JP3818889B2

JP3818889B2 - Pipe propulsion machine and pipe propulsion method

Info

Publication number: JP3818889B2
Application number: JP2001310281A
Authority: JP
Inventors: 秀樹森谷; 茂呂　　隆; 正巳大木
Original assignee: Hitachi Construction Machinery Co Ltd
Current assignee: Hitachi Construction Machinery Co Ltd
Priority date: 2001-10-05
Filing date: 2001-10-05
Publication date: 2006-09-06
Anticipated expiration: 2021-10-05
Also published as: JP2003120181A

Description

【０００１】
【発明の属する技術分野】
この出願の発明は、先導体と元押し装置とを備え、先導体を元押し装置で推進しつつ先導体で地山を掘削するとともに掘削土砂へ粘性付与液を注入して塑性流動性のある泥土を生成し、その泥土を後方へ送ってその一部を先導体後部から取り込んで地上に排出するとともに残りを埋設管の外周に導くようにした管推進機及びこうした管推進機を使用する管推進工法に関する。
【０００２】
【従来の技術】
管を地中に埋設する管推進工法は、カッタヘッドを有する先導体の後方にヒューム管等で形成した埋設管を順次連結し、発進立坑に設置した元押し装置によりそれらの埋設管を推進しながら前方の地山をカッタヘッドで掘削して、各埋設管を順次地中に押し込んで埋設して行く方法が通常採用されている。管推進機は、こうした管推進工法を実施するため、先導体と元押し装置とで構成された装置である。従来、出願人が独自に開発したこの種の管推進機では、カッタヘッドで掘削した掘削土砂に、粘性付与液としての添加剤を掘削土砂に注入、撹拌混合することにより塑性流動性のある泥土を生成し、その泥土を後方へ送って泥土の一部を先導体後部の土砂取り込み口から取り込んで土砂圧送装置で地上に排出するとともに残りを先導体の後端部に取り付けられた埋設管の外周に導くようにしている。そのため、埋設管を推進する際、埋設管と周辺地山との摩擦抵抗を低減して埋設管の貫入抵抗を軽減できるとともに、土砂圧送装置での掘削土砂の排出を容易に行うことができる。この種の管推進機は、特に直径略８００ｍｍ以下の小口径の埋設管を埋設する小口径管推進機に実用化して良好な成果を収めている。
【０００３】
この種の管推進機は、こうした利点がある反面、土砂取り込み口を先導体の後部に配置していて、発進の初期段階において土砂取り込み口が地山の外の発進立坑に位置するため、土砂取り込み口が地山に入りきるまでは、掘進する過程で生成される泥土は、地上に排出することができず発進立坑内に排出することを余儀なくされ、発進立坑内を泥土で汚して作業環境を悪化させるという問題が発生していた。また、土砂取り込み口が地山に入りきるまでは、泥土圧を立てることができないため、切羽を泥土圧で支持することができず、発進時に地山の崩壊や地下水の湧出が発生する危険性もあった。
【０００４】
出願人は、こうした問題を解消するため、改良を重ねて、先導体本体の周囲に泥土通路を形成するように外筒を取り付けて構成した先導体と、先導体本体の後端部に装着して埋設管を先導体本体に接続するための埋設管接続具と、先導体を押し込む押し台に設けられ先導体の発進時に外筒に密接して泥土が発進立坑内に漏れないようにシールするシール筒とを有する元押し装置とを備えた管推進機を最近開発した。この出願の発明は、こうした管推進機やこの管推進機を使用する管推進工法を、更に改良しようとするものである。
【０００５】
そこで、この出願人が最近開発した管推進機を従来例として取り上げ、その技術内容を図３及び図４を用いて説明する。図３は、発進時に先導体を地山に突入させた後に埋設管を接続するときの状態を示す従来例の管推進機の縦断面図、図４は、発進時に地山に突入した先導体に埋設管を接続して推進しているときの状態を示す従来例の管推進機の縦断面図である。
【０００６】
これらの図に示す管推進機は、大別すると、先導体１０と埋設管接続具２０と元押し装置４０とで構成される。この管推進機を使用して管推進工法を実施するときには、地中に埋設するためのヒューム管等で形成された埋設管３０と、泥土化されて先導体本体１１内に取り込まれた掘削土砂を地上に排出するための排土管３１とが先導体１０の後端部に連結され適宜継ぎ足される。
【０００７】
まず、先導体１０やこれに関連する部分の構造について説明する。先導体１０は、大別すると、前方にカッタヘッド２を有する先導体本体１１と、先導体本体１１の周囲に泥土通路５を形成するように取り付けられた外筒１２とで構成される。ここに例示する先導体１０は、中折れ式のものであり、先導体本体１１及び外筒１２が中折れできるように前部と後部とに二分割して構成されている。カッタヘッド２は、その前端中心部分に、添加剤を掘削土砂に対して放射状に注入できるように、図示していない添加剤注入孔が設けられており、この添加剤注入孔から注入した添加剤を掘削土砂に撹拌混合して塑性流動性のある泥土６を切羽近傍で生成できるようにしている。
【０００８】
先導体本体１１は、先導体１０の胴体をなす部分であり、その内部には、カッタヘッド２を回転駆動するためのカッタ駆動装置、泥土通路５に送られた泥土６を地上に圧送するための土砂圧送ポンプ４、方向修正ジャッキ等種々の機器が設置されている。また、先導体本体１１の後側底部には、泥土通路５に送られた泥土６を一部取り込むための土砂取り込み口７を設けている。切羽近傍で生成された泥土６は、外筒１２と先導体本体１１の間の環状の泥土通路５に送られ、その一部が土砂取り込み口７から取り込まれて、排土管３１を通じて地上に排出されるとともに、残りが、カッタヘッド２で掘削された掘削穴と埋設管３０との間の環状の泥土通路５に送られる。
【０００９】
外筒１２は、泥土通路５を塞がないように、スペーサ等の適宜の部材で先導体本体１１に取り付けられて先導体本体１１との間の間隔を保持できるよう構成されている。この外筒１２は、先導体１０の方向修正時に地山に押し付けて反力を伝達する反力伝達部材としての働きをするほか、先導体１０を安定した状態で地山に支持できるようにする働きをする。カッタヘッド２は、この外筒１２の外径よりも若干大きい外径の穴が掘削できるように掘削外径が定められている。
【００１０】
埋設管接続具２０やこれに関連する部分の構造について説明する。３０は先導体本体１１の後端部に接続される埋設管であり、先導体本体１１と略同径のものが接続されている。埋設管接続具２０は、先導体本体１１の後端部に装着して埋設管３０を先導体本体１１に接続する働きをする。ここに示す例では、埋設管接続具２０は、先導体本体１１の後端部に嵌着して着脱可能に連結される先導体側アタッチメント２１と、埋設管３０の前端部に嵌着して着脱可能に連結される埋設管側アタッチメント２２とで構成されている。また、先導体側アタッチメント２１と埋設管側アタッチメント２２とは、前者を後者の内部に嵌着することにより着脱可能に連結できるように構成されている。先導体１０は、一機種で数種類のサイズの埋設管３０を接続できるように設計されているが、埋設管接続具２０をこのように分割構成したのは、各サイズの埋設管３０に適合する埋設管側アタッチメント２２を容易に入手できるようにするため、埋設管側アタッチメント２２に市販品を使用できるようにするためである。
【００１１】
３１は土砂取り込み口７から取り込まれ土砂圧送ポンプ４で圧送される泥土６を発進立坑１００内に搬送する排土管であるが、埋設管接続具２０は、図４に示すように、この排土管３１を挿通することができるように構成されている。排土管３１は、埋設管３０の内部に一体的に取り付けられている。これら埋設管３０と排土管３１とは、単位長さに製作されて、適宜継ぎ足すことにより延長することができるようになっており、排土管３１は、後述するように発進立坑１００を経て排土ホース３１ａに接続される。
【００１２】
管推進機の元押し装置４０や発進立坑１００に関連する部分の構造について説明する。４０は先導体１０や埋設管３０を推進する元押し装置で、大別すると、推進用のシリンダ４１とフレーム４２と押し台４３とからなり、管埋設の出発点となる発進立坑１００内に設置されている。５０は発進立坑１００の発進口周囲に設けられ、発進時に先導体１０と発進立坑１００の坑壁との間をシールしながら先導体１０を通過させ得るようにするためのエントランスパッキンであり、止水器とも称せられる。このエントランスパッキン５０は、発進立坑１００の坑壁を形成する図示しない矢板に取り付けられている。発進立坑１００には、排土管３１で発進立坑１００内に搬送された泥土６を地上に搬出するための排土ホース３１ａが敷設されて地上に引き出されている。
【００１３】
推進用のシリンダ４１は、元押しジャッキとも称せられ、先導体１や埋設管３０に推進力を付与する。フレーム４２は、発進立坑１００の床面に設置され先導体１や埋設管３０を支持する基台４２ａと、この基台４２ａの後端部に立設されシリンダ４１を取り付けるシリンダ支え台４２ｂとからなる。このシリンダ支え台４２ｂは、シリンダ４１による先導体１の推進時に発進立坑１００の坑壁で支持して反力を取れるようにしている。推進用のシリンダ４１は、ピストンロッド部がシリンダ支え台４２ｂに取り付けるとともにシリンダ部を次に述べる押し台４３に取り付けており、伸縮することにより押し台４３を前後に移動する。
【００１４】
