JP2004285578A

JP2004285578A - The last tube of immersed tube and the last joining method

Info

Publication number: JP2004285578A
Application number: JP2003075789A
Authority: JP
Inventors: Osamu Kiyomiya; 理清宮; Takanobu Honjo; 隆宣本庄; Kazuya Aida; 和哉合田; Ryosuke Horii; 良介堀井; Kazuhiro Yamamura; 和弘山村; Hideo Kimura; 秀雄木村; Yoshisuke Katayama; 能輔片山
Original assignee: Nippon Steel Corp; Toa Corp; Toyo Construction Co Ltd
Current assignee: Nippon Steel Corp; Toa Corp; Toray Engineering Co Ltd
Priority date: 2003-03-19
Filing date: 2003-03-19
Publication date: 2004-10-14

Abstract

<P>PROBLEM TO BE SOLVED: To provide the last tube of an immersed tube and the last joining method capable of being easily joined by absorbing even if there are some deviation in the existing tube bodies in a method for making the last joining between the existing tubes and the last tube. <P>SOLUTION: In the last tube 1 for the last joining inserted and installed between the existing tubes A and B, the last tube 1 is divided in the direction of the axis, both divided tube bodies 1a and 1b are connected with an expansible joint 3 such as bellows 3a or the like forming a steel plate having cut-off efficiency along the circumferential wall in a corrugated form, bulk heads 5a and 5b are provided inside of the tube bodies 1a and 1b located on both sides of the expansible joint 3 to form a pressure chamber 6 capable of pouring and discharging water and a pressurizing pump 15 making water pressure inside of the pressure chamber 6 higher than the outside water pressure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は水底に多数の函体を順次沈設・接合して沈埋函を構築する際の最終函と、この最終函を用いた沈埋函の最終接合工法に関する。
【０００２】
【従来の技術】
従来の沈埋函の最終接合方法は、接合すべき箇所の沈埋函の周囲に型枠を設けて水中コンクリートを打設したり、沈設沈埋函内に接続用の函体を内臓させておきスライドさせて最終接合する手段が用いられていた。
【０００３】
しかし、これらの方法は作業性が悪く長い工期を要し、また水深が深くなると作業が困難であることから各種の改良技術が多数提案されている。
【０００４】
例えば、特開平５−４４３９６号公報（特許文献１）に開示されているものは、可撓継手を備え互いに対向する最終接合部の既設函の端面をテーパー状とし、そのテーパーに合わせた形状の楔形連結ブロック（最終函）を挿入設置し、水圧によって端部間を密着させた後、函体内部をドライにして連結ケーブルと場所内コンクリートによって接合するものである。最終函を楔形としたものは、上記以外にも特開２０００−２４００７８号公報（特許文献２）等多数提案されている。
【０００５】
また、特開平６−２２８９７１号公報（特許文献３）には、（Ａ）横断面形状が沈埋函のそれとほぼ同一であり、（Ｂ）開閉可能な排水管を備えた隔壁をほぼ中央部に有し、（Ｃ）一方の端面にゴムガスケットが装着されている２個の函体の他端面間を不透水性柔軟材料で包まれた伸縮可能なフレキシブル継手で相互に係合してなり、（Ｄ）２枚の隔壁と函体周壁とで囲まれる中央室に開口する開閉可能な注水管が周壁を貫通して配設され、（Ｅ）フレキシブル継手部に開口して開閉可能な注入管が配設されている沈埋函接合用接続函（最終函）が開示されている。また、これに類似するものが特開平６−２４０６８２号公報（特許文献４）として開示されている。
【０００６】
【特許文献１】
特開平５−４４３９６号公報
【特許文献２】
特開２０００−２４００７８号公報
【特許文献３】
特開平６−２２８９７１号公報
【特許文献４】
特開平６−２４０６８２号公報
【０００７】
【発明が解決しようとする課題】
上記従来技術の特開平５−４４３９６号公報に開示されているものは、大水深でも施工が可能であり、品質、安全管理が容易であるとされている。しかし、水中工事においては高い施工精度を確保するのは困難であり既設函の設置にずれが生じやすい。このため、既設函のテーパー端面に沿わせて同じテーパー形状の楔形連結ブロックを挿入した際、正確に合致して接合するのが困難である。
【０００８】
一方、特開平６−２２８９７１号公報に示される従来技術は、接続函体に伸縮可能なフレキシブル継手を備えているため、既設函体に多少のずれがあっても吸収できる利点がある。
【０００９】
