JP4889993B2

JP4889993B2 - Construction method of widening shaft

Info

Publication number: JP4889993B2
Application number: JP2005298274A
Authority: JP
Inventors: 範寛大高; 修司丸山; 秀雄中村; 直行三次; 憲司中村; 弘樹高橋; 幸博熊谷; 慎也飯渕; 忠男大岩; 邦彦有本; 孝治片野; 尚人保立; 錦也森岡; 学林; 貴弘山崎; 慎一山口
Original assignee: Nippon Steel Metal Products Co Ltd
Current assignee: Nippon Steel Metal Products Co Ltd
Priority date: 2005-10-13
Filing date: 2005-10-13
Publication date: 2012-03-07
Anticipated expiration: 2025-10-13
Also published as: JP2007107242A

Description

本発明は、下部が拡幅されている拡幅立坑の施工方法に関する。 The present invention relates to a method for constructing a widened vertical shaft whose lower part is widened.

推進工法は、推進管を埋設する路線の両端に、シールド掘進機等を搬入し発進させるための発進立坑と、シールド掘進機等を到達させて地中から撤去するための到達立坑から構築されて施工される。
その発進立坑や到達立坑の大きさは、シールド掘進機等を搬入、据え付け、または、撤去、回収が可能な大きさで決定される。しかし、近年、施工場所の道路事情（道路拡幅幅等）や近隣住宅への環境を配慮して立坑上部に形成された開口部の大きさが制限される場合が多くなってきている。
また、推進工事を行う場所には先行して、水道管、ガス管等のライフラインが埋設されており、一部には、光ケーブルが埋設されている場合もある。このため、複数の埋設物が併走する場所や、道路線形等の事情で立坑位置が制限される場合が多くなり、立坑位置の変更や長距離・曲線化に対応しているのが現状である。しかし、このような回避にも限界があり、既設管路の切り廻しが行われている。
従って、従来、下部が拡幅された拡幅立坑を地中に設ける場合、下部の拡幅部を含めて地盤全体を開削した後、下部が拡幅された拡幅立坑を配置して埋め戻すようにする拡幅立坑の施工法が知られている（例えば、特許文献１参照）。また、開口部の大きさが限定されている場合は、リング状の部材を階段状に設置することにより拡幅する工法（例えば、特許文献２参照）や、土留め壁であるライナープレートを扇形状にして拡幅する立坑構築方法（例えば、特許文献３参照）も知られている。
特開昭５８−９４５９７号公報特開２０００−４５６７６号公報特開２００３−３７８２号公報 The propulsion method is constructed from start shafts for bringing shield excavators etc. to both ends of the line where the propulsion pipes are buried and starting shafts for reaching the shield excavators etc. and removing them from the ground. It is constructed.
The size of the start shaft and the reach shaft is determined by a size that allows a shield machine or the like to be carried in, installed, removed, or collected. However, in recent years, the size of the opening formed in the upper part of the shaft has been often restricted in consideration of the road conditions at the construction site (road widening width, etc.) and the environment to neighboring houses.
In addition, a lifeline such as a water pipe or a gas pipe is buried in advance in a place where the propulsion work is performed, and an optical cable may be buried in a part thereof. For this reason, shaft positions are often restricted due to circumstances where multiple buried objects run side by side, road alignment, etc., and it is currently possible to cope with shaft position changes, long distances, and curving. . However, there is a limit to such avoidance, and the existing pipelines are being turned around.
Therefore, conventionally, when a widened vertical shaft with a widened lower portion is provided in the ground, after the entire ground including the lower widened portion has been excavated, a widened vertical shaft with a widened lower portion is disposed and backfilled. Is known (see, for example, Patent Document 1). In addition, when the size of the opening is limited, a method of widening the ring-shaped member by installing it in a step shape (see, for example, Patent Document 2), or a liner plate that is a retaining wall is a fan shape. A shaft construction method (see, for example, Patent Document 3) that widens the width is also known.
JP 58-94597 A JP 2000-45676 A JP 2003-3782 A

前記従来の場合は、道路路盤下の地中に、下部が拡幅された発進または到達用等の下部拡幅立坑等を設ける場合、下部の拡幅された拡幅立坑の平面外形寸法よりも大きな平面外形寸法の縦孔を開削して、拡幅立坑を配置した後、埋め戻すようにしていたので、大きい平面施工敷地面積が必要になり、例えば、道路下部の地中に拡幅立坑を設ける場合、道路を全面通行止めにして施工していた。
また、開口部の大きさが制限されている場合は、立坑の拡幅部の掘削にはオーバーハング部が生じ、地盤が堅固であれば崩れる恐れがないので問題はないが、軟弱地盤であると、崩れる不安があった。
本発明は、小さい平面敷地面積で施工することができ、片側交互交通等により交通させることが可能で、崩壊の不安がない拡幅立坑の施工方法を提供することを目的とする。 In the case of the conventional case, in the case of providing a lower widening shaft for starting or reaching with the lower portion widened in the ground under the roadbed, the planar outer size is larger than the planar outer size of the lower widened shaft. After excavating the vertical hole and arranging the widening shaft, it was necessary to refill it, so a large area for the construction of the flat work was required.For example, when installing the widening shaft in the ground below the road, The road was closed.
Also, if the size of the opening is limited, there is no problem because excavation of the widened portion of the shaft will cause an overhang, and if the ground is firm, there is no problem, but if it is soft ground I was worried about breaking down.
An object of this invention is to provide the construction method of the widening shaft which can be constructed with a small plane site area, can be made to pass by one-sided alternating traffic, etc., and does not have the fear of collapse.

