JP4043129B2

JP4043129B2 - Replacement method of buried pipe and woven tubular body

Info

Publication number: JP4043129B2
Application number: JP05415799A
Authority: JP
Inventors: 博幸城
Original assignee: Osaka Gas Co Ltd
Current assignee: Osaka Gas Co Ltd
Priority date: 1999-03-02
Filing date: 1999-03-02
Publication date: 2008-02-06
Anticipated expiration: 2019-03-02
Also published as: JP2000249256A

Description

【０００１】
【発明の属する技術分野】
本発明は、地中に埋設された既設管内に破砕手段を引き込み、前記既設管を拡径して破砕しながら、その既設管の破砕部内に、前記破砕手段に連結した新設管を引き込む埋設管の入れ替え工法及びその工法に使用する新設管保護のための織布筒状体に関する。
【０００２】
【従来の技術】
近年、埋設管に置き換えて新設管を埋設する入れ替え工事においては、道路等の工事占有期間、工事占有面積を極力低減するために、非開削でその入れ替え工事を行う工法が採用されるようになってきている。例えば図５（イ）に示すように、予め、工事箇所の両端位置に発進立坑１６と到達立坑１７の二つの作業用立坑を掘削し、夫々の作業用立坑１６，１７内で地中の埋設管９を露出させて切り離し、入れ替えの対象となる既設管１内に破砕手段６を引き込み、引き込んだ破砕手段６によって前記既設管１を拡径しながら破砕し、その既設管１の破砕跡２内に、前記破砕手段６に連結した新設管３を引き込むことが行われている。尚、上述の破砕には、既設管１の切り開き或いは切り裂きも含むものとし、上記破砕手段６にも切り開き或いは切り裂きにより既設管１を破壊する装置も含むものとする。この点に関しては以下においても同じとする。
【０００３】
上記既設管１の破砕と、新設管３の引き込みとにつき、鋳鉄製の既設管１をポリエチレン管３Ａに入れ替える工事を例に挙げて詳しく説明すると、先ず、入れ替え工事区間の両端部に掘削した発進立坑１６と到達立坑１７とで埋設管９を夫々切り離す。そして、前記発進立坑１６内に作業設備１８を設置する。そして、その作業設備１８を駆動して、既設管１である鋳鉄管１Ａ内に操作用ロッド１０を挿入し、前記到達立坑１７に突出させる。前記到達立坑１７では、既設管１の破砕と新設管３の引き込みの準備として、例えば図５（ロ）に示すように、前記操作用ロッド１０の先端に拡管プラグ６Ａを破砕手段６として取り付け、さらに、その拡管プラグ６Ａの後端部に、ポリエチレン管３Ａの先端部３ａを固定したガイドカバー１１を、連結金具１５を介して連結する。以上で作業準備を終わり、前記発進立坑１６内に設置した作業設備１８を操作して、先に既設管１内に挿通した操作用ロッド１０を徐々に引き戻す。これに伴って、この操作用ロッド１０に牽引される拡管プラグ６Ａが、既設管１である鋳鉄管１Ａ内に無理に引き込まれる結果、延性のない鋳鉄が損壊して、前記鋳鉄管１Ａは破片に分離する。同時に、前記鋳鉄管１Ａの損壊した跡である破砕跡２には、前記拡管プラグ６Ａに連結されたポリエチレン管３Ａが引き込まれる。
【０００４】
【発明が解決しようとする課題】
上記入れ替え工法においては、前記鋳鉄管１Ａを破砕した直後の破砕跡２内に、前記ポリエチレン管３Ａを引き込むから、その破砕跡２には、前記鋳鉄管１Ａの尖鋭な破断部を有する破片が既設管の残骸２ａとして密集しており、これが前記ポリエチレン管３Ａの表面３ｂを擦り、傷付けるおそれがある。これを一般的にいえば、前記破砕手段６が前記既設管１を切開或いは切り裂き拡管するものであれば、切り開かれ或いは切り裂かれた既設管１の残骸２ａが、また、上述のように、前記破砕手段６が拡管破砕するものであれば、破砕された既設管１の破片等の残骸がその破砕跡２に延在し、前記破砕手段６に連結された新設管３は、前記残骸２ａに接触するようになる。引き込まれる新設管３は、近年、上記のように、主としてポリエチレン管等の合成樹脂製管が主に用いられるから、こうした新設管３の表面が鋳鉄管等の金属管の残骸に接すれば、こうした残骸が前記新設管３の表面に突き刺さり、或いは、前記表面に切り傷を残すおそれがある。前記残骸が前記新設管３に突き刺されば、新設管３に漏れを生ずるおそれがあり、また、前記新設管３は、長期埋設されるものであるから、その表面に傷が残ることは、前記新設管３を埋設管９として長期使用する観点からも好ましくない。
【０００５】
そこで、本発明の目的は、従来同様に既設管の破砕と同時に新設管を引き入れながら、その新設管を傷付けることが防止できる埋設管の入れ替え工法、及びそのための用具を提供する点にある。
【０００６】
【課題を解決するための手段】
〔本発明の特徴構成〕
請求項１に係わる本発明の埋設管の入れ替え工法第１特徴手段は、地中に埋設した既設管を拡径しながら破砕し、その既設管の破砕跡内に、その破砕のための破砕手段に連結した新設管を、織布筒状体を縦糸を前記新設管の軸方向に沿わせ、かつ、横糸を前記新設管の軸方向に対して直交する方向に沿わせて被せた状態で引き込む点にある。