しかし、この公報に開示されているフレキシブル継手の構成は明確でなく、またフレキシブル継手を包む不透水性柔軟材料は厚手の織物や合成樹脂製とされているため、大水深の沈埋函では、中央室がドライ状態では函体外の外水圧によって大きな変形が生じてしまう。また、フレキシブル継手部の函体外の水を中央室に注入することによって水圧を生じさせるようにされているが、中央室内の水圧は隔壁外の水圧以上にはならないため接続函体のフレキシブル継手を伸張することは出来ない。
【００１０】
このため、接合端のゴムガスケットを圧接して止水状態にするには別に引寄せジャッキ等の手段を用いなければならない。
【００１１】
本発明は上記の従来技術の課題を解消し、最終函と既設函とを容易に接合可能な最終函の構造とこの最終函を用いた沈埋函の最終接合工法を提供する。
【００１２】
【課題を解決するための手段】
本発明に係る沈埋函の最終函構造は、
既設函Ａ，Ｂの間に挿入設置される最終接合用の最終函において、該最終函を軸方向に分割し、この分割した両函体を周壁に沿って止水性を有する伸縮継手で結合し、該伸縮継手の両側に位置する函体内にバルクヘッドを設けて注排水可能な加圧室とし、該加圧室内の水圧を外水圧より高くする加圧ポンプを備えたことを特徴とする沈埋函の最終函である。
前記伸縮継手としては、鋼板を波形に形成したベローズを用いるのが望ましい。
【００１３】
また、本発明に係る沈埋函の最終接合工法は、
既設函Ａ，Ｂの間に最終函を挿入して接合する沈埋函の最終接合工法であって、沈埋函の最終接合に使用する最終函を軸方向に分割し、この分割した両函体を周壁に沿って止水性を有する伸縮継手で結合し、該伸縮継手の両側に位置する函体内にバルクヘッドを設けて注排水可能な加圧室とし、該加圧室内の水圧を外水圧より高くする加圧ポンプを備えた最終函を用いて、以下の工程で沈埋函を最終接合するものである。
１．前記伸縮継手を縮めた状態で仮固定した前記最終函を既設函Ａ，Ｂの間に沈設し、
２．最終函の一方の端部を既設函Ａ側に引寄せ端部同士を接合し、
３．伸縮継手の仮固定を解除した後、前記加圧室内に注水して加圧室内の水圧を外水圧より高くなるように加圧して伸縮継手を伸長し、
４．最終函の他方の端部を既設函Ｂの端部に止水状態で当接させ、
５．最終函の端部と既設函Ｂのバルクヘッド間の水を排出した後、端部同士を接合し、
６．前記加圧室内の水を排水した後、加圧室のバルクヘッドを解体撤去し、
７．前記伸縮継手部の周壁を結合する。
【００１４】
【発明の実施の形態】
以下、本発明に用いる沈埋函の最終函構造について説明する。
【００１５】
図１は本発明の請求項１に係る最終函１の実施形態であって、既設函Ａ、既設函Ｂの間に施工途中の最終函１の全体を示す縦断面図で、図２は本発明の要部である伸縮継手部４の詳細である。図３は伸縮継手３の配置を示す最終函１の横断面である。
本発明に用いる最終函１の全体形状は、図１に示すように、軸方向に分割した函体１ａ，１ｂを周壁２に沿って伸縮継手３で連結し、この伸縮継手３を備えた伸縮継手部４の函内を水密バルクヘッド５ａ，５ｂで仕切った加圧室６としたものである。最終函１の軸方向長さは伸縮継手３を縮めた状態で余裕をもって既設函Ａ，Ｂの間に挿入可能とし、伸縮継手３を伸長した状態では、既設函Ａ，Ｂに接合できるようにする。なお、既設函Ａ，Ｂと最終函１の間は、いずれかの周壁に沿って止水用のゴムガスケット７が設けられている。
【００１６】
最終函１の軸方向の端面は、両端を垂直または斜め状（傾斜面）にしてもよいが、図１のように一方を斜め状とし、他方（伸縮継手側）を垂直とした方が設置作業面で有利である。
また、最終函１の分割位置（伸縮継手位置）は、最終函１の函軸方向中間部のいずれの位置に設けてもよいが、図１のように最終函１の端部に分割位置を設けた方が施工途中の構造安定の面から望ましい。
【００１７】
最終函１の一方の端部は、既設函Ａの端部傾斜面に対向する面を平行な傾斜面とし（一方の函端面が下方に向って外側に突出する傾斜面とし、これに対向する他方の函端面が下方に向って函中間部に凹む逆向きの傾斜面とし）、水密バルクヘッド８を備えている。この端部同士の接合は公知な手段で行うため詳細説明は省く。
【００１８】
図２は本発明における最終函１の伸縮継手部４付近の詳細であって、最終函１を分割した函体１ａの端部に短尺の函体１ｂを配置し、周壁２に沿って設けた伸縮継手３で水密に連結している。
【００１９】
また、この伸縮継手３を挟んで函体１ａと函体１ｂ内には、水密バルクヘッド５ａ，５ｂを設けて伸縮継手部４の函体内を加圧室６としている。また、函体１ｂ側のバルクヘッド５ｂは、最終函１の端部バルクヘッドを兼ねたものとしている。加圧室６内には注排水可能し、注水した水を加圧可能とするためバルブ１１付きの外水の注水配管１２、加圧ポンプ配管１３の端部またはその端部のバルブ１３ａおよびエア抜き装置１４が設けられている。前記エア抜き装置１４は、加圧室６内に配置された配管とその配管端部で函体１ａ内に配置のバルブとを備えている。
【００２０】
加圧ポンプ配管１３には、沈埋函の設置水深の水圧より高い圧力で送水可能な加圧ポンプ１５が接続されている。
【００２１】
また、最終函１の上端には、既設函Ｂ側に向けて仮受け材１６が基端を固定して突出されている。この仮受け材１６は最終函１を沈降時に位置決めするストッパーの役割を担うため、伸縮継手３を縮めた状態で端部が既設函Ｂの上端に支持できる長さにする必要がある。
【００２２】
また、仮受け材１６には、加圧室６内に注入した水を加圧して伸縮継手３を伸長し函体１ｂを既設函Ｂに向けて移動する際に生じる摩擦抵抗を軽減するため、突出部下側に滑動材を塗布しておいた方がよい。
【００２３】
図３は、函体１ａ，１ｂの横断面における伸縮継手３の配置を示したものである。図中の函体内部の通路隔壁に設けた伸縮継手３ａは，分割函体１ａ，１ｂの連結強度を確保するためのものである。
【００２４】
伸縮継手３は水密性を有し、所定の伸縮量を発揮でき、施工途中において適当な剛性を有し、且つ外水圧に対して変形し難いものとする必要がある。この条件に適合するものとして鋼製ベローズを採用するのが望ましい。
【００２５】
鋼製ベローズを用いれば、その端部を溶接することで完全止水が得られ、鋼板の板厚、高さ、屈曲山数を選定することで、必要とする伸縮量、剛性、耐圧強度を容易に設定できる。なお、上記の条件を満たすものであれば、他の伸縮継手を使用してもよい。
【００２６】
