められることになる。特に、瞬結性の薬液と中結性の薬液とを同一の薬液注入箇所で切替えて順次注入することで、隣接する瞬結性の薬液の注入によって形成された強化支持地盤間が、中結性の薬液の浸透によって地盤の改良強化範囲を拡大できることになり、目的構築物の基礎部全般が一体に強化されて、薬液の注入圧力による持上げ作用を広範囲で有効に機能させることが可能になる。したがって、構築物の傾斜状態並びにその高さや構築面積などが異なっても、その状況に応じて薬液注入箇所の数や注入薬液の注入圧力及び注入量（吐出量）などを調整して任意対応することができ、薬液注入の準備とその薬液注入作業を容易にし、短期間で傾斜構築物の復元作業が実施できる。
【００１７】
また、本発明において、傾いた構築物の基礎上部に上載荷重を掛けて基礎部に当該構築物の自重量以上に負荷が付加されるようにするとともに、前記の薬液注入操作を行ない、基礎部の持上げ状況に対してバランスさせながら前記負荷を徐々に低減させることにより、例えば建築地盤がシルト層のような粘性土層のような圧縮性地層の場合、前述の薬液注入操作による地盤強化部下の地層の早期圧密強化が促進される。その結果、圧縮性の粘性土層のような地盤であっても再沈下によって構築物が再び傾くなどの現象を未然に防止できる効果が併せ得られる。
【００１８】
【実施例】
次に、本発明の不等沈下構築物の復元工法について、その一実施例を図面を参照しつつ説明する。
【００１９】
図１に示されるのは本発明の不等沈下構築物の復元工法によって傾いた建物を復元させる態様を模式的に表す図であって、(a) は建物が正常状態にあるのを示し、(b) は地盤が不等沈下して建物が傾いている態様を示し、(c) は本発明の工法を施工開始する態様を示し、(d) は本発明の工法による薬液注入操作で建物が正常に復元された態様を示している。図２は図１で示される建物の基礎下部に対する複数の薬液注入箇所とそれらの注入の配管態様を表した平面図である。図３は薬液注入ロッドに対する薬液供給ユニットからの薬液供給系統を示す図である。図４は薬液の注入操作を加えている態様を模式的に表す要部断面図である。
【００２０】
本発明の工法は、これらの図によって示されるように、まず傾いた建築物１の状況（図１(b) 参照）を調査把握して、最適な作業手段を検討する。この場合、傾いた建築物１を支持する地盤３０と基礎２の構築状態とによって以後の作業状態が設定される。
【００２１】
まず、地盤３０が非圧縮土層、例えば砂質層のような地層であって、基礎２がいわゆる“べた基礎”である場合を想定して前記図で表されるような建物１を復元する手段について説明する。なお、この実施例では注入する薬液としてゲル化タイムの異なる２種類の液を使用して行われる場合について説明する。
【００２２】
最も好ましいのは建物１の内部から薬液の注入作業を行う。この場合、基礎面積と構築物（建物１および基礎２）の推定重量，べた基礎の剛性，地中梁の剛性などの関係を勘案して薬液注入ロッド５の挿入箇所の数並びに配置間隔を設定する。したがって、基礎面積が広く、基礎部の剛性が充分大で、しかも構築物の推定重量が大であれば、薬液注入ロッド１本の負担が過度にならないようにして多く使用することになり、逆に基礎面積が小さくて構築物の推定重量が小であれば、薬液注入ロッド５の配置本数も少なくてすむ。また、基礎部の剛性が小であれば、薬液注入ロッド５の配置本数を多くして薬液の注入を前者より緩やかに行わせるなど、対象となる構築物の状況に対応させる。
【００２３】
薬液注入ロッド５には薬液のＡ液とＢ液との混合注入部を有する公知の二重管構造のロッドが使用される。そして、この薬液注入ロッド５は、図２で例示されるように、所要の間隔（通常約２〜２．５ｍ程度）で複数本を建物１の基礎２を貫通させて基礎下部の地盤３０に対して挿入する。この場合、その薬液注入ロッド５の先端部が基礎部の下側まで挿入され、以後の薬液の注入（圧入）による持上げ作用力が即構築物の基礎２下面に働くように配されるのが好ましい。また、予め地盤３０の状態を推定するには、構築物の近接部で地層のサンプリングを行うのが好ましい。
【００２４】
薬液注入ロッド５を所要間隔で複数箇所に配置すれば、これら各薬液注入ロッド５には、図３で示されるように、薬液供給ユニット１０の高圧ポンプＰ，Ｐ’から切替バルブ１１，１１を介してそれぞれＡ液とＢ液との供給管１２，１３（ホースなど）が配管される。また、使用する薬液としてゲル化タイムの短い瞬結性の薬液（以下単に瞬結性の薬液という）と、ゲル化タイムがやや短い中結性と称される薬液（以下中結性の薬液という）の二種類の薬液が使用される。なお、前記薬液供給ユニット１０には、瞬結性の薬液と中結性の薬液との二系統の薬液供給装置が設けられる。これら薬液供給装置は、Ａ液とＢ液との各調製用のタンク１５，１６及び１５’，１６’から前記瞬結性の薬液と中結性の薬液とを切替える液切替バルブ１７，１７’と１８，１８’を経てＡ液用の高圧ポンプＰ，Ｂ液の高圧ポンプＰ’に各々接続されてそれぞれの供給管１２，１３に繋がるようにされている。そして、前記瞬結性の薬液と中結性の薬液とを切替える液切替バルブ１７，１８にはそれぞれ洗浄水の供給管１９がバルブ１９’を介して配管されている。これらは公知の機器によって構成されている。
【００２５】
ここで取扱われる注入薬液としては、まず瞬結性の薬液には例えば、
Ａ液としては硫酸（６２．５％）１６リットル，
珪酸ソーダ（３号）６０リットル，
水１２４リットル、
の割合のものを２００リットル、
Ｂ液としてはセメント１２０Ｋｇ，
重炭酸ナトリウム４Ｋｇ，
水残量
の割合のものを２００リットル
として１：１の割合で混合注入されるゲル化タイムが約０．５〜１sec のグラウトが用いられる。
そして、中結性の薬液には例えば、
Ａ液としては珪酸ソーダ（３号）６０リットル，
水１４０リットル
の割合のものを２００リットル、
Ｂ液としてはセメント１２０Ｋｇ，
水残量
の割合のものを２００リットル
として１：１の割合で混合注入されるゲル化タイムが３０〜６０sec のグラウトが用いられる。
なお、この薬液の成分については、上記成分に特定されるのではなく、ゲル化タイムを変えるとともに結合強度を維持できるに適した成分のものを採用することができる。
【００２６】
このような薬液は、薬液供給ユニット１０におけるＡ液，Ｂ液各１台の高圧ポンプによって、約３０〜１００Kg／cm² の圧力で１０〜２０リットル／min 程度の吐出量にて供給される。そして、前記注入圧力については、目的構築物の推定重量が軽くて地盤が砂質層の比較的注入速度が早い状態では低圧での注入で目的を達成できる。また、構築物の推定重量が大きい場合には、注入圧力を高める必要がある。そして、薬液の注入に際して、その初期の段階では圧力を高めて注入する必要があるが、薬液が地中に流入していわゆる流れが始ると注入圧力は低下するので予め設定される注入時間内で注入する。なお、注入操作は地盤など目的構造物の状況に応じて選択されることになり、最適の条件は復元作業を行いつつ設定することになる。したがって、薬液の注入には前記能力の範囲で作動できるポンプを用いて実施するのが好ましい。
【００２７】
薬液注入に際しては、まず、基礎２の上面からこの基礎下部地盤３０のぐり石層などに向って先に掘削された孔に薬液注入ロッド５を所要深度まで挿入して設置する。薬液注入ロッド５が設置されると、この薬液注入ロッド５に前述の瞬結性の薬液（Ａ液とＢ液）と中結性の薬液（Ａ液とＢ液）が予め設定された手順によって薬液供給ユニット１０から接続された供給管１２，１３を通じて圧送され、当該薬液注入ロッド５の先端混合部で混合されて地中に注入される。
【００２８】
前記薬液注入ロッド５による注入箇所は、一般的に約２ｍ間隔（これに限定されることはなく、基礎部の剛性を考慮して、より広い間隔あるいは狭い間隔であってもよい。）で目的構築物（建物１）を復元させるに要する基礎部全般に対応する数応分の配列で複数箇所に配設される。そして、これら薬液注入箇所の各薬液注入ロッド５には、切替バルブ１１，１１を図示されない遠隔操作装置によって所要のインターバルで切替えて、別途場所に設置される薬液供給ユニット１０から、Ａ液とＢ液とが、前記薬液供給ユニット１０の高圧ポンプＰ，Ｐ’によって所要の割合で供給される。
【００２９】
各薬液注入箇所の薬液注入ロッド５に対する供給順序は、目的構築物の沈下傾斜状態に応じて採択される。その一例を図５によって説明する。構築物の沈下状態を図上ａ側が１０ｃｍ，ｂ側が５０ｃｍとする。この状態で基礎部下に薬液注入するポイントを１から１２と三列に、各列四箇所ずつと設定する。そこで、予め設定される薬液の注入インターバルは、例えば１〜４の注入箇所で５秒、５〜８の注入箇所で１５秒、９〜１２の注入箇所で２５秒とする。このようなインターバルで１番の注入箇所からその隣接位置に順次第２，第３，第４‥‥１２と薬液注入箇所を切替バルブ１１，１１が切替えられて薬液が供給される。このような薬液注入箇所に対する薬液の注入順序を一巡する場合に使用される薬液は、そのゲル化タイムが最初の位置１に対して次回注入時までの時間（前記例で１８０秒）よりも短いものが使用される。そして、この薬液の供給は、まず中結性の薬液を各薬液注入箇所に前記要領で注入する。この際薬液の供給量は、例えば前記薬液で１０〜２０リットル／min の範囲で選択される（地盤の地質及び構築物の推定重量・基礎面積などを勘案して作業の進捗状況に応じ任意に選択変更される）。
【００３０】
このようにして薬液が注入されると、その第１回目においては、図４の符号アで示されるように、最初に注入される中結性の薬液は地中において何等大きな抵抗を受けることがないので、ゲル化するまでの範囲で注入位置を中心とするほぼ円形に比較的広い範囲で周囲に拡散して土砂と結合凝結される。この際、注入薬液は薬液注入ロッド５の吐出端から上下並びに水平方向に拡散され、そのゲル化タイム（３０〜６０秒）の範囲で凝結が始まる。したがって、予定時間の注入が終ると、直ちに次の注入箇所に切替えて隣接位置に注入を行う。以下このようにして前述のインターバルですべての注入箇所に薬液を所要量ずつ注入する。このような操作によって、地中には各注入箇所ごとに薬液と土砂との凝結されたほぼ円形の地盤強化層３１が形成される。
【００３１】
薬液が地中に注入されると砂質層の地層では、砂粒同士が非圧縮状態で地層を形成しているので、それら砂粒間に薬液が浸透して砂粒の周面に付着凝結し、いわば接着剤の働きをして浸透した範囲が１群の硬化体として強化され、安定した地盤強化層３１として支持強化地盤が各薬液注入箇所を中心として形成されることになる。
【００３２】
