JP3765719B2

JP3765719B2 - Closure adjustment element and underground structure construction method

Info

Publication number: JP3765719B2
Application number: JP2000307479A
Authority: JP
Inventors: 忠良石橋; 昭夫伊藤; 明之渡邊; 達児長尾
Original assignee: East Japan Railway Co
Current assignee: East Japan Railway Co
Priority date: 2000-10-06
Filing date: 2000-10-06
Publication date: 2006-04-12
Anticipated expiration: 2020-10-06
Also published as: JP2002115497A

Description

【０００１】
【発明の属する技術分野】
本発明は、鋼製エレメントにより閉合状のエレメント構造体を地盤内に構成する場合に最後の閉合部に配置される閉合部調整用エレメント、及びこの閉合部調整用エレメントを用いて地下構造物を構築する方法に関するものである。
【０００２】
【従来の技術】
従来、鉄道線路や道路等の下方に非開削方式で地下構造物を構築する方法として、地盤を掘削しつつ鋼製エレメントをけん引又は推進により地中に順次挿入して組み合わせ、鋼製エレメントを相互に接合して閉合状のエレメント構造体を地盤内に構成し、エレメント構造体により囲まれた部分の土砂等を掘削し、エレメント構造体を地下構造物の本体構造として利用する方法が用いられている。
【０００３】
【発明が解決しようとする課題】
このような工法においては、エレメント構造体が最後に閉合する部分（以下、「閉合部」という。）に、各鋼製エレメントの製作誤差や、鋼製エレメントの地盤内へのけん引掘削、各鋼製エレメント相互の接合作業等の過程において発生する施工誤差が累積し、閉合部の形状、寸法が設計された値等からはずれることがある。このような場合には、設計通りに製作された閉合部エレメントでは施工ができない、という問題があった。
【０００４】
本発明は上記の問題を解決するためになされたものであり、本発明の解決しようとする課題は、閉合部の状態に応じて誤差を吸収可能な閉合部調整用エレメント、及びこのエレメントを用いた地下構造物構築工法を提供することにある。
【０００５】
【課題を解決するための手段】
上記課題を解決するため、本発明の請求項１に係る閉合部調整用エレメント（４０）は、
エレメント軸方向に延設される鋼製部材に前記エレメント軸方向に沿って略「Ｃ」字状断面のエレメント継手部（１３又は２３）を設け、隣接するエレメント継手部（１３又は２３）の嵌合により相互の接合を行う鋼製エレメント（１０、２０、２０Ｌ、２０Ｒ、３０、又は４０）を相互に接合させつつ地盤内に複数個を挿入して閉合状のエレメント構造体（Ｅ）を構成する場合に、最後の閉合部に配置される閉合部調整用エレメント（４０）であって、
エレメント軸方向に延在する鋼製平板部（４３ａ）の一端部に前記エレメント軸方向に沿って前記エレメント継手部（１３又は２３）と嵌合可能な略「Ｃ」字状断面の結合継手部（４３ｂ）が設けられた結合継手部材（４３）を４枚備え、
略「コ」字状に形成された複数の第１鉄筋（４４）の一端である上側直線部（４４ａ）が、第１の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されるとともに、前記複数の第１鉄筋（４４）の他端である下側直線部（４４ｂ）が、第２の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されて第１閉合部材（４１）を構成し、
略「コ」字状に形成された複数の第２鉄筋（４５）の一端である上側直線部（４５ａ）が、第３の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されるとともに、前記複数の第２鉄筋（４５）の他端である下側直線部（４５ｂ）が、第４の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されて第２閉合部材（４２）を構成し、
前記第１鉄筋（４４）と前記第２鉄筋（４５）の一部（４４ａと４５ａ、又は４４ｂと４５ｂ）を互いに近接させて重複配置させることにより重ね鉄筋継手が形成可能であるとともに、前記第１鉄筋（４４）と前記第２鉄筋（４５）を前記エレメント軸方向に直角な方向であるエレメント軸直角方向にスライド移動可能な構成とし、前記第１鉄筋（４４）と前記第２鉄筋（４５）を前記エレメント軸直角方向に相互にスライド移動させることにより前記閉合部における前記エレメント軸直角方向の誤差を吸収可能としたこと
を特徴とする。
【０００６】
また、本発明の請求項２に係る閉合部調整用エレメント（４０）は、
請求項１記載の閉合部調整用エレメント（４０）において、
前記第１鉄筋（４４）と前記第２鉄筋（４５）の周囲を包囲しカゴ状に構成する横拘束鉄筋（４６）が配置されること
を特徴とする。
【０００７】
また、本発明の請求項３に係る閉合部調整用エレメント（４０）は、
請求項１記載の閉合部調整用エレメント（４０）において、
前記閉合部の地盤を掘削する時の土留めと現場打ちコンクリートを打設する時の型枠の機能を有する保護部材（４８、４８）が配置されること
を特徴とする。
【０００８】
また、本発明の請求項４に係る閉合部調整用エレメント（４０）は、
請求項１記載の閉合部調整用エレメント（４０）において、
前記第１鉄筋（４４）と前記第２鉄筋（４５）の近傍に前記エレメント軸方向に延びる補強鉄筋（４７）が配置されること
を特徴とする。
【０００９】
また、本発明の請求項５に係る閉合部調整用エレメント（４０）は、
請求項４記載の閉合部調整用エレメント（４０）において、
前記補強鉄筋（４７）は、前記略「コ」字状の第１鉄筋（４４）の上側直線部（４４ａ）の一端と下側直線部（４４ｂ）の一端を連結する連結部（４４ｃ）の近傍、及び前記略「コ」字状の第２鉄筋（４５）の上側直線部（４５ａ）の一端と下側直線部（４５ｂ）の一端を連結する連結部（４５ｃ）の近傍に配置されること
を特徴とする。
【００１０】
また、本発明の請求項６に係る閉合部調整用エレメント（４０）は、
請求項１記載の閉合部調整用エレメント（４０）において、
前記結合継手部材（４３）は、「−」字状断面を有し長手方向に延在する鋼製平板部（４３ａ）の前記「−」字状断面における両端部に前記長手方向に沿って略「Ｃ」字状断面の結合継手部（４３ｂ）が設けられた直線鋼矢板（５１）の前記鋼製平板部（４３ａ）を前記長手方向に沿って切断することにより形成されること
を特徴とする。
【００１１】
また、本発明の請求項７に係る閉合部調整用エレメント（４０）は、
請求項１記載の閉合部調整用エレメント（４０）において、
前記第１鉄筋（４４）又は第２鉄筋（４５）は、溶接又は機械的接合により前記鋼製平板部（４３ａ）に接合されること
を特徴とする。
【００１２】
また、本発明の請求項８に係る閉合部調整用エレメント（４０）は、
請求項１記載の閉合部調整用エレメント（４０）において、
前記嵌合されたエレメント継手部（１３又は２３）と結合継手部（４３ｂ）の内部に形成される嵌合空間（１３ｅ又は２３ｅ）内にグラウト材が注入され硬化することにより固定されること
を特徴とする。
【００１３】
また、本発明の請求項９に係る地下構造物構築工法は、
エレメント軸方向に延設される鋼製部材に前記エレメント軸方向に沿って略「Ｃ」字状断面のエレメント継手部（１３又は２３）を設け鋼製エレメント（１０、２０、２０Ｌ、２０Ｒ、又は３０）を、前記エレメント軸方向を挿入方向として地中に挿入し、
次いで、他の鋼製エレメントを、前記エレメント継手部（１３又は２３）どうしを相互に嵌合させつつ地中に挿入することを繰り返して複数の鋼製エレメントを地中で連結させ、
次いで、前記複数の鋼製エレメントが閉合する前に、閉合箇所の地盤（Ｇ）を掘削して閉合空間（Ｓ）を形成し、
次いで、エレメント軸方向に延在する鋼製平板部（４３ａ）の一端部に前記エレメント軸方向に沿って前記エレメント継手部（１３又は２３）と嵌合可能な略「Ｃ」字状断面の結合継手部（４３ｂ）が設けられた結合継手部材（４３）を４枚備え、略「コ」字状に形成された複数の第１鉄筋（４４）の一端である上側直線部（４４ａ）が、第１の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されるとともに、前記複数の第１鉄筋（４４）の他端である下側直線部（４４ｂ）が、第２の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されて構成される第１閉合部材（４１）と、略「コ」字状に形成された複数の第２鉄筋（４５）の一端である上側直線部（４５ａ）が、第３の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されるとともに、前記複数の第２鉄筋（４５）の他端である下側直線部（４５ｂ）が、第４の結合継手部材（４３）の前記結合継手部（４３ｂ）とは反対側の他端部付近に接続されて構成される第２閉合部材（４２）を備え、前記第１鉄筋（４４）と前記第２鉄筋（４５）の一部（４４ａと４５ａ、又は４４ｂと４５ｂ）を互いに近接させて重複配置させることにより重ね鉄筋継手が形成可能であるとともに、前記第１鉄筋（４４）と前記第２鉄筋（４５）を前記エレメント軸方向に直角な方向であるエレメント軸直角方向にスライド移動可能な構成とし、前記第１鉄筋（４４）と前記第２鉄筋（４５）を前記エレメント軸直角方向に相互にスライド移動させることにより前記閉合部における前記エレメント軸直角方向の誤差を吸収可能とした閉合部調整用エレメント（４０）の前記結合継手部（４３ｂ）と前記閉合空間（Ｓ）内のエレメント継手部（１３又は２３）を相互に嵌合させつつ前記閉合部調整用エレメント（４０）を前記掘削された閉合空間（Ｓ）内に挿入し、
次いで、前記閉合部調整用エレメント（４０）が挿入された閉合空間（Ｓ）内に現場打ちコンクリート（５２）を打設し硬化させ、
次いで、前記地中で連結された鋼製エレメントと前記閉合空間（Ｓ）に形成された硬化後の現場打ち鉄筋コンクリートによって構成されたエレメント構造体（Ｅ）を防護工として前記エレメント構造体（Ｅ）の内部の地盤を掘削し、
次いで、前記エレメント構造体（Ｅ）を本体として利用して地下構造物（１００）を構築すること
を特徴とする。
【００１４】
【発明の実施の形態】
以下、本発明の実施形態について、図面を参照しながら詳細に説明する。
【００１５】
図１は、本発明の一実施形態である地下構造物の全体構成を示す断面図である。
【００１６】
図１に示すように、この地下構造物１００は、「ロ」字状の断面形状を有する箱型の構造物である。地下構造物１００は、「ロ」字状の断面形状を有するエレメント構造体Ｅにより構成されている。
【００１７】
また、エレメント構造体Ｅは、上床版部の中央位置に設置される基準管鋼製エレメント１０と、基準管鋼製エレメント１０に隣接させるように設置される一般部鋼製エレメント２０と、エレメント構造体の４つの隅角位置に設置される隅角部鋼製エレメント３０が組み合わされ、最後の閉合部（図１における下床版部の中央位置）に閉合部調整用エレメント４０が配置されることによって構成されている。
【００１８】
図２は、基準管鋼製エレメント１０と、一般部鋼製エレメント２０の構成と、これらのエレメント相互の接合状態を示している。図２（Ａ）は、基準管鋼製エレメント１０と、一般部鋼製エレメント２０の断面図を示している。また、図２（Ｂ）は、エレメント継手部１３、２３の接合状態を示す拡大断面図である。図２（Ａ）と図２（Ｂ）は、いずれも、鋼製エレメントの長手方向の軸の方向（以下、「エレメント軸方向」という。）に垂直な平面で切断した場合の基準管鋼製エレメント１０と、一般部鋼製エレメント２０の断面図を示している。
【００１９】
図２（Ａ）に示すように、基準管鋼製エレメント１０は、２つの鋼製板状部材１１と、２つの鋼製板状部材１２と、４つのエレメント継手部１３を有している。鋼製板状部材１１と他の鋼製板状部材１１は、互いに対向するように配置されてエレメント軸方向に延設されている。また、鋼製板状部材１２と他の鋼製板状部材１２は、互いに対向するように配置されるとともに鋼製板状部材１１と直角となるように配置され、エレメント軸方向に延設される。これにより、２つの鋼製板状部材１１と２つの鋼製板状部材１２は、全体として矩形管状（「ロ」字状）の断面の鋼製部材を形成している。
【００２０】
また、各鋼製板状部材１１、１２、１１、１２によって形成される矩形管状断面の４つの隅部のそれぞれには、エレメント軸方向に沿って延びる鋼製のエレメント継手部１３が配設されている。
【００２１】
エレメント継手部１３の断面は、図２（Ｂ）に示すように、概略「Ｃ」字状の嵌合部１３ａと、嵌合部１３ａの背後に接続する基部１３ｂを有して構成されている。また、嵌合部１３ａは、２つの突出した部分である主爪部１３ｃと、副爪部１３ｄを有している。主爪部１３ｃの先端は球根状に断面が拡大されている。また、主爪部１３ｃと副爪部１３ｄの中間は、ほぼ楕円状断面の凹部となっており、この部分は、略楕円状断面でエレメント軸方向に延びる溝１３ｅとなっている。
【００２２】
なお、図２（Ｂ）は、図２（Ａ）における上部中央位置のエレメント継手部１３の断面を示しているが、図２（Ａ）における下部中央位置、右上位置、右下位置の隅部のエレメント継手部１３についてもまったく同一形状のエレメント継手部位１３が用いられており、その構成は図２（Ｂ）に図示するものとまったく同様である。
【００２３】
また、各鋼製板状部材１１、１２と各エレメント継手部１３との各接合箇所は、溶接部Ｗ１、Ｗ２、Ｗ３、Ｗ４によって接合されている。各鋼製板状部材１１、１２と各エレメント継手部１３との接合は、ボルト等の機械的接合であってもよい。
【００２４】
上記のような構成により、エレメント継手部１３の主爪部１３ｃの先端付近にエレメント軸方向に直角な方向（以下、「エレメント軸直角方向」という。）の力を作用させた場合、例えば、図２（Ｂ）における左方向に引張ると、この引張り力（以下、「第１引張り力」という。）は、主爪部１３ｃから基部１３ｂに伝達され、基部１３ｂから鋼製板状部材１１に伝達され、鋼製板状部材１１の図２（Ｂ）における左端に、図２（Ｂ）における左方向への引張り力を作用させることになる。
【００２５】
一方、エレメント継手部１３の副爪部１３ｄの先端付近にエレメント軸直角方向の力を作用させた場合、例えば、図２（Ｂ）における左方向に引張ると、この引張り力（以下、「第２引張り力」という。）は、副爪部１３ｄから基部１３ｂを経て鋼製板状部材１１に伝達され、鋼製板状部材１１の図２（Ｂ）における左端に、図２（Ｂ）における左方向への引張り力を作用させることになる。
【００２６】
上記のことから、エレメント継手部１３の主爪部１３ｃ及び副爪部１３ｄと、基部１３ｂは、外部から加えられる上記のエレメント軸直角方向の力（例えば、第１引張り力、第２引張り力）に抵抗可能な所定の強度と所定の断面を有している。また、エレメント継手部１３の副爪部１３ｄには、上記の第１引張り力の一部と第２引張り力の一部との合成力が作用することを考慮し、その力に抵抗可能な所定の強度と所定の断面を有している。例えば、副爪部１３ｄの厚みは十分な厚みとなっている。
【００２７】
また、エレメント継手部１３の基部１３ｂには、上記の第１引張り力と第２引張り力の一部との合成力が作用することを考慮し、その力に抵抗可能な所定の強度と所定の断面（例えば十分な厚み）を有している。また、鋼製板状部材１１は、エレメント継手部１３から伝達される上記のエレメント軸直角方向の力に抵抗可能な所定の強度と所定の断面を有している。
【００２８】
また、図２（Ａ）に示すように、一般部鋼製エレメント２０は、２つの鋼製板状部材２１と、１つの鋼製板状部材２２と、２つのエレメント継手部１３と、２つのエレメント継手部２３を有している。鋼製板状部材２１と他の鋼製板状部材２１は、互いに対向するように配置されてエレメント軸方向に延設されている。また、鋼製板状部材２２は、鋼製板状部材２１、２１と直角となるように配置され、エレメント軸方向に延設される。これにより、２つの鋼製板状部材２１と１つの鋼製板状部材２２は、全体として「コ」字状の断面の鋼製部材を形成している。
【００２９】
また、各鋼製板状部材２１、２２、２１によって形成される「コ」字状断面の４つの隅部のうち、外部に対して開放された隅部、すなわち図２（Ａ）における右上隅部及び右下隅部のそれぞれには、エレメント軸方向に沿って鋼製のエレメント継手部２３が配設されている。
【００３０】
また、各鋼製板状部材２１、２２、２１によって形成される「コ」字状断面の４つの隅部のうち、外部に対して閉塞された隅部、すなわち図２（Ａ）における左上隅部及び左下隅部のそれぞれには、エレメント軸方向に沿って上述したエレメント継手部１３が配設されている。
【００３１】
エレメント継手部２３の断面は、概略「Ｃ」字状の嵌合部２３ａと、嵌合部２３ａの背後に接続する基部２３ｂを有して構成されている。また、嵌合部２３ａは、２つの主爪部２３ｃ、副爪部２３ｄを有している。主爪部２３ｃの先端は球根状に断面が拡大されている。また、主爪部２３ｃと副爪部２３ｄの中間は、ほぼ楕円状断面の凹部となっており、この部分は、略楕円状断面でエレメント軸方向に延びる溝２３ｅとなっている。
【００３２】
なお、図２（Ｂ）は、図２（Ａ）における上部中央位置のエレメント継手部２３の断面を示しているが、図２（Ａ）における下部中央位置の隅部のエレメント継手部２３についてもまったく同一形状のエレメント継手部２３が用いられており、その構成は図２（Ｂ）に図示するものとまったく同様である。また、一般部鋼製エレメント２０におけるエレメント継手部１３とその付近の構成は、上述した基準管鋼製エレメント１０におけるエレメント継手部１３とその付近の構成とまったく同様である。
【００３３】
また、各鋼製板状部材２１、２２と各エレメント継手部１３、２３との各接合箇所は、溶接部Ｗ５、Ｗ６等によって接合されている。各鋼製板状部材２１、２２と各エレメント継手部１３、２３との接合は、ボルト等の機械的接合であってもよい。
【００３４】
上記のような構成により、エレメント継手部２３の主爪部２３ｃの先端付近にエレメント軸直角方向の力を作用させた場合、例えば、図２（Ｂ）における右方向に引張ると、この引張り力（以下、「第３引張り力」という。）は、主爪部２３ｃから基部２３ｂに伝達され、基部２３ｂから鋼製板状部材２１に伝達され、鋼製板状部材２１の図２（Ｂ）における右端に、図２（Ｂ）における右方向への引張り力を作用させることになる。
【００３５】
一方、エレメント継手部２３の副爪部２３ｄの先端付近にエレメント軸直角方向の力を作用させた場合、例えば、図２（Ｂ）における右方向に引張ると、この引張り力（以下、「第４引張り力」という。）は、副爪部２３ｄから基部２３ｂに伝達され、基部２３ｂから鋼製板状部材２１に伝達され、鋼製板状部材２１の図２（Ｂ）における右端に図２（Ｂ）における右方向への引張り力を作用させることになる。
【００３６】
上記のことから、エレメント継手部２３の主爪部２３ｃ及び副爪部２３ｄは、外部から加えられる上記のエレメント軸直角方向の力（例えば、第３引張り力、第４引張り力）に抵抗可能な所定の強度と所定の断面を有している。また、エレメント継手部２３の副爪部２３ｄには、上記の第４引張り力と、第４引張り力に起因する曲げモーメントによる力の合成力が作用することを考慮し、その力に抵抗可能な所定の強度と所定の断面を有している。例えば、副爪部２３ｄの厚みは十分な厚みとなっている。
【００３７】
また、エレメント継手部２３の基部２３ｂには、上記の第３引張り力と第４引張り力との合成力が作用することを考慮し、その力に抵抗可能な所定の強度と所定の断面（例えば十分な厚み）を有している。また、鋼製板状部材２１及び２２は、エレメント継手部１３、２３から伝達される上記のエレメント軸直角方向の力に抵抗可能な所定の強度と所定の断面を有している。
【００３８】
次に、上記した基準管鋼製エレメント１０と一般部鋼製エレメント２０によるエレメント構造体の施工方法について説明する。
【００３９】
まず、、基準管鋼製エレメント１０を、けん引又は推進により、エレメント軸方向に向けて地中に挿入する。この場合、基準管鋼製エレメント１０の内部にオーガードリル等を配備して、エレメント内部の土砂等を掘削、除去しつつ、エレメントの地中への挿入を行う。その後、一般部鋼製エレメント２０の開放側隅部に設けられたエレメント継手部２３、２３のそれぞれを、基準管鋼製エレメント１０のエレメント継手部１３のうちの２つ（例えば、図２（Ａ）における左上隅部の継手と左下隅部の継手）と嵌合させて接合する。
【００４０】
その後、これらのエレメント継手部１３、２３を嵌合させた状態で、一般部鋼製エレメント２０を、基準管路鋼製エレメント１０に沿わせながら、基準管鋼製エレメント１０の場合と同様にしてエレメント軸方向に向けて地中に挿入する。これにより、図２（Ａ）に示した状態となる。
【００４１】
この場合、図２（Ｂ）に示すように、接合状態となっている基準管鋼製エレメント１０のエレメント継手部１３と、一般部鋼製エレメント２０のエレメント継手部２３においては、エレメント継手部１３の溝１３ｅ内にエレメント継手部２３の主爪部２３ｃの拡大された先端が入り込んで嵌合し、かつ、エレメント継手部２３の溝２３ｅ内にエレメント継手部１３の主爪部１３ｃの拡大された先端が入り込んで嵌合している。このように、基準管鋼製エレメント１０のエレメント継手部１３と一般部鋼製エレメント２０のエレメント継手部２３が互いに嵌合することにより、基準管鋼製エレメント１０と一般部鋼製エレメント２０の相互間で、エレメント軸直角方向の力が伝達可能となっている。
【００４２】
上記のように嵌合している基準管鋼製エレメント１０のエレメント継手部１３と、一般部鋼製エレメント２０のエレメント継手部２３の内部の溝１３ｅ、２３ｅには、必要に応じて、適宜の時期に、エレメント軸方向の一方の端（以下、「注入端」という。）から、無収縮モルタル、無収縮コンクリート、樹脂材料等のグラウト材（図示せず）を注入し、硬化させて継手接合を補強してもよい。このグラウト注入を行うと、継手が固定されるため、接合された後の複数の鋼製エレメントが、上載荷重等によりたわむなどの変形を生じることを防止することができる。また、この補強により、エレメント軸直角方向の力の伝達性能も向上する。
【００４３】