図５（ａ），（ｂ）に示すものは、鋼板を折り曲げて製作した内側３山、外側２山の鋼製ベローズ３ａであって、伸縮継手３の縮小状態（ａ）と伸長状態（ｂ）を示す。鋼製ベローズ（伸縮継手）３ａ（３）は、函体１ａ、函体１ｂの端部に溶接等により水密・強固に固定される。
【００２７】
図５に示す鋼製ベローズ３ａの下部に設けた２枚の重ね鋼板１８ａ，１８ｂは、伸縮継手部４を最終的に剛結する際の外側鋼板となるもので、各重ね鋼板１８ａ，１８ｂの一端を函体に固定し，鋼製ベローズ３ａが自由に伸長可能とし、継手剛結時には２枚の鋼板１８ａ，１８ｂ同士を溶接により固定する。なお、重ね鋼板１８ｂの前端と函体との間に、別途突合せ鋼板１８ｃを挿入し、突合せ溶接してもよい（この場合、重ね鋼板１８ａは裏当材となる。）。
【００２８】
また、前記鋼板１８ａはブラケット１９で支持され、鋼製ベローズ３ａが外圧によって変形するのを防止する役割も担っている。さらに前記ブラケット１９は前記伸縮継手部４にコンクリート２０を注入して剛結する際、せん断補強材としても機能する。
【００２９】
最終函１を沈降する際、施工途中において伸縮継手３が弱点となり損傷の心配がある。そのため、伸縮継手部４において函体１ａと函体１ｂを仮止めで結合し、安全に施工するようにした方が望ましい。
【００３０】
図３、図４は伸縮継手部４の函体１ａと函体１ｂに仮止め２１の配置を示したものである。
この仮止め手段２１は、圧縮変形を阻止する袋詰めモルタル２２と、引張り・曲げ変形を阻止する形鋼連結材２３を用いている。
【００３１】
仮止め２１は、伸縮継手３を縮めた状態で、袋詰めモルタル２２を伸縮継手部４の函体１ａと函体１ｂの端面の空間に適宜間隔で配置し、沈埋函の通路隔壁１７の上下に函体１ａと函体１ｂの各通路隔壁１７を形鋼（例えば溝形鋼３００＊９０）連結材２３で連結固定している。
なお、この仮止め２１は伸縮継手３を伸長する前に撤去する。
【００３２】
最終函１を沈降する際、既設函Ａ、Ｂ間に誘導して容易に位置決めするためガイド２４を用いるが、このガイド２４は公知のものを既設函Ａ、Ｂ側、最終函１側のいずれに設けてもよいため詳細説明は省く。
【００３３】
また、既設函Ａ，Ｂと最終函１の端部周壁には、止水用のゴムガスケット７を設けるが、このゴムガスケット７は公知のものを使用し、既設函Ａ，Ｂ側または最終函１側のいずれに、設けてもよい。
【００３４】
次に、本発明に係る沈埋函の最終接合工法の工程（手順）について説明する。請求項３に係る沈埋函の最終接合工法の実施形態は前記の如き構造とした最終函１を用い、以下の工程で行う。（図６（ａ）〜図８（ｇ）参照）
▲１▼ 準備工
最終函１を設置する基盤の所定場所に支承ジャッキ受け２５を設けておく。（図６（ａ）参照）
▲２▼ 最終函の沈降
洋上曳航してきた最終函１を図示省略のクレーン船または沈設台船で吊り下げ、函体１ａ，１ｂ内のバラスト調整によって沈降する。沈降は既設函Ａ，Ｂまたは最終函１の端部に設けたガイド２４によって正確に位置調整しながら行う。（図６（ａ）参照）
▲３▼ 最終函の着底完了
沈降した最終函１は、その既設函Ａ側の一端を支承ジャッキ２６で支持し、他端を最終函上端に固定した仮受け材１６で既設函Ｂの上端に支持させる。（図６（ｂ）参照）
▲４▼ 最終函１を既設函Ａ端部に引寄せ
引寄せジャッキ２７によって最終函１の端部を既設函Ａ側に移動し、既設函Ａと最終函１の外周端部に介在するゴムガスケット７で止水可能な状態とする。その後、既設函Ａの端部バルクヘッド２８と対向する最終函１の一端のバルクヘッド８間の水を排水する。この結果、最終函１の他端側バルクヘッド５ｂに作用する水圧によって、最終函１の端部と既設函Ａの端部は、前記ゴムガスケット７を介して圧接状態となる。（公知のジャッキ引寄せ水圧接合手段）（図７（ｃ）参照
▲５▼ 最終函１の一端側と既設函Ａの接合
最終函１の端部と既設函Ａの端部の外周間に設けたゴムガスケット７が所定形状に圧縮され止水状態が確保できたら、両函体Ａ，１のバルクヘッド２８，８を切断撤去し、最終函１の端部と既設函Ａの端部を可撓接合または剛接合の何れか公知な接合手段で接合する。
次に、最終函１の底面と基盤３４の隙間２９に前記伸縮継手３の手前までコンクリート３０を注入して最終函１を支持する。（図７（ｄ）参照）
【００３５】
▲６▼ 最終函１の他端側を既設函Ｂに伸張（伸縮継手の伸張）
次に、加圧室６内の伸縮継手３の仮止め２１を解除し、伸縮継手３を伸張可能な状態とする。なお、加圧室６内に入って作業する必要があるため函体１ａの函体内側バルクヘッド５ａには、止水可能な出入口（図示省略）を設けておく必要がある。
【００３６】
伸縮継手３の仮止め２１を解除したら、函体内側バルクヘッド５ａを止水状態とした後、加圧室６内にエア抜き装置１４のバルブを開放して、エア抜きしながら注水する。（注水手段は最終函１外に配管した注水管１２のバルブを開いて注入するか、または加圧ポンプ１５を利用する）（図８（ｅ）参照）
【００３７】
加圧室６内に注水が完了したら、加圧ポンプ１５によって加圧室６内の水圧を最終函１の端部バルクヘッド５ｂの外水圧より高くなるように差圧を与える。この差圧によってバルクヘッド面に押広げ力が生じて、伸縮継手（ベローズ）３のばね強度より大きくなると伸縮継手３が伸張し、最終函１の全体長さが長くなって既設函Ｂの端部と最終函１の外周端部との間に設けたゴムガスケット７を圧縮変形して止水状態を確保できることとなる。（図８（ｆ）参照）
【００３８】
差圧の大きさは、加圧室６のバルクヘッド面の広さ、沈埋函（１，Ｂ）の設置水深および伸縮継手３のばね強度（抵抗力）等の条件によって定める必要がある。（例えば、大型沈埋函を水深２０ｍに設置する場合においては、差圧を０．０２〜０．１Ｍｐａ程度とすればよい）。
【００３９】
▲７▼ 最終函１の他端側と既設函Ｂの接合
既設函Ｂの端部と最終函１の外周端部がゴムガスケット７で止水状態を確保できたら、既設函Ｂの端部バルクヘッド３１と最終函１の他端側バルクヘッド５ｂ間の水を排水ポンプ３２で排水する。前記バルクヘッド間３１，５ｂの排水によって、加圧室６の差圧が増大して、水圧接合作用により既設函Ｂの端部と最終函１の外周端部はゴムガスケット７を介してより強固に圧接される。
次に、既設函Ｂのバルクヘッド３１を切断撤去し、最終函１の端部と既設函Ｂの端部を可撓接合または剛接合の何れか公知な接合手段で接合する。（図８（ｇ）参照）
【００４０】
▲８▼ 伸縮継手部の結合
加圧室６の水を前記加圧ポンプ１５の送水方向を逆にするか、または排水ポンプ３２を用いて排水した後、両側のバルクヘッド３１，５ｂを切断撤去し、伸縮継手部４を結合する。
