JP2004169367A

JP2004169367A - Shield machine for partial hard ground, method for excavating partial hard ground and tunnel construction method for partial hard ground

Info

Publication number: JP2004169367A
Application number: JP2002335171A
Authority: JP
Inventors: Osamu Urata; 修浦田; Junichi Aikawa; 潤一相川; Hiroyuki Kawaguchi; 博行川口; Shinji Seki; 伸司関; Katsumi Kadota; 克美門田; Yoshito Nakajima; 芳人中島; Hidefumi Shibuya; 英文渋谷
Original assignee: Shimizu Construction Co Ltd; IHI Corp; Shimizu Corp
Current assignee: Shimizu Construction Co Ltd; IHI Corp; Shimizu Corp
Priority date: 2002-11-19
Filing date: 2002-11-19
Publication date: 2004-06-17
Anticipated expiration: 2022-11-19
Also published as: JP4079754B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shield machine for a partial hard ground capable of realizing a stable pipe-jacking even when there is a hard ground in a part of a facing. <P>SOLUTION: In the shield machine 1 for the partial hard ground pipe-jacking a ground 7, in which there are a hard ground section 5 and a normal ground section 6 in the longitudinal direction, and cutting the facing 3 in which the hard ground section 5 and the normal ground section 6 are mixed, a rotary cutter 4 is installed to the front section of a shield machine body 2 while being opposed to the facing 3, a surface on the facing side of the cutter 4 is divided supposedly into a region X, in which only the normal ground section 6 is excavated, and a region Y, in which the normal ground section 6 and the hard ground section 5 are excavated, while being partitioned by a concentric circle centering around the center of rotation of the cutter, and a plurality of bits 18 for the hard ground are arranged so that at least one is brought into contact with the hard ground section 5 at all times during the rotation of the cutter 4 in the region Y in which the normal ground section 6 and the hard ground section 5 are excavated. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、部分硬質地盤用シールド掘進機に関する。
【０００２】
【従来の技術】
シールド掘進機として、掘進機本体の前部に切羽に対向させて回転駆動されるカッタを設け、そのカッタに複数のビット（ティースビット、ローラビット等）を取り付け、掘進機本体の内部で組み立てた既設セグメントに掘進機本体の内部に設けた推進ジャッキを押し付けて前進させるものが知られている。
【０００３】
かかる回転カッタ式のシールド掘進機よって、硬質地盤部と通常地盤部とが長手方向に配置された地山をそれらの境界に沿って掘進すると、硬質地盤部と通常地盤部とが混在する切羽（掘削断面）をカッタのビットが周回して切削することになるため、次のような問題が生じる。
【０００４】
なお、関連する先行技術として特許文献１及び２に記載されたものが知られている。
【０００５】
【特許文献１】
特許第２８４９６０５号公報
【特許文献２】
特開平９−３１７３９７号公報
【０００６】
【発明が解決しようとする課題】
硬質地盤部が切羽の一部であるため、カッタの回転に伴ってビットが硬質地盤部からそれ以外の領域（硬質地盤部よりも軟らかい地盤部）に回動すると、急激に切羽での抗力が下がってその分だけ推進ジャッキ（一定油圧制御）が伸長し、掘進機が僅かに前進する。次いで、カッタが更に回転してビットが再び硬質地盤部に回動すると、急激に切羽での抗力が上がってその分だけ推進ジャッキが収縮し、掘進機が僅かに後退する。すなわち、カッタの回転に伴って掘進機が前後に息するように微小振動する。
【０００７】
また、カッタの回転に伴ってビットが硬質地盤部からそれ以外の領域に回動して、上述のように掘進機が僅かに前進した後、ビットが再び硬質地盤部に回動して戻るとき、切羽（硬質地盤部）に対するビットの切り込み深さが深くなって、カッタトルクが急増する。そして、急増したカッタトルクの反力によって、掘進機がローリングする。
【０００８】
また、通常、方向制御のために複数の推進ジャッキの内の一部を既設セグメントに押し付けて掘進しているため、ビットの周回に伴う切羽での抗力の増減の影響が推進ジャッキが当接されたセグメントに集中的に作用し、セグメントが変形して掘進機が傾く。また、ビットの周回に伴ってセグメントの圧縮・解放が息するように繰り返され、セグメントが疲労する。
【０００９】