次に、上記と同様にして、他の新たな一般部鋼製エレメント２０の開放側隅部に設けられたエレメント継手部２３、２３のそれぞれを、すでに地中に挿入された一般部鋼製エレメント２０の閉塞側隅部に設けられたエレメント継手部１３、１３のそれぞれと嵌合させて接合する。そして、両継手を嵌合させた状態で、新たな一般部鋼製エレメント２０を、すでに挿入された一般部路鋼製エレメント２０に沿わせながら、エレメント軸方向に向けて地中に挿入する。
【００４４】
以下、上記のようにして一般部エレメント挿入工程を順次繰り返すことによって、地中に挿入され相互に接合された各鋼製エレメント１０、２０等によってエレメント構造体を構成することができる。例えば、平板状の構造体、半円状や円状あるいは楕円状等に囲まれた形状のエレメント構造体である。
【００４５】
次に、必要により、各エレメント内にコンクリート等を充填する。次に、地中に形成されたエレメント構造体を防護工として利用し、エレメント構造体の内部の土砂等を掘削する。次に、エレメント内面をコンクリートで被覆する等の施工を行うことにより、地下構造物を構築することができる。
【００４６】
エレメント構造体が「ロ」字状断面などの場合には、エレメントが直角に曲がる隅角部が必要となる。この隅角部には、上記した基準管鋼製エレメント１０や一般部鋼製エレメント２０とは異なる構成の隅角部構成エレメント３０が用いられる。
【００４７】
次に、隅角部鋼製エレメント３０の構成を、図３を参照しつつ説明する。図３は、図１に示すエレメント構造体Ｅの左側壁の下端位置となる隅角部鋼製エレメント３０付近の断面図を示している。
【００４８】
図３に示すように、隅角部鋼製エレメント３０は、５つの鋼製板状部材３１、３１、３２、３４、３４と、２つのエレメント継手部１３と、２つのエレメント継手部２３を有している。鋼製板状部材３１と他の鋼製板状部材３１は、互いに対向するように配置されてエレメント軸方向に延設されている。また、鋼製板状部材３４と他の鋼製板状部材３４は、互いに対向するように配置されるとともに鋼製板状部材３１と直角となるように配置され、エレメント軸方向に延設される。鋼製板状部材３２は、鋼製板状部材３１と直角となるとともに、鋼製板状部材３４と平行となるように配置され、エレメント軸方向に延設される。これにより、５つの鋼製板状部材３１、３１、３２、３４、３４は、全体として矩形管状の断面の鋼製部材を形成している。
【００４９】
また、各鋼製板状部材３１、３１、３２、３４、３４によって形成される矩形管状断面の４つの隅部のうち、エレメント軸直角方向のうちの一方向、例えば、図３における上下方向において互いに隣接する２つの隅部、すなわち図３における左上隅部と右上隅部のそれぞれに、エレメント軸方向に沿ってエレメント継手部２３、２３が設けられている。
【００５０】
また、上記した上下方向と直角となる他方向、例えば、図３における左右方向において互いに隣接する２つの隅部、すなわち図３における右上隅部と右下隅部のそれぞれにエレメント軸方向に沿ってエレメント継手部１３、１３が設けられている。
【００５１】
各エレメント継手部１３、２３の構成は上記とまったく同様である。また、鋼製板状部材３１、３２、３４は、エレメント継手部１３、２３から伝達される上記のエレメント軸直角方向の力に抵抗可能な所定の強度と所定の断面を有している。また、各鋼製板状部材３１、３２、３１、３４と各エレメント継手部１３、２３との各接合箇所は、溶接部によって接合されている。この接合は、ボルト等の機械的接合であってもよい。
【００５２】
隅角部鋼製エレメント３０は、エレメント構造体Ｅの右上、右下、左上の各隅部にも設けられている。隅角部鋼製エレメント３０は、上記した構成により、エレメント軸直角方向の力のうち、「Ｌ」字状の隅角部の各方向の成分、例えば、図３における左右方向（水平方向）の成分は、隅角部鋼製エレメント３０の側に設けられた水平方向のエレメント継手部１３と、相手側に設けられた継手部（例えばエレメント継手部２３）により伝達可能である。また、エレメント軸直角方向の力のうち、上下方向（垂直方向）の成分は、隅角部鋼製エレメント３０の側に設けられた上下方向のエレメント継手部１３と、相手側に設けられた継手部（例えばエレメント継手部２３）により伝達可能である。
【００５３】
上記した隅角部鋼製エレメント３０の地中への挿入については、上記した基準部鋼製エレメント１０、一般部鋼製エレメント２０の場合とまったく同様であり、すでに地中に挿入された隣接するエレメントに沿わせて挿入すればよい。また、隅角部鋼製エレメント３０の下方に隣接する一般部鋼製エレメント２０についても同様である。
【００５４】
上記した隅角部鋼製エレメント３０については、エレメント構造体の隅角部の内側、例えば、図３における右上隅部に大きな引張り力が発生する場合があるが、この引張り力は、例えば上側の鋼製板状部材３４に負担させ、エレメント構造体の強度を高めることができる。
【００５５】
また、エレメント構造体の隅角部の内側（図３の右上隅部）の引張り力が小さい場合には、上側の鋼製板状部材３４を省略してもよい。あるいは、施工時（隅角部鋼製エレメント３０の挿入時）には鋼製板状部材３４を省略した「コ」字状断面としておき、エレメントの地中挿入後に溶接や、ボルト接合等の機械的接合などによって鋼製板状部材３４を取り付けるようにしてもよい。下側の鋼製板状部材３４についても適宜に付加又は省略可能である。
【００５６】
図４は、閉合部調整用エレメント４０の構成を示している。図４は、閉合部調整用エレメントのエレメント軸方向に垂直な平面で切断した場合の断面図を示している。
【００５７】
図４に示すように、閉合部調整用エレメント４０は、カゴ状部材４９と、２つの保護部材４８、４８を有して構成されている。
【００５８】
カゴ状部材４９は、第１閉合部材４１と、第２閉合部材４２と、横拘束鉄筋４６と、補強鉄筋４７を有している。
【００５９】
第１閉合部材４１は、図６に示すように、２個の結合継手部材４３に、略「コ」字状の第１鉄筋４４を複数個接合することにより構成されている。
【００６０】
結合継手部材４３は、図５の断面図（エレメント軸方向に垂直な平面で切断した場合の断面図）に示すように、直線鋼矢板５１を、矢板長手方向の中央線Ｌに沿って２等分するように切断することによって形成される。
【００６１】
図５に示すように、結合継手部材４３は、鋼製平板部４３ａと結合継手部４３ｂを有している。鋼製平板部４３ａは、「−」字状の断面を有し、エレメント軸方向に延在する鋼製の平板状部分である。また、結合継手部４３ｂは、鋼からなり、鋼製平板部４３ａの「−」字状断面における一端部に、エレメント軸方向に沿って形成された略「Ｃ」字状断面の部分であり、上述したエレメント継手部１３、２３と同様の構成を有しており、エレメント継手部１３、２３と嵌合可能な構成となっている。
【００６２】
また、第１鉄筋４４は、上側直線部４４ａと、上側直線部４４ａに平行な下側直線部４４ｂと、上側直線部４４ａの一端と下側直線部４４ｂの一端を連結する連結部４４ｃを有し、全体として「コ」字状に形成されている。
【００６３】
図６に示すように、第１閉合部材４１においては、上側の結合継手部材４３の鋼製平板部４３ａのうち、結合継手部４３ｂが設けられている一端部とは反対側の他端部付近に、第１鉄筋４４の上側直線部４４ａが溶接部（図示せず）によって接合されている。また、下側の結合継手部材４３の鋼製平板部４３ａのうち、結合継手部４３ｂが設けられている一端部とは反対側の他端部付近に、第１鉄筋４４の下側直線部４４ｂが溶接部Ｗ７によって接合されている。鋼製平板部４３ａと第１鉄筋４４との接合は、ボルト等の機械的接合であってもよい。
【００６４】
第２閉合部材４２は、図４に示すように、２個の結合継手部材４３に、略「コ」字状の第２鉄筋４５を複数個接合することにより構成されている。第２閉合部材４２は、図６に示す第１閉合部材４１における第１鉄筋４４のかわりに第２鉄筋４５を用いており、その形状等は第１閉合部材４１と同様である。
【００６５】
カゴ状部材４９においては、第１閉合部材４１の第１鉄筋４４と、第２閉合部材４２の第２鉄筋４５が、図７に示すように、互いに長さＺだけ重複するように、第１鉄筋４４と第２鉄筋４５が相互に差し込まれるように挿入されて配置されている。この状態で、第１鉄筋４４の上側直線部４４ａと第２鉄筋４５の上側直線部４５ａの同じ位置、あるいは第１鉄筋４４の下側直線部４４ｂと第２鉄筋４５の下側直線部４５ｂの同じ位置を軟鉄線材等でゆるく結束し、エレメント軸直角方向に相互にスライド移動可能な可変構造とし、上側直線部４４ａと４５ａ、及び下側直線部４４ｂと４５ｂの鉄筋重複長さＺが適宜調整可能なように構成する。
【００６６】
さらに、図８に示すように、第１鉄筋４４と第２鉄筋４５を横拘束鉄筋４６で取り囲むようにし、横拘束鉄筋４６は、軟鉄線材等で第１鉄筋４４又は第２鉄筋４５に取り付けられる。
【００６７】
さらに、図４に示すように、第１鉄筋４４と第２鉄筋４５の適宜箇所には、エレメント軸方向に延びる補強鉄筋４７が適宜の本数だけ配置され、軟鉄線材等で第１鉄筋４４又は第２鉄筋４５の適宜箇所に取り付けられる。例えば、図４に示すように、第１鉄筋４４と第２鉄筋４５の屈曲部が重なる位置の近傍、第１鉄筋４４の連結部４４ｃの中間位置の近傍、第２鉄筋４５の連結部４５ｃの中間位置の近傍などである。エレメント軸方向に延びる補強鉄筋４７の配置状態は、図６に破線で示すような状態となる。
【００６８】
次に、図９、図１０を参照しつつ、閉合部調整用エレメント４０の施工方法について説明する。
【００６９】
まず、あらかじめ、上記のカゴ状部材４９を作成しておく。
【００７０】
次に、上記した基準管鋼製エレメント１０、一般部鋼製エレメント２０、隅角部鋼製エレメント３０のエレメント継手部１３、２３等を相互に嵌合させ、掘削しつつ各エレメントを地盤Ｇ内に挿入し、嵌合したエレメント継手部内にグラウト材を注入し硬化させ、鋼製エレメントどうしを固定することを繰り返し、複数の鋼製エレメントを地盤Ｇ中で連結させ、「ロ」字の下床版中央付近の一部分（一般部鋼製エレメント２０Ｌと２０Ｒとの間）である閉合部が欠けた形状の断面を有するエレメント構造体Ｅを地中に形成する（図９（Ａ）参照）。
【００７１】
次に、一般部鋼製エレメント２０Ｌと２０Ｒとの間が閉合していない状態で、閉合部の上部の地盤Ｇ中に保護部材４８を挿入する（図９（Ｂ）参照）。また、同様にして、閉合箇所の下部の地盤Ｇ中に保護部材４８を挿入する。保護部材４８は、鋼鈑等からなり、断面形状が略「コ」字状の部材が用いられる。この場合、上部の保護部材４８、及び下部の保護部材４８の両端部は、一般部鋼製エレメント２０Ｌ、２０Ｒに、固定部２５を用いて溶接等によって接合され固定される。一般部鋼製エレメント２０Ｌ等への固定部２５の接合は、ボルト等の機械的接合であってもよい。
【００７２】
次に、図９（Ｂ）に示すように、保護部材４８、４８を土留め手段として利用し、保護部材４８、４８によって囲まれた部分の内部の地盤Ｇを掘削して除去し、閉合空間Ｓを形成する。
【００７３】
その後、図１０（Ａ）に示すように、上記したカゴ状部材４９の結合継手部４３ｂを一般部鋼製エレメント２０Ｌ等のエレメント継手部１３に嵌合させ、エレメント軸方向にスライドさせるように挿入し、カゴ状部材４９を閉合空間Ｓ内に設置する。カゴ状部材４９は、エレメント軸方向の長さが１メートル程度になるように作製されており、構造物のエレメント軸方向の長さに応じた個数を順次挿入する。
【００７４】
この場合、カゴ状部材４９の結合継手部４３ｂと、一般部鋼製エレメント２０Ｌ等のエレメント継手部１３の内部の溝１３ｅ等には、必要に応じて、適宜の時期に、エレメント軸方向の一方の注入端から、無収縮モルタル、無収縮コンクリート、樹脂材料等のグラウト材（図示せず）を注入し、硬化させて継手接合を補強してもよい。
【００７５】
次に、図１０（Ｂ）に示すように、保護部材４８、４８をコンクリート型枠として利用し、カゴ状部材４９が挿入された閉合空間Ｓ内に現場打ちコンクリート５２を打設して硬化させる。これにより、閉合部に鉄骨鉄筋コンクリート構造が形成され、エレメント構造体Ｅが、「ロ」字状断面となって閉合する。
【００７６】
図１０（Ｂ）において、左側の一般部鋼製エレメント２０Ｌの右上隅部のエレメント継手部１３と、カゴ状部材４９の上段左端の結合継手部４３ｂが互いに嵌合するとともに、左側の一般部鋼製エレメント２０Ｌの右下隅部のエレメント継手部１３と、カゴ状部材４９の下段左端の結合継手部４３ｂが互いに嵌合している。
【００７７】
また、右側の一般部鋼製エレメント２０Ｒの左上隅部のエレメント継手部１３と、カゴ状部材４９の上段右端の結合継手部４３ｂが互いに嵌合するとともに、右側の一般部鋼製エレメント２０Ｒの左下隅部のエレメント継手部１３と、カゴ状部材４９の下段右端の結合継手部４３ｂが互いに嵌合している。
【００７８】
また、図１０（Ｂ）に示すように、カゴ状部材４９においては、第１閉合部材４１の上下各結合継手部材４３、４３と第１鉄筋４４が溶接等によって接合され、第２閉合部材４２の上下各結合継手部材４３、４３と第２鉄筋４５が溶接等によって接合されている。
【００７９】
また、ここで、第１鉄筋４４の上側直線部４４ａと第２鉄筋４５の上側直線部４５ａの重複部分（図７の上側における重ね合わせ長さＺの部分）は、コンクリート５２内で鉄筋の重ね継手を構成している。また、第１鉄筋４４の下側直線部４４ｂと第２鉄筋４５の下側直線部４５ｂの重複部分（図７の下側における重ね合わせ長さＺの部分）は、コンクリート５２内で鉄筋の重ね継手を構成している。
【００８０】
このため、第１鉄筋４４の上側直線部４４ａの重複部分Ｚとその近傍の周囲のコンクリート５２との付着、また、このコンクリート５２と第２鉄筋４５の上側直線部４５ａの重複部分Ｚとの付着により、第１鉄筋４４の上側直線部４４ａの応力は、コンクリート５２を介して第２鉄筋４５の上側直線部４５ａに伝達される。
【００８１】
同様にして、第１鉄筋４４の下側直線部４４ｂの重複部分Ｚとその近傍の周囲のコンクリート５２との付着、また、このコンクリート５２と第２鉄筋４５の下側直線部４５ｂの重複部分Ｚとの付着により、第１鉄筋４４の下側直線部４４ｂの応力は、コンクリート５２を介して第２鉄筋４５の下側直線部４５ｂに伝達される。
【００８２】
また、この場合、連結部４４ｃ、４５ｃは、コンクリート５２における連結部４４ｃ、４５ｃの近傍部分のせん断応力を負担している。
【００８３】
このような構成により、閉合部調整用エレメント４０に現場打ちコンクリート５２が打設されて構成された鉄骨鉄筋コンクリート構造により、左側の一般部鋼製エレメント２０Ｌと、閉合部調整用エレメント４０と、右側の一般部鋼製エレメント２０Ｒの相互間で、エレメント軸直角方向の力が伝達可能となり、閉合部が確実に補強される。
【００８４】
次に、上記のようにして閉合した「ロ」字状の構造体を防護工として、その内部の地盤を掘削する。次に、閉合した「ロ」字状の構造体を本体構造として利用し、地下構造物を構築する。
【００８５】
このように施工すれば、エレメント構造体の剛結閉合を短時間で行うことができる。また、第１鉄筋４４と第２鉄筋４５は、エレメント軸直角方向に可変な構造となっており、第１鉄筋４４と第２鉄筋４５をエレメント軸直角方向に相互にスライド移動させることにより、第１鉄筋４４と第２鉄筋４５の重ね合わせ長さＺを適宜調整することができ、これにより、閉合部に累積するエレメントの製作誤差及び施工誤差等を吸収することができる。
【００８６】
また、上記した閉合部調整用エレメントによれば、略「コ」字状の鉄筋どうしを相互に重複させているため、従来の鉄筋の重ね合わせ継手よりも大きな耐力を発揮することができ、重ね合わせ長さＺが、従来の鉄筋の重ね合わせ継手における重ね合わせ長さよりも短い場合であっても、従来の場合と同等以上の継手強度を得ることができる。
【００８７】
なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は、例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。
【００８８】
例えば、上記実施形態においては、直線鋼矢板を切断することにより結合継手部材（例えば４３）を形成する例について説明したが、本発明はこの例には限定されず、他の構成の結合継手部材、例えば、帯状の鋼鈑の一側端にエレメント継手部（例えば１３又は２３）を溶接や機械的接合によって接合させて結合継手部材を形成してもよい。
【００８９】
また、上記実施形態においては、矩形管状の断面を有する基準管鋼製エレメント１０及び隅角部鋼製エレメント３０、略「コ」字状の断面を有する一般部鋼製エレメント２０によってエレメント構造体を構成する例について説明したが、本発明はこの例には限定されず、他の構成の鋼製エレメント、例えば、略「日」字状、略「目」字状、略「田」字状、略「円」字状等の断面を有する鋼製エレメントであってもよい。
【００９０】
また、上記実施形態においては、基準管鋼製エレメント１０等の隅部にエレメント継手部（例えば１３又は２３）が設けられている場合を例に挙げて説明したが、本発明はこの例には限定されず、他の構成の鋼製エレメント、例えば、鋼製エレメントの辺の中間部分にエレメント継手部が設けられるように構成してもよい。
【００９１】
また、横拘束鉄筋４６、補強鉄筋４７は、状況に応じて適宜設ければよく、場合によっては、設けなくてもよい。
【００９２】
また、保護部材４８についても、他の土留め部材等を利用できる場合には、設けなくてもよい。
【００９３】
【発明の効果】
以上説明したように、本発明によれば、略「コ」字状の第１鉄筋（４４）を２つの結合継手部材（４３、４３）に接合した第１閉合部材（４１）と、略「コ」字状の第２鉄筋（４５）を２つの結合継手部材（４３、４３）に接合した第２閉合部材（４２）を有し、第１鉄筋（４４）と第２鉄筋（４５）がエレメント軸直角方向にスライド移動可能な構造とした閉合部調整用エレメント（４０）を用い、結合継手部（４３ｂ）によって既設の鋼製エレメントのエレメント継手部（１３又は２３）に嵌合させるとともに現場打ちコンクリートの補強部材として利用するため、閉合部におけるエレメント軸直角方向の力を伝達させ確実に補強することができ、かつ閉合部の誤差を容易に吸収することができる、という利点を有している。また、略「コ」字状の鉄筋（４４、４５）どうしを相互に重複させることにより、従来の鉄筋の重ね合わせ継手よりも大きな耐力を発揮することができ、重ね合わせ長さが、従来の鉄筋の重ね合わせ継手における重ね合わせ長さよりも短い場合であっても、従来の場合と同等以上の継手強度が得られる、という利点も有している。
【図面の簡単な説明】
【図１】本発明の一実施形態である地下構造物の全体構成を示す断面図である。
【図２】図１の地下構造物における基準管鋼製エレメントと一般部鋼製エレメントの構成を示す図である。
【図３】図１の地下構造物における隅角部鋼製エレメントの構成を示す図である。
【図４】図１の地下構造物の閉合部における閉合部調整用エレメントの構成を示す断面図である。
【図５】図４の閉合部調整用エレメントにおける結合継手部材の構成を示す図である。
【図６】図４の閉合部調整用エレメントにおける第１閉合部材の構成を示す図である。
【図７】図４の閉合部調整用エレメントにおける第１鉄筋と第２鉄筋の配置状態を示す図である。
【図８】図４の閉合部調整用エレメントにおける横拘束鉄筋の配置状態を示す図である。
【図９】図１の地下構造物における閉合部の施工方法を説明する図（１）である。
【図１０】図１の地下構造物における閉合部の施工方法を説明する図（２）である。
【符号の説明】
１０基準管鋼製エレメント
１１、１２鋼製板状部材
１３エレメント継手部
１３ａ嵌合部
１３ｂ基部
１３ｃ主爪部
１３ｄ副爪部
１３ｅ溝
２０、２０Ｌ、２０Ｒ一般部鋼製エレメント
２１、２２鋼製板状部材
２３エレメント継手部
２３ａ嵌合部
２３ｂ基部
２３ｃ主爪部
２３ｄ副爪部
２３ｅ溝
２５固定部
３０隅角部鋼製エレメント
３１、３２、３４鋼製板状部材
４０閉合部調整用エレメント
４１第１閉合部材
４２第２閉合部材
４３結合継手部材
４３ａ鋼製平板部
４３ｂ結合継手部
４４第１鉄筋
４４ａ上側直線部
４４ｂ下側直線部
４４ｃ連結部
４５第２鉄筋
４５ａ上側直線部
４５ｂ下側直線部
４５ｃ連結部
４６横拘束鉄筋
４７補強鉄筋
４８保護部材
４９カゴ状部材
５１直線鋼矢板
５２現場打ちコンクリート
１００地下構造物
Ｅエレメント構造体
Ｇ地盤
Ｌ中央線
Ｓ閉合空間
Ｗ１〜Ｗ７溶接部[0001]
BACKGROUND OF THE INVENTION
The present invention provides a closing portion adjusting element disposed at the last closing portion when a closed element structure is formed in the ground with a steel element, and an underground structure using the closing portion adjusting element. It is about how to build.
[0002]
[Prior art]
Conventionally, as a method of constructing an underground structure under a railroad track or road by a non-opening method, steel elements are sequentially inserted and combined into the ground by towing or propelling while excavating the ground, and the steel elements are mutually connected. A closed element structure in the ground, excavating the earth and sand surrounded by the element structure, and using the element structure as the main body structure of the underground structure Yes.
[0003]
[Problems to be solved by the invention]