結合は、剛結合手段または柔結合手段のいずれを採用してもよい。なお、図中符号３５は、既設函Ｂのバルクヘッド３１に設けられたバルブ付きエアー抜き配管、符号３６はリリーフ弁である。
【００４１】
剛結合手段を採用する場合は、函体周壁２の伸縮継手部４内側に設けた外側鋼板１８ａ，１８ｂを溶接固定し、函体内面の位置に内側鋼板３３を溶接して分割した函体１ａ、１ｂの端部間を結合する（図５ｂ参照）。前記内側鋼板３３は、図示を省略するが、２枚の鋼板を重ねてスライド可能としたものを分割函体１ａ，１ｂのそれぞれに一端を固定し、伸縮継手３が伸長する際に摺動するようにしたものを事前に設けておいた場合は、伸縮継手３の最終伸長状態で重ね合わせた鋼板同士を隅肉溶接で固定して結合するか、又は突合せ鋼板を挿入して突合せ溶接して結合する。
【００４２】
なお、外側鋼板１８（１８ａ，１８ｂ）と内側鋼板３３の間には、せん断補強用の形鋼や鋼板或いはジベルを設け、一部は前記外側鋼板１８および内側鋼板３３と溶接して結合する。
【００４３】
次に、あらかじめ配管されている注入管１２を用いて外側鋼板１８と内側鋼板３３の間に高流動性コンクリート２０を注入充填する。この結果、コンクリートが硬化した後、伸縮継手部４は剛結合されることになる。（図５（ｂ））
【００４４】
また、柔結合手段を採用する場合は、図示を省略するが、前記伸縮継手３を一次止水材とし、函体内側に二次止水ゴムを取付け、さらにその内側に板ばねや油圧ダンパー等を設ける公知な柔結合とすればよい（詳細説明は省略した）。
【００４５】
次に、最終函１の底面と基盤３４の隙間２９にコンクリート３０ａを注入して最終函１の接合を完了して沈埋函を完成する。（図８（ｇ）参照）
【００４６】
【実施例】
以下、本発明の最終函の具体的な実施例を説明する。
水深３０ｍの海底に、幅３０〜４０ｍ、高さ１０ｍ、長さ１００ｍの大型鋼・コンクリート合成沈埋函８基を接合して構築する沈埋函の最終接合において、
（１）最終函
前記実施形態で述べた図１と同様な形状の最終函（１）は一方の端部を斜めにした長尺函体１ａと短尺函体１ｂに分割し（最終函１の端部を分割）、鋼製ベローズ３ａの伸縮継手３で連結する構造とする。
（２）伸縮継手
鋼製ベローズ３ａとし、その諸元は厚さ１２ｍｍの鋼板を外側２山・内側３山の波形状とし、波高３００ｍｍ、伸縮方向長さを縮小時で５４０ｍｍ、最大伸長時８６０ｍｍまで伸長可能とした。（設計伸長長さは３２０ｍｍ）
【００４７】
（３）加圧ポンプ
加圧ポンプ１５は、圧力０．３Ｍｐａにおいて４ｍ^３／分、０．４５Ｍｐａにおいて１ｍ^３／分のヒューガルポンプ３７ＫＷを用いる。
（４）加圧室の加圧水圧
継手伸長時の加圧室６内の加圧水圧は外圧０．３Ｍｐａ（水深圧）より高い０．３５Ｍｐａとし、差圧０．０５Ｍｐａを作用させる。
【００４８】
【発明の効果】
本発明では、既設函Ａ，Ｂの間に挿入設置される最終接合用の最終函において、該最終函を軸方向に分割し、この分割した両函体を周壁に沿って止水性を有する伸縮継手で結合し、該伸縮継手の両側に位置する函体内にバルクヘッドを設けて注排水可能な加圧室とし、該加圧室内の水圧を外水圧より高くする加圧ポンプを備えた沈埋函の最終函としたので、簡単な構成で最終函側の伸縮継手を伸長させて、既設函体との接合が容易な最終函とすることができる。
【００４９】
また本発明では、既設函Ａ，Ｂの間に最終函を挿入して接合する沈埋函の最終接合工法であって、沈埋函の最終接合に使用する最終函を軸方向に分割し、この分割した両函体を周壁に沿って止水性を有する伸縮継手で結合し、該伸縮継手の両側に位置する函体内に水密バルクヘッドを設けて注排水可能な加圧室とし、且つ加圧室内の水圧を加圧可能とした最終函を用いて、
前記加圧室内に注水して加圧室内の水圧を外水圧より高くして伸縮継手を伸長し、最終函の他方の端部を既設函Ｂの端部に止水状態で当接させ端部同士を接合した後、伸縮継手部の周壁に接続鋼板を固着すると共にコンクリートを注入して分割した最終函を剛結合する沈埋函の最終接合工法であるため、
既設函の間に挿入した最終函を、伸縮継手部の加圧室に加圧水圧を作用させて最終函の長さを伸張させ既設函と最終函の端部を合致させて接合するため、容易な作業で沈埋函の最終接合を行うことができる。
【００５０】
さらに、伸縮継手に鋼製ベローズを用いると、端部を溶接することで完全止水が得られ、鋼板の板厚、高さ、屈曲山数を選定することで必要とする伸縮量、剛性、耐圧強度を容易に設定でき、既設函に大きなずれがあっても対応できる。
【図面の簡単な説明】
【図１】本発明に係る最終函の実施形態であって、既設函Ａ、既設函Ｂの間に施工途中の最終函の全体を示す縦断面図である。
【図２】本発明の要部である伸縮継手部の詳細図である。
【図３】伸縮継手の配置を示す最終函の横断面図である。
【図４】図３のＡ−Ａ断面図である。
【図５】鋼製ベローズを用いた伸縮継手の縮小状態と伸張状態である。
【図６】（ａ）〜（ｂ）は本発明に係る沈埋函の最終接合工法の工程説明図である。
【図７】（ｃ）〜（ｄ）は本発明に係る沈埋函の最終接合工法の工程説明図である。
【図８】図８（ｅ）〜（ｇ）は本発明に係る沈埋函の最終接合工法の工程説明図である。
【符号の説明】
Ａ既設函
Ｂ既設函
１最終函
１ａ函体
１ｂ函体
２周壁
３伸縮継手
４伸縮継手部
５ａ水密バルクヘッド
５ｂ水密バルクヘッド
６加圧室
７ゴムガスケット
８水密バルクヘッド
１１バルブ
１２注水配管
１３加圧ポンプ配管
１４エア抜き装置
１５加圧ポンプ
１６仮受け材
１７通路隔壁
１８重ね鋼板
１８ａ重ね鋼板
１８ｂ重ね鋼板
１９ブラケット
２０コンクリート
２１仮止め
２２袋詰めモルタル
２３形鋼連結材
２４ガイド
２５支承ジャッキ受け
２６支承ジャッキ
２７引き寄せジャッキ
２８既設函Ａの端部バルクヘッド
２９間隙
３０コンクリート
３０ａコンクリート
３１既設函Ｂの端部バルクヘッド
３２排水ポンプ
３３内側鋼板
３４基盤[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a final box for constructing a buried box by sequentially laying and joining a large number of boxes on a water bottom, and to a final joining method of the buried box using the final box.