やがて、最初に注入した注入箇所における地盤強化層３１が薬液の反応にともなって固結して所定の強度を発現する過程の途中に差し掛かる時点で、次に薬液を瞬結性の薬液に切替えて、再び薬液注入ロッド５から薬液を注入する。この薬液の切替えに際しては、薬液供給ユニット１０において、液切替えバルブを操作して一旦液の供給を停止し、管路に洗浄水を供給して各供給管１２，１３と各切替バルブ１１及び各薬液注入ロッド５を水洗して、先の中結性の薬液と次に供給する瞬結性の薬液とが反応して流通路の閉塞を起こすのを防止する処置を行う。
【００３３】
瞬結性の薬液が前記インターバルで各薬液注入箇所に注入されると、先に注入された中結性の薬液が反応してホモゲル化しつつあるが（図６参照）、その強度が未だ安定域に達していない状態であるために、注入される薬液に作用する圧力で薬液注入ロッド５の先端から地盤強化層３１の一部を割裂して、この地盤強化層３１内部からその近傍に向って薬液が圧入される。この圧入初期においては、前述の地盤強化層３１の割裂を起こさせるまで高い注入圧力を要するが、その割裂現象が生じた後注入圧力が低下して以後の注入を容易にし、急速に注入が行える。
【００３４】
すると、圧入される薬液は、前述のような初期の注入時と異なって、地盤３０に働く土圧力並びに構築物の負荷と先に形成されている地盤強化層３１による下側への流動阻止作用で、主にこの地盤強化層３１の上側に流動可能な制限を受けることになり、前記土圧力並びに構築物の負荷に打ち勝つ圧力で圧入されることになる。その結果、圧入される薬液は、硬化されていない強化部で主に水平方向に拡散され、概ね地盤強化層３１の上層内部に沿って薄い層になって拡散流動して、そのゲル化タイムの範囲内（ホモゲル）の液状態で薬液の注入圧力が蓄圧されることになる。この際、地盤強化層３１は既に地盤３０中で固定された状態を呈していると同時に、前述のように地盤３０を形成している砂質層は非圧縮性であるので、この地盤強化層３１に前記薬液による蓄圧力の反力が作用して、蓄圧される薬液の拡散された範囲で上側の地層が押し上げられることになる。（図１(c) 及び図４参照）。
【００３５】
このようにして瞬結性の薬液が所定の順序で各注入箇所にて注入されると、再び薬液供給ユニット１０において液供給を停止して、前述のように薬液供給系の管路を水洗する。その後に中結性の薬液に切替えて前記操作を繰り返す。以後順次下記のような順序で薬液の注入が所要の回数繰り返し行われる。なお、符号Ｍは中結性の薬液の注入を、Ｓは瞬結性の薬液の注入を、水は管路の水洗を、それぞれ表している。
注入開始Ｍ→水→Ｓ→水→Ｍ→水→Ｓ→‥‥‥‥水→Ｍ→水→Ｓ→水→
と所要の回数切替えて作業を行う。
【００３６】
このような作用が配列された各薬液注入箇所で順次前記インターバルにて行われる薬液の注入（圧入）で、各地盤強化層３１上の地層が徐々に持上げられることになる。したがって、前述の薬液注入操作を所要のインターバルで、各薬液注入箇所を順番に繰り返し継続して行うとともに、その注入（圧入）操作箇所を地層の上昇状態に応じて上部の構築物の沈下量の大きい範囲と少ない範囲との操作に差をつけて、沈下量の大きい部分から次第に上昇させるように調整する。このようにすることにより、それら薬液注入箇所を中心とする連続した地盤３０が次第に隆起して、その地盤３０が隆起する高さに応じて傾いた構築物の沈下している基礎部が押上げられる。予め、測量器具によって沈下していた部分の構築物の上昇量を作業の経過とともに計測して、あるいは建物の床面の水準を計測して、正常な状態に復帰するまで前記薬液の注入作業を継続する。
【００３７】
前述の薬液注入操作において、中結性の薬液による注入ではそのゲル化タイムがやや長いので、注入位置から周囲への拡散範囲が広がりを持ち、先に注入凝結された地盤強化層３１上で広範囲に薄膜状に拡散して、そのゲル化開始とともに注入圧力が広い範囲で地盤の押上げ力として作用することになり、結果的に強力な押上げ力を発揮させ得る。また、瞬結性の薬液の注入ではそのゲル化タイムが短いので、注入箇所を基準とする狭い範囲で地盤強化層３１を迅速に盛り上げ強化するのに役立てる。したがって、瞬結性の薬液と中結性の薬液との複合使用によって、地盤中に強化支持部をより早く形成させるとともに比較的小さい注入圧力で大きな重量の構築物を容易に持上げることができる。
【００３８】
上述のように施工することよって、図１(b) 〜(d) で示されるように、傾斜状態から正常に復元された構築物の基礎２が支えられる地盤３０は、薬液注入による地盤３０の押上げと同時に改良強化され、広い面積で安定支持されることになり、再び地震に見舞われても地盤３０の液状化現象による土砂の流動での沈下現象を受けることなく安定維持される。なお、前述の薬液注入による復元操作にあたって、注入位置の切替操作や注入時間の管理、注入量の調整、注入圧力の調整などは、薬液供給ユニット１０に付属させる制御手段を予め設定された操作プログラムで作動させて、自動的に操作することが可能である。このようにすれば、設営準備に多くの人手を必要としても、復元操作を自動化することで工期を短縮して経済性を高めることができる。
【００３９】
以上の説明では、“べた基礎”の建物における薬液注入による不等沈下構築物の復元工法について述べたが、構築物の躯体支持柱の下部分に基礎を配した構造（一般に布基礎と呼ばれている）の構築物の場合には、構築物の外部などから前記基礎部の地盤３０に対して、前述と同様に薬液注入ロッド５を複数箇所で設置し、それら各薬液注入ロッド５に前述と同じ要領で順次薬液の注入（圧入）を繰り返す操作を実施することによって傾いた構築物を復元させることができる。
【００４０】
また、前述の操作の説明では中結性の薬液を先に注入して、その後に瞬結性の薬液を注入する方式によっているが、この操作と逆の組合わせによっても実施可能である。また、前述の複数の薬液注入箇所に対する薬液注入順序については、前記例のように１〜１２を一巡するごとに中結性の薬液と瞬結性の薬液を切替える操作のみならず、建物の持上げ状況によってはランダムに注入順序を変更するとともに、両薬液の切替操作も変更して行うことができる。さらにまた、建物の構築状態が、例えば鍵の手状、あるいはくの字状に建設されている場合、又は細長い状態の場合などでは、薬液供給ユニット１０を複数基配置し、それぞれ別個に前述の要領で複数の薬液注入箇所に配管して各薬液注入系統を同時進行で操作することにより構築物全体を無理なく持上げて復元させることができる。
【００４１】
また、本発明の不等沈下構築物の復元工法によれば、図７で示されるように、地盤３０が主にシルト層のような粘性土からなる地層３０ａ上に構築されて傾斜した建物１などの構築物を有効に復元維持できる付加的な工法をも実施できる。この復元工法では、構築物基礎が支持される地盤３０の圧縮性の地層３０ａに圧力を付加して圧密強化を促進させる操作を併用できるのである。
【００４２】
この復元工法は、まず建物１の下部基礎（この例ではいわゆる“べた基礎”である）上から地中深く（できれば岩盤，砂礫層３５などまで）掘削して金属棒にてなるアンカー２０を所要の間隔で、基礎面積に応じた配分にて複数本適宜打込み、これらアンカー２０の先端部２１を瞬結性の薬液５で地中に固定する。なお、このアンカー２０は必要に応じて途中で公知の手段によって接続して１本に繋がれる。
【００４３】
このアンカー２０の上端部２２は基礎上に突出させ、基礎部４の上に敷設した強固な盤木２５に反力を受けさせて公知手段でジャッキ２６（例えば油圧ジャッキ）により適度な引張力を付加させる。その後において、基礎部４からその下側に前述のように所要の間隔（約２ｍ）で複数の二重管型薬液注入ロッド５を挿入設置して、これら各薬液注入ロッド５に前記要領で別途設置の薬液供給ユニット（図示せず）からそれぞれに配管され、前記要領で所要のインターバルにて前記同様の薬液を供給圧入する。
【００４４】
この薬液の注入操作によって基礎部４下の地盤３０には、前述のように繰り返し薬液が注入されて地盤強化層３１が形成され、注入（圧入）される薬液の蓄圧作用によってその地盤強化層３１によって基礎部４とともに建物１が順次持上げられ、傾斜した構築物が次第に正常に復元される。この際、前述のアンカー２０によって深層部と連結されている状態の構築物（建物１）は、前述の薬液圧入による押上げ作用によって上方に戻されると、そのアンカー２０にはさらに強い引張力が作用する。したがって、その復元工程での状況に応じてジャッキ２６によるアンカーへの引張力を緩めるようにする。その結果、構築物の基礎部を支える前記地盤３０の強化層が地盤３０中のシルト層のような圧縮性地層３０ａを押圧して、その押圧部分において地層の圧縮作用が生じ、当該圧縮性地層３０ａの早期圧密が促進される。
【００４５】
このような手段によって不等沈下構築物の復元工法を実施すれば、傾斜復元操作時に、圧縮性の地盤３０ａの改良を同時に施され、長期間に発生するであろう地盤３０の沈下が防止されて地盤の安定化が図れ、不等沈下などによる構築物躯体への影響を未然に防止できる効果がある。もちろん、地盤３０の改良と前述の地層を隆起させて沈下した基礎部を押上げる操作については、前述の実施例と同様でその作業性に何等支障を来すことはない。
【００４６】
前記圧縮性の地層３０ａの圧密強化を伴う不等沈下構築物の復元工法におけるアンカー２０使用の方式に代えて、構築物に付加する上載荷重として、水槽に水を満たして使用することができる。この水槽としては、公知のタンクに水を注入して所要の重量となるように構築物の基礎上面に配置する。そして、前述の薬液注入操作によって基礎とともに建物が持上げられる上昇過程で、徐々に水槽内の水を放出することにより、基礎に対する上載荷重を加減することが容易に行えることになる。したがって、この方式によれば、水槽の設置スペースを必要とするが、アンカー方式のような掘削とアンカーの植込み作業を要しないので、作業性が容易となる。
【００４７】
また、本発明の不等沈下構築物の復元工法を実施するに際し、その作業現場の環境によっては、前述の薬液注入に伴い地盤中での薬液の拡散作用によって、注入箇所の周辺に薬液の浸透が生じて地盤に対する負荷の小さい部分において地盤を隆起させる恐れがある。そのために、予め前述の復元作業を実施する前に目的構築物の近隣位置に所要深さまで矢板（シートパイル）を打込んで、注入位置から構築物基礎下の地盤以外に薬液が流出するのを防止する手段を構じておくのが好ましい。また、このようにすることで、薬液注入による復元作用を有効に実施できることになる。
【００４８】