押し台４３は、フレーム４２の基台４２ａ上に設置され、埋設管３０の推進方向に前後に移動できるように構成されている。この押し台４３は、その前進時に先導体１０を押し込む働きをする。そのため、押し台４３は、先導体１０や最後部の埋設管３０の後端面に当接させてこれらを押し込むための環状の当接部材４５を備えている。また、押し台４３には、先導体１０の発進時に外筒１２に密接して泥土が発進立坑１００内に漏れないようにシールするためのシール筒４７を設けている。そのため、このシール筒４７は、外筒１２の後端部に嵌入させることができその嵌入時に外筒１２の内周面に密接する環状のシール部材４６を備えている。押し台４３には、元押し排土管４４が取り付けられ、この元押し排土管４４の前端部は、先導体本体１１後端部の土砂圧送口４ａやこの土砂圧送口４ａに接続された排土管３１を着脱可能に連結させることができ、その後端部には、排土ホース３１ａを着脱可能に連結している。
【００１５】
以上のような管推進機を使用して管推進工法を実施するための手順について説明する。まず、先導体１０の発進時には、埋設管接続具２０を装着しない状態で先導体１０を発進立坑１００内のフレーム４２の基台４２ａ上に設置した後、押し台４３を推進用のシリンダ４１で押すことにより、押し台４３の当接部材４５を先導体本体１１後端面に直接当接させ、元押し排土管４４を土砂圧送口４ａに連結して先導体１０を推進する。そして、カッタヘッド２を回転駆動すると、先導体１０は、地山を掘進しながらエントランスパッキン５０を通過して発進し、掘削穴を掘削して行く。このとき、エントランスパッキン５０は、図３に示すように外筒１２の外周面に密接するため、発進口近辺の地山の地下水や土砂が外筒１２と発進口の間から発進立坑１００内に浸入するようなことはない。
【００１６】
こうして掘削穴を掘削する過程で、粘性付与液を掘削土砂へ注入しカッタヘッド２で撹拌混合して塑性流動性のある泥土６を生成する。この泥土６は、後方に送られ、先導体１０と外筒１２とで形成された泥土通路５に圧入、充填されて泥土通路５を通過するが、泥土通路５の後端部は、押し台４３やシール筒４７で閉鎖されているので、その泥土６は、先導体１０後部の土砂取り込み口７がエントランスパッキン５０を通過する以前の発進の初期段階から、土砂圧送ポンプ４で泥土６の排出量を制御して適切な値の泥土圧を立てながら土砂取り込み口７に取り込み、土砂圧送口４ａ、元押し排土管４４及び排土ホース３１ａを通じて地上に圧送、排出することができる。したがって、この従来例の管推進機によれば、発進の初期段階でも切羽を泥土圧で支持することができるため、発進時に地山の崩壊や地下水の湧出を確実に防止して安全な施工を行うことができる。また、泥土６を発進の初期段階から土砂取り込み口７に取り込んで地上に圧送、排出することができるため、泥土６を発進立坑１００内に排出しなくても済み、発進立坑１００内の作業環境を悪化させるようなこともない。
【００１７】
先導体１０を発進させて地山に貫入した後は、図３に示すように、推進用のシリンダ４１を縮めて押し台４３を後退させることにより、埋設管３０を先導体本体１１の後端部に接続するための作業空間を先導体１０の後方に形成する。このとき、土砂圧送ポンプ４は、ピストンをフルストローク伸ばした状態で停止させているので、先導体本体１１の土砂圧送口４ａから泥土６が大量に漏出するようなことはない。次いで、埋設管接続具２０の先導体側アタッチメント２１を先導体本体１１の後端部に取り付けた後、埋設管３０の前端部を埋設管接続具２０の埋設管側アタッチメント２２に取り付けるとともに、埋設管３０の後端部を押し台４３の当接部材４５に当接させる。このとき、排土管３１の前端部は、先導体本体１１の土砂圧送口４ａに接続されるとともに、排土管３１の後端部は、元押し装置４０の元押し排土管４４に接続される。
【００１８】
しかる後、先導体１０を元押し装置４０で推進しつつカッタヘッド２で地山を掘削して埋設管３０を地山に貫入するが、先導体１０は、外筒１２で地山に支持されて、安定した状態で掘進することができる。この間、カッタヘッド２から粘性付与液を掘削土砂へ注入して泥土６を生成し、この泥土６を泥土通路５へ送るが、このとき、エントランスパッキン５０は、図４に示すように埋設管３０の外周面に接触して泥土通路５の後端を閉鎖しているので、泥土６の排出量を土砂圧送ポンプ４で制御して切羽を適切な値の泥土圧で支持することができる。また、こうして排出された残りの泥土６は、埋設管３０の外周に導かれて埋設管３０の貫入抵抗を軽減するが、その場合、泥土通路５の後端を前記のように閉鎖しているので、泥土６が発進立坑１００内に排出されることはない。
【００１９】
【発明が解決しようとする課題】
以上の説明から明らかなように、この従来例の管推進機では、土砂取り込み口７がエントランスパッキン５０を通過する以前の発進の初期段階から切羽を適切な泥土圧で支持することができるとともに発進時に泥土６を発進立坑１００内に排出しなくても済むという点に特長がある。しかしながら、その後開発を進める過程で、先導体本体１１への埋設管３０の接続作業を行うときに泥土６が発進立坑１００内に排出されるという問題が生じることが判明した。
【００２０】
すなわち、埋設管３０の接続作業を行うため、図３に示すように押し台４３を後退させてその接続作業を行うための作業空間を先導体１０の後方に形成するとき、外筒１２の後端部に嵌入して密接していたシール筒４７のシール部材４６が外筒１２から離脱して泥土通路５の後端が開放されるため、泥土通路５内の泥土６が発進立坑１００内に排出されることとなる。また、このとき、泥土圧を立てることがでず切羽を泥土圧で支持することもできなくなる。そのため、特に、地下水圧の高い危険な地山では、地下水の湧出やこの地下水の湧出による地山の崩落を防止して安全な施工が行えるようにするため、経費のかかる地盤改良を地山に施さなければならなくなるという事態が生じる。
【００２１】
この出願の発明は、こうした従来の技術の問題を解消するために創作されたもので、発進後に埋設管の接続作業を行うときに切羽を泥土圧で支持することができ泥土を発進立坑内に排出しなくても済む管推進技術を提供することにある。
【００２２】
【課題を解決するための手段】
こうした技術課題を達成するため、この出願の管推進機の発明では次の１）の手段を採用し、この出願の管推進工法の発明では次の２）の手段を採用した。
【００２３】
１）前方にカッタヘッドを有する先導体本体及び先導体本体の周囲に泥土通路を形成するように取り付けられた外筒により構成された先導体と、先導体本体の後端部に装着して埋設管を先導体本体に接続するための埋設管接続具と、推進用のシリンダに設けられ先導体を押し込む押し台及びこの押し台に設けられ先導体の発進時に外筒に密接して泥土が発進立坑内に漏れないようにシールするシール筒を有する元押し装置とを備え、先導体を元押し装置で推進しつつカッタヘッドで地山を掘削するとともに掘削土砂へ粘性付与液を注入して塑性流動性のある泥土を生成し、この泥土を泥土通路へ送ってその泥土の一部を先導体後部の土砂取り込み口から取り込んで地上に排出するとともに残りを先導体本体に接続した埋設管の外周に導くようにした管推進機において、
先導体の発進時に先導体本体に装着した埋設管接続具を押し込むことができるように押し台を構成し、その埋設管接続具の押し込み過程で、シール筒を、その内部に埋設管接続具を納めた状態で外筒に密着させることができるように構成するとともに、先導体本体に装着した埋設管接続具を押し台で押し込んだときにシール筒をエントランスパッキングに嵌め込むことができ、このシール筒をエントランスパッキングから抜き出したときにエントランスパッキングを埋設管接続具に密着させることができるように構成する。
【００２４】
２）前記１）に記載の管推進機を使用して管推進工法を実施する場合、
先導体を発進するに際して埋設管接続具を先導体本体に予め装着する第１の工程と、推進用のシリンダを伸ばして埋設管接続具を押し台で押し込むことにより先導体を推進しつつカッタヘッドで地山を掘削するとともに掘削土砂へ粘性付与液を注入して先導体を前進させ、シール筒をエントランスパッキングに嵌め込む第２の工程と、推進用のシリンダを縮めてシール筒を後退させることにより、シール筒をエントランスパッキングから抜き出してエントランスパッキングを埋設管接続具に密着させるとともに、埋設管を埋設管接続具に接続するための作業空間を埋設管接続具の後方に形成する第３の工程とを経て、埋設管を埋設する。
【００２５】
前記１）の手段を採用したこの出願の管推進機の発明では、先導体の発進時に先導体本体に装着した埋設管接続具を押し込むことができるように押し台を構成するとともに、その埋設管接続具の押し込み過程で、シール筒を、その内部に埋設管接続具を納めた状態で外筒に密着させることができるように構成しているので、先導体を発進するに際して埋設管接続具を先導体本体に予め装着した後、推進用のシリンダを伸ばして埋設管接続具を押し台で押し込むと、押し台のシール筒が埋設管接続具を内部に納めて先導体の外筒に密着した状態、すなわち、先導体本体と外筒の間に形成された泥土通路の後端側をシール筒により閉鎖した状態において、先導体を推進することができる。
【００２６】
その間、カッタヘッドで地山を掘削するとともに掘削土砂へ粘性付与液を注入して塑性流動性のある泥土を生成し、この泥土を泥土通路へ送るが、泥土通路の後端側は、前記のように閉鎖されているので、泥土は、先導体本体後部の土砂取り込み口がエントランスパッキンを通過する以前の発進の初期段階から、泥土圧を立てながら土砂取り込み口に取り込んで地上に圧送、排出することができる。したがって、本発明の管推進機では、発進の初期段階でも切羽を泥土圧で支持することができるとともに、泥土を発進の初期段階から地上に排出することができて発進立坑内に排出しなくても済む。
【００２７】
こうして先導体を前進させる過程で、外筒がエントランスパッキンに嵌め込まれて密着することにより、発進口近辺の地山の地下水や土砂が外筒の外周側から発進立坑内への浸入を防いでいるが、本発明では、特に、先導体本体に装着した埋設管接続具を押し台で押し込んだときに外筒だけでなくシール筒もエントランスパッキングに嵌め込むことができるように構成しているので、シール筒をエントランスパッキングに嵌め込むことができる位置まで押し込むことができ、このときも、発進口近辺の地山の地下水や土砂がシール筒の外周側から発進立坑内へ浸入するのを防ぐことができる。
