JP3544764B2

JP3544764B2 - How to lay pipes in the ground using buoyancy

Info

Publication number: JP3544764B2
Application number: JP30328895A
Authority: JP
Inventors: 信一大沢; 啓太野崎; 憲一作田
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 1995-10-30
Filing date: 1995-10-30
Publication date: 2004-07-21
Anticipated expiration: 2015-10-30
Also published as: JPH09126353A

Description

【０００１】
【発明の属する技術分野】
本発明は、泥水を用いながら地中を掘削し、鋼管等の管を弧状に地中敷設する方法に関するものであり、管の敷設軌道の掘削孔の孔壁の状況変化に対して的確に対応し、管を円滑に敷設軌道に配設することに供することができる。
【０００２】
【従来の技術】
ガス、水道、工業用水等の管を非開削で地中に敷設する方法は、各種の工法が実用されている。このうち、比較的大口径管を長距離に渡って弧状に地中敷設する工法として、特公昭６０−５９３９８号公報による技術が開示されている。
特公昭６０−５９３９８号公報において示される、水路等の地表面障害部の下に大口径の埋設管を据え付ける方法について、図６、図７用いて説明すると、
（１）後部にパイロツト管１９を取り付けたドリル２０を用い、水路２１下に弧状のパイロット孔２２を貫通させ、
（２）パイロツト管１９にパイロツト孔２２の全長を占居させながら、リーマ２３の先行端をパイロツト管１９の一端に取付け、
（３）埋設管２４の一端をリーマ２３の後尾端に、埋設管２４がリーマ２３に関して相対的に回転しないようにして取付け、
（４）埋設管２４及びリーマ２３に対して回転力及び推進力を加え、その際前記のパイロツト管１９を通してリーマ２３に掘削用泥水を与えて該リーマ２３がパイロツト孔２２沿いにパイロツト管１９により案内され、パイロツト孔２２の拡大とともに埋設管２４がパイロツト孔２２沿いに埋設される。
と記述される。
この特公昭６０−５９３９８号公報の技術は、埋設管に対する掘削用泥水の浮力を有利に利用するため、内部の空間を含めた場合の埋設管の密度と、掘削用の泥水の比重との関係に着目し、より大なる埋設管に対しては、中立状態の浮力を確保するため、管の中に重量物を置く、等の手段を講ずる（特公昭６０−５９３９８号公報４頁左欄下から第２行〜下から第１行）。
即ち、地中の掘削用泥水中に置かれた中空状態の埋設管の浮力が埋設管の自重と相殺するように、重量物を付加して中立状態とすることによって、孔壁との摩擦力を低減させ、埋設管の押し込み、又は引き込みを容易にするものである。
【０００３】
このような中立状態の浮力にする手段として提示される中に、特開平４−１１９２７９号公報がある。
この特開平４−１１９２７９号公報は、図８に示すように、水２９を充填した既設老朽管２６内に内部に浮力調整管２７を挿通した新管２８を挿入し（（イ））、新管２８の挿入完了後浮力調整管２７を回収する方法である。浮力調整管２７を引き出し、回収する場合には、新管２８と浮力調整管２７間に水２９を充填し、浮力調整管２７を浮力中立の状態とする（（ロ））。また、（イ）とは別の方法として、（ハ）に示すように、浮力調整管２７内に水３０を充填して自重付加し、新管２８について浮力調整を図る場合が示される。
【０００４】
【発明が解決しようとする課題】
ところで、管の推進距離が長大となる場合、また管が大径となる場合、或いは管の推進作業を中断した場合、掘削孔の孔壁と管の外周面に吸着現象（スタック）による過大な摩擦力を生じることがある。かかる事態が発生すると、管の円滑なる推進を妨げることになり、推進作業を続行させるためには、より強力な押込み力、又は引込み力を作用させて、増大した摩擦力に対抗する必要がある。そのため、押込み・引込み装置を大規模にする必要があった。
【０００５】
本発明の目的は、上述の従来技術の問題点に鑑み、掘削孔の孔壁と管の外周面との吸着現象に対応して、大規模な押込み・引込み装置を必要とすることなく円滑に管を配設する、浮力を利用して管を弧状に地中敷設する方法を提供することにある。
【０００６】
【課題を解決するための手段】
本発明の、浮力を利用して管を弧状に地中敷設する方法は、外管と内管からなる管の該外管と掘削孔との間隙に泥水を満たすとともに、該外管と該内管の間、又は該内管内に水を充填して、該外管に作用する泥水による浮力と、前記管と前記充填された水との重量とを釣り合わせ、管を弧状に地中敷設する方法において、管を押し込み又は引き込み敷設する過程において、該外管と該内管の間と該内管内の一方又は双方において水を排除又は充填することにより、前記した泥水による浮力と管、水との釣合い状態を崩して該管の長さ方向に沿って該管を浮揚又は沈降させて前記掘削孔の孔壁を押圧し、上方又は下方に掘削孔を拡大し、最終的には該外管と該内管の間、又は該内管内に水を充填して、前記泥水による浮力と、該管と該充填された水との重量とを釣り合わせ、管を敷設軌道に配設することにより構成される。
【０００７】
本発明において、掘削孔の孔壁と管の外周面に吸着現象が発生した場合に、泥水による浮力と管、水との釣合い状態を崩して対処するために、管を浮揚傾向又は沈降傾向の挙動をとらせる手段として、次のようなものが包含される。
（１）該外管に作用する泥水による浮力と、前記管と前記充填された水との重量とを釣り合わせるために、該外管と該内管の間に充填した水、又は該内管内に充填した水を排出することにより、前記した泥水による浮力と管、水との釣合い状態を崩して該管の長さ方向に沿って該管を浮揚させて前記掘削孔の孔壁を押圧し、次いで該外管と該内管の間、又は該内管内に水を充填して、前記泥水による浮力と、該管と該充填された水との重量とを釣り合わせる状態に復帰させることを一度、又は数度行い、管を敷設軌道に配設する。
