JP4342517B2

JP4342517B2 - Steel plate impermeable wall and construction method of steel plate impermeable wall

Info

Publication number: JP4342517B2
Application number: JP2005508918A
Authority: JP
Inventors: 邦登酒井; 裕司浅上; 卓也田中
Original assignee: Tokyu Construction Co Ltd
Current assignee: Tokyu Construction Co Ltd
Priority date: 2003-09-11
Filing date: 2003-09-11
Publication date: 2009-10-14
Anticipated expiration: 2023-09-11
Also published as: AU2003262084A1; WO2005026448A1; JPWO2005026448A1

Description

【技術分野】
【０００１】
本発明は、軟弱地盤や固化材と原地盤を混合撹拌して造成される固化壁に鋼板を挿入して遮水壁を形成する鋼板遮水壁と、かかる鋼板の端部に設けた継手部に混合撹拌土が浸入固化するのを防ぐための継手部防護体、および鋼板遮水壁の構築方法に関するものである。
【背景技術】
【０００２】
液状化対策や汚染土壌（例えば廃棄物処分場）からの汚染物質の拡散防止対策、河川の漏水防止壁や地下ダムの遮水壁として、遮水壁工法が使用されている。
遮水壁工法としては、オーガーにて原地盤を掘削し原地盤とセメントを混合撹拌しながらソイルセメント固化壁を構築する方法や、固化材と原地盤を混合撹拌した固化壁に遮水材を建込む方法、高分子膜シートや鋼板シートをはじめとするシートウオール、鋼矢板などを打設して遮水壁とする方法など多岐にわたっている。
【０００３】
固化材と原地盤を混合撹拌した固化壁に遮水材を建込む方法において使用される遮水材としては、鋼板（鋼矢板）が使用されるのが一般的である。鋼板（鋼矢板）の両端部に継手を設け、隣接する鋼板（鋼矢板）同士を双方の継手をジョイントすることによって連続した鋼板遮水壁が構築される。
【０００４】
ところで、鋼板（鋼矢板）の継手の製作はその継手構造によって大きく２種類に大別できる。その一つは、１枚の鋼板を熱間成形又は冷間成形によって折り曲げ加工して継手を製作する方法である（特許文献１参照）。かかる製作方法は、鋼板を直角に折り曲げ成形する場合などに使用されている。
【０００５】
他の一つは、図７に示すように、ジョイントする一方の鋼板ａの継手ｂを断面リング状の筒体ｃとし、ジョイントする他方の継手ｂはリング状の筒体ｃを挿入可能とした筒体ｃよりも大径の断面円弧状の柱状体ｄとするものである。かかる断面リング状の筒体ｃおよび断面円弧状の柱状体ｄからなる継手ｂは鋼板ａをかかる形状に成形後、鋼板ａの端部に上記継手ｂを溶接接合することにより製作される（特許文献２参照）。
【特許文献１】
特開２０００−１０４２４４号公報
【特許文献２】
実開平５−２７１２９号公報
【発明の開示】
【発明が解決しようとする課題】
【０００６】
前記した従来の遮水壁および遮水壁の構築方法にあっては、次のような問題点がある。
＜１＞鋼矢板やシートウオールを打設する方法では、建込み時に生じ得る部材のねじれ等により、継手が外れる可能性がある。また、継手には土砂の介在が不可避となり、継手からの漏水等、遮水壁としての信頼性が低い。
＜２＞ソイルセメント固化壁を構築する方法では、固化壁の品質のばらつきが大きい。さらに固化壁のクラック制御が困難であり、特に地震時の地盤変形に対して漏水を誘発し得るクラックが発生する可能性が極めて高い。
＜３＞固化材と原地盤を混合撹拌した固化壁に遮水材を建込む方法では、固化材の硬化後に継手を連結できないため、連続施工を余儀なくされている。
＜４＞遮水材として使用する鋼板（鋼矢板）の継手において特許文献１の継手を使用する場合、隣接鋼板同士の双方の継手の接続は継手同士を噛み合せる構成となっているため、鋼板の打設精度が低いと接続が困難となる。
＜５＞遮水材として使用する鋼板（鋼矢板）の継手において特許文献２の継手を使用する場合、鋼板とその両端部に設ける継手を溶接接合するため、製作に困難性を伴うとともに遮水壁の製作コストが嵩むといった問題が生じ得る。
【課題を解決するための手段】
【０００７】
上記のような課題を解決するために、本発明の鋼板遮水壁は、原地盤に鋼板を挿入して遮水壁を形成する鋼板遮水壁であって、
１枚の前記鋼板の両端部付近を略円筒形に曲げ加工して、夫々の折り曲げ部と該鋼板の端辺との間に間隙を形成するように製作した継手部と、
前記の両端部の継手部の最下端に溶接接合した底蓋と、からなり、
前記継手部のうち、一方の該継手部の内径を他方の該継手部の外径に対して相対的に大径となるように成形して小径継手部および大径継手部を備えた前記鋼板とし、前記鋼板の前記大径継手部に隣接して設置する前記鋼板の前記小径継手部を挿入可能としたことを特徴とする。
また、前記鋼板において、前記鋼板の一端には一つ或いは複数の前記小径継手部を設け、他端には該小径継手部と同数の前記大径継手部を設けたことを特徴とする鋼板遮水壁を使用できる。