前記の課題を有利に解決するために、第１発明の拡幅立坑の施工方法においては、縦方向に配置された縦土留め体と、縦土留め体に横方向に接続された拡幅土留め体とにより内壁面を土留めして立坑を形成する拡幅立坑の施工方法において、地表より地中縦方向に掘削し縦土留め体を配置し、次に、縦土留め体下部より横方向に拡幅土留め体の奥行き長さより若干奥深く掘削して奥行き方向の空間部を形成し、その奥行き方向の空間部に天井用拡幅土留め体を配置し、さらに、天井用拡幅土留め体が配置された前記空間部より下の縦方向を掘削して下部拡幅空間を形成し、その下部拡幅空間の奥部に、下部拡幅縦土留め体を配置し、親杭または縦梁からなる縦支持部材に取り付けられた支持梁を、前記奥行き方向の空間部に張り出すように配置し、間隔をおいて隣り合う前記支持梁の張り出し部に支持させるように複数の桁を架設し、その桁に天井用拡幅土留め体を架設して支持させることを特徴とする。
また、第２発明の拡幅立坑の施工方法においては、縦方向に配置された縦土留め体と、縦土留め体に横方向に接続された拡幅土留め体とにより内壁面を土留めして立坑を形成する拡幅立坑の施工方法において、地中に埋設されている埋設物近傍の地表より地中縦方向に掘削して縦土留め体を配置し、次に、前記埋設された埋設物の下側を、縦土留め体下部より横方向に拡幅土留め体の奥行き長さを掘削して奥行き方向に天井用拡幅土留め体が挿入できる空間部を形成し、その奥行き方向の空間部に天井用拡幅土留め体を配置し、さらに天井用拡幅土留め体が配置された前記空間部の下側を縦方向に掘削して下部拡幅空間を形成し、その下部拡幅空間の側壁部に、下部拡幅土留め体を配置し、親杭または縦梁からなる縦支持部材に取り付けられた支持梁を、前記奥行き方向の空間部に張り出すように配置し、間隔をおいて隣り合う前記支持梁の張り出し部に支持させるように複数の桁を架設し、その桁に天井用拡幅土留め体を架設して支持させることを特徴とする。
また、第３発明においては、第１又は第２発明のいずれかの拡幅立坑の施工方法において、地表より地中縦方向に掘削して縦土留め体を配置し、次に、縦土留め体下部より横方向に仮屋根材を土中に押込んで配置し、さらに、土中に配置された仮屋根材の下部を横方向に拡幅土留め体の奥行き長さを掘削して奥行き方向に前記支持梁の張り出し部に架設の桁上に架設される天井用土留め体が挿入できる空間部を形成することを特徴とする。
また、第４発明では、第１発明〜第３発明のいずれかの拡幅立坑の施工方法において、土留め体がライナープレートの組立て体であることを特徴とする。
なお、本発明において、土留め体とは、一つまたは複数の土留めパネルの組立て体（一つまたは複数の土留めパネルの部分組立て体を含む）である。
In order to solve the above-mentioned problem advantageously, in the construction method of the widening shaft according to the first aspect of the invention, the vertical earth retaining body arranged in the vertical direction, and the widening earth retaining body connected to the vertical soil retaining body in the lateral direction. In the construction method of the widening shaft, in which the inner wall surface is soiled and the shaft is formed, the vertical soil retaining body is arranged by excavating from the ground surface in the vertical direction, and then the lateral width is expanded from the lower portion of the vertical soil retaining body. A space part in the depth direction was formed by digging slightly deeper than the depth length of the earth retaining body, a widening earth retaining body for ceiling was arranged in the space part in the depth direction, and a wide earth retaining body for ceiling was further arranged. A lower widening space is formed by excavating the vertical direction below the space portion, and a lower widening vertical earth retaining body is disposed at the back of the lower widening space and attached to a vertical support member made of a parent pile or a vertical beam. The supported beam is arranged so as to overhang the space in the depth direction. And, bridged a plurality of digits so as to support the overhanging portion of the support beam adjacent at intervals, you characterized thereby supported bridged the ceiling widening earth retaining member on the digit.
Also, in the construction method of widening shafts of the second aspect of the invention, a vertically disposed a vertical earth retaining member, the vertical earth earth retaining tanning the inner wall surface by a laterally connected widened earth retaining body retaining member In the construction method of the widening shaft that forms the vertical shaft, the vertical earth retaining body is arranged by excavating in the vertical direction from the surface near the buried object buried in the ground, and then the buried buried object Under the vertical side of the vertical earth retaining body, the depth of the widening earth retaining body is excavated in the lateral direction to form a space where the widening earth retaining body for ceiling can be inserted in the depth direction, and the space in the depth direction A widened earth retaining body for ceiling is disposed on the upper side, and a lower widened space is formed by vertically excavating the lower side of the space where the widened earth retaining body for ceiling is disposed, and is formed on a side wall portion of the lower widened space. , place the lower widening earth retaining member, mounted on the vertical support member made from a parent piles or vertical beam A support beam is disposed so as to project into the space in the depth direction, and a plurality of girders are installed so as to be supported by the projecting portions of the adjacent support beams with an interval between them, and the widening earth retaining for ceiling is installed on the girders. It is characterized in that the body is constructed and supported .
Further, in the third invention, in the construction method of the widening shaft according to any one of the first and second inventions, the vertical soil retaining body is arranged by excavating from the ground surface in the underground vertical direction, and then the vertical soil retaining body. the temporary roofing from the bottom in the transverse direction and arranged in push you in the ground, further wherein a bottom of the temporary roofing material disposed in the soil laterally drilled depth length of the widening earth retaining member in the depth direction A space part into which a ceiling earth retaining member erected on the erected girder can be inserted is formed in the projecting part of the support beam .
According to a fourth aspect of the present invention, in the construction method of the widening shaft according to any one of the first to third aspects, the earth retaining body is an assembly of liner plates.
In the present invention, the earth retaining body is an assembly of one or more earth retaining panels (including a partial assembly of one or more earth retaining panels).