以上に述べたように、本発明によれば、ゲル化タイムの短い薬液を地層中に適宜時間をおいて繰り返し注入して、極く短時間で凝結して地中に圧密された地盤強化層を広い範囲に形成し、かつ全体が一体的に形成されるようにできる。そして、その形成された地盤強化層が圧縮に対して強く、引張りに対して弱い物性を巧に利用して、短い時間のインターバルで所要のローテーションにて注入位置を切替える操作により、徐々に地盤強化層を増大形成して次第に地盤を固めつつ盛り上げて強力な地盤強化層に順次反力を作用させ、広い範囲に注入液圧を分布させるようにすることで、比較的小さい液圧力でもってより大きい持上げ力を得られ、合理的にかつ無理なく構築物を上昇させることができる。したがって、構築物に局部的な押上げ力が作用せず、全体を緩やかに押上げて比較的短時間で所期の目的を達成できる。
【００４９】
上記本発明の実施例では、複数のゲル化タイムの異なる薬液を使用して構築物の支持地盤を強化するとともに持上げる操作について説明したが、使用する薬液について１種類のゲル化タイムの短い薬液（例えば中結性）を使用して、複数の薬液注入箇所に対してそのゲル化タイムに対応させたインターバルで所要の範囲で注入位置を巡らせて順次注入操作を行うようにすることもでき。
【００５０】
【発明の効果】
本発明の不等沈下構築物の復元工法によれば、上述のように、構築物の建設地盤を地層内部から徐々に持上げて復元させる方法であるから、構築物の不等な押上げ力が作用することなく安全に復元でき、準備作業についても直接構築物に大きな外力を加えるような作業を必要せず作業上も安全で、しかも短期間で作業を終了できるので工費も少なくてすみ経済的効果著しいものである。また、対象となる構築物は大小を問わず採用できるので、特に大きい建造物の復元に偉効を発揮できる。
【図面の簡単な説明】
【図１】本発明の不等沈下構築物の復元工法によって傾いた建物を復元させる態様を模式的に表す図であって、(a) は建物が正常状態にあるのを示し、(b) は地盤が不等沈下して建物が傾いている態様を示し、(c) は本発明の工法を施工開始する態様を示し、(d) は本発明の工法による薬液注入操作で建物が正常に復元された態様を示している。
【図２】図１で示される建物の基礎下部に対する複数の薬液注入箇所とそれらの注入の配管態様を表した平面図である。
【図３】薬液注入ロッドに対する薬液供給ユニットからの薬液供給系統を示す図である。
【図４】薬液の注入操作を加えている態様を模式的に表す要部断面図である。
【図５】薬液注入箇所の配置の一例を示し注入のインターバルを説明する図である。
【図６】注入薬液の強度−時間曲線における薬液注入許容時点を例示する図である。
【図７】本発明の不等沈下構築物の復元工法に地盤の圧密促進操作を付加された場合の態様を模式的に表す図である。
【符号の説明】
１建物
２基礎
４基礎部
５薬液注入ロッド
１０薬液供給ユニット
１１切替バルブ
１２，１３薬液の供給管
１５，１５’ Ａ液の調製用のタンク
１６，１６’ Ｂ液の調製用のタンク
１７，１７’，１８，１８’ 瞬結性の薬液と中結性の薬液の液切替バルブ
２０アンカー
２１アンカーの先端部
２２アンカーの上端部
２６ジャッキ
３０地盤
３０ａ圧縮性の地層
３１地盤強化層
Ｐ，Ｐ’ 高圧ポンプ[0001]
[Industrial application fields]
The present invention mainly relates to a method of restoring a structure that has been sunk unevenly, and more specifically, the foundation of the structure is sunk unevenly and the structure body is tilted to effectively inject the chemical into the lower part of the foundation to strengthen the support ground. The present invention relates to a method for restoring an unequal subsidence structure that is improved and lifts the structure body by pressing force with an injecting chemical solution to return it to normal.
[0002]
[Prior art]
In general, in a structure where the ground is built on a formation such as alluvium, when the liquefaction phenomenon of the formation occurs due to a severe impact such as a large earthquake, the support base collapses and the foundation stability is lost. Many of the recent earthquake disasters make it difficult to maintain the living environment by tilting the upper body.
[0003]
Such a structure with a slanted frame maintains the strength of the frame in normal architectural design, but the ground supporting the foundation flows due to liquefaction and the support of the frame is lost. It is out of balance and tilted. For this reason, it is not easy to restore the tilted structure (building).
[0004]
As a usual means to restore such a tilted structure, a strong beam material is laid on the lower side of the tilted structure (building), and this strong beam material and the building foundation of the building A means of putting a jack between important points and gradually lifting the housing with the jack to repair it can be considered.
[0005]
[Problems to be solved by the invention]
However, such a measure is very dangerous because the ground must be dug down in order to place the strong beam material underneath the frame foundation, and it requires a powerful jack. Many difficulties are involved in the work. Furthermore, since a jack is used, a lifting force is inevitably applied locally, and if it is attempted to support and restore a wide range without difficulty, a great deal of labor and work is required, and workability is not good. Of course, there is a problem in economic efficiency because of the great construction cost.
[0006]
In the present invention, such a problem is solved, and even if the foundation is wide and a heavy structure (such as a multi-story building), the ground can be improved safely using chemical solution injection. It is an object of the present invention to provide a highly economical method for restoring an uneven settlement that can be restored in a short period of time.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the restoration method of the unequal subsidence structure of the present invention is to install a plurality of chemical solution injection rods at a required interval so that the tip discharge part is located at the lower part of the foundation of the target structure. Repeated operation to press and press the chemical solution with short gelation time into each chemical solution injection site in the required order at the required interval with the injection rod, and the ground was strengthened by the next chemical injection operation at each chemical injection site first Then, by splitting the homogel part of the chemical solution and injecting