【０００８】
さらに、本発明の鋼板遮水壁の構築方法は、前記鋼板遮水壁の構築方法であって、固化材と原地盤を混合撹拌して造成される未固化状態の固化壁において、前記鋼板の両端部の小径継手部および前記大径継手部の最下端に溶接接合した前記底蓋を建込治具にて上方から押し込んで前記鋼板を前記固化壁内に挿入する鋼板設置工程と、
前記鋼板設置工程にて設置した既設鋼板に隣接設置する隣接鋼板の小径継手部を、前記既設鋼板の大径継手部に挿入しながら前記隣接鋼板の底蓋を建込治具にて上方から押し込んで隣接鋼板を順次設置していく隣接鋼板設置工程と、からなることを特徴とする。
また、前記する鋼板遮水壁の構築方法において、前記隣接鋼板の隣接設置を一時停止する場合には、前記隣接鋼板設置工程にて設置した最終端に位置する前記隣接鋼板の前記大径継手部に前記大径継手部に嵌装可能に成形した一つの棒体、又は板材を介して連結した複数の該棒体からなる継手部防護体を嵌装させておき、
再び前記隣接鋼板の設置を開始するときに前記継手部防護体を取り外してから隣接鋼板を順次設置していくことを特徴とする。
【発明の効果】
【０００９】
本発明の鋼板遮水壁および継手部防護体および鋼板遮水壁の構築方法は、上記した課題を解決するための手段により、次のような効果の少なくとも一つを得ることができる。
＜１＞固化材と原地盤を混合撹拌した固化壁に本発明の鋼板を建て込んで形成した鋼板遮水壁は、遮水壁（特に継手部）からの漏水の可能性が極めて低く、遮水壁としての信頼性が高い。
＜２＞固化材と原地盤を混合撹拌した固化壁に本発明の鋼板を建て込んで形成した鋼板遮水壁は、地震時の地盤変形などに対しても遮水壁からの漏水の可能性は低い。
＜３＞大径継手部の内空と小径継手部の外径との間には余裕をもったクリアランスを備えることができるため、遮水壁として使用する鋼板同士の接続は容易である。
＜４＞原則として１枚の鋼板から継手部を含んだ鋼板を製作するため、鋼板の製作コストは低廉となる。
＜５＞必ずしも連続施工をする必要がない。すなわち、鋼板の隣接設置において最終端に位置する隣接鋼板の大径継手部には継手部防護体を嵌装させておくことにより、鋼板同士の隣接設置の一時停止を可能とした固化材と原地盤を混合撹拌した固化壁に遮水材を建込む遮水壁の構築を実現できる。
【図面の簡単な説明】
【００１０】
図１は、本発明の鋼板遮水壁の施工状況を説明した説明図である。
図２は、１枚の鋼板の断面図である。
図３は、２枚の鋼板を隣接設置した状況の断面図である。
図４は、１枚の鋼板の他の実施例を示した断面図および他の実施例の鋼板を隣接設置した状況の断面図である。
図５は、他の実施例の鋼板を隣接設置した状況の断面図である。
図６は、継手部防護体を示した説明図である。
図７は、従来の鋼矢板（端部の継手部を含む）を示した断面図である。
【符号の説明】
【００１１】
１・・・鋼板遮水壁２・・・鋼板２２・・継手部
２２１・大径継手部２２２・小径継手部３・・・底蓋
４・・・固化材５・・・継手部防護体５１・・棒体
５２・・板材６１・・建込治具７・・・原地盤
８・・・固化壁
【発明を実施するための最良の形態】
【００１２】
＜１＞鋼板遮水壁
本発明の鋼板遮水壁１は、軟弱地盤や、固化材４と原地盤７を混合撹拌して造成される固化壁８に鋼板２を挿入して形成した遮水壁である。
固化壁８を造成する場合は、遮水壁の平面線形に沿ってバックホウ６４などで掘削溝７の地表付近を先行掘りし、原地盤７と固化材４として使用するセメントなどを混合撹拌しながら所定深度にわたる固化壁８の造成を追随させる（図１参照）。本発明の鋼板遮水壁１は、ほぐれた状態で、かつ未固化状態の固化壁８内に建込治具６１を介して鋼板２を挿入設置していくものである（図１参照）。なお、固化壁８の造成においては公知のＴＲＤ工法用ベースマシン６２を使用し、鋼板２の建込みはクレーン６３などを使用しておこなうのがよい。
また、鋼板遮水壁１は、上記する固化壁８内に挿入設置する方法のほかに、軟弱地盤内に直接圧入設置することにより遮水壁を構築することもできる。
【００１３】
＜２＞鋼板
本発明において使用する鋼板２は、例えば１枚の鋼板２をその両端部付近を同一の側に略円筒形に曲げ加工して製作する。ここで、略円筒形とは、断面視円形やほぼ円形とした場合のほか断面視楕円形なども含み、鋼板２の鉛直方向にわたって同一の断面視形状に折り曲げ成形してできた筒状をいう。曲げ加工された鋼板２の両端部は継手部２２として、鋼板２のその他の部分（中央部）は板部２１として製作される（図２参照）。なお、継手部２２では、鋼板２の折り曲げ部２３と鋼板２の端辺２４との間に間隙２２３を形成するように製作する。隣接設置する鋼板２の継手部２２を既設鋼板２の継手部２２に挿入可能とするためである。したがって、上記する略円筒形は筒状の一部に一条の鉛直方向にわたる切欠き（隙間２２３）を備えて構成される。
なお、継手部２２，２２は、必ずしも同一の側に設ける必要はない（図示せず）。
【００１４】
鋼板２の両端に形成する継手部２２，２２は、一方の継手部２２の内径を他方の継手部２２の外径に対して相対的に大径となるように成形するのがよい（この場合の継手部２２を小径継手部２２２および大径継手部２２１とする）。例えば、既設の鋼板２の大径継手部２２１に隣接設置する鋼板２の小径継手部２２２を挿入させながら設置させることができる（図３参照）
