JP2004316126A

JP2004316126A - Construction method of large section tunnel and shield section excavator with irregular section

Info

Publication number: JP2004316126A
Application number: JP2003108373A
Authority: JP
Inventors: Kenichi Kaneko; 金子研一; Mitsuhiko Ota; 太田光彦; Masaki Yuguchi; 湯口正樹; Yutaka Ohata; 大畑裕; Kenro Ueda; 植田堅朗; Katsumi Kadota; 門田克美; Hiroyuki Ito; 伊藤広幸; Yuji Sakuma; 佐久間裕治; Hirohide Hashimoto; 橋本博英; Masanori Wakabayashi; 若林正憲
Original assignee: Taisei Corp; Ishikawajima Kenzai Kogyo Co Ltd; Ishikawajima Construction Materials Co Ltd; Ishikawajima Harima Heavy Industries Co Ltd
Current assignee: Taisei Corp; IHI Corp; Ishikawajima Kenzai Kogyo Co Ltd; Ishikawajima Construction Materials Co Ltd
Priority date: 2003-04-11
Filing date: 2003-04-11
Publication date: 2004-11-11
Anticipated expiration: 2023-04-11
Also published as: JP4303512B2

Abstract

【課題】土被りの浅い大断面トンネルの施工方法を提供すること。
【解決手段】地盤に断面視矩形の掘削溝３を造成して函体２を隣接設置しながら函体上部を埋戻して函体列２３を構築し、函体２の底版２１下面にトンネル軸方向に刻設した溝条２２に推進管７の上床版７２上面においてトンネル軸方向に延伸した凸条７１を嵌装させながら推進管７を函体２下に設置して推進管列７３を構築し、間隔６を置いて略並行に構築した複数の函体列２３及び推進管列７３の間を掘削し、函体列２３及び推進管列７３を山留め支保部材として利用しながら本設大断面トンネル４を構築する。また、函体列２３を先行構築し、その上に掘削溝３を造成しながら上段函体２４を設置することもできる。掘削溝３の造成に際しては、オープンシールド掘進機１１、または異形断面シールド掘進機１２を使用する。
【選択図】図２An object of the present invention is to provide a method for constructing a large-section tunnel having a shallow earth covering.
SOLUTION: The excavation groove 3 having a rectangular cross section is formed in the ground, and the upper part of the box is buried while the box 2 is installed adjacently to form a box row 23, and a tunnel shaft is provided on the lower surface of the bottom plate 21 of the box 2. The propulsion pipes 7 are installed under the box 2 while the protruding ridges 71 extending in the tunnel axis direction on the upper floor slab 72 of the propulsion pipes 7 are fitted into the grooves 22 engraved in the direction, and the propulsion pipe row 73 is constructed. The excavation is performed between the plurality of casing rows 23 and the propulsion pipe rows 73 that are constructed substantially in parallel at intervals 6, and the main cross section is formed while using the casing rows 23 and the propulsion pipe rows 73 as retaining members. Build tunnel 4. Alternatively, the upper row of boxes 24 can be installed while constructing the row of boxes 23 in advance and forming the excavation groove 3 thereon. When the excavation groove 3 is formed, an open shield excavator 11 or a deformed section shield excavator 12 is used.
[Selection] Figure 2