【００２８】
こうして先導体の発進を終了した後、先導体本体後端部への埋設管の接続作業を行うため、押し台を後退させることによりシール筒をエントランスパッキングから抜き出して外筒から離脱させると、これまで外筒に密着していたエントランスパッキングは、今度は埋設管接続具に密着するため、発進口近辺の地山の地下水や土砂が埋設管接続具の外周側から発進立坑内へ浸入するのを防ぐことができる。しかも、その場合、エントランスパッキングは、埋設管接続具に密着して埋設管接続具の外周側だけでなく泥土通路の後端側も閉鎖するので、泥土通路内の泥土が発進立坑内に排出されることなく泥土通路内の泥土圧がこれまで通りに保持されて、切羽を泥土圧で支持することができる。
【００２９】
この出願の管推進工法の発明は、前記２）の手段を採用していて、前記１）の管推進機を直接使用して実施する工法の発明に相当しているから、当然、この出願の管推進機の発明と同様の作用効果を奏する。
【００３０】
【発明の実施の形態】
以下、この出願の管推進機の発明及び管推進工法の発明が実際上どのように具体化されるのかを示す具体化例を図１および図２に基づいて説明することによりこの出願の各発明の実施の形態を明らかにする。図１は、発進時に先導体を地山に突入させたときの状態を示す本発明の具体化例の管推進機の縦断面図、図２は、発進時に先導体への埋設管の接続作業をするときの状態を示す本発明の具体化例の管推進機の縦断面図である。図１及び図２において図３及び図４と同一の符号を付けた部分は、これら両図と同等の部分を表わすので、詳述しない。
【００３１】
本発明の具体化例の管推進機は、図３及び図４に示した従来例の管推進機と同様、前方にカッタヘッド２を有する先導体本体１１及び先導体本体１１の周囲に泥土通路５を形成するように取り付けられた外筒１２により構成された先導体１０と、先導体本体１１の後端部に装着して埋設管３０を先導体本体１１に接続するための先導体側アタッチメント２１及び埋設管側アタッチメント２２で構成された埋設管接続具２０と、推進用のシリンダ４１に設けられ先導体１０を押し込む押し台４３及びこの押し台４３に設けられ先導体１０の発進時に外筒１２に密接して泥土６が発進立坑１００内に漏れないようにシールするシール部材４６を設けたシール筒４７を有する元押し装置４０とを備えている。そして、先導体１０を元押し装置４０で推進しつつカッタヘッド２で地山を掘削するとともに掘削土砂へ粘性付与液を注入して塑性流動性のある泥土６を生成し、この泥土６を泥土通路５へ送ってその泥土６の一部を先導体１０の後部の土砂取り込み口７から取り込んで排土管３１、元押し排土管４４及び排土ホース３１ａを通じて土砂圧送ポンプ４で地上に圧送、排出するとともに残りを先導体本体１１に接続した埋設管３０の外周に導くようにしており、これらの点では、基本的な構成が従来例のものと変わらない。
【００３２】
元押し装置４０は、推進用のシリンダ４１及び押し台４３のほか、フレーム４２を備え、押し台４３は、シール筒４７のほか、土砂圧送口４ａや排土管３１を着脱可能に連結させることができる元押し排土管４４と先導体１０や埋設管３０を押し込むための当接部材４５とを備えていて、これらの点でも、基本的な構成は従来例のものと変わらない。この管推進機により管推進工法を実施するときに使用する埋設管３０は、従来例で使用するものと同様、排土管３１を内部に一体的に取り付ている。
【００３３】
そこで、図１及び図２を用いて、本発明の具体化例の管推進機の特徴的な技術内容について説明する。
【００３４】
まず、押し台４３は、先導体側アタッチメント２１により先導体本体１１に装着した埋設管接続具２０を押し込むことができるように構成されている。すなわち、押し台４３の当接部材４５は、先導体本体１１に埋設管接続具２０を介して接続した埋設管３０だけでなく、先導体本体１１に予め装着した埋設管接続具２０の埋設管側アタッチメント２２それ自体も直接押し込むことができるような構造に設計されている。
【００３５】
次に、シール筒４７は、埋設管接続具２０の押し込み過程で、内部に埋設管接続具２０を納めた状態で外筒１２に密着させることができるように構成されている。そのため、図１に示す例では、シール筒４７を従来例の管推進機におけるシール筒４７よりも軸方向の長さ（前後方向の長さ）を長く形成することにより、埋設管接続具２０をその押し込み時にシール筒４７内に入れ込んだ状態でシール筒４７のシール部材４６を外筒１２に密着させ得るように構成している。また、その場合、シール部材４６を、従来例と同様、外筒１２の内周面に密着させ得るように構成している。このシール部材４６は、埋設管３０の推進時には、外筒１２の内周面よりも若干小径の数種類のサイズの埋設管３０の外周面に密着できるように構成されている。
【００３６】
さらに、この管推進機は、先導体本体１１に装着した埋設管接続具２０を押し台４５で押し込んだときにシール筒４７をエントランスパッキング５０に嵌め込むことができるように構成されている。すなわち、推進用のシリンダ４１を全ストローク伸ばすことにより、埋設管接続具２０を押し台４５の当接部材４５で限度まで押し込んだときにシール筒４７をエントランスパッキング５０に嵌め込むことができるように、推進用のシリンダ４１のストロークや当接部材４５の軸方向の長さ（前後方向の長さ）を定めている。こうしたことに伴って、発進立坑１００は、その内径を通常のものよりも若干大きく形成する。
【００３７】
加えて、この管推進機は、こうしてエントランスパッキング５０に嵌め込んだシール筒４７をエントランスパッキング５０から抜き出したときに、図２に示すように、このエントランスパッキング５０を埋設管接続具２０に密着させることができるように構成されている。図２に示す例では、埋設管接続具２０をその押し込み過程でシール筒４７の内部に納めたときに先導体側アタッチメント２１の前端部がシール筒４７の前端部付近に位置固定されるようにすることにより、シール筒４７の前端部をエントランスパッキング５０に嵌め込んだ状態でその前端部を抜き出したときでも、エントランスパッキング５０を埋設管接続具２０の先導体側アタッチメント２１の前端部に密着させ得るように構成している。
【００３８】
図２に示す例では、推進用のシリンダ４１のストロークを極力短くするため、同シリンダ４１を全ストローク伸ばしたときに、シール筒４７の前端部をエントランスパッキング５０に嵌め込むように構成しているが、推進用のシリンダ４１のストロークを更に長くすることにより、前端部より後方位置におけるシール筒４７の部位をエントランスパッキング５０に嵌め込むことができるように構成してもよい。その場合、埋設管接続具２０は、シール筒４７をエントランスパッキング５０から抜き出したときにエントランスパッキング５０を密着させ得るシール筒４７内の位置に位置決めされるようにする。なお、エントランスパッキング５０は、伸縮自在な素材で構成されているため、外筒１２やシール筒４７の外周面だけでなく、これらの筒１２，４７より外径の小さい埋設管接続具２０や各種サイズの埋設管３０の外周面にも密接してこれら外周面の側から泥土６が漏出するのを防ぐことができる。
【００３９】
こうした管推進機を使用して管推進工法を実施するプロセスについて述べる。この管推進機では、前記したように、先導体１０の発進時に先導体本体１１に装着した埋設管接続具２０を押し込むことができるように押し台４３を構成するとともに、その埋設管接続具２０の押し込み過程で、埋設管接続具２０を押し台４３のシール筒４７の内部に納めた状態でシール筒４７のシール部材４６を外筒１２の内周面に密着させることができるように構成しているので、先導体１０を発進するに際して埋設管接続具２０を先導体本体１１に予め装着した後、推進用のシリンダ４１を伸ばして埋設管接続具２０を押し台４３で押し込むと、押し台４３のシール筒４７は、その内部に埋設管接続具２０を入れ込んでシール部材４６を先導体１０の外筒１２の内周面に密着させた状態で先導体１０を推進することができる。そのため、先導体１０は、先導体本体１１と外筒１２の間の泥土通路５の後端側をシール筒４７により閉鎖した状態で推進することができる。
【００４０】
その間、カッタヘッド２で地山を掘削するとともに掘削土砂へ粘性付与液を注入して塑性流動性のある泥土６を生成し、この泥土６を泥土通路５へ送るが、泥土通路５の後端側は、前記のようにシール筒４７で閉鎖されているので、泥土６は、先導体本体１１後部の土砂取り込み口７がエントランスパッキン５０を通過する以前の発進の初期段階から、泥土圧を立てながら土砂取り込み口５に取り込んで地上に圧送、排出することができる。したがって、本管推進機では、発進の初期段階でも切羽を泥土圧で支持することができるとともに、泥土６を発進の初期段階から元押し排土管４４及び排土ホース３１ａを通じて圧送ポンプ４で地上に排出することができて発進立坑１００内に排出しなくても済む。
【００４１】
こうして先導体１０を前進させる過程で、外筒１２がエントランスパッキン５０に嵌め込まれて密着することにより、発進口近辺の地山の地下水や土砂が外筒１２の外周側から発進立坑１００内への浸入を防いでいるが、本管推進機では、前述したように、先導体本体１１に装着した埋設管接続具２０を押し台４３で押し込んだときに外筒１２だけでなく、特にシール筒４７もエントランスパッキング５０に嵌め込むことができるように推進用のシリンダ４１のストロークや当接部材４５の軸方向の長さを設定している。そのため、推進用のシリンダ４１を全ストローク伸ばすことによりシール筒４７をエントランスパッキング５０に嵌め込むことができ、このときも、発進口近辺の地山の地下水や土砂がシール筒４７の外周側から発進立坑１００内へ浸入するのを防ぐことができる。