the chemical solution, a lifting force is applied to the lower portion of the foundation, and by lifting up the chemical solution injection operation, the construct is lifted together with the basic portion to restore the construct to a normal state. In the case of the chemical solution As When using multiple types of chemical solutions with different gelation times and using multiple types of chemical solutions with different gelation times, This These chemical solutions with different gelation times are alternately switched to perform the injection operation, and the reinforced support ground is sequentially formed in the important places with the injected chemical solution, and the range of this reinforced support ground is expanded and lifted to the base part over a wide range It is characterized by acting force.
[0008]
In the present invention Multiple species The gel time of chemicals is Respectively It is preferable that the chemical solution is solidified before being injected next at the chemical solution injection site. And, the chemicals having different gelation times are those having one of the chemicals having an instantaneously short gelation time, and the other chemicals having an intermediate property having a longer gelation time than the former. Good. In addition, the switching injection of the chemical solutions having different gelation times is performed without hindering the injection of the chemical solution by performing a water washing operation. In addition, when the next injection operation is performed before the solidification of the formation by the injected chemical solution progresses and the final strength is generated, the injection operation of the chemical solution is performed again after performing the water washing operation of the injection route. Good.
[0009]
Also, the above Multiple species In order to inject chemical solutions with different gel times, first, a neutral chemical solution is sequentially switched to multiple chemical injection locations at the required interval, and injection operation to each chemical injection location using the chemical solution is required. It is preferable that after the circulation within the range, the instantaneously setting chemical solution is sequentially switched and pressed into the plurality of chemical solution injection portions at a predetermined interval, and thereafter this operation is repeated as many times as necessary. Of course, it can also be carried out by the reverse of this operation.
[0010]
Furthermore, the present invention provides a plurality of chemical injection locations at a required interval with respect to the ground below the foundation of the structure. At The above Multiple species Each time the chemical solution with different gelation time is switched to each chemical solution injection location at the required interval and press-fitted within the required range, the operation of switching and injecting the chemical solution is repeated. In addition to the operation of lifting up, a plurality of anchors of the required length are inserted and fixed to the required depth and a load is applied to the base part, or a load is placed on the base part and the base part of the structure is moved from the normal state. In addition to increasing the overload, the consolidation of the lower formation is promoted, and the structure is lifted together with the foundation while the overload is adjusted to restore the normal state, so that the ground becomes a compressible formation like a viscous soil layer. In this case, early consolidation strengthening of the stratum beneath the ground strengthening part is promoted, and it is possible to prevent such a phenomenon that the structure is tilted again due to re-sinking of the ground.
[0011]
In addition, in order to promote consolidation consolidation of the lower foundation layer of the structure, a load tank to be mounted on the upper part of the foundation of the structure is used with a required water tank, and the loading load is adjusted by adjusting the amount of water in the water tank. Is good. Also, the anchor is bored from the upper part of the foundation to the ground below the foundation to the required depth, and the tip of the anchor is hardened and fixed with a chemical solution. It is preferable that the load be applied in excess of its own weight. In addition, it is preferable that this anchor is provided at a plurality of locations at a predetermined interval in the base portion of the target structure so that an average pressing force is applied to the deep portion of the ground below the base.