（２）該外管に作用する泥水による浮力と、前記管と前記充填された水との重量とを釣り合わせるために、該外管と該内管の間に水を充填した場合には該充填された水を排出するか、該内管内にも水を充填し、また該内管内に水を充填した場合には該充填された水を排出するか、該外管と該内管の間にも水を充填することにより、前記した泥水による浮力と管、水との釣合い状態を崩して該管の長さ方向に沿って該管を浮揚又は沈降させて前記掘削孔の孔壁を押圧し、次いで該外管と該内管の間、又は該内管内に水を充填して、前記泥水による浮力と、該管と該充填された水との重量との釣合い状態に復帰させ、管を敷設軌道に配設する。
（３）該外管に作用する泥水による浮力と、前記管と前記充填された水との重量とを釣り合わせるために、該外管と該内管の間に水を充填した場合には該充填された水を排出するか、該内管内にも水を充填し、該内管内に水を充填した場合には該充填された水を排出するか、該外管と該内管の間にも水を充填することにより、該外管と該内管の間、及び該内管内の双方に水が存在しない状態、又は該外管と該内管の間、及び該内管内の双方に水を充填した状態にすることに続いて、該外管と該内管の間、及び該内管内の双方に水を充填し、又は該外管と該内管の間、及び該内管内の双方の水を排除することを一度又は数度行って前記した泥水による浮力と管との釣合い状態を崩して該管の長さ方向に沿って該管を浮揚又は沈降させて前記掘削孔の孔壁を押圧し、次いで前記泥水による浮力と、該管と該充填された水との重量との釣合い状態に復帰させ、管を敷設軌道に配設する。
【０００８】
【発明の実施の形態】
本発明の実施の形態を図面とともに説明する。
図１において、既にドリルパイプ４が到達側に到達し、掘進機５によりドリルパイプ４を介してカッター６とリーマ７に回転力を付与して掘削孔８を形成するとともに、リーマ７に後続してユニバーサルジョイント９により非回転に接続された外管２を引き込んでいる状態を示す。カッター６とリーマ７とによる掘削孔８の形成に際し、発進側からドリルパイプ４内に泥水１０を送給し、カッター６及びリーマ７から排出する。排出された泥水１０は、外管２と掘削孔８の間隙を流通して、管の地中での推進を容易にする。
管１は、外管２と内管３からなり、外管２内に内管３が挿通され、外管２と内管３の間に水１３ａを充填して、掘削孔８内の泥水１０による浮力と、外管２と内管３との自重と充填された水１３ａの重量とが平衡するようにする。
本例では、外管２と内管３とが、発進側から並行して配設されているが、外管２を先行させて進行させた後、外管２内に内管３を挿入し、内管３を外管２の先端に到達させ、その後に水１３ａを充填させるようにしてもよい。
【０００９】
図１において、外管２と内管３の間に水１３ａを充填して、泥水１０の浮力に対して釣合いの状態を保ち、管１の敷設作業を行っている。
管１の先端が敷設径路の中央を過ぎ、上向きの径路の途中において（（イ））、管を引き込む掘進機５の負荷が異常に大きくなり、掘削孔８の吸着現象（スタック）を発生した。
この現象を、掘進機５の負荷から検知したので、高圧空気を送って、外管２と内管３の間に充填された水１３ａを排出した（（ロ））。この作業により、管１の浮力に対して釣合いは崩れ、管１に上向きの浮揚力が作用して、管１は長さ方向に沿って掘削孔８の孔壁を押圧し、上方に掘削孔８を拡大するようにする。
次いで、外管２と内管３の間だけでなく、内管３内にも水１３ｂを充填して（（ハ））、（ロ）の場合とは逆方向に管１の浮力に対する釣合いを崩し、管１に下向きの沈降力が作用して、管１は長さ方向に沿って掘削孔８の孔壁を押圧し、下方に掘削孔８を拡大するようにする。
続いて、内管３内の水１３ｂを排出して、元の釣合いの状態を復帰させる。
【００１０】
この作業は、吸着現象の程度によっては、図１の（ハ）の状態から（ロ）の状態に移行し、次いで（ロ）の状態から（ハ）の状態に移行する作業を、一度又は数度繰り返して後、元の釣合いの状態を復帰させるようにしてもよい。
また、浮力に対する釣合いを崩し、また元に復帰させる仕方として、図１の（イ）の状態から（ロ）の状態へ、そして（ロ）の状態から（イ）の状態へ復帰する。また、この作業を繰り返してもよい。
また、（イ）の状態から、次のステップとして内管３内にも水を充填し、次いでこの充填した水だけを排出すること、或いはこれらのステップを繰り返すこともできる。この他として、（イ）の状態から、次のステップとして内管３内にも水を充填し、次いで外管２と内管３の間に及び内管３内にある双方の水を排出すること、或いは続いて外管２と内管３の間に及び内管３内の双方に水を充填させる等のステップを適宜介入させ、元の釣合いの状態を復帰させるようにしてもよい。
【００１１】
次に、図２において、内管３内に水１３ｂを充填して、泥水１０の浮力に対して釣合いの状態を保ち、管１の敷設作業を行っている。
管１の先端が敷設径路の中央を過ぎ、上向きの径路の途中において（（イ））、管を引き込む掘進機５の負荷が異常に大きくなり、掘削孔８の吸着現象（スタック）を発生した。
この現象を、掘進機５の負荷から検知したので、高圧空気を送って、内管３内に充填された水１３ｂを排出した（ロ）。この作業により、管１の浮力に対して釣合いは崩れ、管１に上向きの浮揚力が作用して、管１は長さ方向に沿って掘削孔８の孔壁を押圧し、上方に掘削孔８を拡大するようにする。
次いで、内管３内にだけでなく、外管２と内管３の間にも水１３ａを充填（（ハ））して、（ロ）の場合とは逆方向に管１の浮力に対する釣合いを崩し、管１に下向きの沈降力が作用して、管１は長さ方向に沿って掘削孔８の孔壁を押圧し、下方に掘削孔８を拡大するようにする。
続いて、外管２と内管３間の水１３ａを排出して、元の釣合いの状態を復帰させる。
【００１２】
この作業は、吸着現象の程度によっては、図２（ハ）の状態から（ロ）の状態に移行し、（ロ）の状態から（ハ）の状態に移行することを、一度又は数度繰り返して後元の釣合いの状態を復帰させるようにしてもよい。
また、浮力に対する釣合いを崩し、また元に復帰させる仕方として、（イ）の状態から（ロ）の状態へ、そして（ロ）の状態から（イ）の状態へ復帰する。また、この作業を繰り返してもよい。