かかる挿入設置の関係上、大径継手部２２１には上記する間隙２２３を形成するような折り曲げ加工を要する。一方、小径継手部２２２の折り曲げ加工においては間隙２２３を形成してもしなくともよい。
【００１５】
小径継手部２２２の外径と大径継手部２２１の内径は適宜選定できる。小径継手部２２２の外径と大径継手部２２１の内径を大きく相違させれば挿入設置がより簡易となる。
尤も、大径継手部２２１に設けた間隙２２３の間隙幅は少なくとも小径継手部２２２の外径よりも小さくなるように成形することを要する。大径継手部２２１から小径継手部２２２が抜け出さないようにするためである。
また、鋼板２の両端に設ける小径継手部２２２と大径継手部２２１は夫々同じ数だけ複数設けることもできる（図４参照）。複数の小径継手部２２２，２２２と大径継手部２２１，２２１を接合させることにより、継手部２２の接合強度を増加させることができる（図５参照）。特に、地震時の地盤変形において鋼板２周囲の固化壁８にクラックが生じた場合でも、一箇所の継手部２２が強固に接合されていることにより継手同士の離脱の可能性も低くなり、遮水性能を向上させることができる。
鋼板２の有効幅（両端の大径継手部２２１と小径継手部２２２の中心間長さ）は、例えば１〜１．５ｍ程度に成形することができる。
【００１６】
＜３＞底蓋
底蓋３は、大径継手部２２１および小径継手部２２２の最下端に設ける板材である。１枚の鋼板２を固化壁８内に挿入する際に棒状の建込治具６１，６１を大径継手部２２１および小径継手部２２２内に挿入し、夫々の継手部２２，２２の最下端に設けた底蓋３，３を建込治具６１，６１にて均等に押込みながら鋼板２を挿入することができる。鋼板２の両端部にて建込治具６１，６１にて底蓋３，３を均等に押込むことから、押込みが容易であるとともに鋼板２に過度の捩れなどが生じ難い。
底蓋３は、例えば大径継手部２２１および小径継手部２２２夫々の備えた円弧状（各継手部２２の外径円弧）に成形した鋼製の板材からなる。尤も底蓋３の形状は各継手部２２の円弧状に拘束されるものではなく、継手部２２の内空を底部から塞ぐことができればよい。
鋼製の底蓋３は各継手部２２に工場又は現場ヤードにて溶接接合する。
【００１７】
＜４＞継手部防護体
継手部防護体５は、大径継手部２２１に嵌装可能に成形した棒体５１又は板材５２を介して連結した複数の棒体５１，５１から構成される（図６参照）。
棒体５１は、大径継手部２２１の内空形状とほぼ同一の外径を備えたパイプであってもよいし、上記形状を備えた中実の柱状体であってもよい。
継手部防護体５の実施例として、板材５２を介して複数の棒体５１，５１を連結させた継手部防護体５を含めるのは、大径継手部２２１に継手部防護体５を嵌装設置する際の安定性を確保するためである。
継手部防護体５の最上端には嵌装時および大径継手部２２１からの引抜き時に使用するワイヤー等の挿入孔を備えた吊治具５３を設けておくのがよい。
継手部防護体５は、固化壁８内への鋼板２の挿入設置作業を一時停止（例えば次の鋼板２の隣接設置作業を後日におこなうなど）する場合に、最終端に位置する鋼板２の大径継手部２２１内で撹拌混合土（セメント混合土）が固化するのを防止するために設けるものである。
継手部防護体５の大径継手部２２１への嵌装設置は、施工中の最終端に位置する鋼板２の大径継手部２２１内にかかる鋼板２の固化壁８内への挿入に先立って予め設置しておくこともできるし、最終端の鋼板２を固化壁８内に挿入後、大径継手部２２１内に嵌装させることもできる。
継手部防護体５は、例えば鋼材やプラスチック製材料などにて製作することができる。
【実施例１】
【００１８】
以下、本発明の鋼板遮水壁の構築方法の実施例１について説明する。
＜１＞鋼板設置工程
固化材４と原地盤７を混合撹拌して未固化状態の固化壁８を所定延長造成する。
本発明では、固化壁８の造成を公知のＴＲＤ工法にて施工するのが好ましい。ここで、ＴＲＤ工法とは、原地盤７内に挿入したチェーンソー型のカッターを接続したベースマシン６２を横方向に移動させ、溝の掘削と固化材４の注入、原地盤７との混合撹拌を行いながら地中に連続した固化壁８を造成する工法である。
ＴＲＤ工法を使用する場合は、一般に１パス方式又は３パス方式を選定できる。１パス方式とは、原地盤７の掘削と固化材４の注入による固化壁８の造成を同時に行う方法である。一方、３パス方式とは、先に原地盤７の掘削だけを行い、ベースマシン６２の退避部を作ってから逆方向へ戻り固化壁８の造成作業を行う方法である。
未固化状態の固化壁８内に、小径継手部２２２および大径継手部２２１の夫々に設けた底蓋３，３を建込治具６１にて上方から押し込んで鋼板２を固化壁８内に挿入していく。建込治具６１は細長（少なくとも鋼板２の鉛直方向長さ以上の長さを備えた）の鋼製板材やＣ型鋼、Ｌ型鋼など多様に選定使用できる。
【００１９】
＜２＞隣接鋼板設置工程
鋼板設置工程にて設置した鋼板２の継手部２２から建込治具６１を引抜く。
次に、鋼板設置工程にて設置した鋼板２に隣接設置する鋼板２の小径継手部２２２を、鋼板設置工程にて設置した鋼板２の大径継手部２２１に挿入しながら隣接鋼板２の底蓋３，３を建込治具６１にて上方から押し込んで隣接鋼板２を順次設置していく。