Description

【０００１】
【発明の属する技術分野】
本発明は、仮設の小断面分割体を利用しながら大断面トンネルを構築する施工方法に関するものである。
【０００２】
【従来の技術】
地下にトンネルを構築する場合、トンネル軸に沿ってトンネルの両側に山留壁を構築し、その内部を掘削してトンネル函体を構築した後に埋戻しをおこない、山留壁を撤去する開削工法がおこなわれている。
一方、道路や鉄道などの下に地下立体交差トンネルを構築する場合は、上記する開削工法による地上交通への障害を回避するために、シールド工法や推進工法による施工が一般的である。
ところで、近年の交通量の増加や地下トンネルの適用の多様化などから、地下トンネルが大断面化してきている。かかる大断面トンネルを構築する場合、シールド工法にて複数の小断面トンネルを構築して連結させて大断面トンネルを構築している。また、開削工法では、地盤改良等の補助工法を併用し、広範な作業帯を占有しながら施工をおこなっている。
発明者等においては、図１０に示すように、大断面トンネルの構築に際し、複数の小断面トンネルを相互に隣接させるように推進工法にて設置する方法を考案し、開示している（特許文献１参照）。ここで、推進管ａの推進は、一方の側壁に刻設した溝ｂに他方の側壁に設けた突条ｃを嵌装させながら設置していく。
【０００３】
また、開削工法とシールド工法の利点を兼ね備えた工法としてオープンシールド工法が使用されている。オープンシールド工法とは、前方および上方を開放したシールド掘進機を使用し、切羽掘削チャンバー内の地山をバックホウで掘削排土し、油圧ジャッキにより敷設函体を反力にシールド掘進機を推進し、函体を敷設し、テールボイドの注入をおこない、函体上部を埋戻していく工法である。なお、特許文献２にオープンシールド機およびかかるオープンシールド機を使用したオープンシールド工法について開示している。
【０００４】
【特許文献１】
特開２００１−２１４６９９号公報
【特許文献２】
特開２００２−７０４８１号公報
【０００５】
【発明が解決しようとする課題】
前記した従来の大断面トンネルの施工方法にあっては、次のような問題点がある。
＜イ＞開削工法では大型機械の必要性などから広範な作業帯を占有するため、地上の交通渋滞の要因となり得る。
＜ロ＞開削工法においては、施工場所に近接した周辺施設への影響が大きいため、地盤改良等の補助工法の併用が不可避となる。
＜ハ＞シールド工法では大断面に対応した掘削が困難となる。また、大断面を小断面に分割した分割体を結合して大断面トンネルを構築する場合であっても、土被りが少ない場合にはシールド工法の使用は困難となる。
【０００６】
【発明の目的】
本発明は上記したような従来の問題を解決するためになされたもので、大断面トンネルの施工時に地上に広範な作業帯を占有する必要のない大断面トンネルの施工方法を提供することを目的とする。また、施工場所に近接した周辺施設への影響が少ない大断面トンネルの施工方法を提供することを目的とする。また、土被りが少ない条件下での大断面トンネルの施工方法を提供することを目的とする。
本発明は、これらの目的の少なくとも一つを達成するものである。
【０００７】
【課題を解決するための手段】
上記のような目的を達成するために、本発明の大断面トンネルの施工方法は、地盤に断面視矩形の掘削溝を造成し、掘削溝に函体を隣接設置していく函体設置工程と、前記函体の上部を埋戻す埋戻し工程と、によって函体列を構築し、前記函体の底版下面にトンネル軸方向に刻設した溝条に、推進管の上床版上面においてトンネル軸方向に延伸した凸条を嵌装させながら前記推進管を前記函体下に設置して推進管列を構築し、間隔を置いて略並行に構築した複数の前記函体列及び前記推進管列の間を掘削し、前記函体列及び前記推進管列を山留め支保部材として利用しながら本設大断面トンネルを構築することを特徴とする大断面トンネルの施工方法である。
【０００８】
また、本発明の大断面トンネルの施工方法は、地盤に断面視矩形の掘削溝を造成し、掘削溝に函体を隣接設置して函体列を構築していく函体設置工程と、前記函体の上部を埋戻す埋戻し工程と、によって函体列を構築し、前記函体の底版下面にトンネル軸方向に刻設した溝条に、推進管の上床版上面においてトンネル軸方向に延伸した凸条を嵌装させながら前記推進管を前記函体下に設置して推進管列を構築し、前記函体の上床版上面の端部に予め設けた山留め壁を利用して、間隔を置いて略並行に構築した複数の前記函体列及び推進管列の間を掘削し、前記函体列及び前記推進管列を山留め支保部材として利用しながら本設大断面トンネルを構築することを特徴とする大断面トンネルの施工方法である。
【０００９】
さらに、本発明の大断面トンネルの施工方法は、地盤に断面視矩形の掘削溝を造成し、掘削溝に函体を隣接設置して函体列を構築していく函体設置工程と、前記函体において、函体の上床版上面の端部に山留め壁を設置して前記函体の上部を埋戻す埋戻し工程と、によって函体列を構築し、前記函体の底版下面にトンネル軸方向に刻設した溝条に、推進管の上床版上面においてトンネル軸方向に延伸した凸条を嵌装させながら前記推進管を前記函体下に設置して推進管列を構築し、間隔を置いて略並行に構築した複数の前記函体列及び推進管列の間を掘削し、前記函体列及び前記推進管列を山留め支保部材として利用しながら本設大断面トンネルを構築することを特徴とする大断面トンネルの施工方法である。
【００１０】
また、本発明の大断面トンネルの施工方法は、異形断面を掘進可能な異形断面シールド掘進機を使用して函体を設置していく函体設置工程と、前記函体の上床版に沿って地盤に掘削溝を造成しながら、前記函体上に上段函体を設置する上段函体設置工程と、前記上段函体の上部を埋戻す埋戻し工程と、によって函体列及び上段函体列を構築し、間隔を置いて略並行に構築した複数の前記函体列及び前記上段函体列の間を掘削し、前記函体列及び前記上段函体列を山留め支保部材として利用しながら本設大断面トンネルを構築することを特徴とする大断面トンネルの施工方法である。
【００１１】
また、本発明の大断面トンネルの施工方法は、異形断面を掘進可能な異形断面シールド掘進機を使用して函体を設置していく函体設置工程と、前記函体の上床版に沿って地盤に掘削溝を造成しながら、前記函体上に上段函体を設置する上段函体設置工程と、前記上段函体の上部を埋戻す埋戻し工程と、によって函体列及び上段函体列を構築し、前記上段函体の上床版上面の端部に予め設けた山留め壁を利用して、間隔を置いて略並行に構築した複数の前記函体列及び前記上段函体列の間を掘削し、前記函体列及び前記上段函体列を山留め支保部材として利用しながら本設大断面トンネルを構築することを特徴とする大断面トンネルの施工方法である。
【００１２】
さらに、本発明の大断面トンネルの施工方法は、異形断面を掘進可能な異形断面シールド掘進機を使用して函体を設置していく函体設置工程と、前記函体の上床版に沿って地盤に掘削溝を造成しながら、前記函体上に上段函体を設置する上段函体設置工程と、前記上段函体において、上段函体の上床版上面の端部に山留め壁を設置して前記上段函体の上部を埋戻す埋戻し工程と、によって函体列及び上段函体列を構築し、間隔を置いて略並行に構築した複数の前記函体列及び前記上段函体列の間を掘削し、前記函体列及び前記上段函体列を山留め支保部材として利用しながら本設大断面トンネルを構築することを特徴とする大断面トンネルの施工方法である。
【００１３】
また、本発明の大断面トンネルの施工方法は、シールド掘進機の天井を地上に開放してシールド掘進をおこなうオープンシールド掘進機を使用して前記掘削溝を造成することができる。
【００１４】
さらに、本発明の大断面トンネルの施工方法において使用する異形断面シールド掘進機は、間隔を置いて並行に配置した山留め板を直立させ間隔保持部材にて連結させてなる切削山留め体を、異形断面シールド掘進機の天井に着脱可能に備えたことを特徴とする異形断面シールド掘進機を使用できる。
【００１５】
【発明の実施の形態】
以下、図面を参照しながら本発明の実施の形態について説明する。
【００１６】
＜イ＞オープンシールド掘進機（図６（ａ）、（ｂ））
オープンシールド掘進機１１は、左右の側壁板１１１にて土留めをしながら掘進機１の前方及び上方を開放させた公知の掘進機１である。地上からバックホウ９１などで掘削排土しながら函体２を吊下げ設置し、かかる函体２に反力をとって油圧ジャッキ１１２にて掘進する。側壁板１１１にて土留めをしているため掘削の影響が周囲に及びにくく、また油圧ジャッキ１１２を使用するため、騒音や振動が少ないことから住宅街での施工にも好適である。また、側壁板１１１が２分割された中折れ構造のオープンシールド掘進機１１を使用することによって曲線施工も可能である。
本発明においては、土被りの少ない条件にて大断面トンネルを施工する際にオープンシールド掘進機１１を使用するのが好ましい。
【００１７】
＜ロ＞異形断面シールド掘進機（図７（ａ）、（ｂ））
異形断面シールド掘進機１２としては、例えば断面視矩形（または正方形）のシールド掘進機において、掘進機１前面に掘進軸方向の掘進軸１２１回りに揺動する揺動カッター１２２を複数備えた掘進機１を使用することができる。かかる複数の揺動カッター１２２は夫々の揺動カッター１２２の掘削範囲を重複させないように制御することができる。すなわち、例えば２基の揺動カッター１２２を同一平面内又は双方が前後するように配置して夫々の揺動カッター１２２を自己の持分範囲のみを掘削させることである。矩形断面を掘進する場合には、矩形断面を例えば均等に２分割して、２基の揺動カッター１２２が各分割範囲内を揺動しながら地盤を切削することができる。この場合に、揺動カッター１２２の揺動は揺動軸１２１を中心に双方が相反する方向に揺動するように制御することができる。かかる制御によって、２基の揺動カッター１２２は相互に干渉することなく、また掘進機１の進行方向を一定方向に確保しながら掘進させることが可能となる。
【００１８】
異形断面シールド掘進機１２を使用して掘削溝３を造成する際には、かかる掘進機１の天井に切削山留め体１３を設けるのが好ましい。ここで、切削山留め体１３とは、例えば２つの山留め板１３１を異形断面シールド掘進機１２の幅程度の間隔を置いてほぼ並行に直立させて配置し、かかる間隔に複数の間隔保持部材１３２を夫々の山留め板１３１に垂直に連結させて製作したものである。山留め板１３１としては例えば鋼製板など山留め部材としての剛性を有する材料を使用するのが好ましい。また、間隔保持部材１３２としては、例えばＨ型鋼材を使用できる。
切削山留め体１３を使用する目的は、異形断面シールド掘進機１２の掘進に応じて山留め板１３１を地盤内に推進させ、かかる山留め板１３１で土留めをしながら、山留め板１３１内を地上からバックホウ９１等で掘削して函体２を異形断面シールド掘進機１２内に吊り下ろしていくためである。なお、切削山留め体１３は掘進機１の天井に着脱可能な構造とするのが好ましい。
【００１９】
【実施例１】
以下、図面を参照しながら本発明の大断面トンネルの施工方法の実施例１について説明する。
【００２０】
＜イ＞函体設置工程（図１（ａ））
オープンシールド掘進機１１または異形断面シールド掘進機１２を使用して、地盤に断面視矩形の掘削溝３を造成する。掘削溝３を造成しながら函体２を地上からクレーン９２等で吊り下ろして掘削溝３内に設置し、函体列２３を構成させる。かかる函体２は例えば工場にて運搬可能な大きさに製作するのがよい。また、かかる函体２は本設トンネルを構築するための仮設支保部材であるため、函体２構成部材は土圧に耐え得る程度の部材厚を備えていればよい。なお、函体２は例えばセメント系混合材料（コンクリート材料）にて製作できる。
【００２１】
＜ロ＞埋戻し工程及び推進管列の構築（図１（ｂ））
函体列２３を構築しながら、かかる函体列２３の上部を埋戻していく。すなわち、埋戻し工程は、上記の函体設置工程と並行しながら進めていくのが好ましい。埋戻し工程を完了することによってトンネル延長方向に伸びた１列の函体列２３が構築される。
本発明においては、上記の函体列２３を間隔をおいてほぼ並行に複数構築するため、かかる複数の函体列２３の構築は、工期や工費を勘案して１列ごとにおこなうこともできるし、掘進機１を複数使用して各列を同時に構築することもできる。
埋戻し工程完了後は舗装を施工することで、地上道路として供用することができる。
【００２２】
函体列２３を構築後、または函体列２３の構築と同時に函体列２３の下部に推進機１３を推進させながら推進管７を設置していく。ここで、推進管７の設置方法は、函体２の底版２１下面にトンネル軸方向に予め刻設した溝条２２に、推進管７の上床版７２上面にトンネル軸方向に予め延伸した凸条７１を嵌装させながら設置していく。ここで、溝条２２の断面視形状は凸条７１の断面視形状に応じて製作される。凸条７１の断面視形状は、例えば矩形やＴ字形状などに製作できる（図３参照）。また、凸条７１は推進管７と同程度の長さに製作することもできるし、所定長さの凸条７１を所定間隔を置いて設置することもできる。凸条７１はセメント系混合材料や鋼製材料などにより製作できる。また、使用する凸条７１の断面視形状に応じた断面視形状を備えた溝条２２は、溝条２２を構成する型枠を函体２の底版２１に予め埋め込んでおき函体２を製作するのがよい。
【００２３】
なお、上記実施例は函体列２３の下に推進管列７３を構築する場合の実施例であるが、函体列２３の下には複数段の推進管列７３を構築することもできる。すなわち、構築する本設大断面トンネル４の断面寸法と使用する函体２及び推進管７の断面寸法に応じて鉛直下方に設置していく推進管７の段数を調整できる。かかる場合は、推進管７の上床版７２には凸条７１を設け、推進管７の下床版には函体２と同様溝条２２を設けておき、かかる溝条２２に下方に設置される推進管７の上床版７２に設けた凸条７１を嵌装させながら設置していくのが好ましい。
【００２４】
＜ハ＞函体列及び推進管列の間の掘削（図２（ａ））
函体列２３及び推進管列７３の間の掘削は、函体列２３上の土被り部分については、地上から所定の法面を形成しながら開削施工をおこない、函体列２３の函体側壁間及び推進管側壁間の掘削は函体２及び推進管７を山留め支保部材として利用しながら推進管列７３最下段レベル付近まで掘り下げていくことができる。
また、その他の方法としては、トンネル延長端部より並行する函体列２３の最上段レベルおよび推進管列７３の最下段レベル付近に例えば鋼製の間隔掘削山留め板をトンネル延長方向に推進させ、上下の土圧は間隔掘削山留め板にて支保させ、左右は函体２及び推進管７を山留め支保部材として利用しながらかかる函体列２２及び推進管列７３の間の掘削をおこなうこともできる。この方法によれば、地上において開削に伴う工事占有帯を確保する必要がないため、工事占有帯による交通障害の問題を最小限に抑えることができる。
【００２５】