また、（イ）の状態から、次のステップとして外管２と内管３の間にも水１３ａを充填し、次いでこの充填した水だけを排出すること、或いはこれらのステップを繰り返すこともできる。
図１、図２により示した作業のステップは、管の釣合い状態を崩して孔壁による抵抗を緩和、減少させ、或いは管を浮揚又は沈降させて孔壁を拡大するということで、上記に準じてその他の各種のステップをとることができる。
【００１３】
図３に管１への注・排水管１２と注・排気管１１を取り付けた状態を示す。注・排水管１２ａは外管２と内管３間の水の注・排水を行い、注・排水管１２ｂは内管３内の水の注・排水を行う。また、注・排気管１１ａは外管２と内管３間の空気の注・排気を行い、注・排気管１１ｂは内管３内の空気の注・排気を行う。外管２と内管３の先端には、それぞれ蓋１４、１５を設けて、水封を保ち、外管２と内管３間の後端、及び内管３の後端を密封するための蓋１６、１７を設けて、注・排気管から高圧空気を送った際の注・排水管からの水の排出を可能とする。１６ａ、１７ｂはそれぞれ蓋１６、１７における注・排気孔である。
【００１４】
図４、図５は管が吸着状態になり、管内への水の給・排水により管の釣合い状態を崩して吸着現象を除去し、管の釣合い状態に復帰する各ステップでの管の挙動を断面図により例示する。
図４は外管２と内管３間に水１３ａを充填して釣合い状態にあった管が吸着状態になり（（イ））、水１３ａを排水して上向きの浮揚力を付与し（（ロ））、次いで外管２と内管３間、及び内管３内に水１３ａ、１３ｂを充填して下向きの浮揚力を付与し（（ハ））、内管３内の水１３ｂを排除し、元の管の釣合い状態に復帰させる。
図５は内管３内に水１３ｂを充填して釣合い状態にあった管が吸着状態になり（（イ））、水１３ｂを排水して上向きの浮揚力を付与し（（ロ））、次いで外管２と内管３間、及び内管３内に水１３ａ、１３ｂを充填して下向きの浮揚力を付与し（（ハ））、外管２と内管３間の水１３ａを排除し、元の管の釣合い状態に復帰させる（（ニ））。
図４、図５のいずれの場合も、管の浮揚、沈降により掘削孔８の孔壁を押圧し、掘削孔８の孔壁の大きさを拡大するように働く。
【００１５】
【実施例】
本発明の実施例を図面を参照して説明する。
図１により実施例を説明する。
管１は、外径１２７ｍｍのドリルパイプ４の後端にカッター６、リーマ７、ユニバーサルジョイント９を介して結合される。ここで、管１は外径８００ｍｍの本管２と、外径６００ｍｍの内管３からなる。
（１）外管２と内管３の間に予め水１３ａを注水し、泥水１０による浮力と、管１と充填した水１３ａの重量とが釣合い状態になるようにする。注水には、外径５０ｍｍの注・排水管を用いる。
（２）推進距離１０００ｍのうち、７００ｍの地点で、推力が２００ｔｏｎから徐々に上昇し、３００ｔｏｎに達したため、推進作業を中断した。
（３）管１の後端部から注・排水管（図３で１２ａ、１２ｂ）を管１の敷設軌道最下点まで挿入し、注・排気孔１６ａ、１７ｂを備えた蓋１６、１７を管１の後端部に接続した。詳細は図３において示す。
（４）蓋の接続後、コンプレッサー（図示せず）により空気の注・排気孔１６ａから空気を注入し、外管２と内管３の間の水１３ａを管１外に排出する。排水により浮力の釣合い状態は崩れ、管１は浮力勝ちとなって上方に浮揚する挙動を呈する。
（５）次いで、外管２と内管３の間、及び内管３内に注・排水管１２ａ、１２ｂを介して水を注水する。注水により自重勝ちとなり、管１は下方に沈降する挙動を呈する。
（６）続いて、上記（４）、（５）の作業を５回繰り返した後、最終的には外管２と内管３の間に水を注水、充填して元の（１）の状態とし、管１の引込み作業を再開した。その時の推力は２００ｔｏｎであり、管１の外周の吸着現象は解消し、管を円滑に軌道敷設することができた。
【００１６】
図２により他の実施例を説明する。
管１は、外径１２７ｍｍのドリルパイプ４の後端にカッター６、リーマ７、ユニバーサルジョイント９を介して結合される。ここで、管１は外径１０００ｍｍの外管２と、外径６００ｍｍの内管３からなる。
（１）内管３内に予め水１３ｂを注水し、泥水１０による浮力と、管１と充填した水１３ｂの重量とが釣合い状態になるようにする。注水には、外径５０ｍｍの注・排水管を用いる。
（２）推進距離１０００ｍのうち、５００ｍの地点で、推進作業を一時中断し、２４ｈｒ後に推進作業を再開したところ、推力が３００ｔｏｎに達したため、推進作業再開を中止した。
（３）管１の後端部から注・排水管（図３で１２ａ、１２ｂ）を管１の敷設軌道最下点まで挿入し、注・排気孔１６ａ、１７ｂを備えた蓋１６、１７を管１の後端部に接続した。詳細は図３において示す。
（４）蓋の接続後、コンプレッサー（図示せず）により空気の注・排気孔１７ｂから空気を注入し、内管３内の水１３ｂを管１外に排出する。排水により浮力の釣合い状態は崩れ、管１は浮力勝ちとなって上方に浮揚する挙動を呈する。
（５）次いで、内管３内に水を注水、充填して元の（１）の状態とし、管１の引込み作業を再開した。その時の推力は２００ｔｏｎであり、管１の外周の吸着現象は解消することができた。
【００１７】
【発明の効果】
本発明によって、次のような効果を奏する。
本発明は、管の外周面において生起する掘削孔の孔壁の吸着現象に対処して、管が孔壁から受ける摩擦抵抗を減少し、また掘削孔を拡大し、地下における管の推進を容易にし、管を円滑に配設することができる。また、管内への水の充填、或いは排出ということで、吸着現象を解消可能となるので、掘進機を大容量にする必要がなく、設備上の観点からも有利であることがいえる。
【図面の簡単な説明】
【図１】本発明においる実施例を説明する図である。
【図２】本発明における他の実施例を説明する図である。
【図３】管へ注・排水管と注・排気管を取り付けた状態を説明する図である。
【図４】吸着現象を解消する場合の管への注・排水と、管の挙動を説明する図である。
【図５】図４とは別の、吸着現象を解消する場合の管への注・排水と、管の挙動を説明する図である。
【図６】従来の技術を示す図である。
【図７】図６の部分の詳細図である。
【図８】他の従来の技術を示す図である。
【符号の説明】
１管
２外管
３内管
４ドリルパイプ