In such a construction method, the manufacturing error of each steel element, the traction excavation of the steel element into the ground, the steel material at the part where the element structure is finally closed (hereinafter referred to as “closed part”) Construction errors that occur in the process of joining the manufactured elements with each other may accumulate, and the shape and dimensions of the closed portion may deviate from the designed values. In such a case, there was a problem that construction could not be performed with the closure element manufactured as designed.
[0004]
The present invention has been made to solve the above problems, and the problem to be solved by the present invention is to use a closing portion adjusting element capable of absorbing an error according to the state of the closing portion, and to use this element. The purpose is to provide a construction method for underground structures.
[0005]
[Means for Solving the Problems]
  In order to solve the above problems, the present inventionThe closing part adjusting element (40) according to claim 1 is:
A steel member extending in the element axial direction is provided with an element joint portion (13 or 23) having a substantially “C” -shaped cross section along the element axial direction, and the adjacent element joint portion (13 or 23) is fitted. A steel element (10, 20, 20L, 20R, 30, or 40) that joins each other by joining together is inserted into the ground to form a closed element structure (E). A closing portion adjusting element (40) disposed at the last closing portion,
A joint joint portion having a substantially “C” -shaped cross section that can be fitted to the element joint portion (13 or 23) along the element axial direction at one end portion of a steel flat plate portion (43a) extending in the element axial direction. Four coupling joint members (43) provided with (43b) are provided,
The upper straight portion (44a) which is one end of the plurality of first reinforcing bars (44) formed in a substantially “U” shape is opposite to the joint joint portion (43b) of the first joint joint member (43). The lower straight portion (44b), which is the other end of the plurality of first reinforcing bars (44), is connected to the vicinity of the other end portion on the side, and the joint joint portion (43) of the second joint joint member (43) 43b) is connected to the vicinity of the other end on the opposite side to constitute the first closing member (41),
The upper straight part (45a), which is one end of the plurality of second reinforcing bars (45) formed in a substantially “U” shape, is opposite to the joint joint part (43b) of the third joint joint member (43). And the lower straight portion (45b) which is the other end of the plurality of second reinforcing bars (45) is connected to the joint joint portion (43) of the fourth joint member (43). 43b) is connected to the vicinity of the other end on the opposite side to constitute a second closing member (42),
The first reinforcing bar (44) and a part of the second reinforcing bar (45) (44a and 45a, or 44b and 45b) are placed close to each other and overlapped to form a lap joint, and the first The first reinforcing bar (44) and the second reinforcing bar (45) are configured to be slidably movable in the direction perpendicular to the element axis, which is a direction perpendicular to the element axis direction. ) Slide mutually in the direction perpendicular to the element axisBy moving, it is possible to absorb errors in the direction perpendicular to the element axis at the closing portion.
  It is characterized by.
[0006]
  Further, the closing part adjusting element (40) according to claim 2 of the present invention is:
In the closing part adjusting element (40) according to claim 1,
A laterally restrained reinforcing bar (46) surrounding the first reinforcing bar (44) and the second reinforcing bar (45) and having a cage shape is disposed.
FeaturesThe
[0007]
  Also,The closing part adjusting element (40) according to claim 3 of the present invention is:
In the closing part adjusting element (40) according to claim 1,
Protective members (48, 48) having a function of a formwork when placing earth retaining and on-site concrete when excavating the ground of the closing portion are disposed.
FeaturesThe
[0008]
  Also,The closing part adjusting element (40) according to claim 4 of the present invention is:
In the closing part adjusting element (40) according to claim 1,
Reinforcing bars (47) extending in the element axial direction are disposed in the vicinity of the first reinforcing bars (44) and the second reinforcing bars (45).
FeaturesThe
[0009]
  Also,The closing part adjusting element (40) according to claim 5 of the present invention is:
In the closing part adjusting element (40) according to claim 4,
The reinforcing reinforcing bar (47) includes a connecting portion (44c) that connects one end of the upper straight portion (44a) and one end of the lower straight portion (44b) of the substantially “U” -shaped first reinforcing bar (44). It is arrange | positioned in the vicinity of the connection part (45c) which connects the end of the upper part linear part (45a) of the 2nd reinforcing bar (45) of the said substantially "U" shape, and the lower end straight part (45b). thing
FeaturesThe
[0010]
  Also,The closing part adjusting element (40) according to claim 6 of the present invention is:
In the closing part adjusting element (40) according to claim 1,
The coupling joint member (43) has a “−”-shaped cross section and substantially extends along the longitudinal direction at both ends of the “−”-shaped cross section of the steel flat plate portion (43a) extending in the longitudinal direction. It is formed by cutting the steel flat plate portion (43a) of the straight steel sheet pile (51) provided with the joint joint portion (43b) having a “C” -shaped cross section along the longitudinal direction.
FeaturesThe
[0011]
  Also,The closing part adjusting element (40) according to claim 7 of the present invention is:
In the closing part adjusting element (40) according to claim 1,
The first reinforcing bar (44) or the second reinforcing bar (45) is joined to the steel flat plate part (43a) by welding or mechanical joining.
FeaturesThe
[0012]
  Also,The closing part adjusting element (40) according to claim 8 of the present invention is:
In the closing part adjusting element (40) according to claim 1,
The grout material is fixed by being injected into the fitting space (13e or 23e) formed inside the fitted element joint (13 or 23) and the joint joint (43b) and cured.
FeaturesThe
[0013]
  In addition, the present inventionThe underground structure construction method according to claim 9 is:
A steel member (10, 20, 20L, 20R, or 20) is provided by providing an element joint (13 or 23) having a substantially “C” -shaped cross section along the element axial direction on a steel member extending in the element axial direction. 30) is inserted into the ground with the element axial direction as the insertion direction,
Next, another steel element is repeatedly inserted into the ground while the element joint portions (13 or 23) are fitted to each other to connect a plurality of steel elements in the ground.
Next, before the plurality of steel elements are closed, a closed space (S) is formed by excavating the ground (G) of the closed portion,
Next, a substantially “C” -shaped cross-section that can be fitted to the element joint portion (13 or 23) along the element axial direction at one end of a steel flat plate portion (43a) extending in the element axial direction. The upper straight portion (44a), which is one end of a plurality of first rebars (44) provided with four coupling joint members (43) provided with joint portions (43b) and formed in a substantially “U” shape, A lower straight portion that is connected to the vicinity of the other end of the first joint member (43) opposite to the joint joint (43b) and that is the other end of the plurality of first reinforcing bars (44). (44b) is connected to the first closing member (41) configured to be connected to the vicinity of the other end of the second coupling joint member (43) on the side opposite to the coupling coupling part (43b). The upper straight portion (45a) which is one end of the plurality of second reinforcing bars (45) formed in a letter shape The joint member (43) is connected to the vicinity of the other end portion on the opposite side of the joint joint portion (43b), and the lower straight portion (45b) which is the other end of the plurality of second reinforcing bars (45). ) Includes a second closing member (42) configured to be connected to the vicinity of the other end portion of the fourth coupling joint member (43) opposite to the coupling coupling portion (43b), and the first reinforcing bar (44) and a part of the second reinforcing bar (45) (44a and 45a, or 44b and 45b) are placed close to each other and overlapped to form a lap joint, and the first reinforcing bar (44 ) And the second reinforcing bar (45) are configured to be slidable in a direction perpendicular to the element axis, which is a direction perpendicular to the element axial direction, and the first reinforcing bar (44) and the second reinforcing bar (45) are connected to the element. Slide and move in the direction perpendicular to the axis The coupling joint portion (43b) of the closing portion adjustment element (40) that can absorb the error in the direction perpendicular to the element axis in the closing portion and the element joint portion (13 or 13) in the closing space (S) 23) inserting the closing part adjusting element (40) into the excavated closing space (S) while fitting them together.
Next, the cast-in-place concrete (52) is placed and cured in the closed space (S) in which the closing portion adjusting element (40) is inserted,