鋼板２の隣接設置を連続しておこなうことにより、施工ヤード内において計画平面線形の鋼板遮水壁１を造成することができる。
なお、連続施工に際して、複数のベースマシン６２を使用することもできる。
【実施例２】
【００２０】
以下、本発明の鋼板遮水壁の構築方法の実施例２について説明する。なお、実施例１と重複する工程については省略する。
本実施例は、鋼板２の隣接設置を一時停止する場合の実施例である。ここで、一時停止とは、隣接鋼板２の設置を一旦停止し、後日改めておこなうことなどをいう。
鋼板２の隣接設置を一時停止する場合、隣接鋼板設置工程にて設置した最終端に位置する鋼板２の大径継手部２２１には継手部防護体５を嵌装させておく。継手部防護体５の嵌装設置は、施工中の最終端に位置する鋼板２の大径継手部２２１内にかかる鋼板２の固化壁８内挿入に先立って予め設置しておくこともできるし、最終端の鋼板２を固化壁８内に挿入後、大径継手部２２１内に嵌装させることもできる。
後日、継手部防護体５を取り外したことにより形成される空間を露出させ、隣接鋼板２を順次設置していく。
かかる構築方法によれば、鋼板遮水壁１の造成延長（平面的な延長および深度方向の延長）が長く、連続施工（固化壁８の硬化前に鋼板２の隣接設置をおこなう）が極めて困難な場合でも、１台のベースマシン６２を使用して鋼板遮水壁１の構築をおこなうことが可能となる。【Technical field】
[0001]
The present invention includes a steel plate impermeable wall that forms a water shielding wall by inserting a steel plate into a solidified wall formed by mixing and stirring soft ground or solidified material and raw ground, and a joint portion provided at an end of the steel plate The present invention relates to a joint protector for preventing mixed agitated soil from entering and solidifying, and a method for constructing a steel plate impermeable wall.
[Background]
[0002]
The impermeable wall method is used as a countermeasure against liquefaction, as a countermeasure to prevent the diffusion of pollutants from contaminated soil (for example, a waste disposal site), as a water leakage prevention wall for rivers, and as a barrier wall for underground dams.
As the impermeable wall construction method, the auger excavates the original ground and constructs the soil cement solidified wall while mixing and agitating the original ground and cement, or the impermeable wall is applied to the solidified wall where the solidified material and the original ground are mixed and agitated. There are a wide variety of methods such as building methods, sheet walls including polymer membrane sheets and steel sheet, and steel sheet piles.
[0003]
A steel sheet (steel sheet pile) is generally used as the water shielding material used in the method of building the water shielding material on the solidified wall obtained by mixing and stirring the solidified material and the raw ground. A continuous steel plate impermeable wall is constructed by providing joints at both ends of a steel plate (steel sheet pile), and joining both steel plates (steel sheet piles) together.