[0002]
[Prior art]
In the conventional method of final joining of a buried box, a formwork is set around the buried box of the part to be joined and underwater concrete is poured, or a connecting body is slid in the buried buried box. In this case, means for final joining was used.
[0003]
However, these methods have poor workability and require a long construction period, and work is difficult when the water depth is deep. Therefore, various improved techniques have been proposed.
[0004]
For example, Japanese Unexamined Patent Application Publication No. 5-44396 (Patent Document 1) discloses an existing box having a flexible joint and having an end face of an existing box of a final joint portion facing each other and having a shape adapted to the taper. A wedge-shaped connecting block (final box) is inserted and installed, and the ends are brought into close contact with each other by water pressure. Then, the inside of the box is dried and joined to the connecting cable with concrete in place. In addition to the above, many proposals have been made for the final box having a wedge shape, such as JP-A-2000-240078 (Patent Document 2).
[0005]
JP-A-6-228971 (Patent Document 3) discloses that (A) the cross-sectional shape is almost the same as that of an immersed box, and (B) a partition wall provided with an openable and closable drain pipe is provided substantially in the center. (C) two boxes having a rubber gasket mounted on one end face are engaged with each other with an extendable flexible joint wrapped with a water-impermeable flexible material between the other end faces, (D) An openable and closable water injection pipe opened through a peripheral wall and opened in a central chamber surrounded by two partition walls and a box peripheral wall, and (E) an openable and closable injection pipe in a flexible joint portion. A connecting box (final box) for connecting a buried box in which is disposed is disclosed. A similar one is disclosed in Japanese Patent Laid-Open No. 6-240682 (Patent Document 4).
[0006]
[Patent Document 1]
JP-A-5-44396 [Patent Document 2]
Japanese Patent Application Laid-Open No. 2000-240078 [Patent Document 3]
JP-A-6-228971 [Patent Document 4]
JP-A-6-240682
[Problems to be solved by the invention]
The above-mentioned prior art disclosed in Japanese Patent Application Laid-Open No. 5-44396 can be constructed even in deep water, and quality and safety management are said to be easy. However, in underwater construction, it is difficult to ensure high construction accuracy, and the installation of existing boxes is likely to shift. For this reason, when the wedge-shaped connecting block having the same taper shape is inserted along the tapered end face of the existing box, it is difficult to join them in an accurate manner.
[0008]
On the other hand, the prior art disclosed in Japanese Patent Application Laid-Open No. 6-228971 has an advantage that the connection box is provided with a flexible joint which can expand and contract, so that even if the existing box has some deviation, it can be absorbed.
[0009]
However, the structure of the flexible joint disclosed in this publication is not clear, and the water-impermeable flexible material surrounding the flexible joint is made of thick fabric or synthetic resin. When the chamber is in a dry state, large deformation occurs due to external water pressure outside the box. In addition, water is generated by injecting water outside the box of the flexible joint into the central chamber, but since the water pressure inside the central chamber does not exceed the water pressure outside the partition, the flexible joint of the connection box must be It cannot be stretched.
[0010]
For this reason, in order to press the rubber gasket at the joint end into a water-stop state by pressing, a means such as a drawing jack must be separately used.
[0011]
The present invention solves the above-mentioned problems of the prior art, and provides a structure of a final box capable of easily joining a final box and an existing box, and a final joining method of a submerged box using the final box.
[0012]
[Means for Solving the Problems]
The final box structure of the submerged box according to the present invention is:
In the final box for final joining inserted and installed between the existing boxes A and B, the final box is divided in the axial direction, and the divided two boxes are joined along the peripheral wall by an expansion joint having a water-blocking property. A submersible pressurizing chamber provided with a bulkhead in a box positioned on both sides of the expansion joint and capable of pouring and draining water, and a pressurizing pump for increasing a water pressure in the pressurizing chamber higher than an external water pressure. This is the last box.
As the expansion joint, it is desirable to use a bellows in which a steel plate is formed in a corrugated shape.
[0013]
In addition, the final joining method of the submerged box according to the present invention,
This is a final joining method of a buried box in which the last box is inserted between the existing boxes A and B and joined. The final box used for the final joining of the buried box is divided in the axial direction, and the divided two boxes are separated. Combined with expansion joints having water blocking properties along the peripheral wall, a bulkhead is provided in a box located on both sides of the expansion joint to form a pressurized chamber capable of pouring and discharging, and the water pressure in the pressurized chamber is higher than the external water pressure. Using a final box equipped with a pressurizing pump, a submerged box is finally joined in the following steps.
1. The final box temporarily fixed in a state where the expansion joint is contracted is sunk between the existing boxes A and B,
2. Pull one end of the final box to the existing box A side and join the ends together,
3. After releasing the temporary fixing of the expansion joint, the expansion joint is extended by injecting water into the pressurized chamber and increasing the water pressure in the pressurized chamber to be higher than the external water pressure,
4. The other end of the final box is brought into contact with the end of the existing box B in a water-stop state,
5. After draining the water between the end of the final box and the bulkhead of the existing box B, the ends are joined together,
6. After draining the water in the pressurized chamber, dismantle and remove the bulkhead of the pressurized chamber,
7. The peripheral walls of the expansion joint are joined.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the final box structure of the submerged box used in the present invention will be described.
[0015]
FIG. 1 is an embodiment of the final box 1 according to claim 1 of the present invention, and is a longitudinal sectional view showing the entirety of the final box 1 during construction between the existing box A and the existing box B, and FIG. It is the detail of the expansion joint part 4 which is the principal part of this invention. FIG. 3 is a cross section of the final box 1 showing the arrangement of the expansion joint 3.
As shown in FIG. 1, the overall shape of the final box 1 used in the present invention is such that the axially divided boxes 1a and 1b are connected along the peripheral wall 2 by an expansion joint 3, and the expansion and contraction provided with the expansion joint 3 The inside of the box of the joint part 4 is a pressure chamber 6 partitioned by watertight bulkheads 5a and 5b. The length of the final box 1 in the axial direction is such that the expansion joint 3 can be inserted between the existing boxes A and B with a margin while the expansion joint 3 is contracted, and can be joined to the existing boxes A and B when the expansion joint 3 is extended. I do. A rubber gasket 7 for stopping water is provided between the existing boxes A and B and the final box 1 along one of the peripheral walls.