Next, the element structure (E) composed of the steel elements connected in the ground and the in-situ reinforced concrete after hardening formed in the closed space (S) is used as a protective work. Drilling the ground inside,
Next, using the element structure (E) as a main body, an underground structure (100)To build
  It is characterized by.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 is a cross-sectional view showing the overall structure of an underground structure that is an embodiment of the present invention.
[0016]
As shown in FIG. 1, the underground structure 100 is a box-shaped structure having a “B” -shaped cross section. The underground structure 100 is configured by an element structure E having a “B” -shaped cross-sectional shape.
[0017]
The element structure E includes a reference pipe steel element 10 installed at the center position of the upper floor slab, a general steel element 20 installed so as to be adjacent to the reference pipe steel element 10, and an element structure. The corner steel elements 30 installed at the four corner positions of the body are combined, and the closing portion adjusting element 40 is arranged at the last closing portion (the center position of the lower floor plate portion in FIG. 1). It is constituted by.
[0018]
FIG. 2 shows the configuration of the reference pipe steel element 10 and the general part steel element 20 and the joined state between these elements. FIG. 2A shows a cross-sectional view of the reference pipe steel element 10 and the general steel element 20. FIG. 2B is an enlarged cross-sectional view showing a joined state of the element joint portions 13 and 23. 2 (A) and 2 (B) are both made of reference tube steel when cut in a plane perpendicular to the direction of the longitudinal axis of the steel element (hereinafter referred to as “element axial direction”). Sectional drawing of the element 10 and the general steel element 20 is shown.
[0019]
As shown in FIG. 2A, the reference pipe steel element 10 has two steel plate members 11, two steel plate members 12, and four element joint portions 13. The steel plate-like member 11 and the other steel plate-like members 11 are arranged so as to face each other and extend in the element axial direction. The steel plate-like member 12 and the other steel plate-like member 12 are arranged so as to face each other and are arranged so as to be perpendicular to the steel plate-like member 11 and extend in the element axial direction. The Thereby, the two steel plate-like members 11 and the two steel plate-like members 12 form a steel member having a rectangular tubular (“B” -shaped) cross section as a whole.
[0020]
Further, steel element joint portions 13 extending along the element axial direction are disposed at each of the four corners of the rectangular tubular cross section formed by the steel plate-like members 11, 12, 11, 12. ing.
[0021]
As shown in FIG. 2 (B), the cross section of the element joint portion 13 is configured to have a substantially “C” -shaped fitting portion 13a and a base portion 13b connected to the back of the fitting portion 13a. . Moreover, the fitting part 13a has the main nail | claw part 13c and the subnail | claw part 13d which are two protruding parts. The tip of the main claw portion 13c has a bulbous cross section. Further, a middle portion between the main claw portion 13c and the sub claw portion 13d is a concave portion having a substantially elliptical cross section, and this portion is a groove 13e having a substantially elliptical cross section and extending in the element axis direction.
[0022]
2B shows a cross section of the element joint portion 13 at the upper center position in FIG. 2A, but the lower center position, the upper right position, and the lower right position corners in FIG. 2A. The element joint portion 13 having exactly the same shape is also used for the element joint portion 13, and the configuration thereof is exactly the same as that illustrated in FIG.
[0023]
Moreover, each joining location of each steel plate-shaped member 11 and 12 and each element joint part 13 is joined by welding part W1, W2, W3, and W4. The steel plate-like members 11 and 12 and the element joint portions 13 may be joined by mechanical joining such as bolts.
[0024]
When a force in a direction perpendicular to the element axial direction (hereinafter referred to as “element axis perpendicular direction”) is applied to the vicinity of the tip of the main claw portion 13c of the element joint portion 13 with the above configuration, for example, FIG. When pulled to the left in 2 (B), this tensile force (hereinafter referred to as “first tensile force”) is transmitted from the main claw portion 13c to the base portion 13b and from the base portion 13b to the steel plate-like member 11. Then, a tensile force in the left direction in FIG. 2 (B) is applied to the left end of the steel plate-like member 11 in FIG. 2 (B).
[0025]
On the other hand, when a force in the direction perpendicular to the element axis is applied to the vicinity of the tip of the sub claw portion 13d of the element joint portion 13, for example, when pulling in the left direction in FIG. 2) is transmitted to the steel plate-like member 11 from the sub-claw portion 13d through the base portion 13b, to the left end in FIG. 2 (B) of the steel plate-like member 11, and to the left in FIG. 2 (B). A tensile force in the direction is applied.
[0026]
From the above, the main claw portion 13c and the sub claw portion 13d of the element joint portion 13 and the base portion 13b are applied from the outside in the direction perpendicular to the element axis (for example, the first tensile force and the second tensile force). It has a predetermined strength and a predetermined cross section capable of resisting. Further, in consideration of the combined force of the part of the first tensile force and the part of the second tensile force acting on the sub claw part 13d of the element joint part 13, a predetermined resistance that can resist the force is given. And has a predetermined cross section. For example, the thickness of the sub claw portion 13d is sufficient.
[0027]
Further, considering that the combined force of the first tensile force and a part of the second tensile force acts on the base portion 13b of the element joint portion 13, a predetermined strength and a predetermined strength that can resist the force are applied. It has a cross section (for example, sufficient thickness). The steel plate-like member 11 has a predetermined strength and a predetermined cross section capable of resisting the force in the direction perpendicular to the element axis transmitted from the element joint portion 13.
[0028]
As shown in FIG. 2A, the general steel element 20 includes two steel plate-like members 21, one steel plate-like member 22, two element joint portions 13, and two steel plate-like members 22. An element joint portion 23 is provided. The steel plate member 21 and the other steel plate members 21 are arranged so as to face each other and extend in the element axial direction. The steel plate-like member 22 is disposed so as to be perpendicular to the steel plate-like members 21 and 21 and extends in the element axial direction. As a result, the two steel plate-like members 21 and the one steel plate-like member 22 form a steel member having a “U” -shaped cross section as a whole.
[0029]
Of the four corners of the “U” -shaped cross section formed by the steel plate-like members 21, 22, 21, the corner opened to the outside, that is, the upper right corner in FIG. A steel element joint portion 23 is disposed along the element axial direction at each of the upper and lower right corners.
[0030]
Of the four corners of the “U” -shaped cross section formed by the steel plate-like members 21, 22, 21, the corner closed to the outside, that is, the upper left corner in FIG. The element joint portion 13 described above is disposed along the element axial direction at each of the portion and the lower left corner.
[0031]
The cross section of the element joint portion 23 is configured to include a substantially “C” -shaped fitting portion 23a and a base portion 23b connected to the back of the fitting portion 23a. Moreover, the fitting part 23a has the two main nail | claw parts 23c and the subnail | claw part 23d. The tip of the main claw portion 23c has a bulbous cross section. Further, a middle portion between the main claw portion 23c and the sub claw portion 23d is a concave portion having an approximately elliptical cross section, and this portion is a groove 23e having a substantially elliptical cross section and extending in the element axis direction.
[0032]
2B shows a cross section of the element joint portion 23 at the upper center position in FIG. 2A, but the element joint portion 23 at the corner portion at the lower center position in FIG. An element joint portion 23 having exactly the same shape is used, and its configuration is exactly the same as that illustrated in FIG. In addition, the configuration of the element joint portion 13 and the vicinity thereof in the general steel element 20 is exactly the same as the configuration of the element joint portion 13 and the vicinity thereof in the reference pipe steel element 10 described above.
[0033]
Moreover, each joining location of each steel plate-shaped member 21 and 22 and each element joint part 13 and 23 is joined by welding part W5, W6, etc. FIG. The joining of the steel plate-like members 21 and 22 and the element joint portions 13 and 23 may be mechanical joining such as bolts.
[0034]
When a force in the direction perpendicular to the element axis is applied to the vicinity of the tip of the main claw portion 23c of the element joint portion 23 by the above-described configuration, for example, when the right direction in FIG. Hereinafter, the “third tensile force” is transmitted from the main claw portion 23c to the base portion 23b, from the base portion 23b to the steel plate member 21, and the steel plate member 21 in FIG. A tensile force in the right direction in FIG. 2B is applied to the right end.