＜ニ＞本設大断面トンネルの構築（図２（ｂ））
函体列２３及び推進管列７３の間の掘削完了後、または函体列２２及び推進管列７３の間の掘削と並行して本設大断面トンネル４の構築をおこなう。函体列２３及び推進管列７３を構成する各構成部材を外型枠とし、函体２及び推進管７の構成部材を撤去しながら本設大断面トンネル４を構成する構成部材（上床版、側壁、柱脚、底版など）を構築する。
【００２６】
【実施例２】
以下、図面を参照しながら本発明の大断面トンネルの施工方法の実施例２について説明する。なお、実施例１と重複する工程については省略する。
【００２７】
函体列２３の上床版上面において、並行する函体列２３側の端部付近には予め山留め壁５を設置した状態でかかる函体２を設置し、埋戻し工程を完了させる。山留め壁５としてはコンクリート壁を設けておいたり、鋼矢板壁を設けておくなどできる（図４（ａ）参照）。
かかる山留め壁５を設けておくことで、地上から法面を形成しながら掘削する場合に比べて地上の工事占有帯幅を極力狭めることができる。
【００２８】
【実施例３】
以下、図面を参照しながら本発明の大断面トンネルの施工方法の実施例３について説明する。なお、他の実施例と重複する工程については省略する。
【００２９】
函体列２３の上床版上面において、並行する函体列２３側の端部付近には山留め壁５を設置するための山留め係止支柱５１などを予め設置した状態でかかる函体２を設置する（図４（ｂ）参照）。山留め係止支柱５１は支柱の安定を図るために断面視Ｌ字状に成形するのもよい。次に、かかる山留め係止支柱５１に例えば鋼矢板などの山留め壁５を係止させた後に函体２の上部を埋戻していく。
【００３０】
【実施例４】
以下、図面を参照しながら本発明の大断面トンネルの施工方法の実施例４について説明する。なお、他の実施例と重複する工程については省略する。
【００３１】
実施例４は、実施例１〜３のように函体列２３の下方に推進管列７３を構築していくのではなく、異形断面シールド掘進機１２を使用して函体列２３（またはセグメント函体列）を構築後、かかる函体列２３の上方に掘進機１により掘削溝３を造成しながら函体列２３を構築する方法である。
まず、函体設置工程として、異形断面シールド掘進機１２により函体列２３（セグメント函体列）を構築する。ここで、本設大断面トンネル４の寸法に応じた数の函体列２３を間隔６を置いてほぼ並行に構築する（図５（ａ）参照）。
函体設置工程完了後、または函体設置工程と同時に、掘進機１を使用して函体列２３の上部に上段函体２４を設置していく（上段函体設置工程）（図５（ｂ）参照）。
掘進機１としては、オープンシールド掘進機１１又は異形断面シールド掘進機１２（切削山留め体１３を備えたもの）を使用して掘削溝３を造成しながら上段函体２４を設置していく。
【００３２】
オープンシールド掘進機１１を使用して上段函体２４を設置する方法を図６（ａ）、（ｂ）に示す。
ここで、オープンシールド掘進機１１を使用する場合は、既に構築された函体列２３をガイドとして利用しながら掘進させるのが好ましい。すなわち、オープンシールド掘進機１１の側壁板１１１を下方の函体２の側壁まで延ばした状態で下方函体上にオープンシールド掘進機１１を設置することにより、下方の函体列２３をガイドとしてオープンシールド掘進機１１が掘進することができる。オープンシールド掘進機１１の前方地山はバックホウ９１等で掘削排土させ、地上からクレーン９２等で上段函体２４を吊下げて設置していき、上段函体２４に反力をとってオープンシールド掘進機１１を掘進させていく。
【００３３】
一方、異形断面シールド掘進機１２を使用して上段函体２４を設置する方法を図７（ａ）、（ｂ）に示す。
異形断面シールド掘進機１２を使用する場合も、既に構築された函体列２３をガイドとして利用しながら掘進させるのが好ましい。すなわち、既設置された函体列２３を構成する函体２の上床版には予めトンネル軸方向に刻設した溝条２２を設けておく。異形断面シールド掘進機１２の掘進機１２底部にはトンネル軸方向に延伸した凸条７１を設けておき、凸条７１を溝条２２に嵌装させながら異形断面シールド掘進機１２を掘進させる。
【００３４】
上段函体列２５の構築完了後、または上段函体列２５の構築と同時に間隔６の掘削をおこなう。掘削方法は、実施例１〜３と同様である（図８（ａ）、図９（ａ）、（ｂ）参照）。
掘削完了後、または掘削と同時に本設大断面トンネル４の構築をおこなう（図８（ｂ）参照）。
【００３５】
【発明の効果】
本発明の大断面トンネルの施工方法は以上説明したようになるから次のような効果を得ることができる。
＜イ＞広範な作業帯を占有しないため、地上の交通障害を少なくして工事をおこなうことができる。
＜ロ＞オープンシールド掘進機または切削山留め体を備えた異形断面シールド掘進機を使用して地上に掘削溝を造成するため、掘削の影響が周辺におよび難い。
＜ハ＞函体の規模を小さくすることにより、函体を吊り下ろすクレーンを小型化できる。
＜ニ＞仮設用の函体や本設の分割函体が土留め壁および土留め支保部材としての役割を担うため、土留め壁の施工や切梁設置などの必要がなく、全体工程を短縮できる。
【図面の簡単な説明】
【図１】本発明の大断面トンネルの施工方法の実施例１を説明した施工フロー図であり、（ａ）函体設置工程の説明図。（ｂ）埋戻し工程および推進管列を構築した説明図。
【図２】本発明の大断面トンネルの施工方法の実施例１を説明した施工フロー図であり、（ａ）函体列及び推進管列の間を掘削している説明図。（ｂ）本設大断面トンネルの構築完了を説明した説明図。
【図３】函体の溝条に推進管の凸条を嵌装させている状況を説明した説明図。
【図４】（ａ）本発明の大断面トンネルの施工方法の実施例２の函体群列の間を掘削している説明図。（ｂ）本発明の大断面トンネルの施工方法の実施例３の函体群列の間を掘削している説明図。
【図５】本発明の大断面トンネルの施工方法の実施例４を説明した施工フロー図であり、（ａ）函体設置工程の説明図。（ｂ）上段函体設置工程の説明図。
【図６】オープンシールド掘進機によって上段函体を設置していることを説明した図であり、（ａ）オープンシールド掘進機の斜視図。（ｂ）オープンシールド掘進機により施工状況を説明した説明図。
【図７】異形断面シールド掘進機によって上段函体を設置していることを説明した図であり、（ａ）異形断面シールド掘進機の正面図。（ｂ）異形断面シールド掘進機の縦断図。
【図８】本発明の大断面トンネルの施工方法の実施例４を説明した施工フロー図であり、（ａ）函体列及び推進管列の間を掘削している説明図。（ｂ）本設大断面トンネルの構築完了を説明した説明図。
【図９】（ａ）本発明の大断面トンネルの施工方法の実施例４において函体列及び上段函体列の間を山留め壁を利用して掘削している説明図。（ｂ）本発明の大断面トンネルの施工方法の実施例４において函体列及び上段函体列の間を山留め係止支柱及び山留め壁を利用して掘削している説明図。
【図１０】従来の大断面トンネルの施工方法を説明した説明図。
【符号の説明】
１・・・掘進機
１１・・オープンシールド掘進機
１２・・異形断面シールド掘進機
１３・・切削山留め体
１３１・山留め板
１３２・間隔保持部材
２・・・函体
２１・・底版
２２・・溝条
２３・・函体列
２４・・上段函体
２５・・上段函体列
３・・・掘削溝
４・・・本設大断面トンネル
５・・・山留め壁
６・・・間隔
７・・・推進管
７１・・凸条
７２・・上床版
７３・・推進管列[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a construction method for constructing a large-section tunnel using a temporary small-section divided body.
[0002]
[Prior art]
When constructing a tunnel underground, open-cutting method is to construct a retaining wall on both sides of the tunnel along the tunnel axis, excavate the inside of the tunnel, construct a tunnel body, and then bury the tunnel and remove the retaining wall. Is being performed.
On the other hand, when constructing an underground flyover tunnel under a road, a railway, or the like, construction using a shield method or a propulsion method is generally performed in order to avoid obstacles to ground traffic due to the above-mentioned excavation method.
By the way, underground tunnels have been increasing in cross section due to an increase in traffic volume and diversification of applications of underground tunnels in recent years. When such a large-section tunnel is constructed, a plurality of small-section tunnels are constructed and connected by a shield method to construct a large-section tunnel. In the excavation method, an auxiliary method such as ground improvement is used in combination, and construction is performed while occupying a wide work zone.
As shown in FIG. 10, the inventors have devised and disclosed a method of installing a plurality of small-section tunnels so as to be adjacent to each other when constructing a large-section tunnel, as shown in FIG. 1). Here, the propulsion of the propulsion pipe a is performed while fitting the protrusions c provided on the other side wall into the grooves b engraved on one side wall.
[0003]
Also, an open shield method is used as a method combining the advantages of the open-cut method and the shield method. With the open shield method, a shield excavator whose front and upper sides are opened is used to excavate and excavate the ground in the face excavation chamber with a backhoe, and a hydraulic jack is used to propel the shield excavator in reaction to the laying box. In this method, a box is laid, tail voids are injected, and the upper part of the box is buried. Patent Document 2 discloses an open shield machine and an open shield method using the open shield machine.
[0004]
[Patent Document 1]
JP 2001-214699A [Patent Document 2]
JP-A-2002-70481 [0005]
[Problems to be solved by the invention]
The above-described conventional method for constructing a large-section tunnel has the following problems.
 The open-cutting method occupies a wide range of work zones due to the necessity of large machines and the like, which may cause ground traffic congestion.
 In the open-cutting method, the peripheral facilities near the construction site are greatly affected, so it is inevitable to use auxiliary methods such as ground improvement.
<C> The shield method makes it difficult to excavate large sections. In addition, even when a large-section tunnel is constructed by combining divided bodies obtained by dividing a large section into small sections, it is difficult to use the shield method when there is little earth covering.
[0006]
[Object of the invention]