[0016]
The end face of the final box 1 in the axial direction may be vertical or diagonal at both ends (inclined surface). However, as shown in FIG. 1, one end is inclined and the other (expansion joint side) is vertical. It is advantageous in terms of work.
Further, the division position (expansion joint position) of the final box 1 may be provided at any position in the middle of the final box 1 in the axial direction of the final box 1. However, as shown in FIG. It is desirable to provide them from the viewpoint of structural stability during construction.
[0017]
One end of the final box 1 has a surface facing the end inclined surface of the existing box A as a parallel inclined surface (an inclined surface having one box end surface protruding downward and outward and facing the same). The other box end face is a reversely inclined surface that is recessed in the middle part of the box downwards), and a watertight bulkhead 8 is provided. Since the joining of the ends is performed by a known means, detailed description is omitted.
[0018]
FIG. 2 shows details of the vicinity of the expansion joint portion 4 of the final box 1 in the present invention. A short box 1b is arranged at an end of a box 1a obtained by dividing the final box 1, and is provided along the peripheral wall 2. The expansion joint 3 is connected in a watertight manner.
[0019]
Watertight bulkheads 5a and 5b are provided in the box 1a and the box 1b with the expansion joint 3 interposed therebetween, and the inside of the expansion joint part 4 is a pressurized chamber 6. The bulkhead 5b on the side of the box 1b also serves as the end bulkhead of the final box 1. The inside of the pressurizing chamber 6 is capable of pouring and draining water, and an external water pouring pipe 12 with a valve 11, a valve 13a at an end of the pressurizing pump pipe 13 or a valve 13a at the end thereof and air for enabling pressurization of the injected water. A punching device 14 is provided. The air venting device 14 includes a pipe disposed in the pressurizing chamber 6 and a valve disposed in the box 1a at an end of the pipe.
[0020]
The pressurizing pump pipe 13 is connected to a pressurizing pump 15 that can supply water at a pressure higher than the water pressure at the installation depth of the submerged box.
[0021]
At the upper end of the final box 1, a temporary receiving material 16 is fixedly protruded toward the existing box B side. Since the temporary receiving member 16 serves as a stopper for positioning the final box 1 at the time of sinking, the temporary receiving member 16 needs to have a length such that the end can be supported by the upper end of the existing box B with the expansion joint 3 contracted.
[0022]
Also, in order to reduce the frictional resistance generated when the water injected into the pressurizing chamber 6 is pressurized to extend the expansion joint 3 and move the box 1b toward the existing box B, It is better to apply a sliding material to the lower side of the protrusion.
[0023]
FIG. 3 shows an arrangement of the expansion joint 3 in a cross section of the boxes 1a and 1b. The expansion joint 3a provided on the passage partition inside the box in the figure is for ensuring the connection strength of the divided boxes 1a and 1b.
[0024]
The expansion joint 3 must be watertight, exhibit a predetermined amount of expansion and contraction, have appropriate rigidity during construction, and be hardly deformed by external water pressure. It is desirable to adopt a steel bellows that meets this condition.
[0025]
If a steel bellows is used, complete water stoppage can be obtained by welding the end of the steel bellows, and by selecting the thickness, height, and number of bending ridges of the steel sheet, the required expansion amount, rigidity, and pressure resistance can be reduced. Can be set easily. Note that another expansion joint may be used as long as the above condition is satisfied.
[0026]
FIGS. 5 (a) and 5 (b) show a steel bellows 3a having three inner ridges and two outer ridges manufactured by bending a steel plate. The expansion joint 3 has a contracted state (a) and an expanded state (b). ). The steel bellows (expansion joint) 3a (3) is water-tightly and firmly fixed to the ends of the boxes 1a and 1b by welding or the like.
[0027]
The two laminated steel plates 18a and 18b provided at the lower part of the steel bellows 3a shown in FIG. 5 are outer steel plates when the expansion joint portion 4 is finally rigidly connected. One end is fixed to the box so that the steel bellows 3a can be freely extended, and the two steel plates 18a and 18b are fixed by welding when the joint is rigidly connected. Note that a butt steel plate 18c may be separately inserted between the front end of the lap steel plate 18b and the box and butt-welded (in this case, the lap steel plate 18a becomes a backing material).
[0028]
The steel plate 18a is supported by a bracket 19, and also has a role of preventing the steel bellows 3a from being deformed by an external pressure. Further, the bracket 19 also functions as a shear reinforcing material when concrete 20 is injected into the expansion joint portion 4 and rigidly connected.
[0029]
When the final box 1 is settled, the expansion joint 3 becomes a weak point during the construction, and there is a fear of damage. For this reason, it is desirable that the box 1a and the box 1b be temporarily joined to each other in the expansion joint portion 4 so as to be constructed safely.
[0030]
3 and 4 show the arrangement of the temporary fixing 21 on the boxes 1a and 1b of the expansion joint part 4. FIG.
The temporary fixing means 21 uses a bagged mortar 22 for preventing compression deformation and a shaped steel connecting member 23 for preventing tension and bending deformation.
[0031]
In the state where the expansion joint 3 is contracted, the temporary fixing 21 arranges the bag-filled mortar 22 in the space between the end surfaces of the box 1a and the box 1b of the expansion joint part 4 at appropriate intervals. Each of the passage partition walls 17 of the box 1a and the box 1b is connected and fixed by a connecting member 23 of a section steel (for example, channel steel 300 * 90).
The temporary fixing 21 is removed before the expansion joint 3 is extended.
[0032]
When the final box 1 is settled, a guide 24 is used for guiding between the existing boxes A and B for easy positioning, and a known guide 24 is used for any of the existing boxes A and B and the final box 1. The detailed description is omitted.
[0033]
A rubber gasket 7 for waterproofing is provided on the end peripheral walls of the existing boxes A and B and the final box 1, and a known rubber gasket 7 is used. It may be provided on any one side.