[0035]
On the other hand, when a force in a direction perpendicular to the element axis is applied to the vicinity of the tip of the sub claw portion 23d of the element joint portion 23, for example, when pulling in the right direction in FIG. 2) is transmitted from the sub claw portion 23d to the base portion 23b, from the base portion 23b to the steel plate-like member 21, and at the right end of the steel plate-like member 21 in FIG. The tensile force in the right direction in B) is applied.
[0036]
From the above, the main claw portion 23c and the sub claw portion 23d of the element joint portion 23 can resist the force in the direction perpendicular to the element axis (for example, the third tensile force and the fourth tensile force) applied from the outside. It has a predetermined strength and a predetermined cross section. Further, the sub-claw portion 23d of the element joint portion 23 can resist the force in consideration of the combined force of the fourth tensile force and the bending moment resulting from the fourth tensile force. It has a predetermined strength and a predetermined cross section. For example, the thickness of the sub claw portion 23d is sufficient.
[0037]
Further, in consideration of the combined force of the third tensile force and the fourth tensile force acting on the base portion 23b of the element joint portion 23, a predetermined strength and a predetermined cross section (for example, resistance to the force) Sufficient thickness). The steel plate-like members 21 and 22 have a predetermined strength and a predetermined cross section that can resist the force in the direction perpendicular to the element axis transmitted from the element joint portions 13 and 23.
[0038]
Next, the construction method of the element structure by the reference pipe steel element 10 and the general part steel element 20 will be described.
[0039]
First, the reference pipe steel element 10 is inserted into the ground in the element axial direction by towing or propulsion. In this case, an auger drill or the like is provided inside the reference pipe steel element 10, and the element is inserted into the ground while excavating and removing the soil and the like inside the element. Then, each of the element joint parts 23 and 23 provided at the open side corner of the general steel element 20 is replaced with two of the element joint parts 13 of the reference pipe steel element 10 (for example, FIG. The upper left corner joint and the lower left corner joint) in FIG.
[0040]
Thereafter, in a state where these element joint portions 13 and 23 are fitted, the general steel element 20 is made to follow the reference pipe steel element 10 in the same manner as in the case of the reference pipe steel element 10. Insert it into the ground in the direction of the element axis. As a result, the state shown in FIG.
[0041]
In this case, as shown in FIG. 2 (B), the element joint portion 13 of the element joint portion 13 of the reference pipe steel element 10 and the element joint portion 23 of the general steel element 20 which are in a joined state are used. The enlarged tip of the main claw portion 23c of the element joint portion 23 enters and fits into the groove 13e of the element joint portion 23, and the main claw portion 13c of the element joint portion 13 is enlarged into the groove 23e of the element joint portion 23. The tip is inserted and fitted. In this way, the element joint portion 13 of the reference pipe steel element 10 and the element joint portion 23 of the general steel element 20 are fitted to each other, so that the reference pipe steel element 10 and the general steel element 20 are mutually connected. The force in the direction perpendicular to the element axis can be transmitted between them.
[0042]
In the groove 13e, 23e inside the element joint part 13 of the reference pipe steel element 10 and the element joint part 23 of the general steel element 20 fitted as described above, an appropriate one can be provided. At one time, grout materials (not shown) such as non-shrink mortar, non-shrink concrete, resin material, etc. are injected from one end in the axial direction of the element (hereinafter referred to as “injection end”), cured and jointed. May be reinforced. When this grout injection is performed, the joint is fixed, so that it is possible to prevent the plurality of steel elements after being joined from being deformed by bending due to an overload or the like. This reinforcement also improves the force transmission performance in the direction perpendicular to the element axis.
[0043]
Next, in the same manner as described above, each of the element joint portions 23 and 23 provided at the open side corners of other new general steel elements 20 is already inserted into the ground. The element joint portions 13 and 13 provided at the corners on the closing side of 20 are fitted and joined. And in the state which fitted both joints, the new general part steel element 20 is inserted in the underground toward the element axial direction, along with the already inserted general part steel element 20.
[0044]
Hereinafter, by repeating the general element insertion process sequentially as described above, an element structure can be configured by the steel elements 10 and 20 inserted into the ground and joined to each other. For example, a flat structure or an element structure having a shape surrounded by a semicircle, a circle, an ellipse, or the like.
[0045]
Next, concrete or the like is filled in each element as necessary. Next, the element structure formed in the ground is used as a protective work to excavate the soil and the like inside the element structure. Next, an underground structure can be constructed by performing construction such as covering the inner surface of the element with concrete.
[0046]
When the element structure has a “B” -shaped cross section or the like, a corner where the element bends at a right angle is required. In this corner portion, a corner portion constituting element 30 having a different configuration from the reference pipe steel element 10 and the general portion steel element 20 is used.
[0047]
Next, the configuration of the corner steel element 30 will be described with reference to FIG. FIG. 3 is a cross-sectional view of the vicinity of the corner steel element 30 that is the lower end position of the left side wall of the element structure E shown in FIG.
[0048]
As shown in FIG. 3, the corner steel element 30 has five steel plate members 31, 31, 32, 34, 34, two element joint parts 13, and two element joint parts 23. is doing. The steel plate-like member 31 and the other steel plate-like member 31 are arranged so as to face each other and extend in the element axial direction. The steel plate-like member 34 and the other steel plate-like member 34 are arranged so as to face each other and are arranged so as to be perpendicular to the steel plate-like member 31 and extend in the element axial direction. The The steel plate-like member 32 is arranged so as to be perpendicular to the steel plate-like member 31 and parallel to the steel plate-like member 34, and extends in the element axial direction. Thereby, the five steel plate-shaped members 31, 31, 32, 34, and 34 form steel members having a rectangular tubular cross section as a whole.
[0049]
Further, of the four corners of the rectangular tubular cross section formed by the steel plate-like members 31, 31, 32, 34, 34, one direction in the direction perpendicular to the element axis, for example, in the vertical direction in FIG. Element joint portions 23, 23 are provided along the element axial direction at two corners adjacent to each other, that is, at the upper left corner and the upper right corner in FIG.
[0050]
Also, the elements along the element axial direction are arranged at two corners adjacent to each other in the other direction perpendicular to the above-described vertical direction, for example, the left-right direction in FIG. 3, that is, the upper right corner and the lower right corner in FIG. Joint portions 13 and 13 are provided.
[0051]
The structure of each element joint part 13 and 23 is completely the same as the above. The steel plate-like members 31, 32, and 34 have a predetermined strength and a predetermined cross section that can resist the force in the direction perpendicular to the element axis transmitted from the element joint portions 13 and 23. Moreover, each joining location of each steel plate-shaped member 31, 32, 31, 34 and each element joint part 13 and 23 is joined by the welding part. This joining may be a mechanical joining such as a bolt.
[0052]
The corner steel elements 30 are also provided at the upper right, lower right, and upper left corners of the element structure E. With the above-described configuration, the corner steel element 30 has a component in each direction of the “L” -shaped corner portion of the force in the direction perpendicular to the element axis, for example, the horizontal direction (horizontal direction) in FIG. The component can be transmitted by the horizontal element joint portion 13 provided on the corner steel element 30 side and the joint portion (for example, the element joint portion 23) provided on the counterpart side. Of the force perpendicular to the element axis, the component in the vertical direction (vertical direction) includes the vertical element joint 13 provided on the corner steel element 30 side and the joint provided on the mating side. It can be transmitted by a part (for example, element joint part 23).
[0053]