５掘進機
６カッター
７リーマ
８掘削孔
９ユニバーサルジョイント
１０泥水
１１注・排気管
１２注・排水管
１３、１３ａ、１３ｂ水
１４蓋
１５蓋
１６蓋
１７蓋
１８姿勢計測装置
１９パイロット管
２０ドリル
２１水路
２２パイロット孔
２３リーマ
２４埋設管
２５水
２６既設老朽管
２７浮力調整管
２８新管
２９水
３０水[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of excavating underground using muddy water and laying a pipe such as a steel pipe in an arc shape underground, and accurately coping with a change in the state of a hole wall of a drilling hole in a pipe laying track. In addition, the pipe can be smoothly disposed on the laying track.
[0002]
[Prior art]
Various methods of laying pipes for gas, water, industrial water, etc. underground without excavation are practically used. Among them, Japanese Patent Publication No. 60-59398 discloses a technique for laying a relatively large-diameter pipe in the ground in an arc over a long distance.
A method of installing a large-diameter buried pipe under a ground surface obstacle such as a water channel, which is described in Japanese Patent Publication No. 60-59398, will be described with reference to FIGS.
(1) Using a drill 20 having a pilot pipe 19 attached to the rear part, an arc-shaped pilot hole 22 is penetrated below a water channel 21,
(2) The leading end of the reamer 23 is attached to one end of the pilot pipe 19 while the pilot pipe 19 occupies the entire length of the pilot hole 22;
(3) One end of the buried pipe 24 is attached to the rear end of the reamer 23 so that the buried pipe 24 does not relatively rotate with respect to the reamer 23;
(4) A turning force and a propulsion force are applied to the buried pipe 24 and the reamer 23, and at this time, muddy water for excavation is given to the reamer 23 through the pilot pipe 19, and the reamer 23 is moved along the pilot hole 22 by the pilot pipe 19. The buried pipe 24 is buried along the pilot hole 22 as the pilot hole 22 is expanded.
Is described.
According to the technique disclosed in Japanese Patent Publication No. 60-59398, the relationship between the density of the buried pipe including the internal space and the specific gravity of the mud for excavation in order to advantageously use the buoyancy of the mud for excavation. For larger buried pipes, take measures such as placing heavy objects in the pipes to secure buoyancy in the neutral state (Japanese Patent Publication No. 60-59398, page 4, lower left column) From the second row to the first row from the bottom).
That is, by adding a heavy material to the neutral state so that the buoyancy of the hollow buried pipe placed in the underground excavation mud balances the weight of the buried pipe, the frictional force with the hole wall is increased. And facilitates pushing or pulling of the buried pipe.