本発明によると、地表より地中縦方向に掘削し縦土留め体を配置し、次に、縦土留め体下部より横方向に拡幅土留め体の前記横方向の奥行き長さより若干奥深く掘削して奥行き方向の空間部を形成し、その奥行き方向の空間部に天井用拡幅土留め体を配置し、さらに、天井用拡幅土留め体が配置された前記空間部より下の縦方向を掘削して下部拡幅空間を形成し、その下部拡幅空間の奥部に、下部拡幅縦土留め体を配置するので、地表側の縦孔の構築する場合に、下部の拡幅部の平面外形寸法に合わせて開削する必要がないので、下部の拡幅部の平面外形寸法に影響されることなく、小さくして縦土留め体を構築することができる。
また、縦土留め体下部より横方向に拡幅土留め体の前記横方向の奥行き長さより若干奥深く掘削して奥行き方向の空間部を形成し、その奥行き方向の空間部に天井用拡幅土留め体を構築するので、拡幅部の天井部地山の下側に天井用拡幅土留め体が構築されるため、拡幅天井部の地山を前記天井用拡幅土留め体により支承することができ、拡幅天井部の地山の崩落がある場合でも、前記天井用拡幅土留め体により支承できるため崩壊の不安がなく、作業の安全性を図りながら確実に拡幅作業をすることができる。また、拡幅立坑を構築するために広く開削する必要がないので、交通障害を少なくすることができる。
さらに、天井用拡幅土留め体の下側の空間部で下部拡幅縦土留め体を配置することができるため、作業の安全性を図りながら確実に拡幅立坑を施工することができる。また、施工方法も容易である等の優れた効果がある。
また、第１又は第２発明のように、親杭または縦梁からなる縦支持部材に取り付けられて片持ち式に支持される支持梁を、前記奥行き方向の空間部に張り出すように配置し、間隔をおいて隣り合う前記支持梁の張り出し部に支持させるように複数の桁を架設し、その桁に天井用拡幅土留め体を架設して支持させると、天井用拡幅土留め体を複数の桁および支持梁を介して親杭または縦梁からなる縦支持部材に強固に支持させることができる。
また、第２発明のように、地中に埋設された埋設物があってもその近傍の地表より、地中縦方向に掘削して縦土留め体を配置し、前記埋設物の下側を縦土留め体下部より横方向に掘削して天井用拡幅土留め体が挿入できる空間部を形成し、その空間部に天井用拡幅土留め体を配置するので、地中に埋設された埋設物があっても、埋設物近傍の横方向に変位した位置の縦土留め体下部から埋設物の下側に天井用拡幅土留め体を設けることができ、また、その天井用拡幅土留め体が配置された下側を縦方向に掘削して下部拡幅空間を形成して、下部拡幅空間の側壁部に、下部拡幅土留め体を配置するので、天井用拡幅土留め体の下側に容易に下部拡幅土留め体を配置することができ、したがって、地中埋設物の近傍の縦土留め体から地中埋設物の下側に拡幅する拡幅立坑を容易に施工することができる。
また、第３発明によると、縦土留め体の下部より横方向に、仮屋根材を押込んで配置することにより、その下部を横方向に拡幅土留め体を配置する空間部を安定した状態で地山を掘削して容易に形成することができる。
第４発明のように、土留め体がライナープレートの組立て体であると、汎用性の高い安価なライナープレートを使用して、強固な拡幅立坑を短工期で施工することができ、拡幅立坑の施工コストを低減することができる。
According to the present invention, the vertical earth retaining body is excavated from the ground surface in the vertical direction in the underground, and then deeper than the horizontal depth length of the widened earth retaining body in the lateral direction from the lower part of the vertical earth retaining body. Forming a space in the depth direction, placing a widening retaining member for the ceiling in the space in the depth direction, and further excavating a vertical direction below the space where the widening retaining member for the ceiling is disposed. The lower widened space is formed, and the lower widened vertical clasp is placed in the back of the lower widened space, so when constructing a vertical hole on the ground surface side, it matches the planar external dimensions of the lower widened portion. Since there is no need to perform excavation, the vertical soil retaining body can be constructed with a small size without being affected by the planar outer dimensions of the lower widened portion.
In addition, a deep space is formed by excavating slightly deeper than the lateral depth of the wide clay retaining body in the lateral direction from the lower part of the vertical soil retaining body, and a widened soil retaining body for ceiling is formed in the space in the depth direction. Therefore, since the widening ceiling retaining body for the ceiling is constructed below the ground portion of the widening portion of the ceiling, the widening ceiling portion can be supported by the widening retaining body for the ceiling. Even if there is a collapse of the natural ground, since it can be supported by the widening earth retaining body for ceiling, there is no fear of collapse, and the widening operation can be performed reliably while ensuring the safety of the work. Moreover, since it is not necessary to excavate widely in order to construct a widening shaft, traffic obstacles can be reduced.
Furthermore, since the lower widening vertical earth retaining body can be disposed in the space below the widening earth retaining body for the ceiling, the widening shaft can be reliably constructed while ensuring the safety of the work. In addition, there is an excellent effect that the construction method is also easy.
Further, as in the first or second invention, the support beam that is attached to the vertical support member including the main pile or the vertical beam and is supported in a cantilever manner is arranged so as to protrude into the space in the depth direction. When a plurality of girders are installed so as to be supported by the overhanging portions of the supporting beams adjacent to each other at intervals, and a widening earth retaining body for ceiling is installed and supported on the girders, a plurality of widening earth retaining bodies for ceiling are provided. It is possible to firmly support the vertical support member made of the parent pile or the vertical beam through the girders and the support beam.
In addition, as in the second invention, even if there is an embedded object buried in the ground, a vertical earth retaining body is arranged by excavating in the vertical direction from the ground surface in the vicinity thereof, and the lower side of the embedded object is Excavation from the bottom of the vertical earth retaining body forms a space where a widening earth retaining body for ceiling can be inserted, and the wide earth retaining body for ceiling is placed in the space, so the buried object buried in the ground Even if there is, there can be provided a widening earth retaining body for the ceiling from the lower part of the vertical earth retaining body in the laterally displaced position near the buried object, and below the buried object. The lower widened space is excavated in the vertical direction to form the lower widened space, and the lower widened earth retaining body is arranged on the side wall of the lower widened space, so it is easy to place under the widened earth retaining body for the ceiling. The lower widened earth retaining body can be placed, and therefore the vertical earth retaining body in the vicinity of the underground buried object The widening pit for widening the side can be easily construction.
Further, according to the third invention, by placing the temporary roofing material in the lateral direction from the lower part of the vertical earth retaining body, the space part in which the widened earth retaining body is arranged in the lateral direction is stabilized in the lower part. It can be easily formed by excavating natural ground.
As in the fourth invention, when the earth retaining body is an assembly of liner plates, a highly versatile and inexpensive liner plate can be used to construct a strong widening shaft in a short construction period. Construction cost can be reduced.

次に、本発明を図示の実施形態に基づいて詳細に説明する。 Next, the present invention will be described in detail based on the illustrated embodiment.

本発明の拡幅立坑の施工方法では、親杭を使用する形態の拡幅立坑の施工方法と、吊り支持される縦梁を使用する拡幅立坑の施工方法があるので、最初に親杭を使用する形態の拡幅立坑の施工方法について説明する。 In the construction method of the widening shaft of the present invention, there is a construction method of the widening shaft using the main pile and a construction method of the widening shaft using the vertical beam supported by the suspension, so that the main pile is used first. The construction method of the widening shaft will be described.

図１から図１２は、本発明の第１実施形態の拡幅立坑の施工方法を説明するための説明図であり、まず、図１（ａ），（ｂ）に示すように、水道管、ガス管等のライフライン用の地下構造物Ｌあるいは地下埋設管等の埋設物近傍の地表から、平面矩形状等の小平面外形寸法に縦方向に地盤１を開削して縦孔２が設けられ、縦孔２の内側に、複数の土留めパネル３が環状に配置されて接合されると共に、上下方向に配置されて接合されて、縦方向に配置された縦土留め体５が形成され、また地山と縦土留め体５との間にグラウトが裏込め充填され、その縦土留め体５の内側に、前後方向に間隔をおいて対向すると共に左右方向に間隔をおいて、複数のH形鋼等の親杭６が地盤１に打設されている。 FIGS. 1 to 12 are explanatory views for explaining the construction method of the widening shaft according to the first embodiment of the present invention. First, as shown in FIGS. 1 (a) and 1 (b), water pipes, gas A vertical hole 2 is provided by cutting the ground 1 in a vertical direction from a ground surface in the vicinity of a buried object such as an underground structure L for a lifeline such as a pipe or an underground buried pipe to a small planar external dimension such as a planar rectangular shape, A plurality of earth retaining panels 3 are annularly arranged and joined inside the vertical hole 2 and are arranged vertically and joined to form a longitudinal earth retaining body 5 arranged in the vertical direction. A grout is back-filled between the natural ground and the vertical soil retaining body 5, and a plurality of H are opposed to the inner side of the vertical soil retaining body 5 with an interval in the front-rear direction and with an interval in the left-right direction. A parent pile 6 such as a shape steel is placed on the ground 1.

次に、縦土留め体５下部（下側）より横方向前方の拡幅側に、親杭６より張り出し設置する支持梁挿入のために、前後方向に対向する親杭６の前方地盤をつぼ状につぼ掘りし、支持梁等の配置用のつぼ状空間部７を設ける。前記のつぼ状空間部７を設ける場合は、図示のように、ハンド式オーガー８等のオーガー式掘削機を使用して作業員により行うことができ、ハンド式オーガー８の基端側を支持用ロッド９に連結して支持させると共に、支持用ロッド９の上部を親杭６に固定して作業員の負担を軽減するようにすればよい。 Next, the front ground of the main pile 6 facing in the front-rear direction is inserted into a pot for insertion of a support beam extending from the main pile 6 on the widening side in front of the vertical soil retaining body 5 (lower side). A crucible-like space portion 7 for arranging support beams and the like is provided. When the crucible space 7 is provided, it can be carried out by an operator using an auger excavator such as a hand auger 8 as shown in the drawing, and the base end side of the hand auger 8 is used for support. What is necessary is just to make it connect with the rod 9 and to support it, and to fix the upper part of the rod 9 for support to the parent pile 6 and to reduce a burden of an operator.