The insertion of the corner portion steel element 30 into the ground is exactly the same as the case of the reference portion steel element 10 and the general portion steel element 20 described above, and is adjacent to the ground portion already inserted into the ground. Insert it along the element. The same applies to the general steel element 20 adjacent to the lower corner steel element 30.
[0054]
For the corner steel element 30 described above, a large tensile force may be generated inside the corner of the element structure, for example, the upper right corner in FIG. The steel plate-like member 34 can be made to bear and the strength of the element structure can be increased.
[0055]
Further, when the tensile force inside the corner portion (upper right corner portion in FIG. 3) of the element structure is small, the upper steel plate member 34 may be omitted. Alternatively, when construction is performed (when the corner steel element 30 is inserted), the steel plate-like member 34 is omitted, and a “U” -shaped cross section is provided. The steel plate-like member 34 may be attached by, for example, mechanical joining. The lower steel plate-like member 34 can be added or omitted as appropriate.
[0056]
FIG. 4 shows the configuration of the closing portion adjusting element 40. FIG. 4 shows a cross-sectional view of the closing portion adjusting element cut along a plane perpendicular to the element axial direction.
[0057]
As shown in FIG. 4, the closing portion adjusting element 40 includes a cage member 49 and two protective members 48 and 48.
[0058]
The cage-like member 49 has a first closing member 41, a second closing member 42, a lateral restraint reinforcing bar 46, and a reinforcing reinforcing bar 47.
[0059]
As shown in FIG. 6, the first closing member 41 is constituted by joining a plurality of substantially “U” -shaped first reinforcing bars 44 to two coupling joint members 43.
[0060]
As shown in the cross-sectional view of FIG. 5 (a cross-sectional view taken along a plane perpendicular to the element axial direction), the coupling joint member 43 is formed by lining the straight steel sheet pile 51 along the central line L in the longitudinal direction of the sheet pile. It is formed by cutting to divide.
[0061]
As shown in FIG. 5, the coupling joint member 43 has a steel flat plate portion 43a and a coupling joint portion 43b. The steel flat plate portion 43a is a flat plate portion made of steel having a “−”-shaped cross section and extending in the element axial direction. The joint joint 43b is made of steel, and is a portion of a substantially “C” -shaped cross section formed along the element axial direction at one end of the “−”-shaped cross section of the steel flat plate portion 43a. It has the same configuration as the element joint portions 13 and 23 described above, and can be fitted to the element joint portions 13 and 23.
[0062]
The first reinforcing bar 44 includes an upper straight portion 44a, a lower straight portion 44b parallel to the upper straight portion 44a, and a connecting portion 44c that connects one end of the upper straight portion 44a and one end of the lower straight portion 44b. However, it is formed in a “U” shape as a whole.
[0063]
As shown in FIG. 6, in the 1st closing member 41, among the steel flat plate parts 43a of the upper coupling joint member 43, the vicinity of the other end part on the opposite side to the one end part where the coupling joint part 43b is provided. In addition, the upper straight portion 44a of the first reinforcing bar 44 is joined by a welded portion (not shown). Further, in the steel flat plate portion 43a of the lower coupling joint member 43, the lower linear portion 44b of the first reinforcing bar 44 is located in the vicinity of the other end portion opposite to the one end portion where the coupling joint portion 43b is provided. Are joined by the weld W7. The joining of the steel flat plate portion 43a and the first reinforcing bar 44 may be a mechanical joining such as a bolt.
[0064]
As shown in FIG. 4, the second closing member 42 is constituted by joining a plurality of substantially “U” -shaped second reinforcing bars 45 to two coupling joint members 43. The second closing member 42 uses a second reinforcing bar 45 instead of the first reinforcing bar 44 in the first closing member 41 shown in FIG. 6, and the shape thereof is the same as that of the first closing member 41.
[0065]
In the cage member 49, the first reinforcing bar 44 of the first closing member 41 and the second reinforcing bar 45 of the second closing member 42 are overlapped with each other by a length Z as shown in FIG. The reinforcing bar 44 and the second reinforcing bar 45 are inserted and arranged so as to be inserted into each other. In this state, the same position of the upper straight portion 44a of the first rebar 44 and the upper straight portion 45a of the second rebar 45, or the lower straight portion 44b of the first rebar 44 and the lower straight portion 45b of the second rebar 45 The same position is loosely bundled with a soft iron wire, etc., and a variable structure is slidable in the direction perpendicular to the element axis, and the rebar overlap length Z of the upper straight portions 44a and 45a and the lower straight portions 44b and 45b is adjusted appropriately. Configure as possible.
[0066]
Further, as shown in FIG. 8, the first reinforcing bar 44 and the second reinforcing bar 45 are surrounded by a laterally constrained reinforcing bar 46, and the laterally constraining reinforcing bar 46 is attached to the first reinforcing bar 44 or the second reinforcing bar 45 with a soft iron wire or the like. .
[0067]
Further, as shown in FIG. 4, an appropriate number of reinforcing bars 47 extending in the element axial direction are arranged at appropriate positions of the first reinforcing bar 44 and the second reinforcing bar 45, and the first reinforcing bar 44 or the second reinforcing bar 47 is made of soft iron wire or the like. It attaches to the appropriate location of 2 rebar 45. For example, as shown in FIG. 4, in the vicinity of the position where the bent portions of the first reinforcing bar 44 and the second reinforcing bar 45 overlap, in the vicinity of the intermediate position of the connecting portion 44c of the first reinforcing bar 44, in the connecting portion 45c of the second reinforcing bar 45 For example, in the vicinity of an intermediate position. The arrangement state of the reinforcing reinforcing bars 47 extending in the element axial direction is as shown by a broken line in FIG.
[0068]
Next, a construction method of the closing portion adjusting element 40 will be described with reference to FIGS. 9 and 10.
[0069]
First, the cage member 49 is prepared in advance.
[0070]
Next, the element joint portions 13 and 23 of the reference pipe steel element 10, the general steel element 20, the corner steel element 30, and the like described above are fitted to each other, and each element is placed in the ground G while excavating. The grout material is poured into the jointed element joint and hardened, and the steel elements are repeatedly fixed to connect the steel elements in the ground G. An element structure E having a cross section with a closed portion, which is a portion near the plate center (between the general steel elements 20L and 20R), is formed in the ground (see FIG. 9A).
[0071]
Next, the protection member 48 is inserted into the ground G at the upper part of the closed portion in a state where the general steel elements 20L and 20R are not closed (see FIG. 9B). Similarly, the protective member 48 is inserted into the ground G at the lower part of the closing position. The protection member 48 is made of steel or the like, and a member having a substantially “U” cross-sectional shape is used. In this case, both ends of the upper protection member 48 and the lower protection member 48 are joined and fixed to the general steel elements 20L and 20R by welding or the like using the fixing portion 25. The joining of the fixing part 25 to the general part steel element 20L or the like may be a mechanical joining such as a bolt.
[0072]
Next, as shown in FIG. 9 (B), the protective members 48 and 48 are used as earth retaining means, and the ground G inside the portion surrounded by the protective members 48 and 48 is excavated and removed, and a closed space is obtained. S is formed.
[0073]
Thereafter, as shown in FIG. 10 (A), the coupling joint portion 43b of the cage member 49 described above is fitted to the element joint portion 13 such as the general steel element 20L and inserted so as to slide in the element axial direction. Then, the cage member 49 is installed in the closed space S. The cage member 49 is manufactured so that the length in the element axial direction is about 1 meter, and the number corresponding to the length in the element axial direction of the structure is sequentially inserted.
[0074]
In this case, the coupling joint portion 43b of the cage member 49 and the internal groove 13e of the element joint portion 13 such as the general steel element 20L are provided with one of the element axial directions at an appropriate time as necessary. A grout material (not shown) such as non-shrink mortar, non-shrink concrete, or a resin material may be injected from the injection end of the resin and cured to reinforce the joint joint.
[0075]
Next, as shown in FIG. 10 (B), the cast-in-place concrete 52 is placed and cured in the closed space S in which the cage-like member 49 is inserted, using the protective members 48 and 48 as a concrete formwork. . As a result, a steel-framed reinforced concrete structure is formed in the closing portion, and the element structure E is closed in a “B” -shaped cross section.
[0076]
10B, the element joint 13 at the upper right corner of the general steel element 20L on the left side and the joint joint 43b at the upper left end of the cage member 49 are fitted to each other, and the left general steel part The element joint portion 13 at the lower right corner of the manufactured element 20L and the joint joint portion 43b at the lower left end of the cage member 49 are fitted to each other.