以上の事情を考慮して創案された本発明の目的は、切羽の一部に硬質地盤が存在しても、安定した掘進を実現できる部分硬質地盤用シールド掘進機を提供することにある。
【００１０】
【課題を解決するための手段】
上記目的を達成するために請求項１に係る発明は、硬質地盤部と通常地盤部とが長手方向に存在する地山を掘進し、硬質地盤部と通常地盤部とが混在する切羽を切削する部分硬質地盤用シールド掘進機であって、掘進機本体の前部に、切羽に対向させて回転カッタを設け、該カッタの切羽側の面を、カッタ回転中心を中心とする同心円で区切って、通常地盤部のみを掘削する領域と通常地盤部及び硬質地盤部を掘削する領域とに仮想的に分け、通常地盤部及び硬質地盤部を掘削する領域に、複数の硬質地盤用のビットをカッタの回転中に少なくとも１個が硬質地盤部に常に接するように配置したものである。
【００１１】
この発明によれば、切羽の一部に存する硬質地盤部に対し、各硬質地盤部用ビットがカッタの回転に伴って順次次々と接し、掘進機の前進力が常に１個以上の硬質地盤部用ビットを介して硬質地盤部に支持される。よって、掘進機が、カッタの回転に応じて、前後に息するように振動したり、ローリングしたり、傾いたりすることが防止され、安定した掘進を実現できる。また、セグメントの圧縮・解放も防止される。
【００１２】
請求項２に係る発明は、上記掘進機本体の内部に、既設セグメントに当接して掘進反力を支持する推進ジャッキを複数設け、それら推進ジャッキは、掘進時に全数が既設セグメントに当接するものである。
【００１３】
こうすれば、掘進機の掘進反力が全ての既設セグメントで支持されるので、特定のセグメントに力が集中することはなく、セグメントの変形が抑えられ、掘進機の傾きを抑制できる。
【００１４】
請求項３に係る発明は、上記掘進機本体の後部に、所定の裏込材地盤部の厚さに形成された円筒状のテール部を設け、該テール部に、その内方にて組み立てられた既設セグメントと掘孔との間に裏込材を注入する注入管を設けたものである。
【００１５】
こうすれば、掘進機の後方に、裏込材が固化した裏込材地盤部（硬質地盤部）が形成され、かかる硬質地盤部とその外側の通常の地盤とが長手方向に配置された地山が形成される。
【００１６】
請求項４に係る発明は、筒状に組み立てられたセグメントの外周を所定の厚さで囲繞する裏込材地盤部と該裏込材地盤部の外側の通常地盤部とからなる地山を掘進し、裏込材地盤部と通常地盤部とが混在する切羽を切削する部分硬質地盤用シールド掘進機であって、掘進機本体の前部に、切羽に対向させて回転カッタを設け、該カッタの切羽側の面を、カッタ回転中心を中心とする同心円で区切って、通常地盤部のみを掘削する領域と通常地盤部及び裏込材地盤部を掘削する領域とに仮想的に分け、通常地盤部及び裏込材地盤部を掘削する領域に、複数の硬質地盤用のビットをカッタの回転中に少なくとも１個が裏込材地盤部に常に接するように配置したものである。
【００１７】
この発明によれば、切羽の一部に存する裏込材地盤部（硬質地盤部）に対し、各硬質地盤部用ビットがカッタの回転に伴って順次次々と接し、掘進機の前進力が常に１個以上の硬質地盤部用ビットを介して裏込材地盤部に支持される。よって、掘進機が、カッタの回転に応じて、前後に息するように振動したり、ローリングしたり、傾いたりすることが防止され、安定した掘進を実現できる。また、セグメントの圧縮・解放も防止される。
【００１８】
請求項５に係る発明は、筒状に組み立てられたセグメントの外周を所定の厚さで囲繞する裏込材地盤部と該裏込材地盤部の外側の通常地盤部とからなる地山を掘進し、裏込材地盤部と通常地盤部とが混在する切羽を切削する部分硬質地盤用シールド掘進機であって、掘進機本体の内部に、当該内部で組み立てられた既設セグメントに当接して掘進反力を支持する推進ジャッキを複数設け、それら推進ジャッキは、掘進時に全数が既設セグメントに当接するものである。
【００１９】
この発明によれば、掘進機の掘進反力が全ての既設セグメントで支持されるので、特定のセグメントに力が集中することはなく、セグメントの変形が抑えられ、掘進機の傾きを抑制できる。
【００２０】
請求項６に係る発明は、筒状に組み立てられたセグメントの外周を所定の厚さで囲繞する裏込材地盤部と該裏込材地盤部の外側の通常地盤部とからなる地山を掘進し、裏込材地盤部と通常地盤部とが混在する切羽を切削する部分硬質地盤用シールド掘進機であって、掘進機本体の前部に、切羽に対向させて回転カッタを設け、該カッタの切羽側の面を、カッタ回転中心を中心とする同心円で区切って、通常地盤部のみを掘削する領域と通常地盤部及び裏込材地盤部を掘削する領域とに仮想的に分け、通常地盤部及び裏込材地盤部を掘削する領域に、複数の硬質地盤用のビットをカッタの回転中に少なくとも１個が裏込材地盤部に常に接するように配置し、上記掘進機本体の内部に、当該内部で組み立てられた既設セグメントに当接して掘進反力を支持する推進ジャッキを複数設け、それら推進ジャッキは、掘進時に全数が既設セグメントに当接するものである。
【００２１】
この発明によれば、切羽の一部に存する裏込材地盤部に対し、各硬質地盤部用ビットがカッタの回転に伴って順次次々と接し、掘進機の前進力が常に１個以上の硬質地盤部用ビットを介して裏込材地盤部に支持される。よって、掘進機が、カッタの回転に応じて、前後に息するように振動したり、ローリングしたり、傾いたりすることが防止され、安定した掘進を実現できる。また、セグメントの圧縮・解放も防止される。また、掘進機の掘進反力が全ての既設セグメントで支持されるので、特定のセグメントに力が集中することはなく、セグメントの変形が抑えられ、掘進機の傾きを抑制できる。
【００２２】
請求項７に係る発明は、硬質地盤部と通常地盤部とが混在する切羽を掘進機本体の前部に設けた回転カッタによって切削する部分硬質地盤の掘削方法であって、カッタの切羽側の面を、カッタ回転中心を中心とする同心円で区切って、通常地盤部のみを掘削する領域と通常地盤部及び裏込材地盤部を掘削する領域とに仮想的に分け、通常地盤部及び裏込材地盤部を掘削する領域に複数取り付けた硬質地盤用のビットを、カッタの回転中に少なくとも１個を切羽の硬質地盤部に押し付け、掘進機本体の前進力をその硬質地盤用のビットを介して裏込材地盤部に常に支持させるものである。
【００２３】
請求項８に係る発明は、筒状に組み立てられたセグメントの外周を所定の厚さで囲繞する裏込材地盤部と該裏込材地盤部の外側の通常地盤部とからなる地山を掘進し、裏込材地盤部と通常地盤部とが混在する切羽を切削する部分硬質地盤のトンネル築造方法であって、請求項１に係る掘進機を用いて、セグメントの組み立てと共に所定厚さの円筒状のテール部から裏込材を注入して裏込材地盤部を形成しながら掘削する際に、掘進機の推進ジャッキを全数既設セグメントに当接することで掘削制御を行いつつ掘進してトンネルを築造するものである。
【００２４】