The present invention has been made to solve the above-described conventional problems, and has an object to provide a method for constructing a large-section tunnel that does not require occupying a wide working zone on the ground when constructing a large-section tunnel. And It is another object of the present invention to provide a method for constructing a large-section tunnel having little effect on peripheral facilities close to a construction site. It is another object of the present invention to provide a method for constructing a large-section tunnel under a condition that the overburden is small.
The present invention achieves at least one of these objects.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a method for constructing a large-section tunnel according to the present invention includes a step of forming a rectangular excavation groove having a rectangular cross section in the ground, and a box installation step of installing a box adjacent to the excavation groove. And a back-filling step of back-filling the upper part of the box, thereby constructing a row of boxes, and in the groove engraved in the tunnel axis direction on the bottom plate lower surface of the box, the tunnel axial direction on the upper floor plate upper surface of the propulsion pipe. The propulsion pipe is installed under the box while fitting the protruding ridges extending to form a propulsion pipe row, and a plurality of the box rows and the propulsion pipe row constructed substantially in parallel at intervals. A method of constructing a large-section tunnel, comprising excavating a space, and constructing a permanent large-section tunnel while using the box row and the propulsion pipe row as retaining members.
[0008]
Further, the method for constructing a tunnel with a large cross section of the present invention is a box installation step of forming a rectangular excavation groove in a cross section in the ground, and installing a box adjacent to the excavation groove to construct a box row, A back-filling step of back-filling the upper part of the box, and a row of boxes is constructed, and is extended in the tunnel axial direction on the upper floor plate upper surface of the propulsion pipe in the groove engraved in the tunnel axis direction on the lower surface of the bottom plate of the container. The propulsion pipes are installed under the box while fitting the formed ridges to form a propulsion pipe row, and a gap is provided by using a retaining wall previously provided at an end of the upper floor slab upper surface of the box. Excavating between the plurality of box rows and the propulsion pipe rows that are placed and constructed substantially in parallel, and constructing a permanent large-section tunnel while using the box rows and the propulsion pipe rows as retaining members for retaining. This is the method of constructing a large section tunnel.
[0009]
Furthermore, the construction method of the large-section tunnel of the present invention is a box installation step of forming a rectangular excavation groove in the ground in a sectional view, constructing a box row by installing a box adjacent to the excavation groove, In the box, a backing step of installing a retaining wall at the end of the upper floor slab upper surface and burying the upper part of the box, and constructing a row of boxes, and a tunnel shaft on the lower side of the bottom plate of the box The propulsion tube is installed under the box while fitting a protruding line extending in the tunnel axis direction on the upper floor slab of the propulsion tube in the groove engraved in the direction. Excavating between the plurality of box rows and the propulsion pipe rows that are placed and constructed substantially in parallel, and constructing a permanent large-section tunnel while using the box rows and the propulsion pipe rows as retaining members for retaining. This is the method of constructing a large section tunnel.
[0010]
Further, the construction method of the large-section tunnel of the present invention is a box installation step of installing a box using a deformed section shield excavator capable of excavating a deformed section, and along the upper floor of the box. An upper box body setting step of installing an upper box body on the box while forming an excavation groove in the ground, and a backfilling step of backfilling an upper portion of the upper box body, and a box row and an upper box row , Excavating between the plurality of box rows and the upper row of boxes constructed substantially in parallel at intervals, and using the box row and the upper row of row boxes as retaining members This is a method for constructing a large-section tunnel, which comprises constructing a large-section tunnel.
[0011]
Further, the construction method of the large-section tunnel of the present invention is a box installation step of installing a box using a deformed section shield excavator capable of excavating a deformed section, and along the upper floor of the box. An upper box body setting step of installing an upper box body on the box while forming an excavation groove in the ground, and a backfilling step of backfilling an upper portion of the upper box body, and a box row and an upper box row Is constructed, using a retaining wall provided in advance at the end of the upper floor slab of the upper box, and between the plurality of box rows and the upper box row that are constructed substantially in parallel at intervals. A method for constructing a large-section tunnel, comprising digging and constructing a permanent large-section tunnel while using the box row and the upper box row as mountain retaining support members.
[0012]
Furthermore, the construction method of the large section tunnel of the present invention is a box installation step of installing a box using a deformed section shield excavator capable of excavating a deformed section, and along the upper floor slab of the box. While forming an excavation groove in the ground, an upper box installation step of installing an upper box on the box, and in the upper box, a mountain retaining wall is installed at an end of the upper floor plate upper surface of the upper box. A backfilling step of backfilling the upper part of the upper box, to construct a row of boxes and an upper row of rows, and between the plurality of row of rows and the upper row of rows constructed substantially in parallel at intervals. And constructing a permanent large section tunnel while using the box row and the upper box row as mountain retaining support members.