そして、図１（ｃ）、（ｄ）に示すように、前後方向に対向する各親杭６の左右方向の一側部における所定のレベルに、ブラケット１０をボルト等により取付け、つぼ状空間部７に拡幅部の支持梁１１の先端側を挿入し、前後のブラケット１０に支持梁１１の基端側を設置してボルト等により取付ける。
次に、図２（ａ），（ｂ）に示すように、前記と同様に隣接する親杭６の前面側も同様につぼ状空間部７を設けて支持梁１１を設ける。次に図２（ｃ）、（ｄ）に示すように、つぼ状空間部７間を、ハンド式オーガー８で掘削して、図３（ａ），（ｂ）に示すように、横溝状に奥行き方向拡幅部の天井空間部３４を形成し、左右方向に隣り合う支持梁１１上に横桁１２を奥行き方向に間隔をおいて平行に複数本設置し、その横桁１２を支持レールとして、ライナープレート等の拡幅部天井用土留めパネル３をスライドさせて押し込み配置して、結合しない状態の天井用拡幅土留め体４を構成する。 And as shown to FIG.1 (c), (d), the bracket 10 is attached with the volt | bolt etc. to the predetermined level in the one side part of the left-right direction of each parent pile 6 which opposes the front-back direction, 7, the distal end side of the support beam 11 of the widened portion is inserted, and the proximal end side of the support beam 11 is installed on the front and rear brackets 10 and attached with bolts or the like.
Next, as shown in FIGS. 2A and 2B, similarly to the above, the front side of the adjacent parent pile 6 is similarly provided with the pot-shaped space portion 7 to provide the support beam 11. Next, as shown in FIGS. 2 (c) and 2 (d), the space between the crucible spaces 7 is excavated with a hand-type auger 8 to form a horizontal groove as shown in FIGS. 3 (a) and 3 (b). A ceiling space portion 34 of the widened portion in the depth direction is formed, and a plurality of horizontal beams 12 are installed in parallel in the depth direction on the support beams 11 adjacent in the left-right direction, and the horizontal beams 12 are used as support rails. The widening section ceiling retaining panel 3 such as a liner plate is slid and pushed in to form the widening ceiling retaining body 4 for ceiling which is not joined.

なお、奥行き方向先端側の天井用土留めパネル３の先端部は、支持梁１１より突出させて、下位に位置する壁用土留めパネルとの接合を容易にしておく。そのために、拡幅土留め体の奥行き長さより若干奥深く掘削して奥行き方向の空間部を形成している。 In addition, the front-end | tip part of the ceiling earth retaining panel 3 of the depth direction front end side is protruded from the support beam 11, and joining with the wall earth retaining panel located in the lower layer is made easy. For this purpose, a space part in the depth direction is formed by excavating slightly deeper than the depth of the widening body retaining body.

次に、図３（ｃ），（ｄ）に示すように、縦土留め体５の下端部に、H形鋼等の分割型リングを組み立てて補強リング１３を設け、図３（ｅ）に示すように、前記補強リング１３のフランジと、拡幅部手前の天井用土留めパネル３の継手板１５をボルト・ナット１４とにより結合して組立て、図３（ｆ）に示すように、また、前記補強リング１３のウエブと縦土留め体５の継手板１５とをボルト・ナット１４とにより結合して組立て、また、適宜支持梁１１と横桁１２との間に高さ調整用プレートを介在させて、天井用土留めパネル３のレベル調整を行い、図４（ａ）およびその一部を拡大した図４（ｃ）に拡大して示すように、隣り合う天井用土留めパネル３の継手板１５をボルト・ナット１４とにより結合して組立て天井用拡幅土留め体４を構成する。 Next, as shown in FIGS. 3C and 3D, a reinforcing ring 13 is provided by assembling a split ring such as H-shaped steel at the lower end portion of the vertical earth retaining member 5, and FIG. As shown in FIG. 3 (f), the flange of the reinforcing ring 13 and the joint plate 15 of the ceiling retaining panel 3 in front of the widened portion are joined and assembled by bolts and nuts 14, as shown in FIG. The web of the reinforcing ring 13 and the joint plate 15 of the vertical earth retaining member 5 are assembled by connecting them with bolts and nuts 14, and a height adjusting plate is appropriately interposed between the support beam 11 and the cross beam 12. Then, the level of the earth retaining panel 3 for the ceiling is adjusted, and the joint plate 15 of the adjacent earth retaining panel 3 for the ceiling is enlarged as shown in FIG. 4A and FIG. Widened earth retaining body 4 for assembling by connecting with bolts and nuts 14 Configure.

その後、天井用土留めパネル３下の地盤を縦方向に掘り下げ、図５に示すように、左右方向端部側の天井用土留めパネル３に、拡幅部における最上部に位置する側部用の側壁パネル１７を取り付ける。天井側部の天井用土留めパネル３と、拡幅部における最上部に位置する側部用の側壁パネル１７との接合には、これらの継手板相互をボルト・ナットによる接合手段でもよいが、図示の形態では、例えば、図７（ａ）または図８（ａ）に拡大して示すように、天井用土留めパネル３側の端部下面側に、下方に向って拡大する傾斜面２０を有する係止フック２１を、前後方向に間隔を置いて直列に複数設けておき、また最上部に位置する側部用の側壁パネル１７における上端部の継手板１５に、広幅透孔２２とこれに接続する狭巾透孔２３とからなる被係止用透孔２４を設けておき、側壁パネル１７を持ち上げて、その側壁パネル１７における前記広幅透孔２２に、天井用土留めパネル３の吊下げ用係止フック２１を挿入した状態で側壁パネル１７を奥部に向って前方に横移動させることにより、係止フック２１の広幅側の傾斜面２０を狭巾透孔の下側に位置させて、前記吊下げ用係止フック２１により側壁パネル１７を支持させるようにしてもよい。なお、縦孔側の縦土留め体５の下側に壁パネルを順次組立てる。
吊下げ用係止フック２１としては、図７に示すようにブロック状の部材を使用してもよく、あるいは、図８に示すように、鋼板を折り曲げ形成したものでもよい。 Thereafter, the ground below the ceiling retaining panel 3 is dug in the vertical direction, and as shown in FIG. 5, the side wall panel for the side located at the top of the widened portion is added to the ceiling retaining panel 3 on the left and right ends. 17 is attached. For joining the ceiling retaining panel 3 on the ceiling side part and the side wall panel 17 for the side part located at the uppermost part in the widened part, these joint plates may be joined by means of bolts and nuts. In the embodiment, for example, as shown in FIG. 7 (a) or FIG. 8 (a) in an enlarged manner, the latch has an inclined surface 20 that expands downward on the lower surface side of the end on the ceiling earth retaining panel 3 side. A plurality of hooks 21 are provided in series at intervals in the front-rear direction, and a wide through hole 22 and a narrow connecting to the wide through-hole 22 are formed in the joint plate 15 at the upper end of the side wall panel 17 for the side part located at the uppermost part. A locked through hole 24 including a wide through hole 23 is provided, the side wall panel 17 is lifted, and the wide hook hole 22 in the side wall panel 17 is attached to the hanging hook for hanging the ceiling earth retaining panel 3. Side wall panel with 21 inserted 7 is moved laterally forward toward the back, so that the inclined surface 20 on the wide side of the locking hook 21 is positioned below the narrow through hole, and the side wall panel is formed by the locking hook 21 for suspension. 17 may be supported. In addition, a wall panel is sequentially assembled under the vertical earth retaining body 5 on the vertical hole side.
As the suspension locking hook 21, a block-like member may be used as shown in FIG. 7, or a steel plate may be bent as shown in FIG. 8.