【発明の実施の形態】
本発明の一実施形態を添付図面に基いて説明する。
【００２５】
図１に本実施形態に係る部分硬質地盤用シールド掘進機の側断面図を示し、図２に上記掘進機の正面図を示し、図３に上記掘進機の背面図を示す。
【００２６】
図示するように、本実施形態に係る部分硬質地盤用シールド掘進機１は、掘進機本体２の前部に、切羽３に対向させて回転駆動されるカッタ４を備えており、図５に示すように硬質地盤部５と通常地盤部６とが長手方向に配置された地山７をそれらの境界に沿って掘進し、硬質地盤部５と通常地盤部６とが混在する切羽３を切削するものである。
【００２７】
図１に示すように、上記掘削機本体２は、円筒状のシールドフレーム８と、その内部を切羽側と坑内側とに仕切る隔壁９とを有する。シールドフレーム８は、図例では、円筒状の前胴１０と後胴１１とを球面継手１２を介して接続し、それら前胴１０と後胴１１とを中折れジャッキ１３で屈曲させる所謂中折れタイプのものを示したが、通常の中折れしないタイプであってもよい。
【００２８】
上記カッタ４は、隔壁９に回転自在に取り付けられており、図示しないモータ及びギヤ機構等を介して回転駆動される。図２に示すように、カッタ４は、切羽３に対向する円板状のカッタ面板１４を有する。カッタ面板１４には、掘削土砂を通過させる土砂取込口１５が開口されている。なお、カッタ４は、図例のような面板タイプではなく、スポークタイプであってもよい。
【００２９】
図１に示す隔壁９には、掘削土砂を坑内に移送する図示しない排土装置（送泥管・排泥管、又はスクリューコンベヤ等）が取り付けられている。よって、回転するカッタ４によって切削された切羽３の土砂は、土砂取込口１５から一旦その後方のカッタ室１６に取り込まれ、切羽３の土圧水圧を保ちつつ排土装置によって坑内に移送される。
【００３０】
カッタ面板１４の切羽側の面には、複数の通常地盤部用ビット１７（ティースビット）と、複数の硬質地盤部用ビット１８（ローラビット、シェルビット又は先行ビット等）とが、取り付けられている。これらのビット１７、１８が、実質的に切羽３を切削する。
【００３１】
図２に示すように、硬質地盤部用ビット１８は、カッタ面板１４がその回転に伴って硬質地盤部５とラップする領域（カッタ面板１４の外周部）に配置され、カッタ４の回転中に少なくとも１個以上が切羽３の硬質地盤部５に対向するように分散されている。すなわち、硬質地盤部用ビット１８は、カッタ４の回転中に少なくとも１個以上が切羽３の硬質地盤部５に掘進機本体２の前進力を支持するように、カッタ面板１４の外周部に分散して取り付けられている。
【００３２】
換言すると、図１、図２及び図５に示すように、カッタ面板１４の切羽側の面を、カッタ回転中心を中心とする同心円Ｚで区切って、通常地盤部６のみを掘削する領域Ｘ（内周側領域）と通常地盤部６及び硬質地盤部５を掘削する領域Ｙ（外周側領域）とに仮想的に分け（図２（ｂ）、図５参照）、通常地盤部６及び硬質地盤部５を掘削する領域Ｙに、複数の硬質地盤用のビット１８をカッタ面板１４の回転中に少なくとも１個が硬質地盤部５に常に接するように分散配置している。図２（ａ）における符合Ｘ、Ｙは、各領域の半径方向の長さを示す。
【００３３】
通常地盤部６及び硬質地盤部５を掘削する領域Ｙには、硬質地盤部用ビット１８としてのローラビット１８のみならず、それより僅かに低く成形されたティースビット１８ｘも取り付けられている。各ローラビット１８で切羽３の硬質地盤部５を含む部分に同心円状の切り込みを複数形成しつつ、各ティースビット１８ｘで切羽３の各切り込みの間の部分を切削するためである。
【００３４】
そして、このローラビット１８が、カッタ４の回転中に少なくとも１個以上が切羽３の硬質地盤部５に対向するように分散配置されるわけである。ローラビット１８は、ティースビット１８ｘよりも僅かに切羽３側に突出されており、硬質地盤部５に対して実質的に掘進機本体２の前進力を支持するからである。
【００３５】
他方、通常地盤部６のみを掘削する領域Ｘには、通常地盤部用ビット１７（ティースビット１７）が、複数取り付けられている。すなわち、通常地盤部用ビット１７は、カッタ４の回転中に常に図５に示す通常地盤部６に対向する位置に、カッタ面板１４の内周側領域に分散して取り付けられている。
【００３６】
なお、領域Ｘに硬質地盤部５用のビット（図示せず）を設け、領域Ｙに通常地盤部６用の通常のビット（図示せず）を設けてもよい。現実の施工では、同心円Ｚを厳密に設定し難いため、領域Ｘにて硬質地盤部５を掘削し、領域Ｙで通常地盤部６のみを掘削する場合があり得るからである。
【００３７】
詳しくは、領域Ｘ内の外周側に硬質地盤部５用のビット（図示せず）を設け、領域Ｙ内の内周側に通常地盤部６用の通常のビットを設け、同心円Ｚに沿って周方向に所定幅の硬質地盤部５及び通常地盤部６の双方に対応できる領域を設定することが好ましい。
【００３８】
掘進機本体２の後部である後胴１１は、所定の厚さに成形された円筒状のテール部１９の一部を構成する。テール部１９は、円筒状に形成された後胴１１と、その内部に放射状に設けられた補強リブ２０と、前記補強リブ２０の内方先端に取り付けられた円筒状の内筒２１と、内筒２１と後胴１１との後端部を覆う円環板状の蓋２２とを有する。
【００３９】
内筒２１と後胴１１との間の厚さすなわち上述の所定の厚さとは、図４及び図５に示す裏込材地盤部すなわち硬質地盤部５の厚さであり、その硬質地盤部５を別の掘進機１が後方からラップして掘進するときのラップ代となる厚さである。このラップ代は、別の掘進機１が後方からラップして掘進する際に、掘進精度上の問題から既設セグメント２３に接触しない厚さに設定されている。
【００４０】
内筒２１の内側には、セグメント２３をリング状に組み立てるエレクタ（図示せず）が設けられている。また、内筒２１の後部内周面には、既設のセグメント２３との間をシールするテールシール２４が設けられている。エレクタは、テールシール２４で止水された既設セグメント２３の前方の空間にて、新たなセグメント２３を組み立てる。
【００４１】
内筒２１と後胴１１との間には、既設セグメント２３の外周面２５と掘孔３０の内周面２６との間すなわちテールボイド２７に、裏込材（モルタル等）を注入するための注入管２８が設けられている。注入管２８は、図３にも示すように、周方向に所定間隔を隔てて複数（図例では４本）設けられており、それぞれ蓋２２に吐出口２８ａを有する。
【００４２】
シールドフレーム８の内部には、図１に示すように、既設セグメント２３に当接して掘進反力を支持する推進ジャッキ２９が複数設けられている。これら推進ジャッキ２９は、図３に示すように、周方向に所定間隔を隔てて複数（図例では１０本）設けられており、掘進時に全数が既設セグメント２３に当接する。
【００４３】