[0013]
In the method of constructing a large-section tunnel according to the present invention, the excavation trench can be formed by using an open shield excavator that performs a shield excavation by opening a ceiling of the shield excavator to the ground.
[0014]
Further, the deformed section shield excavator used in the method for constructing a large section tunnel according to the present invention is characterized in that a cut mountain clasp formed by uprighting and parallelly attaching a gap retaining plate arranged at intervals with a gap retaining member has a modified cross section. A deformed shield excavator characterized by being detachably mounted on the ceiling of the shield excavator can be used.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
 Open shield machine (Fig. 6 (a), (b))
The open shield excavator 11 is a known excavator 1 in which the front and upper sides of the excavator 1 are opened while retaining the soil with left and right side wall plates 111. The box 2 is suspended from the ground while excavating and discharging with a backhoe 91 or the like, and the box 2 is excavated with a hydraulic jack 112 by taking a reaction force. Since the earth retaining is performed by the side wall plate 111, the influence of the excavation is hard to reach the surrounding area, and since the hydraulic jack 112 is used, the noise and the vibration are small, so that it is suitable for the construction in a residential area. Curve construction is also possible by using the open-shield excavator 11 having a middle bent structure in which the side wall plate 111 is divided into two.
In the present invention, it is preferable to use the open shield excavator 11 when constructing a large-section tunnel under the condition of little earth covering.
[0017]
 Deformed shield excavator (Fig. 7 (a), (b))
As the deformed shield excavator 12, for example, a shield excavator having a rectangular shape (or a square shape) in cross section, the excavator having a plurality of swing cutters 122 swinging around an excavation shaft 121 in the direction of the excavation axis in front of the excavator 1. 1 can be used. The plurality of swing cutters 122 can be controlled so that the excavation ranges of the respective swing cutters 122 do not overlap. That is, for example, two rocking cutters 122 are arranged in the same plane or so that both rocking cutters are arranged back and forth, and each rocking cutter 122 is excavated only in its own equity range. In the case of excavating a rectangular cross section, the rectangular cross section can be equally divided into two, for example, and the ground can be cut while the two swing cutters 122 swing in the respective divided ranges. In this case, the swing of the swing cutter 122 can be controlled so that both swing about the swing shaft 121 in opposite directions. With this control, the two rocking cutters 122 can excavate without interfering with each other and while ensuring the traveling direction of the excavator 1 in a fixed direction.
[0018]
When the excavation groove 3 is formed using the deformed section shield excavator 12, it is preferable to provide a cutting mountain retaining body 13 on the ceiling of the excavator 1. Here, the cutting mountain retaining body 13 is, for example, arranged with two mountain retaining plates 131 standing upright substantially in parallel with an interval of about the width of the shielded excavator 12 having a deformed cross section, and a plurality of interval holding members 132 at the interval. It is manufactured by being vertically connected to each of the retaining plates 131. It is preferable to use a material having rigidity as a mountain retaining member such as a steel plate, for example, as the mountain retaining plate 131. Further, as the spacing member 132, for example, an H-shaped steel material can be used.
The purpose of using the cutting mountain retaining body 13 is to propel the mountain retaining plate 131 into the ground in accordance with the excavation of the deformed section shield excavator 12, and while retaining the earth with the mountain retaining plate 131, the inside of the mountain retaining plate 131 is backhoeed from the ground. This is because the excavation is performed at 91 or the like and the box 2 is hung in the shield excavator 12 having the irregular cross section. It is preferable that the cutting mountain retaining body 13 has a structure detachable from the ceiling of the excavator 1.
[0019]
Embodiment 1
Hereinafter, a first embodiment of a method for constructing a large-section tunnel according to the present invention will be described with reference to the drawings.
[0020]
 Box installation process (Fig. 1 (a))
The open shield excavator 11 or the deformed shield excavator 12 is used to form the excavation groove 3 having a rectangular cross section in the ground. The box body 2 is suspended from the ground with a crane 92 or the like while forming the excavation groove 3 and installed in the excavation groove 3 to form a box row 23. Such a box 2 is preferably manufactured to a size that can be transported in a factory, for example. Further, since the box 2 is a temporary support member for constructing a permanent tunnel, the constituent members of the box 2 only need to have a thickness enough to withstand the earth pressure. The box 2 can be made of, for example, a cement-based mixed material (concrete material).
[0021]
 Backfilling process and construction of propulsion pipe row (Fig. 1 (b))
While constructing the box array 23, the upper part of the box array 23 is backfilled. That is, it is preferable that the backfilling step proceeds in parallel with the above-mentioned box installation step. By completing the backfilling process, a single row of boxes 23 extending in the tunnel extending direction is constructed.
In the present invention, since the plurality of box rows 23 are constructed almost in parallel at intervals, the construction of the plurality of box rows 23 can be performed for each row in consideration of the construction period and the cost. However, it is also possible to simultaneously construct each row by using a plurality of excavators 1.
After the completion of the backfilling process, it can be used as a ground road by constructing pavement.
[0022]