【０００７】
【０００８】
請求項２に係わる本発明の埋設管の入れ替え工法の第２特徴手段は、上記第１特徴手段において引き込む新設管として、ポリエチレン製の管を用いる点にある。
【０００９】
請求項３に係わる本発明の織布筒状体の第１特徴構成は、上記第１特徴手段又は第２特徴手段に用いる織布筒状体が、織布をその長さ方向に縫製して、地中の既設管破砕跡内に引き込む際の新設管に外嵌被覆自在にしてある点にある。
【００１０】
請求項４に係わる本発明の織布筒状体の第２特徴構成は、上記第１特徴構成において織布筒状体に縫製して形成される縫い代を、前記織布筒状体の外側に形成してある点にある。
【００１１】
〔特徴構成の作用及び効果〕
上記本発明に係わる埋設管の入れ替え工法の第１特徴手段によれば、引き込んで入れ替える際に新設管に傷つくことを防止できる。つまり、新設管に織布筒状体を縦糸を新設管の軸方向に沿わせ、かつ、横糸を新設管の軸方向に対して直交する方向に沿わせて被せた状態で引き込むことで、引き込まれる前記新設管を、既設管の残骸に傷付けられることから保護できるようになる。
【００１２】
また、織布筒状体は、仮に破れたとしても、破れ穴が拡大しにくく、安定して新設管を保護できるようになる。
【００１３】
上記本発明に係わる埋設管の入れ替え工法の第２特徴手段によれば、上記第１特徴手段が効果的になる。つまり、ポリエチレン製の新設管は、材料が軟質であるから引き込みやすく、入れ替え工事の作業性を向上する。ところで、ポリエチレン製の新設管が、軟質であるために傷つきやすいものであるが、上記第１特徴手段によりこれを損傷から保護できるのである。
【００１４】
上記本発明に係わる織布筒状体の第１特徴構成によれば、上記第１又は第２特徴手段において、入れ替える新設管の表面に傷を付けないようにできる。つまり、織布筒状体を被せることで、地中の既設管破砕跡内に引き込む新設管の外面を、既設管の破砕残骸による損傷から保護できる。そして、前記織布筒状体は、仮に前記新設管を引き込む際に破れたとしても、破れ穴が拡大しにくいから、前記損傷からの保護が確実である。さらに、前記織布筒状体は、長尺反を縦に裁断して縫製することで、簡単に形成できる。従って、引き込む新設管の全長に亘って表面を保護することが可能になる。
【００１５】
上記本発明に係わる織布筒状体の第２特徴構成によれば、上記第１特徴構成の作用効果に加えて、新設管の表面を長期安定して保護できるようになる。つまり、縫い代を外側に形成して縫製したままでよく、織布筒状体を形成するために裏返す必要がなく、製作が容易である。前記縫い代が外側に形成してあることで、前記織布筒状体の内側に突出するものがないから、新設管に被せやすい。しかも、前記縫い代が外側に形成してあることで、仮に、埋設後に前記織布筒状体の外側から大きな土圧が作用して織布に無理な力が作用することがなく、前記織布筒状体の外側からの土圧による損傷を抑制できる。従って、埋設後も長期安定して前記新設管の表面を保護することが可能になる。
【００１６】
【発明の実施の形態】
以下、本発明に係わる埋設管の入れ替え工法及びそのための筒状被覆体について説明する。図１は引き込み作業状態の新設管の先端部の状態の一例を示す説明図であり、図２は図１に示すした新設管の先端部の状態の縦断面図であり、図３は筒状被覆体の一例を示す斜視図であり、図４は引き込み作業の状態の一例を示す説明図である。尚、上記従来の技術に用いた図５における要素と同一の要素乃至同様の機能を果たす要素については、先の図５に付した符号と同一の、或いは関連する符号を付し、詳細の説明の一部を省略する。
【００１７】
以下には、上記埋設管の入れ替え工法の一例を、管の切り開きを管の破砕とする例として、埋設管を管軸に沿って切り開く管切開具６Ｂ（図１参照）を破砕手段６として用いる例を挙げて説明する。以下の例においては、既設管１は圧延鋼管のものであり、新設管３は合成樹脂管のものである。例えば図１に示すように、破砕する既設管１に代わって引き込まれるポリエチレン管３Ａからなる新設管３には、先端部３ａから全長に亘って、筒状被覆体４が被せられる。前記筒状被覆体４は、ナイロン、アラミド等の繊維材を織り上げたカンバス材等を素地とし、例えば図３に示すように、原反を幅方向に分割裁断した長尺の織布５を、幅方向両端縁部５ａを重ねる状態に折り重ねて、前記端縁部５ａに沿って長さ方向に連続縫製して、織布筒状体４Ａに形成したもので、縫い目４ｂを露出させた状態で、縫い代４ａを外側にしたままで用いられる。この織布筒状体４Ａは、縫い代４ａを外側にして前記ポリエチレン管３Ａに外嵌被覆できて、しかも、前記ポリエチレン管３Ａの表面３ｂとの間にあまり隙間を生じない寸法に縫製される。
【００１８】