すなわち、各推進ジャッキ２９の油圧回路は、全数押し式（全数追従式）の回路となっている。なお、全数押しとはいっても、各ジャッキ２９の押し力を異ならせることで、掘進機１の方向制御を行う。つまり、油圧回路には、公知の圧力制御方式やジャッキパターン制御方式等が用いられている。
【００４４】
次に本シールド掘進機を用いたトンネル築造方法を述べる。
【００４５】
予め、図１〜図３に示すシールド掘進機１と同種の掘進機（硬質地盤部用ビット１８を有さないタイプ）を通常の地山に掘進させて、図４に示すように、筒状に組み立てられたセグメント２３の外周をテールボイド２７の厚さで囲繞する固化後の裏込材からなる裏込材地盤部５（以下硬質地盤部５という）と、その外側の通常の地盤からなる通常地盤部６とから構成される地山７を形成しておく。
【００４６】
その後、図５及び図２に示すように、図１〜図３に示すシールド掘進機１を、地山７の硬質地盤部５と通常地盤部６との境界に沿って掘進させ、硬質地盤部５と通常地盤部６とが混在する切羽３を切削する。
【００４７】
このとき、カッタ４には、複数の硬質地盤部用ビット１８（ローラビット１８）が、カッタ４の回転中に少なくとも１個以上が切羽３の硬質地盤部５に対向するように、領域Ｙに分散して取り付けられているので、切羽３の一部に存する硬質地盤部５に対し、各硬質地盤部用ビット１８がカッタ４の回転に伴って順次次々と接し、掘進機１の前進力（推進ジャッキ２９の推力）が常に１個以上の硬質地盤部用ビット１８ａを介して硬質地盤部５に支持される。よって、掘進機１が、カッタ４の回転に応じて、前後に息するように振動したり、ローリングしたり、傾いたりすることが防止され、安定した掘進を実現できる。また、セグメント２３の圧縮・解放も防止される。
【００４８】
また、掘進機本体２の内部に設けられた推進ジャッキ２９は、掘進時に全数が既設セグメント２３に当接するものなので、掘進機１の掘進反力が全ての推進ジャッキ２９を介して全ての既設セグメント２３で支持される。よって、前段で述べた作用効果とも相俟って、特定のセグメント２３に力が集中することはなく、セグメント２３の変形が抑えられ、掘進機１の傾きを抑制できる。
【００４９】
また、掘進機本体２の後部に、所定の厚さに成形された円筒状のテール部１９を設け、テール部１９に、その内方にて組み立てられた既設セグメント外周面２５と掘孔３０の内周面２６との間（テールボイド２７）に裏込材を注入する注入管２８を設けたので、掘進機１の後方に、裏込材が固化した裏込材地盤部５（硬質地盤部５）が形成される。すなわち、先に形成される裏込材地盤部５と後から形成される裏込材地盤部５とが繋がった状態で長手方向に配置される。
【００５０】
そして、図１〜図３に示すシールド掘進機１を、硬質地盤部５と通常地盤部６との境界に沿って掘進させ、再び図５に示すようにして硬質地盤部５と通常地盤部６とが混在する切羽３を切削する。これを繰り返すことで、硬質地盤部５、５同士がラップしたトンネルが形成される。そして、硬質地盤部５、５同士をリング状に繋げるように複数のトンネルを形成し、その内方の土砂を取り除くことで、硬質地盤部５をトンネル壁とする大断面トンネルを得ることができる。
【００５１】
なお、本実施形態では、掘進機１の後方に形成される裏込材地盤部を硬質地盤部５としたものを説明したが、これに限らず、岩盤と通常の地盤とが長手方向に存在する地山において、その岩盤を硬質地盤部５とする実施形態も考えられ、この場合、岩盤と通常地盤との境界に沿って掘進機１が掘進することになる。
【００５２】
【発明の効果】
以上説明したように本発明に係る部分硬質地盤用シールド掘進機によれば、切羽の一部に硬質地盤が存在しても、安定した掘進を実現できる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る部分硬質地盤用シールド掘進機の側断面図である。
【図２】図２（ａ）は上記掘進機の正面図、図２（ｂ）は領域Ｘ、Ｙを示す正面図である。
【図３】上記掘進機の背面図である。
【図４】上記掘進機により構築される地山の側断面図である。
【図５】上記掘進機の掘進状態を示す側断面図である。
【符号の説明】
１部分硬質地盤用シールド掘進機
２掘進機本体
３切羽
４カッタ
５硬質地盤部（裏込材地盤部）
６通常地盤部
７地山
１７通常地盤部用ビット（ティースビット）
１８硬質地盤部用ビット（ローラビット）
１９テール部
２３既設セグメント
２５既設セグメントの外周面
２６掘孔の内周面
２７テールボイド
２８注入管
２９推進ジャッキ
３０掘孔
Ｘ通常地盤部のみを掘削する領域
Ｙ通常地盤部及び硬質地盤部を掘削する領域[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shield machine for partially hard ground.
[0002]
[Prior art]
As a shield excavator, a cutter was provided at the front of the excavator body, which was driven to rotate facing the face, and a plurality of bits (teeth bits, roller bits, etc.) were attached to the cutter and assembled inside the excavator body. 2. Description of the Related Art There is known an existing segment in which a propulsion jack provided inside an excavator body is pressed to move forward.
[0003]
With such a rotary cutter-type shield excavator, when a hard ground portion and a normal ground portion are dug along a boundary where the hard ground portion and the normal ground portion are arranged in the longitudinal direction, the hard ground portion and the normal ground portion coexist. Since the bit of the cutter goes around and cuts the excavated section), the following problem occurs.
[0004]
Note that related prior arts described in Patent Documents 1 and 2 are known.