After the construction of the housing row 23 or at the same time as the construction of the housing row 23, the propulsion pipes 7 are installed at the lower part of the housing row 23 while propelling the propulsion unit 13. Here, the method of installing the propulsion pipe 7 is as follows: a groove 22 formed in advance in the tunnel axis direction on the lower surface of the bottom plate 21 of the box 2; 71 is fitted and installed. Here, the cross-sectional shape of the groove 22 is manufactured according to the cross-sectional shape of the ridge 71. The cross-sectional shape of the ridge 71 can be manufactured in, for example, a rectangular shape or a T-shape (see FIG. 3). Further, the protruding ridges 71 can be manufactured to have the same length as the propulsion pipe 7, or the ridges 71 having a predetermined length can be provided at predetermined intervals. The ridges 71 can be made of a cement-based mixed material or a steel material. Further, the groove 22 having a sectional view shape corresponding to the sectional view shape of the ridge 71 to be used is prepared by embedding a mold forming the groove 22 in the bottom plate 21 of the box 2 in advance. Good to do.
[0023]
The above embodiment is an embodiment in which the propulsion pipe row 73 is constructed below the box row 23. However, a plurality of stages of propulsion pipe rows 73 can be constructed below the box row 23. That is, the number of stages of the propulsion pipes 7 installed vertically below can be adjusted in accordance with the cross-sectional dimensions of the main large-section tunnel 4 to be constructed and the cross-sectional dimensions of the box 2 and the propulsion pipes 7 to be used. In such a case, the upper floor slab 72 of the propulsion pipe 7 is provided with the ridge 71, and the lower slab of the propulsion pipe 7 is provided with the groove 22 similarly to the box 2, and is installed below the groove 22. It is preferable that the protruding tube 7 is installed while fitting the ridge 71 provided on the upper floor slab 72 of the propulsion tube 7.
[0024]
<C> Excavation between the box row and the propulsion pipe row (Fig. 2 (a))
In the excavation between the row of boxes 23 and the row of propulsion pipes 73, the earth covering portion on the row of boxes 23 is cut and formed while forming a predetermined slope from the ground. The excavation between the space and the side wall of the propulsion pipe can be dug down to the vicinity of the lowermost level of the propulsion pipe row 73 using the box 2 and the propulsion pipe 7 as a retaining member.
Further, as another method, for example, a steel interval excavation retaining plate is propelled in the tunnel extension direction near the uppermost level of the casing row 23 and the lowermost level of the propulsion pipe row 73 parallel to the tunnel extension end, The upper and lower earth pressures are supported by the interval excavation retaining plate, and the excavation between the box row 22 and the propulsion pipe row 73 can be performed while using the box 2 and the propulsion pipe 7 as the retaining support members on the left and right. . According to this method, it is not necessary to secure a work occupied zone on the ground due to the excavation, so that the problem of traffic obstruction due to the work occupied zone can be minimized.
[0025]
<D> Construction of a permanent large section tunnel (Fig. 2 (b))
After completion of the excavation between the housing row 23 and the propulsion pipe row 73, or in parallel with the excavation between the housing row 22 and the propulsion pipe row 73, the permanent large-section tunnel 4 is constructed. The constituent members constituting the box body row 23 and the propulsion tube row 73 are outer molds, and the constituent members (the upper floor slab, Build side walls, column bases, bottom slabs, etc.).
[0026]
Embodiment 2
Hereinafter, a second embodiment of the method for constructing a large-section tunnel according to the present invention will be described with reference to the drawings. Steps that overlap with the first embodiment are omitted.
[0027]
On the upper floor slab upper surface of the box row 23, near the end on the side of the parallel box row 23, such a box 2 is installed with the retaining wall 5 installed in advance, and the backfilling step is completed. A concrete wall or a steel sheet pile wall can be provided as the retaining wall 5 (see FIG. 4A).
By providing such a retaining wall 5, the width of the occupied work area on the ground can be reduced as much as possible when excavating while forming a slope from the ground.
[0028]
Embodiment 3
Hereinafter, a third embodiment of the method for constructing a large-section tunnel according to the present invention will be described with reference to the drawings. Steps that are the same as those of the other embodiments are omitted.
[0029]
On the upper floor slab upper surface of the housing row 23, near the end on the side of the parallel housing row 23, the housing 2 is installed in a state where a mountain retaining locking column 51 for installing the mountain retaining wall 5 and the like are installed in advance. (See FIG. 4B). The mountain retaining post 51 may be formed in an L-shape in cross section in order to stabilize the post. Next, after retaining the retaining wall 5 such as a steel sheet pile to the retaining pillar 51, the upper part of the box 2 is buried back.
[0030]
Embodiment 4
Hereinafter, Embodiment 4 of the method for constructing a large-section tunnel according to the present invention will be described with reference to the drawings. Steps that are the same as those of the other embodiments are omitted.
[0031]
The fourth embodiment is different from the first to third embodiments in that the propulsion tube row 73 is not constructed below the box row 23, but the box row 23 (or the segment This is a method of constructing the box array 23 while constructing the excavation groove 3 by the excavator 1 above the box array 23 after constructing the box array.
First, as a box installation step, a box row 23 (segment box row) is constructed by the shielded section machine 12 with a modified cross section. Here, a number of box rows 23 corresponding to the dimensions of the permanent large-section tunnel 4 are constructed substantially in parallel at intervals 6 (see FIG. 5A).
After the box installation step is completed, or simultaneously with the box installation step, the excavator 1 is used to install the upper box body 24 on the upper part of the box row 23 (upper box installation step) (FIG. 5 (b) )reference).