上記埋設管の入れ替え工法の例について、さらに詳しく説明すると、既設管１が鋳鉄製でない場合には、前記破砕手段６としては、例えば図１に示すような管切開具６Ｂが用いられる。図示の管切開具６Ｂは、アメリカのブルックリン・ユニオン社で開発された工法に使用されるものでブレットと称し、先端側の切開部７と後端側の強制拡管部８とからなっており、前記切開部７の先端にはこの管切開具６Ｂを既設管１内に引き込む操作用ロッド１０への取付部を備えており、前記強制拡管部８の後部には、新設管３を連結金具１５を用いて連結可能な連結部を備えている。前記切開部７は、小径に、且つ、偏心して形成してあり、外側にはガイドローラ７ｂが既設管１の内面に接当自在に配列され、内側には、先端側から順次径を大きくした複数の切開丸刃７ａ（図示のものは５枚）を、その円心周りに回転自在に配列して取り付けてある。前記強制拡管部８は、その外周面を後端側を拡径し、偏軸したテーパ面に形成してあり、最後部の径を、切開する既設管１の管径よりも大きくしてある。この管切開具６Ｂを既設管１内に引き込むと、小径側の切開丸刃７ａが先ず既設管１の内面に接当し、外側のガイドローラ７ｂによる反力を基に、前記内面に切り込みを形成する。さらに、次の切開丸刃７ａは、前記切り込みをさらに深くする。最後の切開丸刃７ａが前記切り込みに接当するに至って、前記既設管１は完全に切開される。前記最後部の切開丸刃７ａは、既設管１を接続するクランプ、スリーブ継手をも切開可能のサイズにしてある。
【００１９】
前記新設管３は、例えば図２に示すように、ガイドカバー１１に取り付けられる。つまり、ポリエチレン管３Ａには外周面に前記ポリエチレン管３Ａの管内面に係止可能な突起を備えたエキスパンダ１３が、拡径ナット１３ａを内嵌した状態で内挿される。前記エキスパンダ１３は、前記ポリエチレン管３Ａの内径とほぼ同径に形成してあり、周方向に四分割して、夫々の分割箇所を一部欠如させて、各分割面を密着させた状態では、前記突起が前記ポリエチレン管３Ａの管内面よりも内側に位置するようにしてある。そして、内周には軸方向に後端側を大径にしたテーパ面を形成して、このテーパ面に拡径ナット１３ａを内挿することで、拡径されるようにしてある。前記拡径ナット１３ａは、外周面が後端側を大径にした前記エキスパンダ１３の内周と同勾配のテーパ面に形成してある。前記ポリエチレン管３Ａの先端部３ａには、連結ボルト１４を挿通自在な貫通孔を有し、先端側を小径にしたテーパ面を外周面とする先端プラグ１２を配置し、この先端プラグ１２の貫通孔から前記拡径ナット１３ａに亘って前記連結ボルト１４を挿通する。この連結ボルト１４に前記拡径ナット１３ａを螺合させておいて、前記連結ボルト１４を螺進させれば、前記拡径ナット１３ａが前記先端プラグ１２に向けて引きつけられて、前記拡径ナット１３ａが嵌入して前記エキスパンダ１３が拡径され、前記エキスパンダ１３の外周面の突起が前記ポリエチレン管３Ａの管内面に食い込んで、前記先端プラグ１２に前記ポリエチレン管３Ａが止めつけられた状態になる。
【００２０】
以上のようにして前記先端プラグ１２に前記ポリエチレン管３Ａを止めつけた後、前記先端プラグ１２の側から、筒状被覆体４の一例である前記織布筒状体４Ａを前記ポリエチレン管３Ａに被せ、前記連結ボルト１４をボルト孔に通しつつ、前記織布筒状体４Ａの上からガイドカバー１１を、前記織布筒状体４Ａを前記先端プラグ１２との間に挟み付けて被せ、締め付けナット１４ａを前記連結ボルト１４に螺合して締め付ける。この締め付けナット１４ａを締め付けることにより、前記先端プラグ１２と前記ガイドカバー１１との間に前記筒状被覆体４が確実に挟み付けられ、同時に、エキスパンダ１３により拡径されようとするポリエチレン管３Ａを、間に筒状被覆体４を介在させた状態で外側で受けて、拡径を阻止する。この連結ボルト１４を、連結金具１５を介して前記管切開具６Ｂに取り付けるが、前記ポリエチレン管３Ａと前記織布筒状体４Ａとの間には、予め配管検知用の金属帯線を介装しておく。こうして破砕手段６に連結された新設管３は、表面３ｂを筒状被覆体４で覆われ、先端部３ａが前記筒状被覆体４と共に、ガイドカバー１１を被せた状態になる。このように、前記ガイドカバー１１を牽引して前記新設管３を破砕跡２に引き込む際に、土砂が新設管３内及び前記新設管３と前記筒状被覆体４との間に入り込むことを防止してある。
【００２１】
前記発進立坑１６内に設置される作業設備１８は、主として、破砕手段６を引き込むための操作用ロッド１０を、既設管１内に挿入して、到達立坑１７にまで突出させ、突出させた前記操作用ロッド１０の先端部を、これに取り付けた前記破砕手段６と共に、前記発進立坑１６にまで引き戻す作業を担うものである。通常は、油圧シリンダ式の押し引き装置が用いられる。これは、複動式の油圧シリンダと、そのピストンロッドに設けられ、操作用ロッド１０を繰り返し前記ピストンロッドに固着、切り離しするチャックと、油圧駆動方向を切り替える切替機構を備えたものである。
【００２２】
上述の設備を用いて、埋設された延伸鋼管からなる既設管１を、新設管３としてポリエチレン管３Ａに更新する更新工事の中の管の入れ替え工程は大凡以下のようになる。先ず更新工事区間の決定に伴い、その工事区間の一端側に発進立坑１６を掘削し、他端側に到達立坑１７を掘削する。次いで、例えば図４に示すように、両立坑１６，１７内で埋設管９を夫々切断して切り離し、発進立坑１６内には油圧源を接続した作業設備１８を設置する。前記作業設備１８に操作用ロッド１０を、既設管１内に挿入して装着し、前記作業設備１８を操作して、前記操作用ロッド１０を前記既設管１内に押し込み、前記到達立坑１７内に突出させる。一方、前記到達立坑１７側では、新設管３であるポリエチレン管３Ａに上述の要領で織布筒状体４Ａを被せて、その上からガイドカバー１１を施し、連結金具１５を用いて、破砕手段６である管切開具６Ｂに前記ガイドカバー１１を連結しておき、前記発進立坑１６から押し込まれた操作用ロッド１０の先端部が到達立坑１７内に突出するのを待って、前記操作用ロッド１０の先端部に前記管切開具６Ｂを取り付ける。押し込んだ操作用ロッド１０に前記管切開具６Ｂが取り付けられると、前記発進立坑１６側では、作業設備１８を操作して、押し込んだ操作用ロッド１０を引き抜く操作を開始する。これに伴い、前記管切開具６Ｂは前記既設管１内に引き込まれ、前記既設管を順次切り開き、拡管する。これと同時に、前記管切開具６Ｂに連結されたポリエチレン管３Ａが、前記既設管１の切開拡管された中、即ち破砕跡２内に引き込まれる。前記発進立坑１６側に操作用ロッド１０が全て引き戻され、前記ガイドカバー１１と共に、前記ポリエチレン管３Ａの先端部３ａが引き込まれて、更新工事の中の管の入れ替え工程を終了する。