また、図６に示すように、奥部の天井用土留めパネル３に、拡幅部における最上部に位置する前部用の前壁パネル１９を取り付ける。天井奥部の天井用土留めパネル３と、拡幅部における最上部に位置する前部用の前壁パネル１９との接合には、これらの継手板相互をボルト・ナットによる接合手段でもよいが、図示の形態では、例えば、図７（ａ）または図８（ａ）に拡大して示すように、天井用土留めパネル３側の端部下面側に、下方に向って拡大する傾斜面２０を有する係止フック２１を、左右方向に間隔を置いて直列に複数設けておき、また最上部に位置する前部用の前壁パネル１９の上端部継手板１５に、広幅透孔２２とこれに接続する狭巾透孔２３とからなる被係止用透孔２４を設けておき、前壁パネル１９を持ち上げて、その前壁パネル１９における前記広幅透孔２２に、天井用土留めパネル３の吊下げ用係止フック２１を挿入した状態で前壁パネル１９を横移動させることにより、係止フック２１の広幅側の傾斜面２０を狭巾透孔の下側に位置させることにより、前記吊下げ用係止フック２１により前壁パネル１９を支持させるようにしてもよい。
吊下げ用係止フック２１としては、図７に示すようにブロック状の部材を使用してもよく、あるいは、図８に示すように、鋼板を折り曲げ形成したものでもよい。 Moreover, as shown in FIG. 6, the front wall panel 19 for the front part located in the uppermost part in a wide part is attached to the earth retaining panel 3 for ceilings of a back part. For joining the ceiling retaining panel 3 at the back of the ceiling and the front wall panel 19 for the front part located at the uppermost part in the widened part, these joint plates may be joined by means of bolts and nuts. In the embodiment, for example, as shown in an enlarged view in FIG. 7A or FIG. 8A, an engagement surface having an inclined surface 20 that expands downward is provided on the lower surface side of the end on the ceiling retaining panel 3 side. A plurality of stop hooks 21 are provided in series at intervals in the left-right direction, and are connected to the wide through-hole 22 and the upper joint plate 15 of the front wall panel 19 for the front part located at the uppermost part. A locked through-hole 24 including a narrow-width through-hole 23 is provided, the front wall panel 19 is lifted, and the ceiling-type earth retaining panel 3 is suspended in the wide through-hole 22 in the front wall panel 19. Side the front wall panel 19 with the locking hook 21 inserted The front wall panel 19 may be supported by the suspension hooks 21 by moving the inclined surface 20 on the wide side of the hooks 21 below the narrow through hole. Good.
As the suspension locking hook 21, a block-like member may be used as shown in FIG. 7, or a steel plate may be bent as shown in FIG. 8.

前記の状態で、天井拡幅部土留めパネルに設けられたグラウト孔より、地山と天井拡幅部および一段目の前面パネルおよび側壁パネルとの間にモルタル等を裏込め充填する。 In the state described above, mortar or the like is backfilled and filled between the natural ground and the ceiling widened portion, the front panel and the side wall panel of the ground through the grout hole provided in the ceiling widened portion earth retaining panel.

図６の状態から拡幅部下方の地盤を順次掘削して、２点鎖線で示すように、上位に位置するパネルの下部に下位のパネルを配置する。すなわち、上位に位置する前壁パネル１９の継手板に下位に位置する前壁パネル１９の継手板をボルト等により接合一体化すると共に、横方向の前壁パネル１９相互の継手板を連結して一体化する。また、同様に上位の側壁パネルと下位の側壁パネル１７を連結して一体化する。後部壁パネルも同様に連結一体化して下部拡幅土留め体２５を構成すると共に、適宜、地山との間にグラウトを裏込め充填して、図９〜図１１に示すような、下部が拡幅された拡幅立坑２６を構築する。 The ground below the widened portion is sequentially excavated from the state shown in FIG. 6, and the lower panel is disposed below the upper panel as indicated by a two-dot chain line. That is, the joint plate of the lower front wall panel 19 is joined and integrated with the joint plate of the lower front wall panel 19 with a bolt or the like, and the joint plates of the front wall panels 19 in the lateral direction are connected to each other. Integrate. Similarly, the upper side wall panel and the lower side wall panel 17 are connected and integrated. Similarly, the rear wall panel is connected and integrated to form the lower widening retaining body 25, and the bottom is widened as shown in FIGS. The widened vertical shaft 26 is constructed.

なお、図１２（ａ）に示すように、前記拡幅立坑２６を発進・到達立坑として使用する場合に、左右方向の中間部に配置されている親杭６が邪魔になる場合には、基礎コンクリート２８を打設・硬化して、拡幅部奥部側に適宜ジャッキを介在させて短尺柱２７により拡幅部支持梁１１先端部を支持すると共に連結した状態で、図１２（ｃ）（ｄ）に示すように、短尺柱２７と後部親杭６の間に位置する親杭６を、基礎コンクリート２８上面付近で切断し、支持梁１１と切断された親杭６とを接合しているブラケット１０を取り外して、切断された親杭６を撤去し、内部空間を広くしてもよい。 In addition, as shown to Fig.12 (a), when using the said widening shaft 26 as a start and a reaching shaft, when the main pile 6 arrange | positioned in the intermediate part of the left-right direction gets in the way, it is foundation concrete. 12 (c) and (d) in a state in which the front end portion of the widening portion support beam 11 is supported and connected by a short column 27 with a jack appropriately interposed on the deeper side of the widening portion. As shown, the parent pile 6 located between the short column 27 and the rear parent pile 6 is cut in the vicinity of the upper surface of the foundation concrete 28, and the bracket 10 that joins the support beam 11 and the cut parent pile 6 is joined. It may be removed and the cut parent pile 6 may be removed to widen the internal space.

（吊り支持される縦梁を使用する拡幅立坑の施工方法について）
図１３〜図２３は、本発明の第２実施形態の拡幅立坑の施工方法を説明するための説明図であって、まず、図１３（ａ）（ｂ）に示すように、地表上の開削すべき部分に平行に受け桁３０を敷設する。前記の受け桁３０は、図１３に２点鎖線で示す縦土留め体５の外側に位置するように敷設してもよく、後記する形態のように縦土留め体５に交差するように敷設してもよい。いずれの場合も、前記の受け桁３０に縦土留め体５を介して縦梁３１を間接的に吊下げ支持したり、直接縦梁３１の上端部を連結して支持することができる。なお、図中３７は埋設管である。 (About the construction method of the widening shaft using the vertical beam supported by suspension)
FIGS. 13-23 is explanatory drawing for demonstrating the construction method of the widening shaft of 2nd Embodiment of this invention, Comprising: First, as shown to FIG. 13 (a) (b), excavation on the ground surface is carried out. A receiving girder 30 is laid in parallel to the portion to be. The receiving girder 30 may be laid so as to be located outside the vertical earth retaining body 5 indicated by a two-dot chain line in FIG. 13, or laid so as to intersect the vertical earth retaining body 5 as described later. May be. In either case, the vertical beam 31 can be indirectly suspended and supported by the receiving girder 30 via the vertical earth retaining body 5, or the upper end portion of the vertical beam 31 can be directly connected and supported. In the figure, 37 is a buried pipe.