[0005]
[Patent Document 1]
Japanese Patent No. 2849605 [Patent Document 2]
Japanese Patent Application Laid-Open No. Hei 9-317797
[Problems to be solved by the invention]
Since the hard ground part is part of the face, the bit at the face is suddenly dragged when the bit rotates from the hard ground part to the other area (the ground part softer than the hard ground part) with the rotation of the cutter. The propulsion jack (constant hydraulic control) extends by that amount, and the excavator advances slightly. Next, when the cutter is further rotated and the bit is again rotated to the hard ground portion, the drag at the face is sharply increased, the propulsion jack is contracted by that much, and the excavator slightly retreats. That is, with the rotation of the cutter, the excavator slightly vibrates so as to breathe back and forth.
[0007]
Also, when the bit rotates with the rotation of the cutter from the hard ground portion to the other area, and the excavator slightly advances as described above, and then the bit rotates again with the hard ground portion and returns. As a result, the cutting depth of the bit with respect to the face (the hard ground portion) becomes deep, and the cutter torque sharply increases. Then, the excavator rolls due to the reaction force of the sharply increased cutter torque.
[0008]
In addition, since a part of the plurality of propulsion jacks is normally pressed against the existing segment for directional control and excavation, the influence of the increase or decrease of the drag at the face due to the turning of the bit causes the propulsion jack to abut. Acts intensively on the segment, which is deformed, causing the excavator to tilt. In addition, the compression and release of the segment are repeated as if the bit rotates, and the segment is fatigued.
[0009]
SUMMARY OF THE INVENTION An object of the present invention, which has been made in view of the above circumstances, is to provide a shield excavator for a partially hard ground that can realize stable excavation even when a hard ground exists in a part of a face.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 excavates a ground where a hard ground portion and a normal ground portion exist in the longitudinal direction, and cuts a face where the hard ground portion and the normal ground portion are mixed. A shield excavator for partially hard ground, provided with a rotary cutter in front of the excavator body, facing the face, and separating the face on the face side of the cutter by a concentric circle centered on the cutter rotation center, Virtually divided into a region where only the normal ground portion is excavated and a region where the normal ground portion and the hard ground portion are excavated. At least one piece is arranged so as to always contact the hard ground portion during rotation.
[0011]
According to the present invention, each hard ground portion bit sequentially contacts the hard ground portion existing in a part of the face with the rotation of the cutter, and the forward force of the excavator is always at least one hard ground portion. It is supported on the hard ground part via the tool bit. Therefore, the excavator is prevented from vibrating, rolling, or inclining to breathe back and forth according to the rotation of the cutter, and stable excavation can be realized. In addition, compression and release of segments are also prevented.
[0012]
The invention according to claim 2 is characterized in that a plurality of propulsion jacks are provided inside the excavator body to support the excavation reaction force by contacting the existing segment, and all of the propulsion jacks abut the existing segment during excavation. is there.
[0013]
In this case, since the excavation reaction force of the excavator is supported by all the existing segments, the force does not concentrate on a specific segment, the deformation of the segment is suppressed, and the inclination of the excavator can be suppressed.
[0014]
The invention according to claim 3 is provided with a cylindrical tail portion formed at a predetermined thickness of the backing material ground portion at a rear portion of the excavator main body, and the tail portion is assembled inside the tail portion. An injection pipe for injecting the backing material is provided between the existing segment and the excavation hole.
[0015]
With this configuration, a backing material ground portion (hard ground portion) in which the backing material is solidified is formed behind the excavator, and the hard ground portion and the normal ground outside the hard ground portion are arranged in the longitudinal direction. Mountains are formed.
[0016]
The invention according to claim 4 excavates a ground formed by a backing material ground portion surrounding the outer periphery of the cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion. A partially rigid ground shield excavator for cutting a face in which a backing material ground portion and a normal ground portion are mixed, wherein a rotary cutter is provided at a front portion of the excavator main body so as to face the face, and the cutter is provided. The face on the side of the face is divided by a concentric circle centered on the center of rotation of the cutter, and virtually divided into a region where only the normal ground portion is excavated and a region where the normal ground portion and the backing material ground portion are excavated. A plurality of hard ground bits are arranged in an area where the ground portion and the backing material ground portion are excavated so that at least one bit for the hard ground is always in contact with the backing material ground portion during rotation of the cutter.
[0017]
According to the present invention, the hard ground portion bits sequentially contact the backing material ground portion (hard ground portion) existing in a part of the face with the rotation of the cutter, and the forward force of the excavator is always increased. It is supported on the backing material ground portion via one or more hard ground portion bits. Therefore, the excavator is prevented from vibrating, rolling, or inclining to breathe back and forth according to the rotation of the cutter, and stable excavation can be realized. In addition, compression and release of segments are also prevented.
[0018]
The invention according to claim 5 excavates a ground formed by a backing material ground portion surrounding the outer periphery of a cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion. A shield excavator for partially rigid ground that cuts a face where the backing material ground part and the normal ground part are mixed, and excavates inside the excavator body by abutting an existing segment assembled therein. A plurality of propulsion jacks for supporting the reaction force are provided, and all of the propulsion jacks abut on the existing segment during excavation.
[0019]
According to the present invention, since the excavation reaction force of the excavator is supported by all the existing segments, the force does not concentrate on a specific segment, the deformation of the segment is suppressed, and the inclination of the excavator can be suppressed.
[0020]
The invention according to claim 6 excavates a ground consisting of a backing material ground portion surrounding the outer periphery of a cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion. A partially rigid ground shield excavator for cutting a face in which a backing material ground portion and a normal ground portion are mixed, wherein a rotary cutter is provided at a front portion of the excavator main body so as to face the face, and the cutter is provided. The face on the side of the face is divided by a concentric circle centered on the center of rotation of the cutter, and virtually divided into a region where only the normal ground portion is excavated and a region where the normal ground portion and the backing material ground portion are excavated. In the area where the part and the backing material ground part are excavated, at least one bit for a plurality of hard grounds is arranged so that at least one bit for the hard ground is always in contact with the backing material ground part during rotation of the cutter. Abuts the existing segment assembled inside the Providing a plurality of propulsion jacks supporting the, they promote jacks are those total number is brought into contact with the existing segment during excavation.