【００２３】
管の入れ替え工程を以上のように構成してあるから、筒状被覆体４を被せることで、たとえ前記筒状被覆体４の表面に既設管１の残骸２ａが接触したとしても、新設管３の表面３ｂが既設管１の残骸２ａに傷付けられることから保護できる。しかも、織布製の筒状被覆体４は、仮に破れたとしても、破れ穴が拡大しにくいから、少なくとも広範囲に亘って新設管３が傷付けられることを防止できる。また、織布筒状体４Ａは、長尺反を縦に裁断して縫製することで、製作が簡単で、任意の長さのものを製作できる。上記織布筒状体４Ａは、裏返すことなく縫製のままで、縫い代４ａが外側に形成してある（図３参照）から、その内側に突出するものがなく、新設管３に被せる作業が容易である。また、前記縫い代４ａが外側に形成してあることで、埋設後に前記織布筒状体４Ａの外側からの土圧が作用しても、織布５に対しては、内側のポリエチレン管３Ａに押しつける力だけの作用であり、無理な力が作用することがなく、前記織布筒状体４Ａの土圧による損傷を抑制できる。
【００２４】
尚、以下のような異なる実施の形態も本発明には包含されている。
〔別実施形態〕
〈１〉上記実施の形態においては、既設管の破砕として既設管を切り開く場合を例に挙げて説明したが、前記既設管を破砕するのに、例えば既設管が鋳鉄管である場合には、従来の技術に説明したように、例えば拡管プラグ６Ａを既設管内に圧入して、既設管をその許容変形限度以上に変形させることで破砕するようにしてもよく、複数のカッタエッジを放射状に備える破砕ヘッドを既設管内に導入して、既設管を切り裂きながら、曲げ力によってこれを破砕するようにしてもよく、既設管の材料に応じて、適宜その破砕手法は変化可能である。
〈２〉上記実施の形態においては、新設管３としてポリエチレン管３Ａを導入する例を挙げて説明したが、前記新設管の材料は他の合成樹脂であってもよく、また、例えば圧延鋼管のような金属管であってもよい。
〈３〉上記実施の形態においては、筒状被覆体４を、縫い代４ａを外に形成した織布筒状体４Ａで構成してある例について説明したが、前記縫い代４ａの取り方は任意であって、内側に形成してあってもよく、端縁部５ａ同士を対向させて重ね合わせて縫い上げたものであってもよい。また、前記筒状被覆体４の材質も任意であって、不織布等の織り上げていない布であってもよい。
〈４〉上記実施の形態においては、管切開具６Ｂとして、アメリカから輸入のブレットと称するものを例に挙げて説明したが、破砕手段６をこれに限定するものではなく、異なる方式の管切開具であってもよい。要するに、破砕手段６を挿通した後に、新設管を挿通可能な破砕跡２を形成できるように構成された手段であればよい。
〈５〉上記実施の形態においては、エキスパンダ１３の拡径ナット１３ａとガイドカバー１１の締め付けナット１４ａとを一本の連結ボルト１４に螺合させてある例について説明したが、前記エキスパンダ１３は、図示の形式に限られるものでなく、張出腕を放射状に備えたものであってもよく、この張出腕が連結ボルト１４或いはそれに相当するピン等の操作手段を引きつけるに伴って先端部が拡径変位するように構成されたものであってもよい。また、前記エキスパンダ１３の拡径と前記ガイドカバー１１の締め付けとが異なる操作手段によって行われるものであってもよい。
【図面の簡単な説明】
【図１】本発明に係る筒状被覆体を装着した新設管の一例の要部側面図
【図２】図１に示した新設管の要部縦断面図
【図３】本発明に係る織布筒状体の一例を示す要部斜視図
【図４】本発明に係る埋設管の入れ替え工法の一例を示す説明図
【図５】従来の埋設管の入れ替え工法の一例を示す説明図
【符号の説明】
１既設管
２破砕跡
３新設管
４筒状被覆体
４Ａ織布筒状体
４ａ縫い代
５織布
６破砕手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an embedded pipe that draws a crushing means into an existing pipe buried in the ground, expands the diameter of the existing pipe and crushes, and draws a new pipe connected to the crushing means into a crushing portion of the existing pipe The present invention relates to a woven cloth tubular body for protecting a new pipe used in the replacement method.