[0004]
By the way, the manufacture of steel plate (steel sheet pile) joints can be roughly divided into two types depending on the joint structure. One of them is a method of manufacturing a joint by bending a single steel sheet by hot forming or cold forming (see Patent Document 1). Such a manufacturing method is used when a steel plate is bent at a right angle.
[0005]
As shown in FIG. 7, the other one is that the joint b of one steel plate a to be joined is a ring-shaped cylindrical body c, and the other joint b to be joined is capable of inserting the ring-shaped cylindrical body c. A columnar body d having a larger cross-sectional arc shape than the cylindrical body c is used. A joint b composed of such a ring-shaped cylindrical body c and a columnar body d having an arc-shaped cross section is manufactured by forming the steel plate a into such a shape and then welding the joint b to the end of the steel plate a (patent). Reference 2).
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-104244 [Patent Document 2]
Japanese Utility Model Publication No. 5-27129 [Disclosure of the Invention]
[Problems to be solved by the invention]
[0006]
The above-described conventional impermeable walls and methods for constructing impermeable walls have the following problems.
<1> In the method of placing a steel sheet pile or seat wall, there is a possibility that the joint may come off due to a twist of a member that may occur during installation. In addition, it is inevitable that soil and sand will intervene in the joint, resulting in low reliability as a water shielding wall such as water leakage from the joint.
<2> In the method of building a soil cement solidified wall, the quality of the solidified wall varies greatly. Furthermore, it is difficult to control the cracks in the solidified wall, and there is a very high possibility that a crack that can induce water leakage occurs due to ground deformation during an earthquake.
<3> In the method of building a water shielding material on the solidified wall obtained by mixing and stirring the solidified material and the ground, the joint cannot be connected after the solidified material is hardened, so that continuous construction is forced.
<4> When the joint of Patent Document 1 is used in a joint of a steel sheet (steel sheet pile) used as a water shielding material, the connection of both joints between adjacent steel sheets is configured to mesh the joints. If the placement accuracy is low, connection becomes difficult.
<5> When the joint of Patent Document 2 is used in a joint of a steel sheet (steel sheet pile) used as a water shielding material, the steel sheet and joints provided at both ends thereof are welded and joined, resulting in difficulty in production and water shielding. Problems such as increased wall production costs can arise.
[Means for Solving the Problems]
[0007]
In order to solve the problems as described above, the steel plate impermeable wall of the present invention is a steel plate impermeable wall that forms a impermeable wall by inserting a steel plate into the original ground,
A joint part manufactured by bending a vicinity of both ends of the one steel sheet into a substantially cylindrical shape so as to form a gap between each bent part and the edge of the steel sheet;
A bottom lid weld-joined to the lowermost end of the joint at both ends,
Of the joint parts, the steel plate provided with a small-diameter joint part and a large-diameter joint part formed so that the inner diameter of one of the joint parts is relatively larger than the outer diameter of the other joint part The small-diameter joint portion of the steel plate installed adjacent to the large-diameter joint portion of the steel plate can be inserted.
Further, in the steel sheet, one or a plurality of the small diameter joint portions are provided at one end of the steel plate, and the same number of the large diameter joint portions as the small diameter joint portions are provided at the other end. Water wall can be used.
[0008]
Further, the steel sheet impermeable wall construction method of the present invention is the steel sheet impermeable wall construction method, in the solidified wall in an unsolidified state formed by mixing and stirring the solidified material and the original ground , A steel plate installation step of inserting the steel plate into the solidified wall by pressing the bottom lid welded and joined to the lowermost end of the small diameter joint portion at both ends and the large diameter joint portion from above with a builder;
The bottom cover of the adjacent steel plate is pushed in from above with a mounting jig while the small diameter joint portion of the adjacent steel plate installed adjacent to the existing steel plate installed in the steel plate installation step is inserted into the large diameter joint portion of the existing steel plate. And the adjacent steel plate installation step of sequentially installing the adjacent steel plates.
Moreover, in the construction method of the steel plate impermeable wall described above, when the adjacent installation of the adjacent steel plate is temporarily stopped, the large-diameter joint portion of the adjacent steel plate located at the final end installed in the adjacent steel plate installation step One rod body molded so as to be fitted to the large-diameter joint portion , or a joint portion protection body composed of a plurality of the rod bodies connected via plate members is fitted,
When the installation of the adjacent steel plate is started again, the adjacent steel plates are sequentially installed after the joint protection body is removed.
【The invention's effect】
[0009]
The steel sheet impermeable wall, joint protector and steel sheet impermeable wall construction method of the present invention can obtain at least one of the following effects by means for solving the above-mentioned problems.
<1> A steel plate impermeable wall formed by embedding the steel plate of the present invention in a solidified wall obtained by mixing and stirring the solidified material and the original ground has a very low possibility of water leakage from the impermeable wall (particularly the joint portion). High reliability as a water wall.