[0003]
Japanese Unexamined Patent Application Publication No. 4-119279 discloses a method for providing such a neutral state of buoyancy.
In this Japanese Patent Application Laid-Open No. 4-119279, as shown in FIG. 8, a new pipe 28 having a buoyancy adjusting pipe 27 inserted therein is inserted into an existing aging pipe 26 filled with water 29 ((a)). This is a method of collecting the buoyancy adjusting pipe 27 after the insertion of the pipe 28 is completed. When the buoyancy adjusting pipe 27 is pulled out and collected, the space between the new pipe 28 and the buoyancy adjusting pipe 27 is filled with water 29 to bring the buoyancy adjusting pipe 27 into a buoyancy neutral state ((b)). Further, as a method different from (a), as shown in (c), a case is shown in which the buoyancy adjusting pipe 27 is filled with water 30 and added with its own weight to adjust the buoyancy of the new pipe 28.
[0004]
[Problems to be solved by the invention]
By the way, when the propulsion distance of the pipe is long, when the pipe has a large diameter, or when the propulsion work of the pipe is interrupted, excessive adhesion due to the adsorption phenomenon (stack) occurs between the hole wall of the borehole and the outer peripheral surface of the pipe. May generate frictional force. When such a situation occurs, smooth propulsion of the pipe is hindered, and in order to continue the propulsion operation, it is necessary to apply a stronger pushing or retracting force to counter the increased frictional force. . Therefore, it was necessary to increase the size of the pushing / retracting device.
[0005]
In view of the above-mentioned problems of the prior art, the object of the present invention is to smoothly cope with the phenomenon of adsorption between the hole wall of an excavation hole and the outer peripheral surface of a pipe without requiring a large-scale pushing / retracting device. It is an object of the present invention to provide a method of arranging pipes and laying the pipes underground in an arc shape using buoyancy.
[0006]
[Means for Solving the Problems]
According to the method of the present invention for laying a pipe in an underground arc using buoyancy, a gap between the outer pipe and a drilling hole of a pipe consisting of an outer pipe and an inner pipe is filled with muddy water, and the outer pipe and the inner pipe are filled. Filling water between the pipes or inside the inner pipe, balancing the buoyancy caused by muddy water acting on the outer pipe with the weight of the pipe and the filled water, and laying the pipe in the ground in an arc shape In the method, in the process of pushing or pulling in a pipe, by excluding or filling water between the outer pipe and the inner pipe and in one or both of the inner pipes, the buoyancy due to the muddy water and the pipe, water and The pipe is lifted or settled down along the length direction of the pipe by pressing the hole wall of the borehole, and the borehole is enlarged upward or downward. And filling the space between the inner pipes or the inner pipe with water, and the buoyancy by the muddy water, Mated and weight of the water, and by arranging the pipe laying track.
[0007]
In the present invention, when an adsorption phenomenon occurs on the hole wall of the borehole and the outer peripheral surface of the pipe, the buoyancy due to muddy water and the pipe, in order to cope with the state of equilibrium with water, the pipe has a tendency to float or settle. The following are included as means for causing the behavior.
(1) Water filled between the outer tube and the inner tube or the inner tube to balance the buoyancy of muddy water acting on the outer tube with the weight of the tube and the filled water. By discharging the filled water, the buoyancy due to the muddy water and the pipe, the state of equilibrium with the water is broken, the pipe is levitated along the length direction of the pipe, and the hole wall of the drilling hole is pressed. Next, filling the space between the outer tube and the inner tube or inside the inner tube with water, and returning the buoyancy due to the muddy water and the weight of the tube and the filled water to a state of being balanced. Once or several times, place the pipe on the laying track.
(2) When water is filled between the outer tube and the inner tube, in order to balance the buoyancy of muddy water acting on the outer tube with the weight of the tube and the filled water, Discharging the filled water, or filling the inner tube with water, and discharging the filled water when filling the inner tube with water, or between the outer tube and the inner tube. By filling the water, the buoyancy due to the muddy water and the pipe, the state of equilibrium with the water is broken, and the pipe floats or sinks along the length direction of the pipe to press the hole wall of the drilling hole. Then, the space between the outer tube and the inner tube or the inner tube is filled with water, and the buoyancy due to the muddy water and the weight of the tube and the filled water are returned to a balanced state. Is installed on the laying track.
(3) When water is filled between the outer pipe and the inner pipe in order to balance the buoyancy of muddy water acting on the outer pipe with the weight of the pipe and the filled water, Discharging the filled water, or filling the inner tube with water, and discharging the filled water when filling the inner tube with water, or between the outer tube and the inner tube. Also, by filling with water, water is not present between the outer pipe and the inner pipe and both inside the inner pipe, or water is provided between the outer pipe and the inner pipe and both inside the inner pipe. And then filling the space between the outer tube and the inner tube and inside the inner tube with water, or filling both the outer tube and the inner tube and both the inner tube and the inner tube. The water is removed once or several times to break the buoyancy due to the muddy water and the state of equilibrium with the pipe, and the pipe is levitated or settled along the length direction of the pipe to perform the excavation. The hole wall is pressed and a buoyancy by the mud was then restored to equilibrium with the weight of the tube and said fill water, arranging a tube laying track.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, the drill pipe 4 has already reached the arrival side, and a drilling machine 5 applies a rotational force to the cutter 6 and the reamer 7 via the drill pipe 4 to form a drill hole 8 and follow the reamer 7. 7 shows a state in which the outer tube 2 connected non-rotatably by the universal joint 9 is drawn in. When forming the drilled hole 8 by the cutter 6 and the reamer 7, the muddy water 10 is fed into the drill pipe 4 from the starting side and discharged from the cutter 6 and the reamer 7. The discharged muddy water 10 flows through the gap between the outer pipe 2 and the excavation hole 8 to facilitate the propulsion of the pipe underground.