[0002]
[Prior art]
In recent years, in replacement work in which new pipes are buried instead of buried pipes, in order to reduce the work occupation period of roads, etc. and the work occupation area as much as possible, a construction method in which the replacement work is performed without open cut has been adopted. It is coming. For example, as shown in FIG. 5 (a), two working shafts, a start shaft 16 and a reaching shaft 17, are excavated in advance at both ends of the construction site and buried underground in the respective work shafts 16, 17. The pipe 9 is exposed and cut off, the crushing means 6 is drawn into the existing pipe 1 to be replaced, and the existing pipe 1 is crushed while the diameter thereof is expanded by the drawn crushing means 6. The new pipe 3 connected to the crushing means 6 is drawn into the inside. In addition, the above-mentioned crushing includes the slitting or tearing of the existing pipe 1, and the crushing means 6 includes a device for breaking the existing pipe 1 by slitting or tearing. This also applies to the following.
[0003]
The crushing of the existing pipe 1 and the retraction of the new pipe 3 will be described in detail by taking as an example the construction of replacing the existing pipe 1 made of cast iron with the polyethylene pipe 3A. The buried pipes 9 are separated from each other by the vertical shaft 16 and the reaching vertical shaft 17. Then, work equipment 18 is installed in the start shaft 16. Then, the work equipment 18 is driven, the operation rod 10 is inserted into the cast iron pipe 1 </ b> A that is the existing pipe 1, and is projected to the reaching shaft 17. In the reach shaft 17, as preparation for crushing the existing pipe 1 and drawing in the new pipe 3, for example, as shown in FIG. 5 (b), a tube expansion plug 6 A is attached to the tip of the operation rod 10 as crushing means 6. Further, a guide cover 11 having a distal end portion 3a of the polyethylene pipe 3A fixed thereto is connected to a rear end portion of the pipe expansion plug 6A via a connecting fitting 15. The operation preparation is completed as described above, and the operation equipment 18 installed in the start shaft 16 is operated, and the operation rod 10 previously inserted into the existing pipe 1 is gradually pulled back. Along with this, as a result of the pipe expansion plug 6A pulled by the operating rod 10 being forcibly drawn into the cast iron pipe 1A that is the existing pipe 1, the cast iron having no ductility is damaged, and the cast iron pipe 1A is broken. To separate. At the same time, the polyethylene pipe 3A connected to the pipe expansion plug 6A is drawn into the crushing trace 2 which is a damaged trace of the cast iron pipe 1A.
[0004]
[Problems to be solved by the invention]
In the replacement method, since the polyethylene pipe 3A is drawn into the crushing trace 2 immediately after crushing the cast iron pipe 1A, the crushing trace 2 has a fragment having a sharp fracture portion of the cast iron pipe 1A. The tube debris 2a is densely packed, which may rub and damage the surface 3b of the polyethylene tube 3A. Generally speaking, if the crushing means 6 cuts or expands the existing tube 1, the remnant 2 a of the existing tube 1 that has been opened or cut is also as described above. If the crushing means 6 is expanded and crushed, debris such as fragments of the existing pipe 1 that has been crushed extend to the crushing trace 2, and the new pipe 3 connected to the crushing means 6 is connected to the debris 2a. Come into contact. In recent years, as the new pipe 3 to be drawn in is mainly used as a synthetic resin pipe such as a polyethylene pipe as described above, if the surface of the new pipe 3 comes into contact with the remains of a metal pipe such as a cast iron pipe, There is a risk that debris may pierce the surface of the new pipe 3 or leave a cut on the surface. If the debris is pierced into the new pipe 3, there is a risk that the new pipe 3 will leak, and since the new pipe 3 is buried for a long period of time, the surface remains scratched, It is not preferable from the viewpoint of long-term use of the new pipe 3 as the buried pipe 9.
[0005]
Therefore, an object of the present invention is to provide a buried pipe replacement method that can prevent the new pipe from being damaged while pulling the new pipe simultaneously with the crushing of the existing pipe, and a tool therefor.
[0006]
[Means for Solving the Problems]
[Characteristic configuration of the present invention]
The first feature means of the buried pipe replacement method of the present invention according to claim 1 is that the existing pipe buried in the ground is crushed while expanding the diameter, and the crushing means for crushing the crushing trace of the existing pipe. The new pipe connected to the pipe is drawn in a state in which the woven fabric cylindrical body is covered with the warp along the axial direction of the new pipe and the weft along the direction perpendicular to the axial direction of the new pipe. In the point.
[0007]
[0008]
Second feature means replacement method of buried pipe of the present invention relating to claim 2, as a new tube to draw Oite to the first feature hand stage lies in the use of polyethylene pipe.
[0009]
The first characteristic feature of the woven tubular member of the present invention relating to claim 3, woven tubular body used in the first feature means or the second feature hand stage, sewn fabric along its length Thus, it is possible to cover the newly installed pipe when it is drawn into the existing pipe crushing mark in the ground.