[0012]
In addition, the chemical solution injection operation of the present invention is a multiple injection method using a plurality of chemical solution injection units when the target structure has a wide construction area, or when the base part shape of the structure is a shape other than a square shape. It is better to carry out in parallel.
[0013]
[Action]
According to the restoration method of the unequal settlement structure of the present invention, a chemical solution having a short gelation time is used from each chemical solution injection rod inserted at a plurality of locations under a base portion of the inclined structure. By repeating the operation of sequentially switching and injecting the chemical solution injection site at the required interval, a reinforced support ground is formed under the base in a short time, and then the reinforced support ground formed sequentially by the subsequent chemical solution injection Then, the injection pressure of the next injection chemical solution splits a part of the ground and the homogel portion of the chemical solution, and diffuses and flows the chemical solution mainly in the upper layer portion of the reinforced support ground. Since the flowing chemical is stopped by its own gelation time, the injection pressure is propagated in a wide range above and below the liquid layer. Therefore, the injection pressure of this chemical solution layer is received by the reinforced support ground, and it is as if a "wedge" is driven in, and the structure is gradually lifted together with the foundation by the upwardly acting push-up force, and the chemical solution is repeatedly repeated. The intended purpose can be easily achieved by injecting. Further, by repeating such an operation, the supporting ground is also strengthened.
[0014]
At this time, when multiple different types of chemical solutions having different gelation times are used as the chemical solution, and one chemical solution and the other chemical solution are sequentially injected at each required interval, the injection operation is required. By repeating the operation of switching and injecting the chemical solution every time you visit the chemical injection site in the range, the required lifting and strengthening support ground can be obtained in a short time by injecting the chemical solution with a short gelation time, and this chemical solution with a short gelation time By injecting the chemical solution having a longer gelation time, the chemical solution can be permeated more widely to form a reinforced ground in a wide range exceeding the reinforced support ground. And by the expansion of the reinforced support ground formed by alternately injecting these chemical solutions with different gelation times using the same chemical injection rod, the injection pressure of the injected chemical solution can be applied to the base of the structure widely. For example, a large lifting force can be obtained with a relatively low injection pressure, and the structure can be efficiently lifted together with the base portion. Therefore, the injection pressure, injection volume, and location of the injection of the chemical solution can be easily and easily reduced in a short period of time by adapting the rigidity of the foundation of the target structure, the rigidity of the underground beam, the pushing load of the structure, etc. The construct can be restored successfully. At the same time, the ground under the foundation of the structure can be effectively strengthened and improved over the entire target range.
[0015]
In the method of the present invention, the gelation time of the chemical solution to be used is within the range in which the chemical solution is consolidated before the next injection when switching to a plurality of chemical solution injection locations and performing the injection operation. Is good. In the case of a chemical solution having such a gelation time, when it is repeatedly injected at a required interval, the previously injected chemical solution is already mixed with earth and sand and solidified to form a reinforced support ground (still solidified completely). The reinforced support ground can receive the newly injected chemical solution and support the lifting reaction force of the base portion. In addition, since the above-mentioned switching operation of the chemical solution can be performed at the same injection location, a wide range of sharing can be covered by one pump, and the construction period can be shortened if multiple pumps are used if necessary. Can improve economy.
[0016]
In this way, by adopting a method in which a chemical solution is injected by sequentially switching at a plurality of injection locations with a required interval, the reaction force increasing function at each injection location is enhanced uniformly. In particular, it is possible to switch between adjacent reinforced support ground formed by the injection of the instantaneous instantaneous liquid chemical by switching the instantaneous liquid chemical and the intermediate liquid chemical at the same liquid chemical injection site and sequentially injecting them. The range of ground improvement and strengthening can be expanded by the penetration of the chemical solution, and the entire base portion of the target structure is integrally strengthened, and the lifting action by the injection pressure of the chemical solution can be effectively functioned in a wide range. Therefore, even if the inclined state of the structure, its height, construction area, etc. are different, the number of medicinal liquid injection locations, the injection pressure and the injection amount (discharge amount), etc. of the chemical liquid injection should be adjusted according to the situation. It is possible to facilitate preparation of chemical liquid injection and the chemical liquid injection work, and to perform the restoration work of the inclined structure in a short period of time.
[0017]
Further, in the present invention, an upper load is applied to the upper part of the foundation of the tilted structure so that the load is applied to the foundation more than its own weight, and the above-described chemical solution injection operation is performed to lift the foundation. By gradually reducing the load while balancing against the situation, for example, when the building ground is a compressible formation such as a viscous soil formation such as a silt formation, the formation of the formation below the ground reinforcement portion by the above-described chemical solution injection operation Early consolidation is promoted. As a result, even if the ground is like a compressible cohesive soil layer, the effect of preventing the phenomenon that the structure is inclined again by re-settlement can be obtained.
[0018]
【Example】
Next, one example of the restoration method for the uneven settlement structure of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 is a diagram schematically showing an aspect of restoring a tilted building by the restoration method of the unequal settlement structure of the present invention, wherein (a) shows that the building is in a normal state, (b) shows an aspect in which the ground is unevenly subsidized and the building is tilted, (c) shows an aspect in which the construction method of the present invention is started, and (d) is a state in which the building is injected by the chemical injection operation by the method of the present invention. The mode restored normally is shown. FIG. 2 is a plan view showing a plurality of chemical solution injection locations for the lower part of the foundation of the building shown in FIG. FIG. 3 is a diagram showing a chemical supply system from a chemical supply unit for the chemical injection rod. FIG. 4 is a cross-sectional view of an essential part schematically showing an aspect in which a chemical liquid injection operation is applied.
[0020]
As shown in these drawings, the construction method of the present invention first investigates and grasps the situation of the inclined building 1 (see FIG. 1 (b)) and examines the optimum working means. In this case, the subsequent work state is set according to the ground 30 supporting the inclined building 1 and the construction state of the foundation 2.
[0021]
First, assuming that the ground 30 is a non-compressed soil layer such as a sandy layer and the foundation 2 is a so-called “solid foundation”, the building 1 as shown in the above figure is restored. Means will be described. In this embodiment, a case where two kinds of liquids having different gelation times are used as the chemical liquid to be injected will be described.
[0022]
Most preferably, the chemical solution is injected from the inside of the building 1. In this case, the number of insertion positions of the chemical solution injection rod 5 and the arrangement interval are set in consideration of the relationship between the foundation area and the estimated weight of the structure (building 1 and foundation 2), the rigidity of the solid foundation, and the rigidity of the underground beam. . Therefore, if the foundation area is large, the rigidity of the foundation part is sufficiently large, and the estimated weight of the structure is large, it will be used in a large amount so as not to overload the chemical solution injection rod. If the basic area is small and the estimated weight of the structure is small, the number of the chemical solution injection rods 5 may be reduced. Moreover, if the rigidity of the base portion is small, the number of the chemical solution injection rods 5 is increased to cause the chemical solution to be injected more slowly than the former.
[0023]
As the chemical solution injection rod 5, a well-known double tube structure rod having a mixed injection portion of the liquid A and the solution B is used. And this chemical | medical solution injection | pouring rod 5 penetrates the foundation 2 of the building 1 by the required space | interval (usually about 2-2.5m) by the required space | interval (usually about 2 to 2.5 m), and it becomes the ground 30 of a base lower part. Insert against. In this case, it is preferable that the tip portion of the chemical solution injection rod 5 is inserted to the lower side of the base portion, and the lifting action force by the subsequent injection (press fit) of the chemical solution is immediately applied to the lower surface of the foundation 2 of the structure. . In addition, in order to estimate the state of the ground 30 in advance, it is preferable to sample the formation in the vicinity of the structure.