The pipe 1 is composed of an outer pipe 2 and an inner pipe 3. The inner pipe 3 is inserted into the outer pipe 2, water 13 a is filled between the outer pipe 2 and the inner pipe 3, and muddy water 10 in a drill hole 8 is formed. Buoyancy, the weight of the outer tube 2 and the inner tube 3, and the weight of the filled water 13a.
In this example, the outer pipe 2 and the inner pipe 3 are arranged in parallel from the starting side. However, after the outer pipe 2 is advanced in advance, the inner pipe 3 is inserted into the outer pipe 2. Alternatively, the inner pipe 3 may be made to reach the tip of the outer pipe 2 and then filled with water 13a.
[0009]
In FIG. 1, the space between the outer pipe 2 and the inner pipe 3 is filled with water 13a to keep the buoyancy of the muddy water balanced, and the pipe 1 is laid.
The tip of the pipe 1 passes the center of the laying path, and in the middle of the upward path ((a)), the load on the excavator 5 that pulls in the pipe becomes abnormally large, and the adsorption phenomenon (stacking) of the drill hole 8 occurs. .
Since this phenomenon was detected from the load of the excavator 5, high-pressure air was sent to discharge the water 13a filled between the outer pipe 2 and the inner pipe 3 ((b)). As a result of this operation, the balance with respect to the buoyancy of the pipe 1 is lost, and an upward levitation force acts on the pipe 1 so that the pipe 1 presses the hole wall of the drill hole 8 along the length direction and raises the drill hole upward. Try to magnify 8.
Next, water 13b is filled not only between the outer pipe 2 and the inner pipe 3 but also in the inner pipe 3 ((c)), and the balance with respect to the buoyancy of the pipe 1 is reversed in the case of (b). The pipe 1 collapses, and a downward settling force acts on the pipe 1 so that the pipe 1 presses the hole wall of the drill hole 8 along the length direction to enlarge the drill hole 8 downward.
Subsequently, the water 13b in the inner pipe 3 is discharged to return the state of the original balance.
[0010]
In this operation, depending on the degree of the adsorption phenomenon, the operation of shifting from the state of (c) to the state of (b) in FIG. 1 and then shifting from the state of (b) to the state of (c) is performed once or several times. After repetition, the state of the original balance may be restored.
In addition, as a method of breaking the balance with respect to the buoyancy and returning to the original state, the state shown in FIG. 1A is returned to the state shown in FIG. 1B, and the state shown in FIG. This operation may be repeated.
Further, from the state of (a), the inner pipe 3 may be filled with water as a next step, and then only the filled water may be discharged, or these steps may be repeated. In addition to this, from the state of (a), the inner tube 3 is filled with water as a next step, and then both water between the outer tube 2 and the inner tube 3 and in the inner tube 3 are discharged. Alternatively, a step such as filling both the outer pipe 2 and the inner pipe 3 and the inside of the inner pipe 3 with water may be appropriately interposed to restore the original state of equilibrium.
[0011]
Next, in FIG. 2, the inner pipe 3 is filled with water 13b, and the pipe 1 is laid while the buoyancy of the muddy water 10 is balanced.
The tip of the pipe 1 passes the center of the laying path, and in the middle of the upward path ((a)), the load on the excavator 5 that pulls in the pipe becomes abnormally large, and the adsorption phenomenon (stacking) of the drill hole 8 occurs. .
Since this phenomenon was detected from the load of the excavator 5, high-pressure air was sent to discharge the water 13b filled in the inner pipe 3 (b). As a result of this operation, the balance with respect to the buoyancy of the pipe 1 is lost, and an upward levitation force acts on the pipe 1 so that the pipe 1 presses the hole wall of the drill hole 8 along the length direction and raises the drill hole upward. Try to magnify 8.
Next, water 13a is filled not only in the inner pipe 3 but also between the outer pipe 2 and the inner pipe 3 ((c)), and counterbalances the buoyancy of the pipe 1 in the direction opposite to the case of (b). And a downward sedimentation force acts on the pipe 1 so that the pipe 1 presses the hole wall of the drill hole 8 along the lengthwise direction to enlarge the drill hole 8 downward.
Subsequently, the water 13a between the outer pipe 2 and the inner pipe 3 is discharged to return the state of the original balance.
[0012]
This operation is repeated once or several times by shifting from the state shown in FIG. 2 (c) to the state shown in FIG. 2 (b) and from the state shown in FIG. 2 (b) to the state shown in FIG. Then, the original state of the balance may be restored.
In addition, as a method of breaking the balance with respect to the buoyancy and returning to the original state, the state (a) is returned to the state (b), and the state (b) is returned to the state (a). This operation may be repeated.
In the state (a), the space between the outer pipe 2 and the inner pipe 3 is filled with water 13a as a next step, and then only the filled water is discharged, or these steps can be repeated. .
The steps of the operation shown in FIGS. 1 and 2 are similar to those described above in that the balanced state of the pipe is broken to reduce or reduce the resistance due to the hole wall, or the pipe is lifted or settled to enlarge the hole wall. And various other steps.