【００４２】
こうして先導体１０の発進を終了した後は、先導体本体１１の後端部への埋設管３０の接続作業を行うため、ピストンをフルストローク伸ばした状態で土砂圧送ポンプ４を停止させることにより土砂圧送口４ａからの泥土６の漏出を阻止した後、押し台４３を後退させることによりシール筒４７をエントランスパッキング５０から抜き出して外筒１２から離脱させる。そうすると、これまで外筒１２に密着していたエントランスパッキング５０は、今度は埋設管接続具２０に密着するため、発進口近辺の地山の地下水や土砂が埋設管接続具２０の外周側から発進立坑１００内へ浸入するのを防ぐことができる。しかも、その場合、エントランスパッキング５０は、埋設管接続具２０に密着して埋設管接続具２０の外周側だけでなく泥土通路５の後端側も閉鎖するので、泥土通路５内の泥土６が発進立坑１００内に排出されることなく泥土通路５内の泥土圧がこれまで通りに保持されて、切羽を泥土圧で支持することができる。
【００４３】
その結果、本管推進機によれば、特に地下水圧の高い危険な地山でも、経費のかかる地盤改良を地山に施すことなく、地下水の湧出やこの地下水の湧出による地山の崩落を防止して安全な施工を行うことができる。また、先導体１０の発進時だけではなく、その発進後に埋設管３０の接続作業を行うときにも、従来の技術のように発進立坑１００内を泥土で汚して作業環境を悪化させるようなことはなくなるため、発進立坑１００内で行う種々の作業の能率を従来の技術よりも更に向上させることが可能になる。
【００４４】
埋設管３０を埋設管接続具２０の埋設管側アタッチメント２２を取り付けて先導体本体１１に接続するとともに排土管３１の前端部及び後端部をそれぞれ先導体本体１１の土砂圧送口４ａ及び元押し装置４０の元押し排土管４４に接続して埋設管３０の接続作業を終了した後は、先導体１０を元押し装置４０で推進しつつカッタヘッド２で地山を掘削して埋設管３０を地山に貫入するが、このとき、シール筒４７のシール部材４６は、埋設管３０の外周面に密着している。以後、従来例の管推進機と同様、先導体１０を外筒１２で地山に支持して安定した状態で掘進するとともに、泥土６を泥土通路５を通じて埋設管３０の外周部に送って埋設管３０の貫入抵抗を軽減する。このとき、エントランスパッキン５０が埋設管３０の外周面に密接して埋設管３０の外周部位から泥土６が発進立坑１００内に漏出するのを阻止しているので、泥土６の排出量を土砂圧送ポンプ４で制御することにより切羽を適切な値の泥土圧で支持することができる。
【００４５】
以上、本発明の具体化例の管推進機を使用するプロセスについて述べたが、このプロセスは、この出願の管推進工法の発明に関する手段を具体化して示したものに相当する。
【００４６】
【発明の効果】
以上の説明から明らかなように、この出願の管推進機の発明及び管推進工法のの発明は、それぞれ、「課題を解決するための手段」の項に示した１）及び２）の手段を採用しているので、この出願の各発明によれば、発進後に埋設管の接続作業を行うときに切羽を泥土圧で支持することができ泥土を発進立坑内に排出しなくても済む管推進技術が得られる。その結果、この管推進技術によれば、特に地下水圧の高い危険な地山でも、経費のかかる地盤改良を地山に施すことなく、地下水の湧出やこの地下水の湧出による地山の崩落を防止して安全な施工を行うことができる。また、先導体の発進時だけではなく、その発進後に埋設管の接続作業を行うときにも、従来の技術のように発進立坑内を泥土で汚して作業環境を悪化させるようなことはなくなるため、発進立坑内で行う種々の作業の能率を従来の技術よりも更に向上させることが可能になる。
【図面の簡単な説明】
【図１】発進時に先導体を地山に突入させたときの状態を示す本発明の具体化例の管推進機の縦断面図である。
【図２】発進時に先導体への埋設管の接続作業をするときの状態を示す本発明の具体化例の管推進機の縦断面図である。
【図３】発進時に先導体を地山に突入させた後に埋設管を接続するときの状態を示す従来例の管推進機の縦断面図である。
【図４】発進時に地山に突入した先導体に埋設管を接続して推進しているときの状態を示す従来例の管推進機の縦断面図である。
【符号の説明】
２カッタヘッド
４土砂圧送ポンプ
５泥土通路
６泥土
７土砂取り込み口
１０先導体
１１先導体本体
１２外筒
２０埋設管接続具
２１先導体側アタッチメント
２２埋設管側アタッチメント
３０埋設管
３１排土管
３１ａ排土ホース
４０元押し装置
４１推進用のシリンダ
４２フレーム
４３押し台
４４元押し排土管
４５当接部材
４６シール部材
４７シール筒
５０エントランスパッキング
１００発進立坑[0001]
BACKGROUND OF THE INVENTION
The invention of this application is provided with a leading conductor and a main pushing device, and excavates a natural ground with the leading conductor while propelling the leading conductor with the pushing device and injects a viscosity imparting liquid into the excavated soil and has plastic fluidity. A pipe propulsion unit that generates mud, sends the mud backward, takes a part of it from the rear of the leading conductor, discharges it to the ground, and guides the rest to the outer periphery of the buried pipe, and a pipe using such a pipe propulsion unit It relates to the propulsion method.
[0002]
[Prior art]
The pipe propulsion method for burying pipes in the ground is to sequentially connect buried pipes formed of fume pipes etc. behind the leading conductors with cutter heads, and propel those buried pipes with the main pusher installed in the starting shaft. On the other hand, a method is usually adopted in which a natural ground in front is excavated with a cutter head and each buried pipe is sequentially pushed into the ground and buried. The pipe propulsion device is an apparatus composed of a leading conductor and a main pushing device in order to carry out such a pipe propulsion method. Conventionally, in this type of pipe propulsion machine originally developed by the applicant, mudstone with plastic fluidity is obtained by injecting an additive as a viscosity-imparting liquid into the excavated sediment, excavated with a cutter head, and stirring and mixing. Of the buried pipe attached to the rear end of the front conductor, while sending the mud backward, taking a part of the mud from the earth intake port at the rear of the front conductor and discharging it to the ground with a sand pressure feeder. It is led to the outer periphery. Therefore, when propelling the buried pipe, the frictional resistance between the buried pipe and the surrounding ground can be reduced to reduce the penetration resistance of the buried pipe, and the excavated sediment can be easily discharged by the earth and sand feeding device. This type of tube propulsion device has been put into practical use as a small-diameter tube propulsion device that embeds a small-diameter buried tube having a diameter of approximately 800 mm or less.