[0024]
If the chemical solution injection rods 5 are arranged at a plurality of locations at a required interval, the chemical solution injection rods 5 are provided with switching valves 11 and 11 from the high pressure pumps P and P ′ of the chemical solution supply unit 10 as shown in FIG. The supply pipes 12 and 13 (such as hoses) for the A liquid and the B liquid are respectively connected. In addition, as a chemical solution to be used, an instantaneously setting chemical solution with a short gelation time (hereinafter simply referred to as an instantaneously setting chemical solution) and a chemical solution referred to as an intermediate property with a slightly shorter gelation time (hereinafter referred to as an intermediately setting chemical solution). Two types of chemical solutions are used. Note that the chemical solution supply unit 10 is provided with two systems of chemical solution supply devices, that is, an instantaneous-setting chemical solution and an intermediate-setting chemical solution. These chemical solution supply apparatuses are liquid switching valves 17 and 17 ′ for switching between the instantaneously setting chemical solution and the intermediate setting chemical solution from the tanks 15, 16 and 15 ′ and 16 ′ for preparing the A solution and the B solution, respectively. And 18 and 18 ', respectively, are connected to the high pressure pump P for the A liquid and the high pressure pump P' for the B liquid, and are connected to the supply pipes 12 and 13, respectively. A wash water supply pipe 19 is connected to each of the liquid switching valves 17 and 18 for switching between the instantaneous-setting chemical liquid and the intermediate-setting chemical liquid via a valve 19 '. These are constituted by known devices.
[0025]
As an infusion drug solution handled here, first, for example, a quick setting drug solution
As liquid A, sulfuric acid (62.5%) 16 liters,
60 liters of sodium silicate (No.3),
124 liters of water,
200 liters,
B liquid is 120kg cement,
Sodium bicarbonate 4kg,
Water remaining
200 liters of the ratio
A grout having a gelation time of about 0.5 to 1 sec, which is mixed and injected at a ratio of 1: 1, is used.
And, for example, a neutral chemical solution
As liquid A, 60 liters of sodium silicate (No. 3),
140 liters of water
200 liters,
B liquid is 120kg cement,
Residual amount of water
200 liters of the ratio
A grout having a gelation time of 30 to 60 seconds mixed and injected at a ratio of 1: 1 is used.
In addition, about the component of this chemical | medical solution, the thing of the component suitable for changing the gelatinization time and maintaining a bond strength is not employ | adopted as said component.
[0026]
Such a chemical solution is about 30 to 100 kg / cm by a high pressure pump for each of the A and B solutions in the chemical supply unit 10. ² At a pressure of about 10 to 20 liters / min. With regard to the injection pressure, the objective can be achieved by injection at a low pressure when the estimated weight of the target structure is light and the ground has a relatively high injection rate of the sandy layer. Also, if the estimated weight of the construct is large, it is necessary to increase the injection pressure. When injecting the chemical solution, it is necessary to increase the pressure in the initial stage, but when the chemical solution flows into the ground and the so-called flow starts, the injection pressure decreases, so that the injection time falls within a preset injection time. Inject with. The injection operation is selected according to the condition of the target structure such as the ground, and the optimum condition is set while performing the restoration work. Therefore, it is preferable to inject the chemical solution using a pump that can be operated within the above-mentioned range.
[0027]
In injecting the chemical solution, first, the chemical solution injection rod 5 is inserted to the required depth from the upper surface of the foundation 2 toward the calcite layer of the foundation lower ground 30 to the required depth. When the chemical solution injection rod 5 is installed, the above-mentioned instantaneous setting chemical solution (A solution and B solution) and the interstitial chemical solution (A solution and B solution) are preliminarily set in the chemical solution injection rod 5. It is pumped through the supply pipes 12 and 13 connected from the chemical solution supply unit 10, mixed at the tip mixing portion of the chemical solution injection rod 5, and injected into the ground.
[0028]
The injection locations by the chemical solution injection rod 5 are generally at intervals of about 2 m (not limited to this, and may be wider or narrower in consideration of the rigidity of the base portion). Arranged at a plurality of locations in an arrangement corresponding to the entire foundation required to restore the structure (building 1). Then, each chemical solution injection rod 5 at these chemical solution injection locations is switched at required intervals by a remote control device (not shown) by a remote control device (not shown), and from the chemical solution supply unit 10 installed at a separate place, A liquid and B The liquid is supplied at a required ratio by the high-pressure pumps P and P ′ of the chemical liquid supply unit 10.
[0029]
The supply order to the chemical injection rod 5 at each chemical injection site is selected according to the subsidence inclination state of the target structure. An example of this will be described with reference to FIG. The subsidence state of the structure is 10 cm on the a side and 50 cm on the b side in the figure. In this state, the points for injecting the chemical solution below the base are set to 1 to 12 and 3 rows, 4 locations in each row. Therefore, the preset injection interval of the chemical solution is, for example, 5 seconds at 1 to 4 injection locations, 15 seconds at 5 to 8 injection locations, and 25 seconds at 9 to 12 injection locations. In such an interval, the second, third, fourth,... 12 and chemical solution injection locations are sequentially switched from the first injection location to the adjacent position, and the chemical solution is supplied. The chemical solution used when the injection sequence of the chemical solution to such a chemical injection site is completed has a gelation time shorter than the time (180 seconds in the above example) until the next injection with respect to the first position 1. Things are used. The chemical solution is supplied by first injecting a neutral chemical solution into each chemical solution injection site as described above. At this time, the supply amount of the chemical solution is selected, for example, in the range of 10 to 20 liters / min with the above chemical solution (arbitrarily selected according to the progress of the work in consideration of the geology of the ground and the estimated weight / base area of the structure) Be changed).
[0030]
When the chemical solution is injected in this manner, in the first time, as shown by the symbol a in FIG. 4, the first infused chemical solution is subjected to any resistance in the ground. Since it is not gelled, it is diffused to the periphery in a relatively circular shape centering on the injection position until gelation, and is bound and condensed with the earth and sand. At this time, the injected drug solution is diffused vertically and horizontally from the discharge end of the drug solution injection rod 5, and condensation starts in the range of the gelation time (30 to 60 seconds). Therefore, when the scheduled time injection is completed, the next injection location is immediately switched to perform injection at the adjacent position. Thereafter, in this way, the required amount of the chemical solution is injected into all the injection locations at the aforementioned intervals. By such an operation, a substantially circular ground reinforcing layer 31 in which the chemical solution and the earth and sand are condensed is formed in the ground for each injection point.
[0031]
When a chemical solution is injected into the ground, sand particles form a formation in a non-compressed state in the sandy layer, so the chemical solution penetrates between the sand particles and adheres to the peripheral surface of the sand particles, so to speak. The range penetrated by the action of the adhesive is strengthened as a group of hardened bodies, and the support strengthened ground is formed as the stable ground strengthening layer 31 around each chemical solution injection point.
[0032]
Eventually, when the ground strengthening layer 31 at the injection site where it was first injected is solidified in response to the reaction of the chemical solution and develops a predetermined strength, the chemical solution is then switched to an instantaneous-setting chemical solution. Then, the chemical solution is again injected from the chemical solution injection rod 5. When the chemical solution is switched, in the chemical solution supply unit 10, the liquid switching valve is operated to temporarily stop the supply of the liquid, and the cleaning water is supplied to the pipeline to supply the supply pipes 12 and 13, the switching valves 11, and the respective switching valves. The chemical solution injection rod 5 is washed with water, and a treatment is performed to prevent the flow of the flow path from being blocked by the reaction between the previously solidified chemical solution and the instantaneously supplying chemical solution to be supplied next.
[0033]
When instantaneously setting chemical solution is injected into each chemical solution injection site in the interval, the previously injected intermediate solution is reacting and becoming a homogel (see FIG. 6), but its strength is still in a stable range. Therefore, a part of the ground reinforcing layer 31 is split from the tip of the chemical solution injection rod 5 with the pressure acting on the injected chemical solution, and from the inside of the ground reinforcing layer 31 toward the vicinity thereof. The chemical solution is injected. In the initial stage of the press-fitting, a high injection pressure is required until the above-described ground reinforcement layer 31 is split. However, after the splitting phenomenon occurs, the injection pressure is lowered to facilitate the subsequent injection and the injection can be performed rapidly. .