[0077]
The element joint 13 at the upper left corner of the right general steel element 20R and the upper joint right joint joint 43b of the cage-like member 49 are fitted to each other, and the lower left of the right general steel element 20R. The element joint portion 13 at the corner and the joint joint portion 43b at the lower right end of the cage member 49 are fitted to each other.
[0078]
Further, as shown in FIG. 10B, in the cage member 49, the upper and lower coupling joint members 43, 43 of the first closing member 41 and the first rebar 44 are joined by welding or the like, and the second closing member 42 is joined. The upper and lower coupling joint members 43, 43 and the second rebar 45 are joined by welding or the like.
[0079]
Here, the overlapping portion of the upper straight portion 44 a of the first reinforcing bar 44 and the upper straight portion 45 a of the second reinforcing bar 45 (the portion of the overlapping length Z on the upper side in FIG. 7) overlaps the reinforcing bars in the concrete 52. It constitutes a joint. Further, the overlapping portion of the lower straight portion 44 b of the first reinforcing bar 44 and the lower straight portion 45 b of the second reinforcing bar 45 (the portion of the overlapping length Z on the lower side of FIG. 7) overlaps the reinforcing bars in the concrete 52. It constitutes a joint.
[0080]
For this reason, the overlapping portion Z of the upper straight portion 44 a of the first reinforcing bar 44 adheres to the surrounding concrete 52, and the concrete 52 adheres to the overlapping portion Z of the upper straight portion 45 a of the second reinforcing bar 45. Thus, the stress of the upper straight portion 44 a of the first rebar 44 is transmitted to the upper straight portion 45 a of the second rebar 45 through the concrete 52.
[0081]
Similarly, the overlapping portion Z of the lower straight portion 44b of the first reinforcing bar 44 adheres to the surrounding concrete 52, and the overlapping portion Z of the concrete 52 and the lower straight portion 45b of the second reinforcing bar 45 also. As a result, the stress of the lower straight portion 44 b of the first reinforcing bar 44 is transmitted to the lower straight portion 45 b of the second reinforcing bar 45 through the concrete 52.
[0082]
In this case, the connecting portions 44 c and 45 c bear the shear stress in the vicinity of the connecting portions 44 c and 45 c in the concrete 52.
[0083]
With such a configuration, the steel-framed reinforced concrete structure in which the cast-in-place concrete 52 is placed on the closing portion adjusting element 40, the left general steel element 20 </ b> L, the closing portion adjusting element 40, The force in the direction perpendicular to the element axis can be transmitted between the general steel elements 20R, and the closed portion is reliably reinforced.
[0084]
Next, using the “B” -shaped structure closed as described above as a protective work, the ground inside is excavated. Next, an underground structure is constructed using the closed “B” -shaped structure as the main body structure.
[0085]
If constructed in this way, the element structure can be rigidly closed and closed in a short time. The first reinforcing bar 44 and the second reinforcing bar 45 have a structure that is variable in the direction perpendicular to the element axis. By sliding the first reinforcing bar 44 and the second reinforcing bar 45 in the direction perpendicular to the element axis, The overlapping length Z of the first reinforcing bar 44 and the second reinforcing bar 45 can be adjusted as appropriate, so that the manufacturing error and construction error of the elements accumulated in the closed portion can be absorbed.
[0086]
Further, according to the above-described closing portion adjusting element, the substantially “U” -shaped reinforcing bars are overlapped with each other, and therefore, it is possible to exert a greater proof strength than a conventional lap joint of overlapping reinforcing bars. Even when the joining length Z is shorter than the overlapping length in the conventional lap joint, it is possible to obtain joint strength equal to or higher than that in the conventional case.
[0087]
The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.
[0088]
For example, in the said embodiment, although the example which forms a coupling joint member (for example, 43) by cut | disconnecting a linear steel sheet pile was demonstrated, this invention is not limited to this example, The coupling coupling member of another structure For example, an element joint portion (for example, 13 or 23) may be joined to one side end of a strip-shaped steel plate by welding or mechanical joining to form a joint joint member.
[0089]
In the above embodiment, the element structure is formed by the reference tube steel element 10 and the corner steel element 30 having a rectangular tubular cross section, and the general steel element 20 having a substantially “U” -shaped cross section. Although the example which comprises is explained, the present invention is not limited to this example, steel elements of other constitutions, for example, a substantially “day” shape, a substantially “eye” shape, a substantially “field” shape, It may be a steel element having a substantially “circle” -shaped cross section.
[0090]
Moreover, in the said embodiment, although the case where the element coupling part (for example, 13 or 23) was provided in the corners, such as the reference | standard pipe steel element 10, etc. was mentioned as an example, this invention is shown in this example. It is not limited, You may comprise so that an element coupling part may be provided in the steel element of another structure, for example, the intermediate part of the edge | side of a steel element.
[0091]
Further, the laterally restrained reinforcing bars 46 and the reinforcing reinforcing bars 47 may be provided as appropriate according to the situation, and may not be provided depending on circumstances.
[0092]
Further, the protective member 48 may not be provided when other earth retaining members or the like can be used.
[0093]
【The invention's effect】
  As described above, according to the present invention, the first rebar having a substantially “U” shape.The first closing member (41) in which (44) is joined to the two coupling joint members (43, 43) and the second rebar (45) having a substantially "U" shape are coupled to the two coupling coupling members (43, 43). A closing portion adjusting element (40) having a second closing member (42) joined to the first reinforcing bar and having a structure in which the first reinforcing bar (44) and the second reinforcing bar (45) are slidable in the direction perpendicular to the element axis is used. In order to fit the element joint (13 or 23) of the existing steel element with the joint joint (43b) and to use it as a reinforcing member for the cast-in-place concrete, the force in the direction perpendicular to the element axis is transmitted It has the advantage that it can be reliably reinforced and the error of the closing portion can be easily absorbed. In addition, approximately "U" shaped reinforcing bars (44, 45)By overlapping each other, it is possible to exert a greater proof strength than the conventional lap joints, and the overlap length is shorter than the overlap length of the conventional lap joints. However, there is an advantage that joint strength equal to or higher than that in the conventional case can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall configuration of an underground structure according to an embodiment of the present invention.
FIG. 2 is a diagram showing a configuration of a reference pipe steel element and a general part steel element in the underground structure of FIG. 1;
3 is a diagram showing a configuration of a corner steel element in the underground structure of FIG. 1. FIG.
4 is a cross-sectional view showing a configuration of a closing portion adjusting element in the closing portion of the underground structure shown in FIG. 1. FIG.
5 is a view showing a configuration of a coupling joint member in the closing portion adjusting element of FIG. 4;
6 is a view showing a configuration of a first closing member in the closing portion adjusting element of FIG. 4. FIG.
7 is a view showing an arrangement state of first reinforcing bars and second reinforcing bars in the closing portion adjusting element of FIG. 4;
8 is a diagram showing an arrangement state of lateral restraint reinforcing bars in the closing portion adjusting element of FIG.
FIG. 9 is a diagram (1) for explaining a construction method of a closing portion in the underground structure of FIG. 1;
FIG. 10 is a diagram (2) for explaining a construction method of the closing portion in the underground structure of FIG. 1;
[Explanation of symbols]
10 Reference pipe steel element
11, 12 Steel plate-like member
13 Element joint
13a Fitting part
13b base
13c Main claw part
13d secondary nail
13e groove
20, 20L, 20R General steel element
21, 22 Steel plate-like member
23 Element joint
23a Fitting part
23b base
23c Main nail part
23d minor nail
23e groove
25 Fixed part
30 Corner steel element
31, 32, 34 Steel plate-like members
40 Closure adjustment element
41 First closing member
42 Second closing member
43 Joint joint members
43a Steel plate
43b Joint joint
44 First rebar
44a Upper straight part
44b Lower straight part
44c connecting part
45 Rebar
45a Upper straight part
45b Lower straight part
45c connecting part
46 Lateral Restraint Rebar
47 Reinforcing bars
48 Protection member
49 Basket-shaped member
51 Straight steel sheet pile
52 Cast-in-place concrete
100 underground structure
E Element structure
G ground
L Chuo Line
S closed space
W1-W7 welds