[0034]
Next, the steps (procedure) of the final joining method of the submerged box according to the present invention will be described. An embodiment of the final joining method of a submerged box according to claim 3 is performed by the following steps using the final box 1 having the above-described structure. (See FIGS. 6A to 8G)
{Circle around (1)} A support jack receiver 25 is provided at a predetermined location on the base on which the final box 1 for the preparatory work is installed. (See FIG. 6 (a))
{Circle around (2)} Settling of the final box The final box 1, which has been towed offshore, is suspended by a crane ship or sinking boat (not shown), and sinks by adjusting ballast in the boxes 1a and 1b. The sedimentation is performed while accurately adjusting the position by the guides 24 provided at the ends of the existing boxes A and B or the final box 1. (See FIG. 6 (a))
(3) Landing of the final box is completed. The settled final box 1 has one end on the existing box A side supported by the support jack 26 and the other end fixed to the upper end of the final box by the temporary receiving material 16 at the upper end of the existing box B. To support. (See FIG. 6B)
{Circle around (4)} The final box 1 is drawn to the end of the existing box A. The end of the final box 1 is moved to the existing box A side by the pulling jack 27, and the rubber interposed between the existing box A and the outer peripheral end of the final box 1 is moved. The gasket 7 is set to a state where water can be stopped. Thereafter, the water between the bulkhead 8 at one end of the final box 1 facing the end bulkhead 28 of the existing box A is drained. As a result, the end of the final box 1 and the end of the existing box A are brought into pressure contact with each other via the rubber gasket 7 by the water pressure acting on the other end side bulkhead 5b of the final box 1. (Known jack drawing hydraulic joining means) (see FIG. 7 (c)). (5) Provided between one end of the final box 1 and the end of the existing final box 1 and the end of the existing box A. When the rubber gasket 7 is compressed into a predetermined shape and a water-stop state can be secured, the bulkheads 28 and 8 of both boxes A and 1 are cut off and removed, and the end of the final box 1 and the end of the existing box A are allowed. Joining is performed by any known joining means such as flexible joining or rigid joining.
Next, concrete 30 is poured into the gap 29 between the bottom surface of the final box 1 and the base 34 up to just before the expansion joint 3 to support the final box 1. (See Fig. 7 (d))
[0035]
(6) Extend the other end of the final box 1 to the existing box B (extend the expansion joint)
Next, the temporary fixing 21 of the expansion joint 3 in the pressurizing chamber 6 is released, and the expansion joint 3 is set in a state where it can be extended. In addition, since it is necessary to work inside the pressurizing chamber 6, it is necessary to provide an entrance (not shown) capable of stopping water in the box inner bulkhead 5a of the box 1a.
[0036]
After the temporary stop 21 of the expansion joint 3 is released, the box inner bulkhead 5a is brought into a water-stop state, and then the valve of the air release device 14 is opened into the pressurizing chamber 6, and water is injected while releasing air. (As the water injection means, the valve of the water injection pipe 12 provided outside the final box 1 is opened to inject the water, or the pressure injection pump 15 is used) (see FIG. 8 (e)).
[0037]
When the water injection into the pressurizing chamber 6 is completed, a pressure difference is applied by the pressurizing pump 15 so that the water pressure in the pressurizing chamber 6 becomes higher than the external water pressure of the end bulkhead 5b of the final box 1. This differential pressure causes a spreading force on the surface of the bulkhead, and when the spring strength of the expansion joint (bellows) 3 becomes greater than the spring strength, the expansion joint 3 expands, and the overall length of the final box 1 increases, and the end of the existing box B ends. The rubber gasket 7 provided between the portion and the outer peripheral end of the final box 1 can be compressed and deformed to secure the water stopping state. (See FIG. 8 (f))
[0038]
It is necessary to determine the magnitude of the differential pressure according to conditions such as the size of the bulkhead surface of the pressurizing chamber 6, the installation depth of the submerged box (1, B), the spring strength (resistance) of the expansion joint 3, and the like. (For example, when installing a large buried box at a water depth of 20 m, the differential pressure may be about 0.02 to 0.1 Mpa).
[0039]
{Circle around (7)} Joining the other end of the final box 1 to the existing box B If the end of the existing box B and the outer peripheral end of the final box 1 can secure the water-stop condition with the rubber gasket 7, the end bulk of the existing box B The water between the head 31 and the bulkhead 5b on the other end of the final box 1 is drained by the drain pump 32. Due to the drainage between the bulkheads 31 and 5b, the pressure difference in the pressurizing chamber 6 increases, and the end of the existing box B and the outer peripheral end of the final box 1 are more firmly connected via the rubber gasket 7 due to the hydraulic joining action. Is pressed against.
Next, the bulkhead 31 of the existing box B is cut and removed, and the end of the final box 1 and the end of the existing box B are joined by any known joining means such as flexible joining or rigid joining. (See FIG. 8 (g))
[0040]
{Circle around (8)} After the water in the joint pressurizing chamber 6 of the expansion joint is drained using the pressurizing pump 15 in the opposite direction or using the drainage pump 32, the bulkheads 31 and 5b on both sides are cut and removed. Then, the expansion joint part 4 is connected.
The connection may employ either rigid connection means or flexible connection means. In the drawing, reference numeral 35 denotes an air vent pipe with a valve provided on the bulkhead 31 of the existing box B, and reference numeral 36 denotes a relief valve.
[0041]
In the case of employing the rigid coupling means, the outer steel plates 18a and 18b provided inside the expansion joint portion 4 of the housing peripheral wall 2 are fixed by welding, and the inner steel plate 33 is welded to the inner surface of the housing to divide the housing 1a. , 1b (see FIG. 5b). Although not shown, the inner steel plate 33 is formed by stacking two steel plates and slidable. One end is fixed to each of the split boxes 1a and 1b, and the inner steel plate 33 slides when the expansion joint 3 is extended. In the case where the above is provided in advance, the steel plates overlapped in the final extension state of the expansion joint 3 are fixed by fillet welding and joined, or a butt steel plate is inserted and butt welded. Join.
[0042]
In addition, between the outer steel plate 18 (18a, 18b) and the inner steel plate 33, a shaped steel or a steel plate or a dowel for shear reinforcement is provided, and a part thereof is welded and connected to the outer steel plate 18 and the inner steel plate 33.
[0043]
Next, the high-fluidity concrete 20 is injected and filled between the outer steel plate 18 and the inner steel plate 33 using the injection pipe 12 that has been piped in advance. As a result, after the concrete hardens, the expansion joint 4 is rigidly connected. (FIG. 5 (b))
[0044]
When the flexible coupling means is employed, although not shown, the expansion joint 3 is used as a primary water-stop material, a secondary water-stop rubber is attached inside the box, and a leaf spring, a hydraulic damper, etc. (A detailed description is omitted).
[0045]
Next, concrete 30a is poured into the gap 29 between the bottom surface of the final box 1 and the base 34, and the joining of the final box 1 is completed to complete the sinking box. (See FIG. 8 (g))
[0046]
【Example】
Hereinafter, specific examples of the final box of the present invention will be described.