[0021]
According to the present invention, each hard ground portion bit sequentially contacts the backing material ground portion existing in a part of the face with the rotation of the cutter, and the forward force of the excavator is always at least one hard ground. It is supported by the backing material ground part via the ground part bit. Therefore, the excavator is prevented from vibrating, rolling, or inclining to breathe back and forth according to the rotation of the cutter, and stable excavation can be realized. In addition, compression and release of segments are also prevented. Further, since the excavation reaction force of the excavator is supported by all the existing segments, the force does not concentrate on a specific segment, the deformation of the segment is suppressed, and the inclination of the excavator can be suppressed.
[0022]
The invention according to claim 7 is a method of excavating a partially hard ground in which a cutting surface in which a hard ground portion and a normal ground portion are mixed is cut by a rotary cutter provided at a front portion of an excavator main body, wherein a cutting surface side of the cutter is provided. The surface is divided by a concentric circle centered on the center of rotation of the cutter and virtually divided into a region where only the normal ground portion is excavated and a region where the normal ground portion and the backing material ground portion are excavated. At least one bit for the hard ground attached to the area where the material ground is to be excavated is pressed at least one against the hard ground part of the face during rotation of the cutter, and the forward force of the excavator body is transmitted through the bit for the hard ground. The backing material is always supported by the ground portion.
[0023]
The invention according to claim 8 excavates a ground formed by a backing material ground portion surrounding the outer periphery of a cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion. A method for constructing a tunnel of a partially hard ground for cutting a face in which a backing material ground portion and a normal ground portion are mixed, using the excavator according to claim 1, assembling the segments and forming a cylinder having a predetermined thickness. When excavating while forming backing material ground part by injecting backing material from the tail part of the shape, excavation control is performed by excavating control while excavating machine To build.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the accompanying drawings.
[0025]
FIG. 1 is a side sectional view of a shield machine for partial hard ground according to the present embodiment, FIG. 2 is a front view of the machine, and FIG. 3 is a rear view of the machine.
[0026]
As shown in the figure, the shield excavator 1 for a partially hard ground according to the present embodiment includes a cutter 4 that is rotationally driven in front of an excavator body 2 so as to face the face 3 and is shown in FIG. As described above, the hard ground portion 5 and the normal ground portion 6 are dug along the boundary where the hard ground portion 5 and the normal ground portion 6 are arranged in the longitudinal direction, and the cutting face 3 in which the hard ground portion 5 and the normal ground portion 6 are mixed is cut. Things.
[0027]
As shown in FIG. 1, the excavator body 2 has a cylindrical shield frame 8 and a partition wall 9 that partitions the inside thereof into a face side and a pit inner side. In the illustrated example, the shield frame 8 connects a cylindrical front body 10 and a rear body 11 via a spherical joint 12, and the front body 10 and the rear body 11 are bent by a center-folding jack 13, which is a so-called center bending. Although the type is shown, it may be a normal type that does not break.
[0028]
The cutter 4 is rotatably mounted on the partition wall 9 and is driven to rotate via a motor and a gear mechanism (not shown). As shown in FIG. 2, the cutter 4 has a disk-shaped cutter face plate 14 facing the face 3. The cutter face plate 14 is provided with a sediment intake 15 through which excavated earth and sand can pass. It should be noted that the cutter 4 may be a spoke type instead of the face plate type as shown in the figure.
[0029]
The partition wall 9 shown in FIG. 1 is provided with a not-shown unloading device (such as a sludge pipe or a sludge pipe or a screw conveyor) for transferring excavated earth and sand into the pit. Accordingly, the earth and sand of the face 3 cut by the rotating cutter 4 is once taken into the cutter chamber 16 behind the earth from the earth and sand inlet 15 and is transferred into the pit by the earth removal device while maintaining the earth pressure and water pressure of the face 3. You.
[0030]
A plurality of normal ground portion bits 17 (teeth bits) and a plurality of hard ground portion bits 18 (roller bits, shell bits, preceding bits, etc.) are attached to the face side of the cutter face plate 14. I have. These bits 17, 18 substantially cut the face 3.
[0031]
As shown in FIG. 2, the hard ground portion bit 18 is arranged in an area where the cutter face plate 14 overlaps the hard ground portion 5 with the rotation thereof (the outer peripheral portion of the cutter face plate 14). At least one piece is dispersed so as to face the hard ground portion 5 of the face 3. That is, the hard ground portion bits 18 are distributed around the outer peripheral portion of the cutter face plate 14 so that at least one or more of the hard ground portion bits 18 support the advancing force of the excavator body 2 on the hard ground portion 5 of the face 3 during rotation of the cutter 4. It is attached.
[0032]
In other words, as shown in FIGS. 1, 2, and 5, the face X on the face side of the cutter face plate 14 is separated by a concentric circle Z centered on the center of rotation of the cutter, and an area X (where only the normal ground portion 6 is excavated). The inner ground area) and the area Y (outer circumferential area) where the normal ground section 6 and the hard ground section 5 are excavated are virtually divided (see FIGS. 2B and 5). In the area Y where the portion 5 is excavated, a plurality of bits 18 for a hard ground are dispersedly arranged so that at least one bit 18 is always in contact with the hard ground 5 while the cutter face plate 14 is rotating. Symbols X and Y in FIG. 2A indicate the radial length of each region.
[0033]
In the region Y where the normal ground portion 6 and the hard ground portion 5 are excavated, not only the roller bit 18 as the hard ground portion bit 18 but also a slightly lower tooth bit 18x is attached. This is because a plurality of concentric cuts are formed in the portion including the hard ground portion 5 of the face 3 by each roller bit 18, and a portion between the cuts of the face 3 is cut by each tooth bit 18 x.
[0034]
The roller bits 18 are distributed and arranged so that at least one roller bit 18 faces the hard ground portion 5 of the face 3 while the cutter 4 is rotating. This is because the roller bit 18 is slightly protruded toward the face 3 from the tooth bit 18x, and substantially supports the forward force of the excavator body 2 with respect to the hard ground portion 5.
[0035]
On the other hand, in a region X where only the normal ground portion 6 is excavated, a plurality of normal ground portion bits 17 (teeth bits 17) are attached. That is, the normal ground portion bits 17 are distributed and attached to the inner peripheral region of the cutter face plate 14 at a position facing the normal ground portion 6 shown in FIG.