[0010]
According to a second characteristic configuration of the woven fabric tubular body of the present invention according to claim 4 , a seam allowance formed by sewing the woven fabric tubular body in the first characteristic configuration on the outside of the woven fabric tubular body. It is in a formed point.
[0011]
[Operation and effect of feature composition]
According to the first characteristic means of the buried pipe replacement method according to the present invention, it is possible to prevent the newly installed pipe from being damaged when it is pulled in and replaced. In other words, the woven fabric tubular body is drawn into the new pipe by drawing the warp along the direction of the axis of the new pipe and the weft along the direction perpendicular to the axis of the new pipe. The new pipe can be protected from being damaged by the remains of the existing pipe.
[0012]
In addition, even if the woven tubular body is torn, the torn hole is difficult to expand, and the new pipe can be stably protected.
[0013]
According to a second feature means replacement method of buried pipe according to the present invention, the first feature hand stage is effective. That is, the new pipe made of polyethylene is easy to pull in because the material is soft, and improves the workability of the replacement work. Meanwhile, polyethylene new tube, but those vulnerable to a soft, it can be protected from damage which more to the first feature hand stage.
[0014]
According to the 1st characteristic structure of the woven fabric cylindrical body concerning the said invention, in the said 1st or 2nd characteristic means, it can avoid scratching the surface of the new pipe to replace | exchange. That is, the outer surface of the new pipe drawn into the existing pipe crushing trace in the ground can be protected from damage due to the crushing debris of the existing pipe by covering the woven cloth cylindrical body. And even if the said woven fabric cylindrical body is torn when pulling in the said newly installed pipe, since the torn hole is difficult to expand, the protection from the damage is sure. Furthermore, the woven fabric tubular body can be easily formed by cutting the long sheet vertically and sewing it. Therefore, it becomes possible to protect the surface over the entire length of the new pipe to be drawn.
[0015]
According to the 2nd characteristic structure of the woven fabric cylindrical body concerning the said invention, in addition to the effect of the said 1st characteristic structure, it becomes possible to protect the surface of a new pipe stably for a long period of time. In other words, the seam allowance may be formed on the outer side and sewn, and it is not necessary to turn it over to form the woven fabric cylindrical body, and the production is easy. Since the seam allowance is formed on the outer side, there is nothing protruding inside the woven tubular body, so that it is easy to cover the new pipe. In addition, since the seam allowance is formed on the outside, it is assumed that a large earth pressure acts from the outside of the tubular woven fabric after embedding, and an excessive force does not act on the woven fabric. Damage due to earth pressure from the outside of the cylindrical body can be suppressed. Accordingly, the surface of the new pipe can be protected stably for a long time after being buried.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the buried pipe replacement method according to the present invention and the cylindrical covering for the replacement will be described. FIG. 1 is an explanatory view showing an example of the state of the distal end portion of the new pipe in the retracting operation state, FIG. 2 is a longitudinal sectional view of the state of the distal end portion of the new pipe shown in FIG. 1, and FIG. FIG. 4 is a perspective view illustrating an example of a covering body, and FIG. 4 is an explanatory diagram illustrating an example of a state of a pull-in operation. The same elements as those in FIG. 5 used in the above-described conventional technology or elements having the same functions are denoted by the same or related reference numerals as those in FIG. A part of is omitted.
[0017]
In the following, an example of the above-described method of replacing the buried pipe is used as an example in which the cutting of the pipe is crushing, and the tube cutting tool 6B (see FIG. 1) for cutting the buried pipe along the pipe axis is used as the crushing means 6. An example will be described. In the following example, the existing pipe 1 is a rolled steel pipe, and the new pipe 3 is a synthetic resin pipe. For example, as shown in FIG. 1, a tubular covering 4 is covered over a new pipe 3 made of a polyethylene pipe 3 </ b> A drawn in place of the existing pipe 1 to be crushed from the tip 3 a over the entire length. The cylindrical covering 4 is made of a canvas material or the like woven from a fiber material such as nylon or aramid, and, for example, as shown in FIG. 3, a long woven fabric 5 obtained by dividing and cutting an original fabric in the width direction, Folded in a state where both edge portions 5a in the width direction are overlapped, and continuously stitched in the length direction along the edge portion 5a to form the woven fabric tubular body 4A, with the stitches 4b exposed Thus, it is used with the seam allowance 4a left outside. The woven fabric tubular body 4A is sewn to a dimension that can be externally fitted onto the polyethylene pipe 3A with the seam allowance 4a on the outside and that does not cause a large gap with the surface 3b of the polyethylene pipe 3A.
[0018]
Explaining in more detail an example of the method for replacing the buried pipe, when the existing pipe 1 is not made of cast iron, for example, a tube cutting tool 6B as shown in FIG. The illustrated tube incising tool 6B is used in a method developed by Brooklyn Union of the United States, and is called a bullet. It is composed of an incision 7 on the front end side and a forced expansion portion 8 on the rear end. At the distal end of the incision portion 7, an attachment portion to the operation rod 10 for pulling the tube incision tool 6B into the existing tube 1 is provided. The connecting part which can be connected using is provided. The incision 7 has a small diameter and is eccentric, and a guide roller 7b is arranged on the outer side so as to be in contact with the inner surface of the existing pipe 1, and the inner diameter is sequentially increased from the distal end side. A plurality of incision round blades 7a (five in the drawing) are rotatably arranged around the circle center. The forced pipe expansion part 8 has an outer peripheral surface whose diameter is increased on the rear end side and is formed as an eccentric taper surface, and the diameter of the rearmost part is larger than the pipe diameter of the existing pipe 1 to be incised. . When the tube incising tool 6B is pulled into the existing tube 1, the small-diameter incision round blade 7a first contacts the inner surface of the existing tube 1, and the inner surface is cut based on the reaction force of the outer guide roller 7b. Form. Further, the next incision round blade 7a further deepens the cut. When the last incision round blade 7a comes into contact with the notch, the existing tube 1 is completely incised. The rearmost incision round blade 7a is sized so that the clamp and sleeve joint for connecting the existing pipe 1 can be incised.