次に、図１３（ｃ）（ｄ）に示すように、一対の受け桁３０間の地盤１を縦に平面矩形状に開削して縦孔２を設け、図１４（ａ）（ｂ）に示すように、前記と同様に土留めパネル３を横方向および上下方向に組立てて連結して一体化し、地山間にグラウトを行って平面小外形寸法の縦土留め体５を形成する。 Next, as shown in FIGS. 13 (c) and 13 (d), the ground 1 between the pair of receiving girders 30 is vertically cut into a plane rectangular shape to provide vertical holes 2, and FIGS. 14 (a) and 14 (b). As shown in the figure, the earth retaining panel 3 is assembled and connected in the horizontal direction and the upper and lower direction in the same manner as described above, and is united, and the ground earth retaining body 5 having a small plane external dimension is formed by grouting between the grounds.

次いで、図１４（ｃ）（ｄ）に示すように、前記縦土留め体５の内側における左右方向一端側において、前記縦土留め体５の内側における前後方向に対向するように、縦梁３１を配置して、受け桁３０と縦土留め体５と縦梁３１とをこれらに渡って貫通配置したボルト等の連結部材３２により連結一体化して、垂直に吊下げ支持された縦梁３１を前後方向に間隔をおいて対向するように設置する。 Next, as shown in FIGS. 14 (c) and 14 (d), the longitudinal beam 31 is arranged so as to face the front-rear direction on the inner side of the vertical earth retaining body 5 on one end side in the left and right direction inside the vertical earth retaining body 5. Are connected and integrated by a connecting member 32 such as a bolt penetrating the receiving girder 30, the vertical earth retaining body 5 and the vertical beam 31, and the vertical beam 31 supported by being vertically suspended is supported. Install so as to face each other in the front-rear direction.

前記縦梁３１は前記実施形態の親杭６に対応するものであり、前記縦梁３１の下端部位置は、拡幅部天井部の支持梁１１を、前記実施形態と同様にブラケット１０により支持可能な位置に配置される。 The vertical beam 31 corresponds to the parent pile 6 of the embodiment, and the lower end position of the vertical beam 31 can support the support beam 11 of the widened portion ceiling portion by the bracket 10 as in the embodiment. It is arranged in the position.

次いで、図１５（ａ）（ｂ）に示すように、縦梁３１より張り出し設置する支持梁１１を挿入するために、前後方向に対向する縦梁３１における幅部天井直下の地盤を前方に、ハンド式オーガ等のオーガー式掘削機を使用して、つぼ状につぼ掘りし、図１５（ｃ），（ｄ）に示すように、前後方向に間隔をおいた縦梁３１の下端部にブラケット１０（図示を省略した）を、前記実施形態と同様にボルト・ナットにより取付けて、図１６（ａ），（ｂ）に示すように、支持梁１１を配置し、前後の縦梁３１によりブラケット１０を介して支持する。 Next, as shown in FIGS. 15 (a) and 15 (b), in order to insert the support beam 11 protruding from the vertical beam 31, the ground directly below the width part ceiling in the vertical beam 31 facing in the front-rear direction is forward, Using an auger-type excavator such as a hand-type auger, a pot is dug into a crucible, and as shown in FIGS. 15 (c) and 15 (d), a bracket is attached to the lower end of the longitudinal beam 31 spaced in the front-rear direction. 10 (not shown) is attached with bolts and nuts in the same manner as in the above embodiment, and the support beam 11 is arranged as shown in FIGS. 16 (a) and 16 (b). 10 to support.

次に、図１６（ｃ）（ｄ）に示すように、天井部のつぼ掘りを天井部横方向に拡大して、左右方向中間部および他端側に、前記と同様に前後一対の縦梁３１を吊下げ支持し、左右方向中間部の前後の縦梁３１にブラケット１０を取り付け、前後のブラケット１０に支持させるように、支持梁１１を架設する。 Next, as shown in FIGS. 16 (c) and 16 (d), the urging of the ceiling portion is expanded in the lateral direction of the ceiling portion, and a pair of longitudinal beams in the same manner as described above are provided on the middle portion and the other end side in the left-right direction. 31 is suspended and supported, the bracket 10 is attached to the longitudinal beams 31 at the front and rear of the middle portion in the left-right direction, and the support beams 11 are installed so as to be supported by the front and rear brackets 10.

次いで、図１７（ａ）（ｂ）に示すように、各支持梁１１の張出側に短尺横桁１２ａを各支持梁１１に支持させるようにスライドさせて挿入し、図１７（ｃ）（ｄ）に示すように、前後方向に間隔をおいて平行に複数の短尺横桁１２ａを設置する。 Next, as shown in FIGS. 17 (a) and 17 (b), the short cross beams 12a are slid and inserted on the projecting side of the support beams 11 so as to be supported by the support beams 11, and FIG. As shown in d), a plurality of short cross beams 12a are installed in parallel at intervals in the front-rear direction.

次いで、図１８（ａ）（ｂ）に示すように、各短尺横桁１２ａに支持させるように拡幅部天井用パネル３３を挿入し、図１８（ｃ）（ｄ）に示すように、複数の短尺横桁１２ａに支持させるようにして、左右方向に拡幅部天井用パネル３３を並べて設置する。 Next, as shown in FIGS. 18 (a) and 18 (b), the wide section ceiling panel 33 is inserted so as to be supported by each of the short cross beams 12a, and a plurality of panels as shown in FIGS. 18 (c) and 18 (d). Wide panel ceiling panels 33 are arranged side by side in the left-right direction so as to be supported by the short cross beams 12a.

次に、図１９（ａ）（ｂ）に示すように、他端側をつぼ掘りして、前後の縦梁３１にブラケット１０を取付けて、支持梁１１を張り出し架設し、次いで、図１９（ｃ）（ｄ）に示すように、つぼ掘りを横方向に拡大して、つぼ掘り部間を掘削し、天井空間部３４を形成する。 Next, as shown in FIGS. 19 (a) and 19 (b), the other end side is dug up, the bracket 10 is attached to the front and rear longitudinal beams 31, the support beam 11 is overhanging, and then FIG. 19 ( c) As shown in (d), the pot digging is expanded in the horizontal direction to excavate between the pot digging portions to form the ceiling space portion 34.

次に、図２０（ａ）（ｂ）に示すように、各支持梁１１の張出側に長尺横桁１２ｂを各支持梁１１に支持させるようにスライドさせて挿入し、図２０（ｃ）（ｄ）に示すように、前後方向に間隔をおいて平行に複数の長尺横桁１２ｂを設置する。 Next, as shown in FIGS. 20A and 20B, the long cross beams 12b are slid and inserted so as to be supported by the support beams 11 on the projecting side of the support beams 11, and FIG. ) As shown in (d), a plurality of long horizontal beams 12b are installed in parallel in the front-rear direction.