As the excavator 1, the upper box body 24 is installed while forming the excavation groove 3 using the open shield excavator 11 or the deformed section shield excavator 12 (with the cutting mountain retaining body 13).
[0032]
FIGS. 6A and 6B show a method of installing the upper casing 24 using the open shield machine 11.
Here, when using the open shield excavator 11, it is preferable to excavate while using the already constructed box row 23 as a guide. That is, by installing the open shield excavator 11 on the lower box in a state where the side wall plate 111 of the open shield excavator 11 is extended to the side wall of the lower box 2, the lower box row 23 is used as a guide to open. The shield excavator 11 can excavate. The ground in front of the open shield machine 11 is excavated and excavated with a backhoe 91 or the like, and the upper box 24 is suspended from the ground with a crane 92 or the like and installed. The excavator 11 is excavated.
[0033]
7 (a) and 7 (b) show a method of installing the upper casing 24 using the shield excavator 12 having a modified cross section.
Also in the case of using the deformed shield excavator 12, it is preferable to excavate while using the already constructed box row 23 as a guide. That is, a groove 22 engraved in the tunnel axial direction is provided in advance on the upper floor slab of the housing 2 constituting the installed housing row 23. A protruding ridge 71 extending in the tunnel axial direction is provided at the bottom of the excavator 12 of the deformed section shield excavator 12, and the deformed section shield excavator 12 is excavated while fitting the protruding strip 71 into the groove 22.
[0034]
After the completion of the construction of the upper row 25, or at the same time as the construction of the upper row 25, excavation of the interval 6 is performed. The excavation method is the same as in Examples 1 to 3 (see FIGS. 8A, 9A, and 9B).
After the completion of the excavation or simultaneously with the excavation, the construction of the permanent large section tunnel 4 is performed (see FIG. 8B).
[0035]
【The invention's effect】
Since the method for constructing a large-section tunnel according to the present invention is as described above, the following effects can be obtained.
 Since it does not occupy a wide range of work zones, construction work can be performed with less traffic obstacles on the ground.
 Since an excavation groove is formed on the ground using an open shield excavator or a shield excavator having a deformed cross section provided with a cutting mountain retaining body, the influence of excavation is hard to reach the periphery.
<C> By reducing the size of the box, the crane for hanging the box can be downsized.
<D> Temporary housing and permanent split housing play the role of retaining walls and retaining members, so there is no need to construct retaining walls or install cutting beams, thus shortening the overall process. it can.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a construction flow chart for explaining a first embodiment of a construction method of a large-section tunnel according to the present invention, in which (a) is an explanatory view of a box installation step. (B) Explanatory drawing which built the backfilling process and the propulsion pipe row.
FIG. 2 is a construction flow chart for explaining a first embodiment of a method for constructing a large-section tunnel according to the present invention, in which (a) an excavation is performed between a box row and a propulsion pipe row. (B) Explanatory drawing explaining completion of construction of the permanent large section tunnel.
FIG. 3 is an explanatory view illustrating a situation where a protruding ridge of a propulsion tube is fitted into a groove of a box.
FIG. 4 (a) is an explanatory view showing excavation between boxes in a box group row according to a second embodiment of the method for constructing a large-section tunnel according to the present invention. (B) Explanatory drawing which excavates between the box group rows of Example 3 of the construction method of the large-section tunnel of the present invention.
FIG. 5 is a construction flow chart for explaining a fourth embodiment of the method for constructing a large-section tunnel according to the present invention, in which (a) is an explanatory view of a box installation step. (B) Explanatory drawing of an upper box installation process.
6A and 6B are diagrams illustrating that an upper box is installed by an open shield machine, and FIG. 6A is a perspective view of the open shield machine. (B) Explanatory drawing explaining the construction situation by an open shield machine.
7A and 7B are diagrams illustrating that an upper-stage box is installed by a modified section shield excavator, and FIG. 7A is a front view of the modified section shield excavator. (B) A longitudinal section of a shield excavator with an irregular cross section.
FIG. 8 is a construction flow chart for explaining a fourth embodiment of the method for constructing a large-section tunnel according to the present invention, wherein (a) is an excavation between a row of boxes and a row of propulsion pipes. (B) Explanatory drawing explaining completion of construction of the permanent large section tunnel.
FIG. 9 (a) is an explanatory view of excavation using a mountain retaining wall between a box row and an upper box row in Embodiment 4 of the method for constructing a large-section tunnel according to the present invention. (B) Explanatory drawing in Example 4 of the method for constructing a large-section tunnel according to the present invention, in which excavation is performed between a row of boxes and an upper row of rows using a retaining pillar and a retaining wall.
FIG. 10 is an explanatory view illustrating a conventional method for constructing a large-section tunnel.
[Explanation of symbols]
Reference Signs List 1 excavator 11 open shield excavator 12 deformed section shield excavator 13 cutting mountain retaining body 131 mountain retaining plate 132 spacing member 2 box 21 bottom plate 22 groove 23, box row 24, upper box row 25, upper box row 3, excavation groove 4, permanent large section tunnel 5, mountain retaining wall 6, spacing 7, Propulsion pipe 71 ・・ Protrusion 72 ・・ Top floor slab 73 ・・ Propulsion pipe row