[0003]
This type of pipe propulsion machine has such advantages, but the earth and sand intake is located at the rear of the leading conductor, and the earth and sand intake is located at the start shaft outside the natural ground at the initial stage of starting. Until the intake reaches the ground, the mud produced during the excavation process cannot be discharged to the ground and is forced to discharge into the start shaft. The work environment is contaminated with mud. The problem of worsening has occurred. In addition, mud pressure cannot be raised until the earth and sand intake reaches the ground, so the face cannot be supported by mud pressure, and there is a risk that the ground will collapse or groundwater may be discharged at the start. There was also.
[0004]
In order to solve these problems, the applicant repeated improvements and attached a front conductor configured by attaching an outer cylinder so as to form a mud passage around the front conductor body and a rear end portion of the front conductor body. A buried pipe connector for connecting the buried pipe to the main body of the lead conductor and a push stand that pushes the leading conductor, and seals so that mud does not leak into the starting shaft while closely contacting the outer cylinder when the leading conductor starts. Recently, a pipe propulsion machine equipped with a main pushing device having a seal cylinder has been developed. The invention of this application intends to further improve such a pipe propulsion device and a pipe propulsion method using the pipe propulsion device.
[0005]
Therefore, a pipe propulsion machine recently developed by the applicant will be taken up as a conventional example, and the technical contents will be described with reference to FIGS. FIG. 3 is a longitudinal sectional view of a conventional pipe propulsion device showing a state in which a buried pipe is connected after the leading conductor has entered the ground at the start, and FIG. 4 shows the leading conductor that has entered the ground at the start. It is a longitudinal cross-sectional view of the pipe propulsion machine of the prior art example which shows the state when the buried pipe is connected and propelled.
[0006]
The pipe propulsion device shown in these drawings is roughly composed of a leading conductor 10, an embedded pipe connector 20, and a main pushing device 40. When carrying out the pipe propulsion method using this pipe propulsion device, the buried pipe 30 formed of a fume pipe or the like for burying in the ground, and the excavated earth and sand that has been mud and taken into the leading conductor body 11 Is connected to the rear end portion of the leading conductor 10 and is appropriately added.
[0007]
First, the structure of the leading conductor 10 and parts related thereto will be described. The front conductor 10 is roughly composed of a front conductor body 11 having a cutter head 2 in the front and an outer cylinder 12 attached so as to form a mud passage 5 around the front conductor body 11. The leading conductor 10 illustrated here is a middle folding type, and is configured to be divided into a front part and a rear part so that the leading conductor body 11 and the outer cylinder 12 can be folded. The cutter head 2 is provided with an additive injection hole (not shown) at the center of the front end so that the additive can be injected radially into the excavated sediment, and the additive injected from the additive injection hole Is agitated and mixed with excavated earth and sand so that mud clay 6 having plastic fluidity can be generated in the vicinity of the face.
[0008]
The leading conductor body 11 is a portion that forms the body of the leading conductor 10, in which a cutter driving device for rotationally driving the cutter head 2, and for sending the mud 6 sent to the mud passage 5 to the ground. Various devices such as the earth and sand pressure feed pump 4 and the direction correcting jack are installed. In addition, a sediment intake port 7 for partially capturing the mud 6 sent to the mud passage 5 is provided at the bottom on the rear side of the leading conductor body 11. The mud 6 generated in the vicinity of the face is sent to the annular mud passage 5 between the outer cylinder 12 and the leading conductor main body 11, and a part of the mud is taken in from the earth and sand intake port 7 and discharged to the ground through the earth discharge pipe 31. At the same time, the rest is sent to the annular mud passage 5 between the excavation hole excavated by the cutter head 2 and the buried pipe 30.
[0009]
The outer cylinder 12 is configured to be attached to the front conductor main body 11 with an appropriate member such as a spacer so as not to block the mud passage 5 and to maintain a distance from the front conductor main body 11. The outer cylinder 12 functions as a reaction force transmission member that transmits the reaction force by pressing against the ground when the direction of the leading conductor 10 is corrected, and also allows the leading conductor 10 to be supported on the ground in a stable state. Work. The cutter head 2 has a digging outer diameter so that a hole having an outer diameter slightly larger than the outer diameter of the outer cylinder 12 can be excavated.
[0010]
The structure of the buried pipe connector 20 and related parts will be described. Reference numeral 30 denotes an embedded pipe connected to the rear end portion of the leading conductor main body 11, which is connected to the leading conductor main body 11 having substantially the same diameter. The buried pipe connector 20 is attached to the rear end portion of the leading conductor body 11 and functions to connect the buried pipe 30 to the leading conductor body 11. In the example shown here, the buried pipe connector 20 is fitted to the front conductor side attachment 21 that is detachably connected by being fitted to the rear end part of the leading conductor main body 11, and is attached to the front end part of the buried pipe 30 to be detachable. It is comprised with the buried pipe side attachment 22 connected so that it is possible. Further, the front conductor side attachment 21 and the buried pipe side attachment 22 are configured to be detachably connected by fitting the former into the latter. The leading conductor 10 is designed to connect several types of buried pipes 30 with one model, but the buried pipe connector 20 is divided in this way to suit the buried pipes 30 of each size. This is because a commercially available product can be used for the buried pipe side attachment 22 so that the buried pipe side attachment 22 can be easily obtained.
[0011]
Reference numeral 31 denotes a soil discharge pipe which takes in the mud 6 taken in from the earth intake port 7 and pumped by the earth pressure pump 4 into the start shaft 100. As shown in FIG. It is comprised so that 31 can be penetrated. The soil discharge pipe 31 is integrally attached to the interior of the buried pipe 30. The buried pipe 30 and the earth discharge pipe 31 are manufactured to a unit length, and can be extended by appropriately adding them. The earth removal pipe 31 is discharged through the start shaft 100 as described later. Connected to the earth hose 31a.
[0012]
The structure of the part relevant to the main pusher 40 of the pipe propulsion machine and the start shaft 100 will be described. 40 is a main pushing device for propelling the leading conductor 10 and the buried pipe 30, and is roughly divided into a propelling cylinder 41, a frame 42, and a pushing platform 43, and is installed in the start shaft 100 as a starting point for pipe embedding. Has been. Reference numeral 50 denotes an entrance packing that is provided around the start opening of the start shaft 100 and allows the front conductor 10 to pass through while sealing between the front conductor 10 and the wall of the start shaft 100 when starting. Also called water bottle. The entrance packing 50 is attached to a sheet pile (not shown) that forms a pit wall of the start shaft 100. In the start shaft 100, a soil discharge hose 31a for carrying out the mud 6 conveyed in the start shaft 100 by the soil discharge pipe 31 to the ground is laid and pulled out to the ground.
[0013]
The cylinder 41 for propulsion is also referred to as a main pushing jack, and imparts propulsive force to the leading conductor 1 and the buried pipe 30. The frame 42 includes a base 42 a that is installed on the floor surface of the start shaft 100 and supports the leading conductor 1 and the buried pipe 30, and a cylinder support 42 b that is installed at the rear end of the base 42 a and attaches the cylinder 41. Become. The cylinder support 42b is supported by the well wall of the start shaft 100 when the leading conductor 1 is propelled by the cylinder 41 so as to take a reaction force. In the cylinder 41 for propulsion, the piston rod portion is attached to the cylinder support base 42b and the cylinder portion is attached to a push stand 43 described below, and the push stand 43 is moved back and forth by expanding and contracting.
[0014]
The push stand 43 is installed on the base 42 a of the frame 42 and is configured to be able to move back and forth in the propulsion direction of the buried pipe 30. The push table 43 functions to push the leading conductor 10 when moving forward. Therefore, the push stand 43 includes an annular abutting member 45 for abutting against the leading end of the leading conductor 10 and the rearmost embedded pipe 30 and pushing them in. Further, the push plate 43 is provided with a seal cylinder 47 for sealing the mud soil so as not to leak into the start shaft 100 when the leading conductor 10 starts. Therefore, the seal cylinder 47 includes an annular seal member 46 that can be fitted into the rear end portion of the outer cylinder 12 and is in close contact with the inner peripheral surface of the outer cylinder 12 when fitted. A main pushing and discharging pipe 44 is attached to the push plate 43, and a front end portion of the pushing and discharging pipe 44 is connected to the earth and sand pressure feeding port 4a at the rear end portion of the leading conductor body 11 and the earth and sand pressure feeding port 4a. 31 can be connected detachably, and the earth discharge hose 31a is connected to the rear-end part so that attachment or detachment is possible.