次いで、図２１（ａ）（ｂ）に示すように、各長尺横桁１２ｂに支持させるように天井用パネル３３を挿入し、図２１（ｃ）（ｄ）に示すように、複数の長尺横桁１２ｂに支持させるようにして、左右方向に拡幅部天井用パネル３３並べて設置する。 Next, as shown in FIGS. 21 (a) and 21 (b), the ceiling panel 33 is inserted so as to be supported by the respective long cross beams 12b, and a plurality of long panels as shown in FIGS. 21 (c) and 21 (d). The wide-width portion ceiling panel 33 is arranged side by side in the left-right direction so as to be supported by the horizontal bar 12b.

次いで、図２２（ａ）（ｂ）および（ｃ）（ｄ）に示すように、拡幅部天井下の地山３５を順次掘削し、前壁パネル１９および側部並びに後部の土留めパネル３を組立てて、下部拡幅縦土留め体２５を構築し、適宜地山と下部拡幅土留め体２５との空間にグラウトを充填して拡幅立坑２６を構築する。 Next, as shown in FIGS. 22 (a), 22 (b) and 22 (c) (d), the natural ground 35 below the widened section ceiling is sequentially excavated, and the front wall panel 19 and the side and rear earth retaining panels 3 are removed. After assembling, the lower widened vertical retaining body 25 is constructed, and the widened shaft 26 is constructed by appropriately filling the space between the natural ground and the lower widened retaining body 25 with grout.

次いで、前記実施形態と同様に拡幅立坑２６内の内部作業空間を大きくして作業性を高めるためには、図２３に示すように基礎コンクリート２８を打設し硬化させ、短尺柱２７を左右方向の両端側の各支持梁１１の下部に配置して、図２４に示すように、中間部の縦梁３１を撤去することができる。 Next, in order to increase the work space by increasing the internal working space in the widening shaft 26 as in the above embodiment, foundation concrete 28 is placed and hardened as shown in FIG. As shown in FIG. 24, it is possible to remove the vertical beam 31 in the middle part.

次に、前記第２実施形態の変形形態いついて、図２５および図２６を参照して説明すると、この形態では、受け桁３０を、上部の縦土留め体５内に位置するように敷設し、その受け桁３０の下部に縦梁３１の上端部を固定する形態を示したもので、この場合には、後部側の縦梁３１と支持梁１１の後端部とを左右方向に延長するように配置したＨ形鋼等の継ぎ梁３７により接合することができる。このような形態でも、前記第２実施形態と同様な施工方法により拡幅立坑２６を構築することができる。 Next, a modified embodiment of the second embodiment will be described with reference to FIGS. 25 and 26. In this embodiment, the receiving beam 30 is laid so as to be positioned in the upper vertical earth retaining body 5. In this case, the upper end of the vertical beam 31 is fixed to the lower portion of the receiving beam 30. In this case, the vertical beam 31 on the rear side and the rear end of the support beam 11 are extended in the left-right direction. It can join by the joint beam 37, such as H-shaped steel arrange | positioned in this way. Even in such a form, the widening shaft 26 can be constructed by the same construction method as in the second embodiment.

（仮屋根材を使用する拡幅立坑の施工方法について）
図２７〜図２８は、前記各実施形態にも適用できる本発明の第３実施形態の拡幅立坑の施工方法を説明するための説明図であって、この形態では、図２７（ａ）（ｂ）に示すように、縦孔２の内側に縦土留め体５を形成した後、その縦土留め体５の下部より横方向に仮屋根材４３を地中（地山）３５に押し込み配置し、その下側に設ける天井用拡幅土留め体４の構築を容易にした形態である。

(About construction method of widening shaft using temporary roofing material)
FIGS. 27 to 28 are explanatory views for explaining the construction method of the widened shaft according to the third embodiment of the present invention that can be applied to the above-described embodiments. In this embodiment, FIGS. ), After the vertical soil retaining body 5 is formed inside the vertical hole 2, the temporary roofing material 43 is pushed into the ground (natural ground) 35 in the lateral direction from the lower portion of the vertical soil retaining body 5. This is a form that facilitates construction of the widening earth retaining body 4 for the ceiling provided on the lower side.

さらに説明すると、図２７（ｂ）に拡大して示すように、縦土留め体５の下部内側の地盤上に、支持台４０を介して水平に支承フレーム４１を配置し、前記支承フレーム４１上に高さ調整部材４２を介してシート状の鋼矢板等の仮屋根材４３をスライド可能に載置し、また、前記支承フレーム４１の後部に反力受け４４を介して伸縮式ジャッキ４５を設け、仮屋根材４３の後部とジャッキ４５との間に、仮屋根材４３の挟み込み治具４６を介在させた状態で、図２７（ｃ）に示すように、前記ジャッキ４５を伸長して、仮屋根材４３を横方向に圧入し、また、図２８（ａ）に示すように、挟み込み治具４６とジャッキ４５との間に適宜ピース４７を介在させて、前記ジャッキ４５を伸長する動作を繰り返すことにより、所定の位置に押込み配置している。また、前記仮屋根材４３における継手に、隣接して押込み配置する仮屋根材４３の継手を噛合わせて押込む工程を必要回数繰り返して、拡幅部上部に仮屋根部４８を形成する形態である。なお、仮屋根部４８の基端部は、補強リング１３に設けられた支承板４９を介して補強リング１３に支承されるように構成されている。 More specifically, as shown in an enlarged view in FIG. 27 (b), a support frame 41 is horizontally arranged on the ground inside the lower part of the vertical earth retaining body 5 via a support base 40. A temporary roof material 43 such as a sheet-like steel sheet pile is slidably mounted on the height adjustment member 42, and a telescopic jack 45 is provided on the rear portion of the support frame 41 via a reaction force receiver 44. 27. With the sandwiching jig 46 of the temporary roof material 43 interposed between the rear portion of the temporary roof material 43 and the jack 45, the jack 45 is extended as shown in FIG. The roof material 43 is press-fitted in the lateral direction, and as shown in FIG. 28A, the operation of extending the jack 45 is repeated by appropriately interposing a piece 47 between the sandwiching jig 46 and the jack 45. Push in place It is. Further, the step of engaging the joint of the temporary roof material 43 to be pushed in and adjacent to the joint in the temporary roof material 43 and pushing it in is repeated as many times as necessary to form the temporary roof portion 48 in the upper portion of the widened portion. The base end portion of the temporary roof portion 48 is configured to be supported on the reinforcing ring 13 via a support plate 49 provided on the reinforcing ring 13.

また、縦土留め体５の内側に、間隔をおいて対向するように縦梁３１を設け、その縦梁３１にボルト・ナットにより取付けて支持させるように、分割型のH形鋼材等を組立ててなる補強リング１３を設け、その補強リング１３の外縁側部分で、前記の仮屋根部４８の内端側下面を支持するようにしている。また、前記の仮屋根部４８の先端部は地山に埋め込み配置した状態で、支持梁１１の配置を容易にしている。したがって、仮屋根部４８の基端側から中間部下面をつぼ掘りしても、前記仮屋根部４８は先端部と基端部の両端部で支持されるようにされている。 Also, a vertical beam 31 is provided inside the vertical earth retaining body 5 so as to face each other with a gap, and a split H-shaped steel material or the like is assembled so that the vertical beam 31 is attached and supported by bolts and nuts. The reinforcing ring 13 is provided, and the inner edge side lower surface of the temporary roof portion 48 is supported by the outer edge side portion of the reinforcing ring 13. Further, the support beam 11 is easily arranged in a state where the tip portion of the temporary roof portion 48 is embedded in a natural ground. Therefore, even if the middle lower surface is dug from the base end side of the temporary roof portion 48, the temporary roof portion 48 is supported at both ends of the front end portion and the base end portion.