In the final joining of a submerged box constructed by joining eight large steel / concrete composite submerged boxes with a width of 30-40 m, a height of 10 m, and a length of 100 m to the seabed at a depth of 30 m,
(1) Final Box The final box (1) having the same shape as that of FIG. 1 described in the above embodiment is divided into a long box 1a and a short box 1b having one end inclined. The end is divided), and the bellows 3a is connected by the expansion joint 3 of the bellows 3a.
(2) The expansion joint steel bellows 3a is made of a steel plate having a thickness of 12 mm and is formed into a wave shape with two outer ridges and three inner ridges, a wave height of 300 mm, a length in the expansion and contraction direction of 540 mm when reduced, and a maximum extension of 860 mm. Extendable up to (Design extension length is 320mm)
[0047]
(3) Pressurizing Pump The pressurizing pump 15 uses a Hugal pump 37KW of 4 m ³ / min at a pressure of 0.3 Mpa and 1 m ³ / min at a pressure of 0.45 Mpa.
(4) The pressurized water pressure in the pressurized chamber 6 when the pressurized hydraulic joint of the pressurized chamber is extended is set to 0.35 Mpa, which is higher than the external pressure 0.3 Mpa (water deep pressure), and a differential pressure of 0.05 Mpa is applied.
[0048]
【The invention's effect】
In the present invention, in the final box for final joining inserted and installed between the existing boxes A and B, the final box is divided in the axial direction, and both of the divided boxes are stretched and stretched along the peripheral wall so as to have a waterproof property. A submerged box provided with a bulkhead in a box located on both sides of the expansion joint to form a pressurized chamber that can be poured and drained, and a pressurized pump that makes the water pressure in the pressurized chamber higher than the external water pressure Since the final box of the present invention is used, the expansion joint on the side of the final box can be extended with a simple configuration, and the final box can be easily joined to the existing box.
[0049]
Also, in the present invention, a final joining method of a submerged box in which a final box is inserted between the existing boxes A and B and joined, wherein the final box used for final joining of the submerged box is divided in the axial direction, and this division is performed. The two casings are joined together by an expansion joint having a water blocking property along the peripheral wall, and a watertight bulkhead is provided in a casing located on both sides of the expansion joint to form a pressurized chamber capable of pouring and discharging, and the inside of the pressurized chamber. Using the final box that can pressurize the water pressure,
The water is injected into the pressurized chamber, the water pressure in the pressurized chamber is made higher than the external water pressure to extend the expansion joint, and the other end of the final box is brought into contact with the end of the existing box B in a water-stopped state, and the end After joining them together, the connecting steel plate is fixed to the peripheral wall of the expansion joint, and concrete is injected.
Easy to apply the final box inserted between the existing boxes by applying pressurized water pressure to the pressurizing chamber of the expansion joint to extend the length of the final box and to match the end of the existing box with the end of the final box. The final joining of the buried box can be performed by a simple operation.
[0050]
Furthermore, if a steel bellows is used for the expansion joint, complete water stoppage can be obtained by welding the ends, and the required expansion and contraction amount, rigidity, The pressure resistance can be easily set, and even if there is a large gap in the existing box, it can be handled.
[Brief description of the drawings]
FIG. 1 is an embodiment of a final box according to the present invention, and is a longitudinal sectional view showing the entirety of a final box being constructed between an existing box A and an existing box B;
FIG. 2 is a detailed view of an expansion joint which is a main part of the present invention.
FIG. 3 is a cross-sectional view of a final box showing an arrangement of expansion joints.
FIG. 4 is a sectional view taken along line AA of FIG. 3;
FIG. 5 shows a contracted state and an expanded state of an expansion joint using a steel bellows.
6 (a) and 6 (b) are process explanatory views of a final joining method of a submerged box according to the present invention.
FIGS. 7 (c) to 7 (d) are process explanatory views of the final joining method of the buried box according to the present invention.
FIGS. 8 (e) to 8 (g) are process explanatory views of the final joining method of the buried box according to the present invention.
[Explanation of symbols]
A Existing Box B Existing Box 1 Final Box 1a Box 1b Box 2 Perimeter Wall 3 Expansion Joint 4 Expansion Joint 5a Watertight Bulkhead 5b Watertight Bulkhead 6 Pressurizing Room 7 Rubber Gasket 8 Watertight Bulkhead 11 Valve 12 Water Injection Pipe 13 Addition Pressure pump pipe 14 Air release device 15 Pressurizing pump 16 Temporary receiving material 17 Passage bulkhead 18 Stacked steel plate 18a Stacked steel plate 18b Stacked steel plate 19 Bracket 20 Concrete 21 Temporary fixing 22 Bagged mortar 23 Shaped steel connecting member 24 Guide 25 Bearing jack receiver 26 Bearing jack 27 Pulling jack 28 End bulkhead 29 of existing box A Gap 30 Concrete 30a Concrete 31 End bulkhead of existing box B 32 Drain pump 33 Inner steel plate 34 Base

Claims

In the final box for final joining inserted and installed between the existing boxes A and B, the final box is divided in the axial direction, and the divided two boxes are joined along the peripheral wall by an expansion joint having a water-blocking property. A submersible pressurizing chamber provided with a bulkhead in a box positioned on both sides of the expansion joint and capable of pouring and draining water, and a pressurizing pump for increasing a water pressure in the pressurizing chamber higher than an external water pressure. The last box of the box.

The final box of the submerged box according to claim 1, wherein a bellows formed by corrugating a steel plate is used as the expansion joint.

This is a final joining method for a buried box in which a final box is inserted between the existing boxes A and B and joined. The final box used for final joining of the buried box is divided in the axial direction. Combined with expansion joints having water blocking properties along the peripheral wall, a bulkhead is provided in a box located on both sides of the expansion joint to form a pressurized chamber capable of pouring and discharging, and the water pressure in the pressurized chamber is higher than the external water pressure. Using a final box equipped with a pressurizing pump
1. The final box temporarily fixed in a state where the expansion joint is contracted is sunk between the existing boxes A and B,
2. Pull one end of the final box to the existing box A side and join the ends together,
3. After releasing the temporary fixing of the expansion joint, the expansion joint is extended by injecting water into the pressurized chamber so that the water pressure in the pressurized chamber is higher than the external water pressure,
4. The other end of the final box is brought into contact with the end of the existing box B in a still water state,
5. After draining the water between the end of the final box and the bulkhead of the existing box B, the ends are joined together,
6. After draining the water in the pressurized chamber, dismantle and remove the bulkhead of the pressurized chamber,
7. A final joining method of a buried box, wherein peripheral walls of the expansion joint are joined.