Claims

A steel member extending in the element axial direction is provided with an element joint portion (13 or 23) having a substantially “C” -shaped cross section along the element axial direction, and the adjacent element joint portion (13 or 23) is fitted. A steel element (10, 20, 20L, 20R, 30, or 40) that joins each other by joining together is inserted into the ground to form a closed element structure (E). A closing part adjusting element (40) disposed in the last closing part,
A joint joint portion having a substantially “C” -shaped cross section that can be fitted to the element joint portion (13 or 23) along the element axial direction at one end portion of a steel flat plate portion (43a) extending in the element axial direction. Four coupling joint members (43) provided with (43b) are provided,
The upper straight portion (44a) which is one end of the plurality of first reinforcing bars (44) formed in a substantially “U” shape is opposite to the joint joint portion (43b) of the first joint joint member (43). The lower straight portion (44b), which is the other end of the plurality of first reinforcing bars (44), is connected to the vicinity of the other end portion on the side, and the joint joint portion (43) of the second joint joint member (43) 43b) is connected to the vicinity of the other end on the opposite side to constitute the first closing member (41),
The upper straight part (45a), which is one end of the plurality of second reinforcing bars (45) formed in a substantially “U” shape, is opposite to the joint joint part (43b) of the third joint joint member (43). And the lower straight portion (45b) which is the other end of the plurality of second reinforcing bars (45) is connected to the joint joint portion (43) of the fourth joint member (43). 43b) is connected to the vicinity of the other end on the opposite side to constitute a second closing member (42),
The first reinforcing bar (44) and a part of the second reinforcing bar (45) (44a and 45a, or 44b and 45b) are placed close to each other and overlapped to form a lap joint, and the first The first reinforcing bar (44) and the second reinforcing bar (45) are configured to be slidably movable in the direction perpendicular to the element axis, which is a direction perpendicular to the element axis direction. ) Are mutually slid in the direction perpendicular to the element axis so that the error in the direction perpendicular to the element axis in the closing portion can be absorbed.
A closing part adjusting element (40) characterized by the following .

In the closing part adjusting element (40) according to claim 1 ,
A laterally restrained reinforcing bar (46) surrounding the first reinforcing bar (44) and the second reinforcing bar (45) and having a cage shape is disposed.
A closing part adjusting element (40) characterized by the following .

In the closing part adjusting element (40) according to claim 1 ,
Protective members (48, 48) having a function of a formwork when placing earth retaining and on-site concrete when excavating the ground of the closing portion are disposed.
A closing part adjusting element (40) characterized by the following .

In the closing part adjusting element (40) according to claim 1 ,
Reinforcing bars (47) extending in the element axial direction are disposed in the vicinity of the first reinforcing bars (44) and the second reinforcing bars (45).
A closing part adjusting element (40) characterized by the following .

In the closing part adjusting element (40) according to claim 4 ,
The reinforcing reinforcing bar (47) includes a connecting portion (44c) that connects one end of the upper straight portion (44a) and one end of the lower straight portion (44b) of the substantially “U” -shaped first reinforcing bar (44). It is arrange | positioned in the vicinity of the connection part (45c) which connects the end of the upper part linear part (45a) of the 2nd reinforcing bar (45) of the said substantially "U" shape, and the lower end straight part (45b). thing
A closing part adjusting element (40) characterized by the following .

In the closing part adjusting element (40) according to claim 1 ,
The coupling joint member (43) has a “−”-shaped cross section and substantially extends along the longitudinal direction at both ends of the “−”-shaped cross section of the steel flat plate portion (43a) extending in the longitudinal direction. It is formed by cutting the steel flat plate portion (43a) of the straight steel sheet pile (51) provided with the joint joint portion (43b) having a “C” -shaped cross section along the longitudinal direction.
A closing part adjusting element (40) characterized by the following .

In the closing part adjusting element (40) according to claim 1 ,
The first reinforcing bar (44) or the second reinforcing bar (45) is joined to the steel flat plate part (43a) by welding or mechanical joining.
A closing part adjusting element (40) characterized by the following .

In the closing part adjusting element (40) according to claim 1 ,
The grout material is fixed by being injected into the fitting space (13e or 23e) formed inside the fitted element joint (13 or 23) and the joint joint (43b) and cured.
A closing part adjusting element (40) characterized by the following .

A steel member (10, 20, 20L, 20R, or 20) is provided by providing an element joint (13 or 23) having a substantially “C” -shaped cross section along the element axial direction on a steel member extending in the element axial direction. 30) is inserted into the ground with the element axial direction as the insertion direction,
Next, another steel element is repeatedly inserted into the ground while the element joint portions (13 or 23) are fitted to each other to connect a plurality of steel elements in the ground.
Next, before the plurality of steel elements are closed, a closed space (S) is formed by excavating the ground (G) of the closed portion,
Next, a substantially “C” -shaped cross-section that can be fitted to the element joint portion (13 or 23) along the element axial direction at one end of a steel flat plate portion (43a) extending in the element axial direction. The upper straight portion (44a), which is one end of a plurality of first rebars (44) provided with four coupling joint members (43) provided with joint portions (43b) and formed in a substantially “U” shape, A lower straight portion that is connected to the vicinity of the other end of the first joint member (43) opposite to the joint joint (43b) and that is the other end of the plurality of first reinforcing bars (44). (44b) is connected to the first closing member (41) configured to be connected to the vicinity of the other end of the second coupling joint member (43) on the side opposite to the coupling coupling part (43b). The upper straight portion (45a) which is one end of the plurality of second reinforcing bars (45) formed in a letter shape The joint member (43) is connected to the vicinity of the other end portion on the opposite side of the joint joint portion (43b), and the lower straight portion (45b) which is the other end of the plurality of second reinforcing bars (45). ) Includes a second closing member (42) configured to be connected to the vicinity of the other end portion of the fourth coupling joint member (43) opposite to the coupling coupling portion (43b), and the first reinforcing bar (44) and a part of the second reinforcing bar (45) (44a and 45a, or 44b and 45b) are placed close to each other and overlapped to form a lap joint, and the first reinforcing bar (44 ) And the second reinforcing bar (45) are configured to be slidable in a direction perpendicular to the element axis, which is a direction perpendicular to the element axial direction, and the first reinforcing bar (44) and the second reinforcing bar (45) are connected to the element. Slide and move in the direction perpendicular to the axis The coupling joint portion (43b) of the closing portion adjustment element (40) that can absorb the error in the direction perpendicular to the element axis in the closing portion and the element joint portion (13 or 13) in the closing space (S) 23) inserting the closing part adjusting element (40) into the excavated closing space (S) while fitting them together.
Next, the cast-in-place concrete (52) is placed and cured in the closed space (S) in which the closing portion adjusting element (40) is inserted,
Next, the element structure (E) composed of the steel elements connected in the ground and the in-situ reinforced concrete after hardening formed in the closed space (S) is used as a protective work. Drilling the ground inside,
Next, an underground structure construction method characterized by constructing an underground structure (100) using the element structure (E) as a main body .