[0013]
FIG. 3 shows a state where the injection / drainage pipe 12 and the injection / exhaust pipe 11 for the pipe 1 are attached. The injection / drainage pipe 12a performs injection / drainage of water between the outer pipe 2 and the inner pipe 3, and the injection / drainage pipe 12b performs injection / drainage of water in the inner pipe 3. The injection / exhaust pipe 11a performs injection / exhaust of air between the outer pipe 2 and the inner pipe 3, and the injection / exhaust pipe 11b performs injection / exhaust of air in the inner pipe 3. Lids 14 and 15 are provided at the distal ends of the outer tube 2 and the inner tube 3, respectively, to keep a water seal and seal the rear end between the outer tube 2 and the inner tube 3 and the rear end of the inner tube 3. Lids 16 and 17 are provided to enable water to be discharged from the injection / drainage pipe when high-pressure air is sent from the injection / exhaust pipe. Reference numerals 16a and 17b denote pouring and exhaust holes in the lids 16 and 17, respectively.
[0014]
FIGS. 4 and 5 show the behavior of the pipe in each step of returning the pipe to a balanced state by removing the adsorption phenomenon by displacing the balanced state of the pipe by supplying and draining water into the pipe. This is exemplified by a cross-sectional view.
FIG. 4 shows a state in which the water 13a is filled between the outer pipe 2 and the inner pipe 3, and the balanced pipe becomes an adsorbed state ((a)), and drains the water 13a to give an upward levitation force (( B)) Then, water 13a and 13b are filled between the outer pipe 2 and the inner pipe 3 and in the inner pipe 3 to give a downward levitation force ((c)), and the water 13b in the inner pipe 3 is eliminated. Then, the tube is returned to the original balanced state.
FIG. 5 shows a state in which the inner tube 3 is filled with water 13b and the balanced tube becomes an adsorbed state ((a)), and the water 13b is drained to give an upward buoyancy ((b)). Next, water 13a, 13b is filled between the outer pipe 2 and the inner pipe 3 and inside the inner pipe 3 to give a downward levitation force ((c)), and the water 13a between the outer pipe 2 and the inner pipe 3 is eliminated. Then, the pipe is returned to the original balanced state ((d)).
In both cases of FIGS. 4 and 5, the hole wall of the excavation hole 8 is pressed by floating and sinking of the pipe, so that the size of the hole wall of the excavation hole 8 is enlarged.
[0015]
【Example】
Embodiments of the present invention will be described with reference to the drawings.
An embodiment will be described with reference to FIG.
The pipe 1 is connected to a rear end of a drill pipe 4 having an outer diameter of 127 mm via a cutter 6, a reamer 7, and a universal joint 9. Here, the pipe 1 includes a main pipe 2 having an outer diameter of 800 mm and an inner pipe 3 having an outer diameter of 600 mm.
(1) Water 13a is poured beforehand between the outer pipe 2 and the inner pipe 3 so that the buoyancy of the muddy water 10 and the weight of the water 13a filled with the pipe 1 are balanced. A water injection / drain pipe with an outer diameter of 50 mm is used for water injection.
(2) At a point of 700 m in the propulsion distance of 1000 m, the thrust gradually increased from 200 ton and reached 300 ton, so the propulsion work was interrupted.
(3) Insert the pouring / drainage pipes (12a, 12b in FIG. 3) from the rear end of the pipe 1 to the lowest point of the laying track of the pipe 1, and attach the lids 16, 17 having the pouring / exhaust holes 16a, 17b. The tube 1 was connected to the rear end. Details are shown in FIG.
(4) After the lid is connected, air is injected from an air injection / exhaust hole 16a by a compressor (not shown), and water 13a between the outer pipe 2 and the inner pipe 3 is discharged out of the pipe 1. The balanced state of buoyancy is broken by the drainage, and the pipe 1 exhibits a behavior of buoyancy winning and floating upward.
(5) Next, water is injected between the outer pipe 2 and the inner pipe 3 and into the inner pipe 3 via the injection / drainage pipes 12a and 12b. The water injection causes the player to win the weight, and the pipe 1 behaves downward.
(6) Subsequently, after the above operations (4) and (5) are repeated five times, water is finally injected and filled between the outer tube 2 and the inner tube 3 to fill the original (1). Then, the pipe 1 was retracted. The thrust at that time was 200 tons, the adsorption phenomenon on the outer periphery of the pipe 1 was eliminated, and the pipe could be laid smoothly on the track.
[0016]
Another embodiment will be described with reference to FIG.
The pipe 1 is connected to a rear end of a drill pipe 4 having an outer diameter of 127 mm via a cutter 6, a reamer 7, and a universal joint 9. Here, the pipe 1 includes an outer pipe 2 having an outer diameter of 1000 mm and an inner pipe 3 having an outer diameter of 600 mm.
(1) Water 13b is injected into the inner pipe 3 in advance so that the buoyancy of the muddy water 10 and the weight of the water 13b filled with the pipe 1 are balanced. A water injection / drain pipe with an outer diameter of 50 mm is used for water injection.
(2) The propulsion work was temporarily suspended at a point 500 m out of the 1000 m propulsion distance, and the propulsion work was resumed 24 hours later. When the thrust reached 300 ton, the propulsion work was restarted.
(3) Insert the pouring / drainage pipes (12a, 12b in FIG. 3) from the rear end of the pipe 1 to the lowest point of the laying track of the pipe 1, and attach the lids 16, 17 having the pouring / exhaust holes 16a, 17b. The tube 1 was connected to the rear end. Details are shown in FIG.