[0019]
The new pipe 3 is attached to a guide cover 11, for example, as shown in FIG. That is, the expander 13 provided with a protrusion that can be locked to the inner surface of the polyethylene tube 3A on the outer peripheral surface is inserted into the polyethylene tube 3A in a state in which the expanded nut 13a is fitted. The expander 13 is formed to have substantially the same diameter as the inner diameter of the polyethylene pipe 3A, and is divided into four parts in the circumferential direction, with some of the divided parts being missing and in contact with the divided surfaces. The projection is positioned on the inner side of the inner surface of the polyethylene tube 3A. A tapered surface having a large rear end in the axial direction is formed on the inner periphery, and the diameter is increased by inserting a diameter increasing nut 13a into the tapered surface. The diameter-enlarging nut 13a is formed on a tapered surface having the same gradient as the inner periphery of the expander 13 whose outer peripheral surface has a larger diameter on the rear end side. The distal end portion 3a of the polyethylene pipe 3A is provided with a distal end plug 12 having a through-hole through which a connecting bolt 14 can be inserted and having a tapered surface with a small diameter on the distal end side as an outer peripheral surface. The connecting bolt 14 is inserted through the hole from the hole to the expanded nut 13a. When the connecting bolt 14 is screwed into the connecting bolt 14 and the connecting bolt 14 is screwed, the expanding nut 13a is attracted toward the tip plug 12, and the expanding nut. 13a is inserted, the expander 13 is expanded in diameter, the protrusion on the outer peripheral surface of the expander 13 bites into the inner surface of the polyethylene tube 3A, and the polyethylene tube 3A is fastened to the tip plug 12 become.
[0020]
After the polyethylene pipe 3A is fastened to the tip plug 12 as described above, the woven fabric tubular body 4A, which is an example of the tubular covering body 4, is attached to the polyethylene pipe 3A from the tip plug 12 side. Cover the guide cover 11 from above the woven fabric tubular body 4A and put the woven fabric tubular body 4A between the tip plug 12 and tighten it while passing the connecting bolt 14 through the bolt hole. The nut 14a is screwed onto the connecting bolt 14 and tightened. By tightening the tightening nut 14a, the cylindrical cover 4 is securely sandwiched between the tip plug 12 and the guide cover 11, and at the same time, the polyethylene tube 3A is about to be expanded in diameter by the expander 13. Is received on the outside with the cylindrical covering 4 interposed therebetween to prevent diameter expansion. The connecting bolt 14 is attached to the tube incising tool 6B via a connecting fitting 15, and a metal band for detecting a pipe is previously interposed between the polyethylene tube 3A and the woven tubular body 4A. Keep it. The new pipe 3 thus connected to the crushing means 6 is covered with the cylindrical cover 4 on the surface 3b, and the tip 3a is covered with the guide cover 11 together with the cylindrical cover 4. Thus, when the guide cover 11 is pulled and the new pipe 3 is pulled into the crushing mark 2, earth and sand enter the new pipe 3 and between the new pipe 3 and the cylindrical covering 4. It is prevented.
[0021]
The work equipment 18 installed in the start shaft 16 mainly includes the operation rod 10 for pulling the crushing means 6 inserted into the existing pipe 1 and protrudes to the reach shaft 17 so as to protrude. The operation rod 10 is operated to pull back the distal end portion of the operation rod 10 to the start shaft 16 together with the crushing means 6 attached thereto. Usually, a hydraulic cylinder type push-pull device is used. This is provided with a double-acting hydraulic cylinder, a chuck provided on its piston rod, a chuck for repeatedly fixing and separating the operating rod 10 to and from the piston rod, and a switching mechanism for switching the hydraulic driving direction.
[0022]
Using the above-described equipment, the pipe replacement process in the renewal work for updating the existing pipe 1 made of the stretched steel pipe buried as a new pipe 3 to the polyethylene pipe 3A is as follows. First, with the determination of the renewal work section, the start shaft 16 is excavated at one end side of the work section, and the reaching shaft 17 is excavated at the other end side. Next, for example, as shown in FIG. 4, the buried pipes 9 are cut and separated in the compatible wells 16 and 17, and a work facility 18 connected to a hydraulic power source is installed in the start shaft 16. The operation rod 10 is inserted into the existing pipe 1 and attached to the work equipment 18, the operation equipment 18 is operated to push the operation rod 10 into the existing pipe 1, and the inside of the reach shaft 17 To protrude. On the other hand, on the reach shaft 17 side, the polyethylene pipe 3A which is the newly installed pipe 3 is covered with the woven fabric tubular body 4A in the above-described manner, the guide cover 11 is applied thereon, and the connecting bracket 15 is used for crushing means. The guide cover 11 is connected to the tube cutting tool 6B, which is 6, and the operation rod 10 is waited for the distal end portion of the operation rod 10 pushed from the start shaft 16 to protrude into the reaching shaft 17. The tube incision tool 6B is attached to the distal end portion of 10. When the tube incising tool 6B is attached to the pushed operation rod 10, the operation shaft 18 is operated on the start shaft 16 side, and the operation of pulling out the pushed operation rod 10 is started. Accordingly, the tube incising tool 6B is drawn into the existing tube 1, and the existing tube is sequentially opened and expanded. At the same time, the polyethylene tube 3A connected to the tube incising tool 6B is drawn into the crushing trace 2 while the existing tube 1 is incised and expanded. All the operation rods 10 are pulled back to the start shaft 16 side, and the tip 3a of the polyethylene pipe 3A is drawn together with the guide cover 11, and the pipe replacement process in the renewal work is completed.