[0015]
The procedure for carrying out the pipe propulsion method using the pipe propulsion machine as described above will be described. First, when the leading conductor 10 is started, the leading conductor 10 is installed on the base 42a of the frame 42 in the starting shaft 100 in a state where the buried pipe connector 20 is not mounted, and then the push stand 43 is moved by the cylinder 41 for propulsion. By pushing, the abutting member 45 of the pedestal 43 is brought into direct contact with the rear end surface of the leading conductor body 11, and the leading conductor 10 is propelled by connecting the main pushing earth discharge pipe 44 to the earth and sand pressure feeding port 4a. When the cutter head 2 is rotationally driven, the leading conductor 10 starts to pass through the entrance packing 50 while excavating the natural ground, and excavates the excavation hole. At this time, since the entrance packing 50 is in close contact with the outer peripheral surface of the outer cylinder 12 as shown in FIG. 3, groundwater and earth and sand of the natural ground near the start opening enter the start shaft 100 from between the outer cylinder 12 and the start opening. There is no such thing as intrusion.
[0016]
Thus, in the process of excavating the excavation hole, the viscosity imparting liquid is poured into the excavated soil and stirred and mixed by the cutter head 2 to generate mud 6 having plastic fluidity. The mud 6 is sent rearward, and is press-fitted and filled in the mud passage 5 formed by the leading conductor 10 and the outer cylinder 12, and passes through the mud passage 5. 43 and the seal cylinder 47, the mud 6 is discharged from the initial stage of the start before the earth intake port 7 at the rear of the leading conductor 10 passes through the entrance packing 50 by the earth pressure pump 4. The amount can be controlled and can be taken into the earth and sand intake port 7 while setting an appropriate value of mud pressure, and can be pumped and discharged to the ground through the earth and sand pressure feed port 4a, the main pushing and discharging pipe 44 and the earth discharge hose 31a. Therefore, according to this conventional pipe propulsion device, the face can be supported by mud pressure even at the initial stage of start-up, so it is possible to securely prevent the collapse of ground and the discharge of groundwater during start-up. It can be carried out. Moreover, since the mud 6 can be taken into the earth and sand intake 7 from the initial stage of the start and can be pumped and discharged to the ground, it is not necessary to discharge the mud 6 into the start shaft 100 and the working environment in the start shaft 100 There is no such thing as aggravating.
[0017]
After starting the leading conductor 10 and penetrating into the natural ground, as shown in FIG. 3, the propulsion cylinder 41 is contracted and the pushing table 43 is retracted, whereby the buried pipe 30 is moved to the rear end of the leading conductor body 11. A working space for connection to the section is formed behind the leading conductor 10. At this time, since the earth and sand pumping pump 4 is stopped in a state where the piston is extended by a full stroke, the mud 6 does not leak in a large amount from the earth and sand feeding port 4a of the leading conductor body 11. Next, after attaching the leading conductor side attachment 21 of the buried pipe connector 20 to the rear end portion of the leading conductor body 11, the front end portion of the buried pipe 30 is attached to the buried tube side attachment 22 of the buried pipe connector 20, and the buried pipe. The rear end portion of 30 is brought into contact with the contact member 45 of the push table 43. At this time, the front end portion of the soil discharge pipe 31 is connected to the earth and sand pressure feeding port 4 a of the leading conductor main body 11, and the rear end portion of the soil discharge pipe 31 is connected to the main push earth discharge pipe 44 of the main pushing device 40.
[0018]
After that, the ground conductor is excavated by the cutter head 2 while propelling the leading conductor 10 by the main pushing device 40 and penetrates the buried pipe 30 into the ground, but the leading conductor 10 is supported on the ground by the outer cylinder 12. And can dig in a stable state. During this time, a viscosity imparting liquid is injected from the cutter head 2 into the excavated soil to generate mud 6 and this mud 6 is sent to the mud passage 5. At this time, the entrance packing 50 is embedded in the buried pipe 30 as shown in FIG. Since the rear end of the mud passage 5 is closed in contact with the outer peripheral surface, the discharge amount of the mud 6 can be controlled by the earth pressure pump 4 to support the face with an appropriate mud pressure. Further, the remaining mud 6 discharged in this way is guided to the outer periphery of the buried pipe 30 to reduce the penetration resistance of the buried pipe 30. In this case, the rear end of the mud passage 5 is closed as described above. Therefore, the mud 6 is not discharged into the start shaft 100.
[0019]
[Problems to be solved by the invention]
As is clear from the above description, in this conventional pipe propulsion device, the face can be supported at an appropriate mud pressure from the initial stage before the earth intake port 7 passes through the entrance packing 50 and started. A feature is that sometimes it is not necessary to discharge the mud 6 into the start shaft 100. However, in the process of further development, it has been found that there is a problem that the mud 6 is discharged into the start shaft 100 when the buried pipe 30 is connected to the leading conductor body 11.
[0020]
That is, in order to perform the connection work of the buried pipe 30, when the working space for performing the connection work is formed behind the front conductor 10 as shown in FIG. Since the seal member 46 of the seal cylinder 47 fitted into the end portion is detached from the outer cylinder 12 and the rear end of the mud path 5 is opened, the mud 6 in the mud path 5 is put into the start shaft 100. Will be discharged. At this time, the mud pressure cannot be raised, and the face cannot be supported by the mud pressure. For this reason, especially in dangerous grounds where the groundwater pressure is high, groundwater can be prevented from collapsing due to groundwater spills and groundwater spills, so that safe construction can be performed. A situation arises in which it must be applied.
[0021]
The invention of this application was created in order to solve such problems of the prior art, and when connecting buried pipes after starting, the face can be supported by mud pressure and mud can be put into the starting shaft. The aim is to provide tube propulsion technology that does not require discharge.
[0022]
[Means for Solving the Problems]
In order to achieve such technical problems, the invention of the pipe propulsion device of the present application employs the following means 1), and the invention of the pipe propulsion method of the present application employs the following means 2).
[0023]
1) A front conductor composed of a front conductor body having a cutter head in front and an outer cylinder attached so as to form a mud passage around the front conductor body, and embedded at the rear end of the front conductor body Embedded pipe connector for connecting the pipe to the main body of the leading conductor, a pushing base provided in the propulsion cylinder for pushing the leading conductor, and mud soil starting in close contact with the outer cylinder when the leading conductor is started. It has a main pushing device with a sealing cylinder that seals it so that it does not leak into the shaft, and excavates the natural ground with a cutter head while propelling the tip conductor with the pushing device and injects a viscosity imparting liquid into the excavated soil Generate fluid mud, send this mud to the mud passage, take a part of the mud from the sand intake port at the rear of the preconductor, discharge it to the ground, and connect the rest to the main body of the buried pipe To lead to In the tube propulsion device,
The push stand is configured so that the buried pipe connector attached to the main body of the lead conductor can be pushed in when the leading conductor starts, and in the process of pushing the buried pipe connector, the seal tube is placed and the buried pipe connector is placed inside. The seal tube can be fitted into the entrance packing when the embedded pipe connector attached to the main body of the conductor is pushed in with the push stand. When the tube is extracted from the entrance packing, the entrance packing can be brought into close contact with the buried pipe connector.
[0024]
2) When carrying out the pipe propulsion method using the pipe propulsion device described in 1) above,
A first step of mounting the buried pipe connector on the main body in advance when starting the leading conductor, and a cutter head while propelling the leading conductor by extending the propulsion cylinder and pushing the buried pipe fitting with a push stand. The second step of excavating the natural ground and injecting the viscosity imparting liquid into the excavated earth and sand to advance the leading conductor and fitting the seal cylinder into the entrance packing, and retracting the seal cylinder by retracting the propulsion cylinder The third step of extracting the seal cylinder from the entrance packing and bringing the entrance packing into close contact with the buried pipe connector and forming a work space for connecting the buried pipe to the buried pipe connector behind the buried pipe connector. After that, the buried pipe is buried.
[0025]
In the invention of the pipe propulsion device of the present application adopting the means of 1), the push base is configured so that the buried pipe connector mounted on the leading conductor body can be pushed when the leading conductor starts, and the buried pipe In the process of pushing in the connecting device, the seal tube is configured so that it can be brought into close contact with the outer tube with the embedded tube connecting device contained therein. After attaching to the lead conductor body in advance, when the propulsion cylinder is extended and the buried pipe connector is pushed in with the push stand, the seal cylinder of the push stand fits in the outer pipe of the lead conductor with the buried pipe fitting inside In the state, that is, in the state where the rear end side of the mud passage formed between the leading conductor main body and the outer cylinder is closed by the seal cylinder, the leading conductor can be promoted.
[0026]
Meanwhile, excavating the natural ground with the cutter head and injecting viscosity imparting liquid into the excavated soil to produce mud with plastic fluidity, and sending this mud to the mud passage, the rear end side of the mud passage is The mud is taken into the earth taking-in port while raising the mud pressure from the initial stage before the earth taking-in port at the rear of the main conductor passes through the entrance packing, and is discharged to the ground. be able to. Therefore, in the pipe propulsion device of the present invention, the face can be supported by the mud pressure even at the initial stage of starting, and the mud can be discharged to the ground from the initial stage of starting without being discharged into the starting shaft. It will be over.