<2> The steel plate impermeable wall formed by embedding the steel plate of the present invention in the solidified wall in which the solidified material and the original ground are mixed and agitated may cause water leakage from the impermeable wall against ground deformation during an earthquake. Is low.
<3> Since a clearance with a margin can be provided between the inner space of the large-diameter joint portion and the outer diameter of the small-diameter joint portion, it is easy to connect the steel plates used as the water-impervious wall.
<4> In principle, since a steel plate including a joint portion is manufactured from one steel plate, the manufacturing cost of the steel plate is low.
<5> It is not always necessary to perform continuous construction. In other words, the joint member protector is fitted to the large-diameter joint portion of the adjacent steel plate located at the final end in the adjacent installation of the steel plates, so that the solidified material and the original material can be temporarily stopped adjacent to each other. It is possible to construct a water-impervious wall that builds a water-impervious material on a solidified wall that has been mixed and stirred in the ground.
[Brief description of the drawings]
[0010]
Drawing 1 is an explanatory view explaining the construction situation of the steel plate impermeable wall of the present invention.
FIG. 2 is a cross-sectional view of a single steel plate.
FIG. 3 is a cross-sectional view of a situation where two steel plates are installed adjacent to each other.
FIG. 4 is a cross-sectional view showing another embodiment of a single steel plate and a cross-sectional view of a situation in which the steel plates of other embodiments are adjacently installed.
FIG. 5 is a cross-sectional view of a situation in which steel plates of other embodiments are installed adjacent to each other.
FIG. 6 is an explanatory view showing a joint protection body.
FIG. 7 is a cross-sectional view showing a conventional steel sheet pile (including the end joint).
[Explanation of symbols]
[0011]
DESCRIPTION OF SYMBOLS 1 ... Steel-sheet impermeable wall 2 ... Steel plate 22 ... Joint part 221, Large-diameter joint part 222 Small-diameter joint part 3 ... Bottom cover 4 ... Solidified material 5 ... Joint part protection body 51 .. Rod body 52 .. Plate material 61.. Jig 7. Original ground 8. Solidified wall [Best mode for carrying out the invention]
[0012]
<1> Steel plate impermeable wall The steel plate impermeable wall 1 of the present invention is formed by inserting the steel plate 2 into a soft ground or a solidified wall 8 formed by mixing and stirring the solidified material 4 and the original ground 7. It is a wall.
When the solidified wall 8 is formed, the ground surface of the excavation groove 7 is dug in advance along the plane alignment of the impermeable wall with a backhoe 64, and the raw ground 7 and the cement used as the solidified material 4 are mixed and stirred. The formation of the solidified wall 8 over a predetermined depth is followed (see FIG. 1). The steel plate impermeable wall 1 of the present invention is one in which the steel plate 2 is inserted and installed through the erection jig 61 in the solidified wall 8 in a loose state and in an unsolidified state (see FIG. 1). It should be noted that a known TRD construction base machine 62 is used to create the solidified wall 8, and the steel plate 2 is preferably built using a crane 63 or the like.
In addition to the method of inserting and installing the steel plate impermeable wall 1 in the solidified wall 8, the impermeable wall can be constructed by directly press-fitting and installing in the soft ground.
[0013]
<2> Steel plate The steel plate 2 used in the present invention is manufactured, for example, by bending a single steel plate 2 into a substantially cylindrical shape in the vicinity of both ends on the same side. Here, the substantially cylindrical shape includes a circular shape obtained by bending the steel plate 2 into the same cross-sectional view shape in the vertical direction, including a circular shape in a cross-sectional view and an elliptical shape in a cross-sectional view. . Both ends of the bent steel plate 2 are manufactured as joint portions 22, and the other portion (center portion) of the steel plate 2 is manufactured as a plate portion 21 (see FIG. 2). The joint portion 22 is manufactured so that a gap 223 is formed between the bent portion 23 of the steel plate 2 and the end side 24 of the steel plate 2. This is because the joint portion 22 of the adjacent steel plate 2 can be inserted into the joint portion 22 of the existing steel plate 2. Therefore, the substantially cylindrical shape described above is configured by providing a notch (gap 223) extending in a vertical direction in a part of the cylindrical shape.
Note that the joint portions 22 and 22 are not necessarily provided on the same side (not shown).
[0014]
The joint portions 22 and 22 formed at both ends of the steel plate 2 are preferably formed such that the inner diameter of one joint portion 22 is relatively larger than the outer diameter of the other joint portion 22 (in this case). The joint portion 22 is referred to as a small-diameter joint portion 222 and a large-diameter joint portion 221). For example, the small-diameter joint portion 222 of the steel plate 2 installed adjacent to the large-diameter joint portion 221 of the existing steel plate 2 can be installed (see FIG. 3).
Because of the insertion and installation, the large-diameter joint portion 221 needs to be bent so as to form the gap 223 described above. On the other hand, the gap 223 may or may not be formed in the bending process of the small diameter joint portion 222.