[0023]
Since the tube replacement step is configured as described above, even if the debris 2a of the existing tube 1 comes into contact with the surface of the tubular covering 4 by covering the tubular covering 4, the new tube 3 The surface 3b can be protected from being damaged by the debris 2a of the existing pipe 1. In addition, even if the tubular covering 4 made of woven fabric is torn, it is difficult for the broken hole to expand, so that the new pipe 3 can be prevented from being damaged at least over a wide range. In addition, the woven fabric tubular body 4A can be manufactured easily by cutting the long sheet vertically and sewing it, and can manufacture an arbitrary length. Since the woven fabric tubular body 4A is sewn without turning over, and the seam allowance 4a is formed on the outside (see FIG. 3), there is nothing protruding inside, and the work to cover the new pipe 3 is easy. It is. Further, since the seam allowance 4a is formed on the outer side, even if earth pressure from the outside of the woven fabric tubular body 4A acts after embedment, the inner polyethylene pipe 3A is applied to the woven fabric 5 This is only an action of pressing force, and no excessive force is applied, and damage due to earth pressure of the woven fabric tubular body 4A can be suppressed.
[0024]
The following different embodiments are also included in the present invention.
[Another embodiment]
<1> In the above embodiment, the case where the existing pipe is cut open as a crush of the existing pipe has been described as an example.To crush the existing pipe, for example, when the existing pipe is a cast iron pipe, As explained in the prior art, for example, the expanded pipe 6A may be press-fitted into the existing pipe, and the existing pipe may be crushed by deforming it beyond its allowable deformation limit, and a plurality of cutter edges are provided radially. A crushing head may be introduced into the existing pipe, and the existing pipe may be crushed by a bending force while tearing the existing pipe. The crushing technique can be appropriately changed according to the material of the existing pipe.
<2> In the above-described embodiment, the example in which the polyethylene pipe 3A is introduced as the new pipe 3 has been described. However, the material of the new pipe may be another synthetic resin, for example, a rolled steel pipe Such a metal tube may be used.
<3> In the above-described embodiment, the example in which the tubular covering 4 is configured by the woven tubular body 4A with the seam allowance 4a formed outside has been described. However, the way of taking the seam allowance 4a is arbitrary. It may be formed on the inner side, or may be formed by stitching the edge portions 5a so as to face each other. Moreover, the material of the said cylindrical covering 4 is also arbitrary, The cloth which has not been woven up, such as a nonwoven fabric, may be sufficient.
<4> In the above embodiment, the tube incision tool 6B has been described by taking as an example a bullet imported from the United States, but the crushing means 6 is not limited to this, and a different method of tube incision is used. It may be a tool. In short, any means may be used as long as it can form the crushing mark 2 through which the new pipe can be inserted after the crushing means 6 is inserted.
<5> In the above embodiment, the example in which the diameter-enlarging nut 13a of the expander 13 and the tightening nut 14a of the guide cover 11 are screwed into one connecting bolt 14 has been described. Is not limited to the form shown in the figure, and may have a radially extending overhanging arm, and when the overhanging arm attracts operation means such as a connecting bolt 14 or a corresponding pin, the tip The part may be configured to be displaced in diameter. Further, the expanding diameter of the expander 13 and the tightening of the guide cover 11 may be performed by different operating means.
[Brief description of the drawings]
FIG. 1 is a side view of an essential part of an example of a new pipe equipped with a tubular covering according to the present invention. FIG. 2 is a longitudinal sectional view of an essential part of the new pipe shown in FIG. FIG. 4 is an explanatory diagram showing an example of a buried pipe replacement method according to the present invention. FIG. 5 is an explanatory diagram showing an example of a conventional buried pipe replacement method. Explanation of]
DESCRIPTION OF SYMBOLS 1 Existing pipe 2 Crushing trace 3 New installation pipe 4 Tubular covering 4A Woven tubular body 4a Sewing allowance 5 Woven cloth 6 Crushing means

Claims

The existing pipe embedded in the ground is crushed while expanding the diameter by the crushing means, and the buried pipe replacement method for drawing the new pipe connected to the crushing means into the crushing trace of the existing pipe,
Cover the new pipe connected to the crushing means with a woven fabric cylindrical body with warp yarns along the axial direction of the new pipe and weft yarns along a direction perpendicular to the axial direction of the new pipe. Replacement method for buried pipes to be pulled in.

The buried pipe replacement method according to claim 1, wherein a polyethylene pipe is used as the new pipe.

A woven tubular body used for the replacement method of the buried pipe according to claim 1 or 2,
A woven fabric tubular body that is sewn in the length direction of a woven fabric and can be externally covered with a new tube when it is drawn into an existing tube crushing mark in the ground.

The woven fabric tubular body according to claim 3, wherein a seam allowance formed by sewing the woven fabric tubular body is formed on an outer side of the woven fabric tubular body.