[0027]
In the process of moving the leading conductor in this way, the outer cylinder is fitted into the entrance packing and brought into close contact with it, so that groundwater and earth and sand in the vicinity of the start opening prevent intrusion from the outer periphery of the outer cylinder into the start shaft. However, in the present invention, in particular, it is configured so that not only the outer cylinder but also the seal cylinder can be fitted into the entrance packing when the buried pipe connector mounted on the main conductor body is pushed in with the push stand. It is possible to push the seal cylinder to the position where it can be fitted into the entrance packing, and at this time, it is possible to prevent the underground water and earth and sand in the ground near the start entrance from entering the start shaft from the outer periphery of the seal cylinder. it can.
[0028]
After completing the start of the leading conductor in this way, in order to connect the buried pipe to the rear end of the leading conductor main body, when the seal cylinder is extracted from the entrance packing by moving the push stand backward, The entrance packing that has been in close contact with the outer cylinder is now in close contact with the buried pipe connector, so that groundwater and earth and sand from the ground near the start entrance will enter the start shaft from the outer periphery of the buried pipe connector. Can be prevented. Moreover, in that case, the entrance packing is in close contact with the buried pipe connector and closes not only the outer peripheral side of the buried pipe connector but also the rear end side of the mud path, so that the mud in the mud path is discharged into the start shaft. Therefore, the mud pressure in the mud passage is maintained as before, and the face can be supported by the mud pressure.
[0029]
Since the invention of the pipe propulsion method of this application employs the means of 2) above and corresponds to the invention of the construction method that is directly implemented using the pipe propulsion machine of 1), of course, The same effects as the invention of the pipe propulsion device are achieved.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Each embodiment of the present application will be described below by describing concrete examples showing how the invention of the pipe propulsion device and the invention of the pipe propulsion method of the present application are actually embodied based on FIG. 1 and FIG. The embodiment of the present invention will be clarified. FIG. 1 is a longitudinal sectional view of a pipe propulsion device according to an embodiment of the present invention showing a state when a leading conductor is plunged into a natural ground at the start, and FIG. 2 is a connection work of a buried pipe to the leading conductor at the start. It is a longitudinal cross-sectional view of the pipe propulsion machine of the specific example of this invention which shows the state when carrying out. In FIG. 1 and FIG. 2, the parts denoted by the same reference numerals as those in FIG. 3 and FIG.
[0031]
The pipe propulsion unit according to the embodiment of the present invention is similar to the conventional pipe propulsion unit shown in FIGS. 3 and 4, and includes a leading conductor body 11 having a cutter head 2 in the front and a mud passage around the leading conductor body 11. And a front conductor side attachment 21 for connecting the buried pipe 30 to the front conductor body 11 by attaching to the rear end portion of the front conductor body 11 and the front conductor 10 constituted by the outer cylinder 12 attached so as to form 5. And the buried pipe connector 20 constituted by the buried pipe side attachment 22, the pushing base 43 provided in the propulsion cylinder 41 and for pushing the leading conductor 10, and the outer cylinder 12 when the leading conductor 10 provided in the pushing stand 43 starts. And a main pushing device 40 having a seal cylinder 47 provided with a seal member 46 for sealing so that the mud 6 does not leak into the start shaft 100. Then, the ground conductor is excavated with the cutter head 2 while propelling the leading conductor 10 with the main pushing device 40, and a viscosity imparting liquid is injected into the excavated soil to generate mud 6 having plastic fluidity. A part of the mud 6 is sent to the passage 5 and taken in from the earth and sand intake port 7 at the rear of the leading conductor 10 and is pumped and discharged to the ground by the earth and sand pump 4 through the earth discharging pipe 31, the main pushing earth discharging pipe 44 and the earth discharging hose 31a. In addition, the remainder is guided to the outer periphery of the buried pipe 30 connected to the leading conductor body 11, and in these respects, the basic configuration is the same as that of the conventional example.
[0032]
The main pushing device 40 includes a frame 42 in addition to the cylinder 41 and the pushing stand 43 for propulsion, and the pushing stand 43 can detachably connect the earth and sand pressure feeding port 4a and the earth discharging pipe 31 in addition to the seal cylinder 47. There are provided a main pushing and discharging pipe 44 and an abutting member 45 for pushing the leading conductor 10 and the buried pipe 30. In these respects, the basic configuration is the same as that of the conventional example. The buried pipe 30 used when the pipe propulsion method is carried out by this pipe propulsion machine is integrally attached with the earth discharging pipe 31 as in the conventional example.
[0033]
Therefore, the characteristic technical contents of the pipe propulsion device according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.
[0034]
First, the push stand 43 is configured to be able to push in the buried pipe connector 20 attached to the leading conductor main body 11 by the leading conductor side attachment 21. That is, the abutting member 45 of the push plate 43 is not only the buried pipe 30 connected to the leading conductor main body 11 via the buried pipe connecting tool 20 but also the buried pipe of the buried pipe connecting tool 20 previously attached to the leading conductor main body 11. The side attachment 22 itself is designed to be able to be pushed in directly.
[0035]
Next, the seal cylinder 47 is configured so that it can be brought into close contact with the outer cylinder 12 in a state in which the embedded pipe connector 20 is housed in the process of pushing the embedded pipe connector 20. Therefore, in the example shown in FIG. 1, the buried pipe connector 20 is formed by forming the seal cylinder 47 longer in the axial direction (length in the front-rear direction) than the seal cylinder 47 in the conventional pipe propulsion device. The seal member 46 of the seal cylinder 47 can be brought into close contact with the outer cylinder 12 in a state of being inserted into the seal cylinder 47 at the time of pushing. Further, in that case, the seal member 46 is configured to be in close contact with the inner peripheral surface of the outer cylinder 12 as in the conventional example. The seal member 46 is configured to be able to be in close contact with the outer peripheral surface of the buried tube 30 of several sizes having a slightly smaller diameter than the inner peripheral surface of the outer cylinder 12 when the buried tube 30 is propelled.
[0036]
Furthermore, this pipe propulsion device is configured so that the seal cylinder 47 can be fitted into the entrance packing 50 when the buried pipe connector 20 mounted on the leading conductor body 11 is pushed in by the push stand 45. That is, by extending the full length of the cylinder 41 for propulsion, the seal cylinder 47 can be fitted into the entrance packing 50 when the buried pipe connector 20 is pushed to the limit by the contact member 45 of the push table 45. The stroke of the cylinder 41 for propulsion and the axial length of the contact member 45 (length in the front-rear direction) are determined. Accordingly, the start shaft 100 is formed with a slightly larger inner diameter than a normal one.
[0037]
In addition, when the seal cylinder 47 fitted in the entrance packing 50 is extracted from the entrance packing 50, the pipe propulsion device brings the entrance packing 50 into close contact with the buried pipe connector 20 as shown in FIG. It is configured to be able to. In the example shown in FIG. 2, the front end portion of the front conductor side attachment 21 is fixed in the vicinity of the front end portion of the seal tube 47 when the embedded pipe connector 20 is housed in the seal tube 47 in the pushing process. Thus, even when the front end portion of the seal tube 47 is fitted into the entrance packing 50 and the front end portion is extracted, the entrance packing 50 can be brought into close contact with the front end portion of the front conductor side attachment 21 of the embedded pipe connector 20. It is configured.
[0038]
In the example shown in FIG. 2, in order to shorten the stroke of the cylinder 41 for propulsion as much as possible, the front end portion of the seal cylinder 47 is fitted into the entrance packing 50 when the cylinder 41 is extended for all strokes. However, by further increasing the stroke of the cylinder 41 for propulsion, the portion of the seal cylinder 47 at the rear position from the front end portion may be fitted into the entrance packing 50. In that case, the buried pipe connector 20 is positioned at a position in the seal cylinder 47 where the entrance packing 50 can be brought into close contact when the seal cylinder 47 is extracted from the entrance packing 50. Since the entrance packing 50 is made of a stretchable material, not only the outer peripheral surface of the outer cylinder 12 or the seal cylinder 47 but also the buried pipe connector 20 having various outer diameters than these cylinders 12 and 47 and various types. It is possible to prevent the mud 6 from leaking out from the outer peripheral surface side in close contact with the outer peripheral surface of the sized buried pipe 30.
[0039]
The process for implementing the pipe propulsion method using such a pipe propulsion machine is described. In this pipe propulsion device, as described above, the push base 43 is configured so that the buried pipe connector 20 mounted on the leading conductor main body 11 can be pushed when the leading conductor 10 starts, and the buried pipe connector 20 is also provided. In the pushing process, the seal member 46 of the seal tube 47 can be brought into close contact with the inner peripheral surface of the outer tube 12 in a state where the buried pipe connector 20 is housed in the seal tube 47 of the push plate 43. Therefore, when the leading conductor 10 is started, the buried pipe connector 20 is mounted on the leading conductor main body 11 in advance, and then the propelling cylinder 41 is extended and the buried pipe connector 20 is pushed by the pushing platform 43. The seal tube 47 of the 43 can propel the leading conductor 10 in a state in which the embedded pipe connector 20 is inserted and the sealing member 46 is in close contact with the inner peripheral surface of the outer tube 12 of the leading conductor 10. Therefore, the leading conductor 10 can be propelled in a state where the rear end side of the mud passage 5 between the leading conductor main body 11 and the outer cylinder 12 is closed by the seal cylinder 47.