[0034]
Then, unlike the initial injection as described above, the injected chemical solution is subjected to the soil pressure acting on the ground 30 and the load of the structure and the downward flow blocking action by the ground reinforcing layer 31 formed earlier. The upper part of the ground reinforcing layer 31 is restricted to be flowable, and it is press-fitted at a pressure that overcomes the earth pressure and the load of the structure. As a result, the injected chemical is mainly diffused in the horizontal direction at the uncured reinforced portion, and is diffused and flowed approximately along the inside of the upper layer of the ground reinforcing layer 31, and its gelation time is reduced. The injection pressure of the chemical solution is accumulated in the liquid state within the range (homogel). At this time, the ground reinforcing layer 31 has already been fixed in the ground 30 and, at the same time, the sandy layer forming the ground 30 is incompressible as described above. The reaction force of the accumulated pressure due to the chemical liquid acts on 31, and the upper formation is pushed up in a range where the accumulated chemical liquid is diffused. (See FIG. 1 (c) and FIG. 4).
[0035]
In this way, when the instantaneously setting chemical liquid is injected at each injection location in a predetermined order, the liquid supply is stopped again in the chemical liquid supply unit 10, and the pipe of the chemical liquid supply system is washed with water as described above. . Thereafter, the operation is repeated by switching to a neutral chemical solution. Thereafter, the chemical solution is repeatedly injected a required number of times in the following order. In addition, the code | symbol M represents injection | pouring of the caustic chemical | medical solution, S represents injection | pouring of the instantaneous caustic chemical | medical solution, and water represents the flushing of the pipe line, respectively.
Start of injection M → Water → S → Water → M → Water → S → ・・・・・ Water → M → Water → S → Water →
And switch the required number of times.
[0036]
By the injection (press-in) of the chemical solution sequentially performed at the intervals at the respective chemical solution injection locations where such actions are arranged, the formation on the local board reinforcing layer 31 is gradually lifted. Therefore, the above-mentioned chemical solution injection operation is repeatedly performed in order at each required interval, and the injection (press-in) operation location is large in accordance with the rising state of the formation. Make adjustments to gradually increase from the part where the sinking amount is large by making a difference in the operation between the range and the small range. By doing in this way, the continuous ground 30 centering on these chemical | medical solution injection | pouring locations gradually raises, and the foundation part which the structure which inclined according to the height which the ground 30 raises is pushed up is pushed up. . Continue to inject the chemical solution until it returns to normal by measuring the amount of the building that has been submerged by the surveying instrument in advance, or measuring the level of the floor of the building. To do.
[0037]
In the above-described chemical solution injection operation, since the gelation time is slightly longer in the case of injection with a neutral chemical solution, the diffusion range from the injection position to the surroundings is widened, and a wide range on the ground reinforcement layer 31 that has been injected and condensed first. It diffuses into a thin film shape and acts as a ground lifting force in a wide range of injection pressure as the gelation starts, and as a result, a strong lifting force can be exhibited. In addition, since the gelation time is short in the injection of the instantaneous setting chemical solution, it is useful for quickly raising and strengthening the ground reinforcing layer 31 in a narrow range based on the injection location. Therefore, the combined use of the instantaneous setting chemical solution and the intermediate setting chemical solution makes it possible to form the reinforced support portion earlier in the ground and to easily lift a heavy structure with a relatively low injection pressure.
[0038]
By performing the construction as described above, as shown in FIGS. 1 (b) to (d), the ground 30 on which the foundation 2 of the structure that has been normally restored from the inclined state is supported is pressed by the chemical injection. Improving and strengthening at the same time as raising, it will be supported stably over a wide area, and even if it is hit by an earthquake again, it will be maintained stably without receiving the subsidence phenomenon due to the flow of soil due to the liquefaction phenomenon of the ground 30. In the above-described restoration operation by the chemical solution injection, an operation program in which the control means attached to the chemical solution supply unit 10 is set in advance for the switching operation of the injection position, the management of the injection time, the adjustment of the injection amount, the adjustment of the injection pressure, etc. It can be operated automatically and operated automatically. In this way, even if a lot of manpower is required for the preparation for the installation, the restoration operation can be automated to shorten the construction period and improve the economy.
[0039]
In the above explanation, the restoration method of the unequal subsidence structure by chemical injection in the “solid foundation” building was described, but the structure in which the foundation is arranged in the lower part of the support column of the structure (generally called cloth foundation) In the case of the structure of), the chemical injection rods 5 are installed at a plurality of locations on the ground 30 of the foundation portion from the outside of the structure in the same manner as described above, and each of the chemical injection rods 5 is subjected to the same procedure as described above. A tilted construct can be restored by performing an operation of sequentially repeating injection (press-in) of the chemical solution.
[0040]
Further, in the description of the above-described operation, a method of injecting a caustic chemical solution first and then injecting an instantaneous caustic chemical solution is used, but it can also be implemented by a combination of this operation and the reverse. Moreover, about the chemical | medical solution injection | pouring order with respect to the above-mentioned several chemical | medical solution injection | pouring locations, it is not only the operation which switches between a chemical solution with a conjunctive and a chemical solution with a quick setting every time it goes through 1-12 like the said example, but the lifting of a building Depending on the situation, the injection order can be changed randomly, and the switching operation of both chemicals can be changed. Furthermore, in the case where the building is constructed in the shape of, for example, a hand of a key or a U-shape, or in the case of an elongated state, a plurality of chemical solution supply units 10 are arranged, and each of the above-described units is separately provided. The entire structure can be lifted and restored without difficulty by piping to a plurality of chemical solution injection locations and operating each chemical solution injection system simultaneously.
[0041]
Moreover, according to the restoration method of the unequal settlement structure of the present invention, as shown in FIG. 7, the ground 1 is constructed on a ground layer 30a mainly made of a viscous soil such as a silt layer, etc. It is possible to implement additional construction methods that can effectively restore and maintain these structures. In this restoration method, an operation of applying pressure to the compressible formation 30a of the ground 30 on which the structure foundation is supported to promote consolidation strengthening can be used in combination.
[0042]
This restoration method requires an anchor 20 made of a metal rod by first excavating from the lower foundation of the building 1 (in this example, a so-called “solid foundation”) deeply into the ground (preferably to the bedrock, gravel layer 35, etc.). At the intervals, a plurality of them are appropriately driven in a distribution according to the foundation area, and the tip portions 21 of these anchors 20 are fixed in the ground with the instantaneous setting chemical solution 5. In addition, this anchor 20 is connected by a well-known means on the way as needed, and is connected to one.
[0043]
The upper end portion 22 of the anchor 20 is projected on the foundation, and is subjected to a reaction force by a solid board 25 laid on the foundation portion 4, and an appropriate tensile force is applied by a jack 26 (for example, a hydraulic jack) by known means. Add. Thereafter, a plurality of double-pipe type chemical solution injection rods 5 are inserted and installed from the base portion 4 below the required interval (about 2 m) as described above, and each of these chemical solution injection rods 5 is separately provided as described above. Pipes are respectively installed from installed chemical solution supply units (not shown), and the same chemical solution is supplied and injected at a required interval in the above manner.
[0044]
As described above, the chemical solution is repeatedly injected into the ground 30 under the base portion 4 by the injection operation of the chemical solution to form the ground reinforcing layer 31, and the ground reinforcing layer 31 is formed by the pressure accumulation action of the injected (pressed) chemical solution. As a result, the building 1 is sequentially lifted together with the foundation 4, and the inclined structure is gradually restored to normal. At this time, when the structure (building 1) connected to the deep layer by the anchor 20 is returned upward by the push-up action by the above-described chemical injection, a stronger tensile force acts on the anchor 20. To do. Therefore, the tensile force applied to the anchor by the jack 26 is relaxed according to the situation in the restoration process. As a result, the reinforcing layer of the ground 30 that supports the foundation of the structure presses the compressible formation 30a such as a silt layer in the ground 30, and the compressive action of the formation occurs in the pressed portion. Early consolidation is promoted.