[0036]
Note that a bit (not shown) for the hard ground portion 5 may be provided in the region X, and a normal bit (not shown) for the normal ground portion 6 may be provided in the region Y. This is because, in actual construction, it is difficult to set the concentric circle Z exactly, so that the hard ground portion 5 may be excavated in the region X and only the normal ground portion 6 may be excavated in the region Y.
[0037]
More specifically, a bit (not shown) for the hard ground portion 5 is provided on the outer peripheral side in the region X, and a normal bit for the normal ground portion 6 is provided on the inner peripheral side in the region Y. It is preferable to set a region in the circumferential direction that can correspond to both the hard ground portion 5 and the normal ground portion 6 having a predetermined width.
[0038]
A rear trunk 11, which is a rear part of the excavator main body 2, forms a part of a cylindrical tail part 19 formed to a predetermined thickness. The tail portion 19 includes a rear body 11 formed in a cylindrical shape, a reinforcing rib 20 radially provided therein, a cylindrical inner cylinder 21 attached to an inner end of the reinforcing rib 20, It has a ring-shaped lid 22 that covers the rear end of the cylinder 21 and the rear trunk 11.
[0039]
The thickness between the inner cylinder 21 and the rear trunk 11, that is, the above-mentioned predetermined thickness is the thickness of the backing material ground portion, that is, the hard ground portion 5 shown in FIGS. Is a lap allowance when another excavator 1 laps from behind and excavates. This lap margin is set to a thickness that does not contact the existing segment 23 when another excavator 1 laps from behind and excavates, due to problems in excavation accuracy.
[0040]
An erector (not shown) for assembling the segments 23 into a ring is provided inside the inner cylinder 21. In addition, a tail seal 24 is provided on the rear inner peripheral surface of the inner cylinder 21 to seal the gap between the inner cylinder 21 and the existing segment 23. The erector assembles a new segment 23 in the space in front of the existing segment 23 that has been stopped by the tail seal 24.
[0041]
Injection for injecting backing material (such as mortar) between the inner cylinder 21 and the rear trunk 11 between the outer peripheral surface 25 of the existing segment 23 and the inner peripheral surface 26 of the excavation hole 30, that is, into the tail void 27. A tube 28 is provided. As shown in FIG. 3, a plurality of (four in the illustrated example) injection pipes 28 are provided at predetermined intervals in the circumferential direction, and each of the injection pipes 28 has a discharge port 28 a in the lid 22.
[0042]
As shown in FIG. 1, a plurality of propulsion jacks 29 are provided inside the shield frame 8 to abut on the existing segment 23 and support the excavation reaction force. As shown in FIG. 3, a plurality (10 in the illustrated example) of these propulsion jacks 29 are provided at predetermined intervals in the circumferential direction, and all of them come into contact with the existing segment 23 during excavation.
[0043]
In other words, the hydraulic circuit of each propulsion jack 29 is a 100% push type (100% follow-up type) circuit. Note that the direction control of the excavator 1 is performed by making the pushing forces of the jacks 29 different, even though the pushing is all-in-one. That is, a known pressure control method, jack pattern control method, or the like is used for the hydraulic circuit.
[0044]
Next, a tunnel construction method using the shield machine will be described.
[0045]
An excavator (a type not having the hard ground portion bit 18) of the same type as the shield excavator 1 shown in FIGS. 1 to 3 is excavated in a normal ground in advance, and as shown in FIG. A backing material ground portion 5 (hereinafter referred to as a hard ground portion 5) made of a solidified backing material surrounding the outer periphery of the segment 23 assembled with the thickness of the tail void 27 and a normal ground outside the backing material portion 5 A ground 7 composed of the ground 6 is formed.
[0046]
Thereafter, as shown in FIGS. 5 and 2, the shield machine 1 shown in FIGS. 1 to 3 is excavated along the boundary between the hard ground portion 5 of the ground 7 and the normal ground portion 6, and the hard ground portion The cutting face 3 in which 5 and the normal ground portion 6 are mixed is cut.
[0047]
At this time, a plurality of hard ground portion bits 18 (roller bits 18) are provided on the cutter 4 in the region Y such that at least one or more hard ground portion bits 18 (roller bits 18) face the hard ground portion 5 of the face 3 while the cutter 4 is rotating. Since the cutters 4 are mounted separately, the hard ground portion bits 18 are sequentially in contact with the hard ground portion 5 existing in a part of the face 3 with the rotation of the cutter 4, and the forward force of the excavator 1 ( The thrust of the propulsion jack 29 is always supported by the hard ground portion 5 via one or more hard ground portion bits 18a. Therefore, the excavator 1 is prevented from vibrating, rolling, or inclining to breathe back and forth according to the rotation of the cutter 4, and stable excavation can be realized. Also, compression and release of the segment 23 are prevented.
[0048]
Further, since all the propulsion jacks 29 provided inside the excavator body 2 are in contact with the existing segments 23 during excavation, the excavation reaction force of the excavator 1 is applied to all the existing segments via all the propulsion jacks 29. Supported at 23. Therefore, in combination with the operation and effect described above, the force does not concentrate on the specific segment 23, the deformation of the segment 23 is suppressed, and the inclination of the excavator 1 can be suppressed.
[0049]
Further, a cylindrical tail portion 19 formed to a predetermined thickness is provided at a rear portion of the excavator main body 2, and the tail portion 19 is provided with an existing segment outer peripheral surface 25 and an excavation hole 30 assembled inside the tail portion 19. Since the injection pipe 28 for injecting the backing material is provided between the inner peripheral surface 26 (tail void 27), the backing material ground portion 5 (the hard ground portion 5) having the backing material solidified is provided behind the excavator 1. ) Is formed. That is, the backing material ground portion 5 formed first and the backing material ground portion 5 formed later are arranged in the longitudinal direction in a connected state.
[0050]
Then, the shield machine 1 shown in FIGS. 1 to 3 is excavated along the boundary between the hard ground portion 5 and the normal ground portion 6, and the hard ground portion 5 and the normal ground portion 6 are again formed as shown in FIG. The cutting face 3 in which is mixed is cut. By repeating this, a tunnel in which the hard ground portions 5 and 5 are wrapped with each other is formed. Then, a plurality of tunnels are formed so as to connect the hard ground portions 5 and 5 to each other in a ring shape, and by removing the soil therein, a large-section tunnel having the hard ground portion 5 as a tunnel wall can be obtained. .