Claims

A box installation process in which a rectangular excavation groove with a rectangular cross section is created in the ground, and a box is installed adjacent to the excavation groove,
A backfilling step of backfilling the upper part of the box, to build a box row,
The propulsion tube is installed under the box while fitting a ridge extending in the tunnel axis direction on the upper floor plate upper surface of the propulsion tube into a groove formed in the tunnel plate direction on the bottom plate lower surface of the box. Build a propulsion line,
Excavating between the plurality of casing rows and the propulsion pipe rows constructed substantially in parallel at intervals,
It is characterized by constructing a permanent large section tunnel while using the box row and the propulsion pipe row as a mountain retaining support member,
Construction method of large section tunnel.

A box installation process in which a rectangular excavation groove with a rectangular cross section is created in the ground, and a box is installed adjacent to the excavation groove,
A backfilling step of backfilling the upper part of the box, to build a box row,
The propulsion tube is installed under the box while fitting a ridge extending in the tunnel axis direction on the upper floor plate upper surface of the propulsion tube into a groove formed in the tunnel plate direction on the bottom plate lower surface of the box. Build a propulsion line,
Utilizing a retaining wall provided in advance at the end of the upper floor slab upper surface of the box, excavating between the plurality of box rows and propulsion pipe rows that are constructed substantially in parallel at intervals,
It is characterized by constructing a permanent large section tunnel while using the box row and the propulsion pipe row as a mountain retaining support member,
Construction method of large section tunnel.

A box installation process in which a rectangular excavation groove with a rectangular cross section is created in the ground, and a box is installed adjacent to the excavation groove,
In the box, a backfill step of installing a retaining wall at the end of the upper floor slab upper surface of the box and backfilling the upper part of the box, to build a box row,
The propulsion tube is installed under the box while fitting a ridge extending in the tunnel axis direction on the upper floor plate upper surface of the propulsion tube into a groove formed in the tunnel plate direction on the bottom plate lower surface of the box. Build a propulsion line,
Excavating between a plurality of the container rows and propulsion pipe rows constructed in parallel at intervals,
It is characterized by constructing a permanent large section tunnel while using the box row and the propulsion pipe row as a mountain retaining support member,
Construction method of large section tunnel.

A box installation process of installing a box using a deformed section shield excavator that can excavate a deformed section,
An upper box installation step of installing an upper box on the box while forming an excavation groove in the ground along the upper floor slab of the rectangular shield box,
A back-filling step of back-filling the upper part of the upper box, thereby constructing a box row and an upper box row,
Excavating between the plurality of box rows and the upper row of boxes constructed substantially in parallel at intervals,
Characterized by constructing a permanent large section tunnel while using the box row and the upper box row as mountain retaining support members,
Construction method of large section tunnel.

A box installation process of installing a box using a deformed section shield excavator that can excavate a deformed section,
An upper box installation step of installing an upper box on the box while forming an excavation groove in the ground along the upper floor slab of the box,
A back-filling step of back-filling the upper part of the upper box, thereby constructing a box row and an upper box row,
Utilizing a retaining wall provided in advance at the end of the upper floor slab upper surface of the upper casing, excavating between the plurality of casing rows and the upper casing row constructed substantially in parallel at intervals,
Characterized by constructing a permanent large section tunnel while using the box row and the upper box row as mountain retaining support members,
Construction method of large section tunnel.

A box installation process of installing a box using a deformed section shield excavator that can excavate a deformed section,
An upper box installation step of installing an upper box on the box while forming an excavation groove in the ground along the upper floor slab of the box,
In the upper case, a backfill step of installing a retaining wall at the end of the upper floor slab upper surface of the upper case and backfilling the upper part of the upper case, thereby constructing a body row and an upper body row,
Excavating between the plurality of box rows and the upper row of boxes constructed substantially in parallel at intervals,
Characterized by constructing a permanent large section tunnel while using the box row and the upper box row as mountain retaining support members,
Construction method of large section tunnel.

Opening the ceiling of the shield excavator to the ground and performing the shield excavation by using an open shield excavator to construct the excavation trench,
A method for constructing a large-section tunnel according to any one of claims 1 to 6.

A deformed section shield excavator used in the method for constructing a large section tunnel according to any one of claims 1 to 6,
A cutting mountain retaining body, which is obtained by connecting the mountain retaining plates that are arranged in parallel at intervals with an upright and connected by a spacing retaining member, is provided detachably on a ceiling of the deformed section shield excavator,
Deformed section shield machine.