(4) After connecting the lid, air is injected from the air injection / exhaust hole 17b by a compressor (not shown), and the water 13b in the inner pipe 3 is discharged out of the pipe 1. The balanced state of buoyancy is broken by the drainage, and the pipe 1 exhibits a behavior of buoyancy winning and floating upward.
(5) Next, water was injected and filled into the inner pipe 3 to return to the state of (1), and the drawing operation of the pipe 1 was restarted. The thrust at that time was 200 ton, and the adsorption phenomenon on the outer periphery of the tube 1 could be eliminated.
[0017]
【The invention's effect】
According to the present invention, the following effects can be obtained.
The present invention reduces the frictional resistance of the pipe from the hole wall, reduces the frictional resistance that the pipe receives from the hole wall, and enlarges the borehole to facilitate the propulsion of the pipe underground. And the pipes can be arranged smoothly. In addition, since the adsorption phenomenon can be eliminated by filling or discharging water into the pipe, it is not necessary to increase the capacity of the excavator, which is advantageous from the viewpoint of equipment.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an embodiment according to the present invention.
FIG. 2 is a diagram illustrating another embodiment of the present invention.
FIG. 3 is a diagram illustrating a state in which an injection / drainage pipe and an injection / exhaust pipe are attached to a pipe.
FIG. 4 is a diagram illustrating pouring / draining into a pipe and the behavior of the pipe when the adsorption phenomenon is eliminated.
FIG. 5 is a diagram different from FIG. 4 for explaining pouring / draining into a pipe and a behavior of the pipe when the adsorption phenomenon is eliminated.
FIG. 6 is a diagram showing a conventional technique.
FIG. 7 is a detailed view of the part of FIG. 6;
FIG. 8 is a diagram showing another conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pipe 2 Outer pipe 3 Inner pipe 4 Drill pipe 5 Drilling machine 6 Cutter 7 Reamer 8 Drilling hole 9 Universal joint 10 Muddy water 11 Injection / exhaust pipe 12 Injection / drainage pipe 13, 13 a, 13 b 18 Attitude measuring device 19 Pilot pipe 20 Drill 21 Water channel 22 Pilot hole 23 Reamer 24 Buried pipe 25 Water 26 Existing aging pipe 27 Buoyancy adjusting pipe 28 New pipe 29 Water 30 Water

Claims

Filling the gap between the outer pipe and the drilling hole of the pipe consisting of the outer pipe and the inner pipe with muddy water, filling the gap between the outer pipe and the inner pipe, or filling the inner pipe with water, acts on the outer pipe. In the method of balancing the buoyancy due to muddy water and the weight of the pipe and the filled water and laying the pipe in the ground in an arc shape, in the process of pushing or pulling the pipe, the outer pipe and the inner pipe are laid. By excluding or filling water in one or both of the inner pipe and the inner pipe, the above-mentioned buoyancy due to muddy water and the pipe, the state of equilibrium with water is broken, and the pipe is lifted or floated along the length direction of the pipe. Sinking and pressing the hole wall of the drilling hole, expanding the drilling hole upward or downward, and finally filling the space between the outer pipe and the inner pipe or inside the inner pipe with the muddy water Balancing the buoyancy of the pipe with the weight of the pipe and the filled water, and arranging the pipe on a laying track. How to underground laying tube by utilizing the buoyancy, characterized in an arc.

In order to balance the buoyancy of muddy water acting on the outer tube with the weight of the tube and the filled water, water filled between the outer tube and the inner tube or filled in the inner tube was used. By discharging the water, the buoyancy due to the muddy water and the pipe, the state of equilibrium with the water is broken, and the pipe is levitated along the length direction of the pipe to press the hole wall of the drilling hole. Filling water between the outer pipe and the inner pipe, or inside the inner pipe, once returning the state of buoyancy due to the muddy water and the weight of the filled water to the pipe, or 2. The method according to claim 1, wherein the pipe is laid in an arc shape using buoyancy.

In order to balance the buoyancy caused by the muddy water acting on the outer tube and the weight of the tube and the filled water, when water was filled between the outer tube and the inner tube, the water was filled. Drain the water, or fill the inner tube with water, and if the inner tube is filled with water, discharge the filled water, or supply water between the outer tube and the inner tube. By filling, the buoyancy by the muddy water and the pipe, the state of equilibrium with the water is broken, and the pipe is lifted or settled along the length direction of the pipe to press the hole wall of the drilling hole. Filling water between the outer pipe and the inner pipe or inside the inner pipe to return to a state of balance between the buoyancy due to the muddy water and the weight of the pipe and the filled water, and lay the pipe on the track. The method according to claim 1, wherein the pipe is laid underground in an arc shape using buoyancy.

In order to balance the buoyancy caused by the muddy water acting on the outer tube and the weight of the tube and the filled water, when water was filled between the outer tube and the inner tube, the water was filled. Drain the water, or fill the inner tube with water, and if the inner tube is filled with water, discharge the filled water, or supply water between the outer tube and the inner tube. To fill the space between the outer tube and the inner tube and the inner tube without water, or between the outer tube and the inner tube and the inner tube with water filled therein. In particular, it is possible to fill the space between the outer tube and the inner tube and the inner tube with water, or to exclude water between the outer tube and the inner tube and the inner tube once or several times. The buoyancy due to the muddy water and the balanced state of the pipe are broken, and the pipe is lifted or settled along the length direction of the pipe to press the hole wall of the drilling hole. 2. The pipe according to claim 1, wherein the buoyancy caused by the muddy water and the weight of the pipe and the filled water are returned to a balanced state, and the pipe is arranged on a laying track. How to lay underground.