[0045]
If the restoration method of the unequal settlement structure is implemented by such means, at the time of the slope restoration operation, the compressible ground 30a is improved at the same time, and the settlement of the ground 30 that will occur for a long time is prevented. The ground can be stabilized and the effect on the structure of the structure due to uneven settlement can be prevented. Of course, the improvement of the ground 30 and the operation of pushing up the foundation that has been sunk by raising the above-mentioned formation are the same as in the above-described embodiment, and do not hinder the workability.
[0046]
Instead of using the anchor 20 in the restoration method of the uneven settlement structure with consolidation consolidation of the compressible formation 30a, the aquarium can be filled with water as an overload to be added to the structure. As this water tank, water is poured into a publicly known tank and arranged on the upper surface of the foundation of the structure so as to have a required weight. Then, in the ascending process in which the building is lifted together with the foundation by the above-described chemical liquid injection operation, it is possible to easily increase or decrease the load on the foundation by gradually discharging water in the water tank. Therefore, according to this method, an installation space for the water tank is required, but excavation and anchor implantation work as in the anchor method are not required, so that workability is facilitated.
[0047]
In addition, when carrying out the restoration method of the unequal settlement structure of the present invention, depending on the environment of the work site, due to the diffusion of the chemical solution in the ground accompanying the chemical solution injection described above, the penetration of the chemical solution around the injection site This may cause the ground to rise in a portion where the load on the ground is small. Therefore, before carrying out the above-mentioned restoration work in advance, a sheet pile (sheet pile) is driven to the required depth in the vicinity of the target structure to prevent the chemical solution from flowing out of the ground other than the foundation under the structure from the injection position. It is preferable to have a means. Moreover, by doing in this way, the restoration | restoration effect | action by chemical | medical solution injection | pouring can be implemented effectively.
[0048]
As described above, according to the present invention, a ground strengthening layer in which a chemical solution having a short gelation time is repeatedly injected into the formation at appropriate intervals and condensed in a very short time and consolidated in the ground. Can be formed in a wide range and can be formed integrally. The formed ground reinforcement layer is strong against compression and skillfully utilizes physical properties weak against tension, and gradually strengthens the ground by switching the injection position at the required rotation at short time intervals. By increasing the number of layers and gradually raising the ground while solidifying it, the reaction force is applied to the strong ground reinforcement layer in order to distribute the injection liquid pressure over a wide range, which is greater with a relatively low liquid pressure. The lifting force can be obtained, and the structure can be raised reasonably and easily. Therefore, a local lifting force does not act on the structure, and the entire object can be gently lifted to achieve the intended purpose in a relatively short time.
[0049]
In the embodiment of the present invention, the operation of strengthening and lifting the support ground of the structure using a plurality of chemical solutions having different gelation times has been described. However, one type of chemical solution having a short gelation time ( For example, it is possible to perform injection operations sequentially around the injection position within a required range at intervals corresponding to the gelation times for a plurality of drug solution injection locations.
[0050]
【The invention's effect】
According to the restoration method of the uneven settlement structure of the present invention, as described above, since the construction ground of the structure is gradually lifted from the inside of the formation and restored, the unequal lifting force of the structure acts. It can be safely restored without any need to apply large external force directly to the structure, and it is safe to work. In addition, the work can be completed in a short period of time, so the construction cost is low and the economic effect is significant. is there. In addition, since the target structure can be adopted regardless of the size, it can be particularly effective in restoring large structures.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram schematically showing a mode of restoring a tilted building by the restoration method of an unequal settlement structure of the present invention, wherein (a) shows that the building is in a normal state, and (b) shows (C) shows the mode of starting construction of the method of the present invention, and (d) shows normal restoration of the building by the chemical injection operation by the method of the present invention. FIG.
FIG. 2 is a plan view showing a plurality of chemical solution injection locations for the lower part of the foundation of the building shown in FIG.
FIG. 3 is a diagram showing a chemical supply system from a chemical supply unit to a chemical injection rod.
FIG. 4 is a cross-sectional view of an essential part schematically showing an aspect in which a chemical liquid injection operation is applied.
FIG. 5 is a diagram illustrating an example of an arrangement of chemical solution injection locations and explaining an injection interval.
FIG. 6 is a diagram exemplifying a medicinal solution injection allowable time point in an infusion medicinal solution strength-time curve;
FIG. 7 is a diagram schematically showing an aspect in the case where an operation for promoting consolidation of the ground is added to the restoration method of the uneven settlement structure of the present invention.
[Explanation of symbols]
1 building
2 Basics
4 foundation
5 chemical injection rod
10 Chemical supply unit
11 Switching valve
12,13 Chemical liquid supply pipe
Tank for preparing 15,15 'A liquid
16,16 'Tank for preparing B liquid
17, 17 ', 18, 18' Liquid switching valve for instantaneously setting liquid and intermediate setting liquid
20 Anchor
21 Anchor tip
22 Upper end of anchor
26 Jack
30 ground
30a Compressible formation
31 Ground reinforcement layer
P, P 'high pressure pump

Claims

A plurality of chemical solution injection rods are installed at the required intervals so that the tip discharge part is located below the foundation of the target structure, and these chemical solution injection rods allow a chemical solution with a short gelation time to be provided at each chemical solution injection site at the required intervals. Repeat the operation of switching and press-fitting in order, and at the place where each chemical solution is injected, lift the ground below the base by splitting the ground and the homogel part of the chemical solution that were previously intensified by the next chemical solution injection operation and injecting the chemical solution When a force is applied and the structure is lifted together with the base by accumulation of the chemical solution injection operation to restore the structure to a normal state,
Using a plurality of different chemical gelation time as the chemical,
The different chemical of these gelling time for each glove Tour the liquid injection portion performs injection operation is switched alternately, causes sequentially forming a reinforcing support ground at important in injection drug solution, expand the scope of this enhanced support ground A method for restoring an unequal subsidence structure, wherein a lifting force is applied to the foundation in a wide range.

The restoration method for an unequal subsidence structure according to claim 1, wherein the gel times of the plurality of types of chemical solutions are each within a range in which the chemical solutions are consolidated before the next injection at the chemical solution injection site.

The plurality of types of chemical solutions having different gelation times are ones in which one chemical solution has an instantaneous setting property with a very short gelation time, and the other chemical solution has an intermediate setting property in which the gelation time is longer than the former. The restoration method of the uneven settlement structure of claim | item 1.

In order to inject the plurality of types of chemical solutions having different gelation times, first, inject the neutralized chemical solution by switching to a plurality of chemical solution injection locations at a required interval in the required order, and inject each chemical solution by the chemical solution After the injection operation to the location is made within the required range, the instantaneously setting chemical solution is sequentially switched to the plurality of drug solution injection locations at the required interval, and thereafter this operation is repeated as many times as necessary. The restoration method of the uneven settlement structure according to claim 1 or 3.

It is necessary to sequentially switch and inject the plurality of types of chemical solutions having different gelation times at the required intervals to the ground below the foundation of the structure at the required intervals. In addition to the operation of lifting the structure together with the foundation by the chemical injection operation, multiple anchors of the required length are inserted and fixed to the required depth. Applying a load to the foundation or placing a load on the upper part of the foundation to increase the upper load on the foundation of the structure compared to the normal state to promote consolidation strengthening of the lower formation and adjusting the upper load The restoration method for an unequal subsidence structure according to any one of claims 1 to 4, wherein the construction is lifted and restored to a normal state together with the foundation.