[0040]
In the meantime, the cutter head 2 excavates the ground and injects the viscosity imparting liquid into the excavated soil to generate mud 6 having plastic fluidity, and sends the mud 6 to the mud passage 5. Since the side is closed by the sealing cylinder 47 as described above, the mud 6 is put in the mud pressure from the initial stage of the start before the earth intake port 7 at the rear part of the leading conductor body 11 passes through the entrance packing 50. However, it can be taken into the earth and sand intake port 5 and pumped and discharged to the ground. Therefore, in the main propulsion machine, the face can be supported by the mud pressure even at the initial stage of starting, and the mud 6 is put on the ground by the pumping pump 4 from the initial stage of starting through the main pushing drain pipe 44 and the discharging hose 31a. It can be discharged and does not have to be discharged into the start shaft 100.
[0041]
In the process of moving the leading conductor 10 forward in this way, the outer cylinder 12 is fitted into the entrance packing 50 and brought into close contact, so that groundwater and earth and sand in the vicinity of the starting port can enter the starting shaft 100 from the outer peripheral side of the outer cylinder 12. In the main propulsion unit, as described above, not only the outer cylinder 12 but also the seal cylinder 47 when the embedded pipe connector 20 attached to the leading conductor main body 11 is pushed by the push stand 43 as described above. Also, the stroke of the cylinder 41 for propulsion and the length in the axial direction of the abutting member 45 are set so that they can be fitted into the entrance packing 50. For this reason, the seal cylinder 47 can be fitted into the entrance packing 50 by extending the propulsion cylinder 41 for the entire stroke. At this time, groundwater and earth and sand in the ground near the start opening start from the outer peripheral side of the seal cylinder 47. Intrusion into the shaft 100 can be prevented.
[0042]
After the start of the leading conductor 10 in this way, the buried pipe 30 is connected to the rear end portion of the leading conductor main body 11, so that the earth and sand pumping pump 4 is stopped and the earth and sand pumping pump 4 is stopped to extend the earth and sand. After preventing the mud 6 from leaking out from the pressure feed port 4 a, the seal cylinder 47 is extracted from the entrance packing 50 by moving the push pad 43 backward and detached from the outer cylinder 12. Then, since the entrance packing 50 that has been in close contact with the outer cylinder 12 is now in close contact with the buried pipe connector 20, groundwater and earth and sand in the ground near the start port start from the outer peripheral side of the buried pipe connector 20. Intrusion into the shaft 100 can be prevented. Moreover, in that case, the entrance packing 50 is in close contact with the buried pipe connector 20 and closes not only the outer peripheral side of the buried pipe connector 20 but also the rear end side of the mud path 5, so that the mud 6 in the mud path 5 is removed. The mud pressure in the mud passage 5 is maintained as before without being discharged into the start shaft 100, and the face can be supported by the mud pressure.
[0043]
As a result, according to the main propulsion device, even in dangerous grounds where the groundwater pressure is high, groundwater is prevented from flowing out, and groundwater collapse due to the groundwater is prevented without costly ground improvement. And safe construction can be performed. Further, not only when the leading conductor 10 starts, but also when the buried pipe 30 is connected after the starting conductor, the inside of the starting shaft 100 is soiled with mud as in the prior art, thereby deteriorating the working environment. Therefore, the efficiency of various operations performed in the start shaft 100 can be further improved as compared with the conventional technique.
[0044]
The buried pipe 30 is connected to the leading conductor main body 11 by attaching the buried pipe side attachment 22 of the buried pipe connector 20, and the front end and the rear end of the earth discharging pipe 31 are respectively connected to the earth and sand pressure feed port 4a and the main push of the leading conductor main body 11. After the connection work of the buried pipe 30 is completed by connecting to the main pushing and discharging pipe 44 of the device 40, the ground pipe 30 is excavated by the cutter head 2 while the leading conductor 10 is being pushed by the pushing device 40. At this time, the seal member 46 of the seal cylinder 47 is in close contact with the outer peripheral surface of the buried pipe 30. Thereafter, as in the case of the conventional pipe propulsion device, the leading conductor 10 is supported on the ground by the outer cylinder 12 and is dug in a stable state, and the mud 6 is sent to the outer periphery of the buried pipe 30 through the mud passage 5 and buried. The penetration resistance of the tube 30 is reduced. At this time, since the entrance packing 50 is in close contact with the outer peripheral surface of the buried pipe 30 to prevent the mud 6 from leaking into the start shaft 100 from the outer peripheral portion of the buried pipe 30, By controlling with the pump 4, the face can be supported with an appropriate mud pressure.
[0045]
As mentioned above, although the process using the pipe propulsion device of the concrete example of the present invention was described, this process is equivalent to what concretely showed the means about the invention of the pipe propulsion method of this application.
[0046]
【The invention's effect】
As is clear from the above description, the invention of the pipe propulsion device and the invention of the pipe propulsion method of this application are respectively the means 1) and 2) shown in the section “Means for Solving the Problems”. Therefore, according to the inventions of this application, the pipe propulsion can be supported by mud pressure when the buried pipe is connected after starting, and the mud does not have to be discharged into the starting shaft. Technology is obtained. As a result, with this pipe propulsion technology, even in dangerous grounds where the groundwater pressure is high, groundwater can be prevented from flowing out and the ground from collapsing due to the groundwater being discharged without costly ground improvement. And safe construction can be performed. Also, not only when the leading conductor starts, but also when the buried pipe is connected after the start, the start up shaft will not be soiled with mud like the conventional technology, and the working environment will not be deteriorated. The efficiency of various operations performed in the start shaft can be further improved as compared with the conventional technique.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a pipe propulsion device according to an embodiment of the present invention showing a state when a leading conductor is plunged into a natural ground at the time of starting.
FIG. 2 is a longitudinal sectional view of a pipe propulsion device according to an embodiment of the present invention showing a state when a buried pipe is connected to a leading conductor at the time of starting.
FIG. 3 is a longitudinal sectional view of a conventional pipe propulsion device showing a state in which a buried pipe is connected after a leading conductor has entered a natural ground at the start.
FIG. 4 is a longitudinal sectional view of a conventional pipe propulsion device showing a state in which a buried pipe is connected to a leading conductor that has entered a natural ground at the time of starting and propelled.
[Explanation of symbols]
2 Cutter head
4 Sediment pressure pump
5 Mud passage
6 Mud
7 Sediment intake port
10 Leading conductor
11 Lead conductor body
12 outer cylinder
20 buried pipe connector
21 Lead conductor side attachment
22 Buried pipe side attachment
30 buried pipe
31 Drainage pipe
31a earth removal hose
40 former pusher
41 Cylinder for propulsion
42 frames
43 pedestal
44 Extrusion pipe
45 Contact member
46 Sealing member
47 Seal tube
50 Entrance packing
100 Starting shaft

Claims

A front conductor composed of a front conductor body having a cutter head in front and an outer cylinder attached so as to form a mud passage around the front conductor body, and a buried pipe attached to the rear end portion of the front conductor body A buried pipe connector for connection to the main body of the leading conductor, a pushing base provided on the propulsion cylinder for pushing the leading conductor, and mud soil in close contact with the outer cylinder when starting the leading conductor, And a main pushing device having a sealing cylinder for sealing so that it does not leak into the ground, and excavating a natural ground with a cutter head while propelling the leading conductor with the pushing device and injecting a viscosity imparting liquid into the excavated soil A mud is created, and this mud is sent to the mud passage, a part of the mud is taken in from the earth intake port at the rear of the leading conductor and discharged to the ground, and the rest is led to the outer periphery of the buried pipe connected to the leading conductor body. Like In a pipe propulsion machine, a push stand is constructed so that the buried pipe connector attached to the main body of the leading conductor can be pushed in when the leading conductor starts, and the sealing cylinder is inserted inside the pushing pipe in the pushing process of the buried pipe fitting. It is constructed so that it can be brought into close contact with the outer cylinder with the buried pipe connector in place, and the sealed cylinder is fitted into the entrance packing when the buried pipe connector attached to the main conductor body is pushed in with the push stand. A pipe propulsion device characterized in that when the seal cylinder is extracted from the entrance packing, the entrance packing can be brought into close contact with the buried pipe connector.

A pipe propulsion method using the pipe propulsion device according to claim 1, wherein a first step of mounting an embedded pipe connector in advance on a main body of a conductor when starting the leading conductor, and extending a propulsion cylinder While pushing the buried pipe connector with a pushing stand, the tip conductor is pushed forward, the ground is excavated with the cutter head, the viscosity imparting liquid is injected into the excavated soil, the tip conductor is advanced, and the seal cylinder is fitted into the entrance packing. The second step and retracting the cylinder for retraction and retreating the seal cylinder allows the seal cylinder to be removed from the entrance packing, bringing the entrance packing into close contact with the buried pipe connector and connecting the buried pipe to the buried pipe connector And a third step of forming a working space behind the buried pipe connector to bury the buried pipe.