[0051]
In this embodiment, the backing material ground portion formed behind the excavator 1 is described as the hard ground portion 5, but the present invention is not limited to this, and the rock ground and the normal ground exist in the longitudinal direction. An embodiment in which the rock is used as the hard ground portion 5 in the ground where the rock is excavated is also considered. In this case, the excavator 1 excavates along the boundary between the rock and the normal ground.
[0052]
【The invention's effect】
As described above, according to the shield excavator for a partially hard ground according to the present invention, stable excavation can be realized even when the hard ground exists in a part of the face.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a shield machine for partial hard ground according to an embodiment of the present invention.
FIG. 2A is a front view of the excavator, and FIG. 2B is a front view showing regions X and Y.
FIG. 3 is a rear view of the excavator.
FIG. 4 is a side sectional view of a ground built by the excavator.
FIG. 5 is a side sectional view showing a state in which the excavator advances.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shield excavator for partial hard ground 2 Excavator main body 3 Face 4 Cutter 5 Hard ground part (backing material ground part)
6 Normal ground 7 Ground 17 Normal ground bit (teeth bit)
18 Bits for hard ground (roller bits)
19 Tail portion 23 Existing segment 25 Outer peripheral surface 26 of existing segment Inner peripheral surface 27 of excavation hole Tail void 28 Injection pipe 29 Propulsion jack 30 Excavation hole X Excavation of normal ground only Y Excavation of ordinary ground and hard ground region

Claims

Partial hard ground shield excavator that excavates the ground where the hard ground part and the normal ground part exist in the longitudinal direction, and cuts the face where the hard ground part and the normal ground part are mixed. A rotary cutter is provided in front of the cutter so as to face the face, and the face on the face of the cutter is separated by a concentric circle centered on the center of rotation of the cutter, and a region where only the normal ground portion is excavated, a normal ground portion, and the hard ground. Virtually divided into a region for excavating a part, and in a region for excavating a normal ground part and a hard ground part, at least one bit for a plurality of hard grounds is always in contact with the hard ground part during rotation of the cutter. A shield machine for partial hard ground, which is arranged.

2. The partially rigid body according to claim 1, wherein a plurality of propulsion jacks are provided inside the excavator body to abut on the existing segment to support the excavation reaction force, and all of the propulsion jacks abut on the existing segment during excavation. Ground shield machine.

At the rear of the excavator body, a cylindrical tail portion formed to a predetermined thickness of the backing material ground portion is provided, and the tail portion has an existing segment and an excavation hole assembled inside thereof. 3. The shield machine for partial hard ground according to claim 1, wherein an injection pipe for injecting a backing material is provided therebetween.

Digging the ground consisting of a backing material ground portion surrounding the outer periphery of the cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion, the backing material ground portion and A shield excavator for a partially hard ground which cuts a face where a normal ground part is mixed, and a rotary cutter is provided in front of the excavator main body so as to face the face, and the face on the face side of the cutter is provided with a cutter. Separated by a concentric circle centered on the rotation center, the region where only the normal ground portion is excavated and the region where the normal ground portion and the backing material ground portion are excavated are virtually divided, and the normal ground portion and the backing material ground portion are divided. A shield excavator for a partial hard ground, wherein at least one bit for a plurality of hard grounds is arranged in an excavation area so that at least one bit for a hard ground is always in contact with a backing material ground portion.

Digging the ground consisting of a backing material ground portion surrounding the outer periphery of the cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion, the backing material ground portion and A shield excavator for a partially hard ground that cuts a face where a normal ground part is mixed, and a propulsion jack that supports an excavation reaction force in contact with an existing segment assembled inside the excavator body, inside the excavator body. A shield excavator for partially rigid ground, in which a plurality of propulsion jacks are provided, all of which abut against existing segments during excavation.

Digging the ground consisting of a backing material ground portion surrounding the outer periphery of the cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion, the backing material ground portion and A shield excavator for a partially hard ground which cuts a face where a normal ground part is mixed, and a rotary cutter is provided in front of the excavator main body so as to face the face, and the face on the face side of the cutter is provided with a cutter. Separated by a concentric circle centered on the rotation center, the region where only the normal ground portion is excavated and the region where the normal ground portion and the backing material ground portion are excavated are virtually divided, and the normal ground portion and the backing material ground portion are divided. In the area to be excavated, a plurality of bits for a hard ground are arranged so that at least one bit for the hard ground is always in contact with the backing material ground part during rotation of the cutter, and an existing assembly assembled inside the excavator main body is provided inside the excavator body. A propulsion jack that abuts the segment to support the excavation reaction A a plurality, they promote jacks partial hard ground for the shield machine total number is to abut against the existing segment during excavation.

A method of excavating a partially hard ground in which a hard ground portion and a normal ground portion are mixed by a rotary cutter provided at a front portion of an excavator body, wherein a face on a face side of the cutter is centered on a cutter rotation center. Is divided virtually into a region where only the normal ground portion is excavated and a region where the normal ground portion and the backing material ground portion are excavated, and a region where the normal ground portion and the backing material ground portion are excavated. During the rotation of the cutter, at least one of the attached bits for the hard ground is pressed against the hard ground portion of the face, and the forward force of the excavator body is constantly applied to the backing material ground portion via the hard ground bit. A method for excavating partially hard ground, characterized by supporting the ground.

Digging the ground consisting of a backing material ground portion surrounding the outer periphery of the cylindrically assembled segment with a predetermined thickness and a normal ground portion outside the backing material ground portion, the backing material ground portion and A tunnel construction method for a partially hard ground for cutting a face where a normal ground part is mixed, wherein the backing material is formed from a cylindrical tail part having a predetermined thickness together with the assembly of the segment using the excavator according to claim 1. When excavating while forming the backing material ground part by injecting the backing material, all the jacks of the excavator are abutted against the existing segments to perform excavation control while excavating and constructing a tunnel Tunnel construction method for hard ground.