[0015]
The outer diameter of the small diameter joint portion 222 and the inner diameter of the large diameter joint portion 221 can be selected as appropriate. If the outer diameter of the small-diameter joint portion 222 and the inner diameter of the large-diameter joint portion 221 are greatly different from each other, the insertion and installation becomes easier.
However, it is necessary to mold the gap 223 provided in the large-diameter joint portion 221 so that the gap width is at least smaller than the outer diameter of the small-diameter joint portion 222. This is to prevent the small diameter joint portion 222 from coming out of the large diameter joint portion 221.
Further, the same number of small-diameter joint portions 222 and large-diameter joint portions 221 provided at both ends of the steel plate 2 can be provided (see FIG. 4). By joining the plurality of small-diameter joint portions 222 and 222 and the large-diameter joint portions 221 and 221, the joint strength of the joint portion 22 can be increased (see FIG. 5). In particular, even when a crack occurs in the solidified wall 8 around the steel plate 2 due to ground deformation at the time of an earthquake, the joint portion 22 at one place is firmly joined, so that the possibility of the joints being separated becomes low and the shielding is reduced. Water performance can be improved.
The effective width of the steel plate 2 (the length between the centers of the large-diameter joint portion 221 and the small-diameter joint portion 222 at both ends) can be formed to about 1 to 1.5 m, for example.
[0016]
<3> Bottom Cover The bottom cover 3 is a plate material provided at the lowermost ends of the large-diameter joint part 221 and the small-diameter joint part 222. When inserting one steel plate 2 into the solidified wall 8, rod-shaped erection jigs 61 and 61 are inserted into the large-diameter joint portion 221 and the small-diameter joint portion 222, and the lowermost ends of the respective joint portions 22 and 22 are inserted. The steel plate 2 can be inserted while the bottom lids 3, 3 provided on the metal plate are pressed evenly by the erection jigs 61, 61. Since the bottom lids 3 and 3 are pushed evenly at the both ends of the steel plate 2 by the laying jigs 61 and 61, the pushing is easy and excessive twisting or the like hardly occurs in the steel plate 2.
The bottom lid 3 is made of, for example, a steel plate formed into an arc shape (an outer diameter arc of each joint portion 22) provided in each of the large-diameter joint portion 221 and the small-diameter joint portion 222. However, the shape of the bottom lid 3 is not restricted to the arc shape of each joint portion 22, and it is sufficient that the inner space of the joint portion 22 can be blocked from the bottom portion.
The steel bottom lid 3 is welded and joined to each joint portion 22 at a factory or on-site yard .
[0017]
<4> Joint part protector The joint part protector 5 is composed of a rod body 51 formed so as to be fitted to the large-diameter joint part 221 or a plurality of rod bodies 51 and 51 connected via a plate member 52 (see FIG. 6).
The rod 51 may be a pipe having an outer diameter substantially the same as the inner diameter of the large-diameter joint portion 221 or may be a solid columnar body having the above shape.
As an embodiment of the joint protector 5, the joint protector 5 in which a plurality of rod bodies 51, 51 are connected via the plate material 52 is included because the joint protector 5 is fitted to the large-diameter joint part 221. This is to ensure stability during installation.
A suspension jig 53 provided with an insertion hole for a wire or the like used for fitting and withdrawing from the large-diameter joint portion 221 is preferably provided at the uppermost end of the joint portion protection body 5.
The joint protector 5 is used for temporarily stopping the installation work of inserting the steel plate 2 into the solidified wall 8 (for example, performing the next installation work of the next steel plate 2 later). It is provided in order to prevent the stirring mixed soil (cement mixed soil) from solidifying in the large-diameter joint portion 221.
Prior to the insertion of the steel plate 2 into the solidified wall 8 in the large-diameter joint portion 221 of the steel plate 2 located at the final end during construction, the fitting protection body 5 is fitted into the large-diameter joint portion 221. It can be installed in advance, or can be fitted into the large-diameter joint portion 221 after the steel plate 2 at the end is inserted into the solidified wall 8.
The joint protection body 5 can be made of, for example, a steel material or a plastic material.
[Example 1]
[0018]
Hereinafter, Example 1 of the construction method of the steel plate impermeable wall of the present invention is described.
<1> Steel plate installation step The solidified material 4 and the raw ground 7 are mixed and stirred to create a predetermined extension of the solidified wall 8 in an unsolidified state.
In the present invention, it is preferable to construct the solidified wall 8 by a known TRD method. Here, the TRD method means that the base machine 62 connected to the chain saw type cutter inserted in the raw ground 7 is moved in the horizontal direction, and the excavation of the groove, the injection of the solidified material 4 and the mixing and stirring with the raw ground 7 are performed. It is a construction method for creating a continuous solidified wall 8 in the ground while performing.
When using the TRD method, a one-pass method or a three-pass method can be generally selected. The 1-pass method is a method in which excavation of the raw ground 7 and creation of the solidified wall 8 by injection of the solidified material 4 are performed simultaneously. On the other hand, the three-pass method is a method in which only the original ground 7 is excavated first, a retracting portion for the base machine 62 is formed, and then the solidified wall 8 is created in the reverse direction.
The bottom lids 3 and 3 provided on the small diameter joint portion 222 and the large diameter joint portion 221 are pushed into the solidified wall 8 by pushing the bottom lids 3 and 3 provided on the small diameter joint portion 222 and the large diameter joint portion 221 from above. Insert it. The erection jig 61 can be selected and used in various forms such as an elongated steel plate (having at least a length equal to or greater than the length of the steel plate 2 in the vertical direction), C-shaped steel, and L-shaped steel.
[0019]
<2> Adjacent steel plate installation process The construction jig 61 is pulled out from the joint part 22 of the steel plate 2 installed in the steel plate installation process.
Next, the bottom lid of the adjacent steel plate 2 is inserted while inserting the small diameter joint portion 222 of the steel plate 2 installed adjacent to the steel plate 2 installed in the steel plate installation step into the large diameter joint portion 221 of the steel plate 2 installed in the steel plate installation step. The adjacent steel plates 2 are sequentially installed by pushing 3 and 3 from above with the erection jig 61.
By performing the adjacent installation of the steel plates 2 continuously, it is possible to create the steel plate impermeable wall 1 having a plan plane alignment in the construction yard.
It should be noted that a plurality of base machines 62 can be used in the continuous construction.
[Example 2]
[0020]
Hereinafter, Example 2 of the construction method of the steel plate impermeable wall of the present invention is described. In addition, about the process which overlaps with Example 1, it abbreviate | omits.
The present embodiment is an embodiment in the case where the adjacent installation of the steel plates 2 is temporarily stopped. Here, the temporary stop means temporarily stopping the installation of the adjacent steel plate 2 and performing it again at a later date.
When the adjacent installation of the steel plate 2 is temporarily stopped, the joint protection body 5 is fitted to the large-diameter joint portion 221 of the steel plate 2 located at the final end installed in the adjacent steel plate installation process. The joint protector 5 can be installed in advance prior to insertion of the steel plate 2 into the solidified wall 8 within the large-diameter joint portion 221 of the steel plate 2 located at the final end during construction. The steel plate 2 at the final end can be fitted into the large-diameter joint portion 221 after being inserted into the solidified wall 8.
Later, the space formed by removing the joint protection body 5 is exposed, and the adjacent steel plates 2 are sequentially installed.
According to such a construction method, the construction extension (planar extension and extension in the depth direction) of the steel plate impermeable wall 1 is long, and continuous construction (adjacent installation of the steel plate 2 is performed before the solidified wall 8 is hardened) is extremely difficult. Even in such a case, the steel plate impermeable wall 1 can be constructed using one base machine 62.

Claims

A steel plate impermeable wall that inserts a steel plate into the original ground to form a impermeable wall,
A joint part manufactured by bending a vicinity of both ends of the one steel sheet into a substantially cylindrical shape so as to form a gap between each bent part and the edge of the steel sheet;
A bottom lid weld-joined to the lowermost end of the joint at both ends,
Of the joint parts, the steel plate provided with a small-diameter joint part and a large-diameter joint part formed so that the inner diameter of one of the joint parts is relatively larger than the outer diameter of the other joint part And, the small diameter joint portion of the steel plate installed adjacent to the large diameter joint portion of the steel plate can be inserted,
Steel plate impermeable wall.

In the steel sheet according to claim 1,
One or more small-diameter joint portions are provided at one end of the steel plate, and the same number of the large-diameter joint portions as the small-diameter joint portions are provided at the other end,
Steel plate impermeable wall.

It is a construction method of the steel plate impermeable wall according to claim 1 or 2,
In the solidified wall in an unsolidified state formed by mixing and stirring the solidified material and the raw ground, the bottom lid welded and joined to the lower end of the small-diameter joint part and the large-diameter joint part of both ends of the steel plate A steel plate installation step of inserting the steel plate into the solidified wall by pushing from above with a tool;
The bottom cover of the adjacent steel plate is pushed in from above with a mounting jig while the small diameter joint portion of the adjacent steel plate installed adjacent to the existing steel plate installed in the steel plate installation step is inserted into the large diameter joint portion of the existing steel plate. In the adjacent steel plate installation process of sequentially installing the adjacent steel plates,
Construction method of steel plate impermeable walls.

It is a construction method of the steel plate impermeable wall according to claim 3 ,
When temporarily stopping the adjacent installation of the adjacent steel plate, the large steel joint portion of the adjacent steel plate located at the final end installed in the adjacent steel plate installation step is formed so as to be fitted to the large diameter joint portion. A joint body protection body composed of a plurality of rod bodies connected through one rod body or a plate member is fitted,
When the installation of the adjacent steel sheet is started again, the adjacent steel sheet is sequentially installed after removing the joint protection body,
Construction method of steel plate impermeable walls.