また、前記実施形態と同様に、拡幅側をつぼ掘りして、支持梁１１を縦梁３１に設けたブラケット１０により支持するようにし、左右方向に隣り合う支持梁１１に横桁１２を支持させる（図示の形態では、補強リング１３側に横桁１２を３本寄せた状態で配置されている）。また、図示を省略するが、天井空間３４が形成された後、各横桁１２は前後方向に間隔をおいて展開され、各横桁１２間の隙間から、前記の横桁１２の上部に天井用パネル３３を設置して天井用拡幅土留め体を形成する。なお、天井用拡幅土留め体の下側を縦方向に掘削して下部拡幅空間を形成する点、下部拡幅空間に下部拡幅土留め体を配置し、適宜裏込め材を充填して拡幅立坑を構築する点は、前記各実施形態と同様である。 Further, similarly to the above-described embodiment, the widening side is dug so that the support beam 11 is supported by the bracket 10 provided on the vertical beam 31, and the horizontal beam 12 is supported by the support beam 11 adjacent in the left-right direction. (In the form shown in the figure, the three cross beams 12 are arranged on the reinforcing ring 13 side). Although illustration is omitted, after the ceiling space 34 is formed, each cross beam 12 is developed with a space in the front-rear direction, and a ceiling is formed above the cross beam 12 from a gap between the cross beams 12. Panel 33 is installed to form a widening earth retaining body for ceiling. Note that the lower widening space is formed by excavating the lower side of the widening retaining body for the ceiling in the vertical direction, the lower widening retaining body is disposed in the lower widening space, and the backfill material is appropriately filled to form the widening shaft. The points to be constructed are the same as those in the above embodiments.

なお、図示を省略するが、前記のような仮屋根材４３を使用する仮屋根部４８を前記各実施形態１、２等に適用してもよく、これらの場合に、縦土留め体５と仮屋根材４３との間に支持部材を介在させて連結してもよく、例えば、各仮屋根材４３の縦孔側の基端部を、縦土留め体５の下部に支持部材を介在させて前記仮屋根材４３の基端部を支持すると共に、前記支持部材の上部を縦土留め体５にボルト・ナットにより連結し、前記支持部材の下部を補強リング１３にボルト・ナットにより連結するようにしてもよく、また、仮屋根材４３の埋め込み長さが確保でき、片持ち式で十分である場合には、図２８に示す形態よりも奥部に圧入して、補強リング１３と緩衝しない位置に埋め込み配置する形態でもよい。 Although illustration is omitted, the temporary roof portion 48 using the temporary roof material 43 as described above may be applied to each of the first and second embodiments. For example, a base member on the vertical hole side of each temporary roof material 43 may be connected to the lower portion of the vertical earth retaining body 5. While supporting the base end part of the temporary roof material 43, the upper part of the support member is connected to the vertical earth retaining body 5 by bolts and nuts, and the lower part of the support member is connected to the reinforcing ring 13 by bolts and nuts. In addition, when the embedded length of the temporary roof material 43 can be secured and the cantilever type is sufficient, it is press-fitted into the back of the configuration shown in FIG. It may be in a form of being embedded in the position.

前記のように、仮屋根部４８を設けるようにすると、仮屋根部４８上の地山が支承されるので、その下側でつぼ掘りする場合でも、拡幅天井地山の崩落を確実に防止でき、より安全に拡幅部の構築が可能になる。 As described above, when the temporary roof portion 48 is provided, the natural ground on the temporary roof portion 48 is supported, so even when digging underneath, the collapse of the widened ceiling natural ground can be reliably prevented, and more The widened part can be constructed safely.

なお、前記各実施形態の場合は、拡幅部が１段の場合であるが、２段３段と拡幅部を多段にして立坑下部を広げる必要がある場合には、下部拡幅土留め壁体２５の下部を、つぼ堀して第２の支持梁を親杭６または縦梁３１に支持させるように設けるようにした上で、横桁および拡幅部天井用土留めパネルを設置することで、第２の天井用拡幅土留め体を設けることができ、さらに下部を拡幅する必要がある場合には、前記と同様な工程を繰り返すことで、３段以上の多段型の拡幅立坑にすることも可能である。また、拡幅方向については、前記実施形態では、前壁パネル１９の前方について説明したが、後方についても、同様に拡幅施工することができ、また、側壁パネル１７側についても同様に拡幅するようにしてもよい。 In addition, in the case of each said embodiment, it is a case where a widening part is 1 step | paragraph, However, When it is necessary to expand a shaft lower part by making 2 steps | paragraphs 3 steps | paragraphs and a widening part multistage, the lower widening earth retaining wall 25 By installing a cross girder and a widening ceiling ceiling retaining panel, the second support beam is provided so as to be supported by the main pile 6 or the vertical beam 31 by digging the lower part of If it is necessary to widen the lower part of the ceiling, it is possible to make a multi-stage widening shaft with three or more stages by repeating the same process as above. is there. Moreover, about the widening direction, in the said embodiment, although the front of the front wall panel 19 was demonstrated, widening construction can be performed similarly also about back, and it is made to widen similarly about the side wall panel 17 side. May be.

本発明の拡幅立坑の施工方法の第１実施形態の工程説明図であって、（ａ）は、縦土留め体下部の拡幅天井部を奥部に向かってつぼ掘りしている状態の横断平面図、（ｂ）はその縦断側面図、（ｃ）は支持梁の張り出し部付近を示す縦断側面図、（ｄ）親杭にブラケットを介して支持されている支持梁付近を示す正面図、（ｅ）は（ｄ）の一部を拡大して示す拡大図である。BRIEF DESCRIPTION OF THE DRAWINGS It is process explanatory drawing of 1st Embodiment of the construction method of the widening shaft of this invention, Comprising: (a) is the transverse plane of the state which is digging the widening ceiling part of a vertical earth retaining body lower part toward the back part. (B) is a longitudinal side view of the supporting beam, (c) is a longitudinal side view showing the vicinity of the protruding portion of the supporting beam, (d) a front view showing the vicinity of the supporting beam supported by the parent pile via a bracket, e) is an enlarged view showing a part of (d) in an enlarged manner. （ａ）縦土留め体下部の拡幅天井空間部に支持梁を架設している状態を示す横断平面図、（ｂ）はその縦断側面図、（ｃ）および（ｄ）はつぼ掘り空間部間の地山を掘削している状態を示す横断平面図と縦断側面図である。(A) Transverse plan view showing a state in which a support beam is erected in the widened ceiling space at the bottom of the vertical earth retaining body, (b) is a vertical side view thereof, and (c) and (d) are between the potholes It is the cross-sectional top view and the vertical side view which show the state which is excavating the natural ground. （ａ）は、支持梁の張り出し側に横桁を架設し天井用土留めパネルを設置している状態（左側）および支持梁の張り出し側に横桁を架設している状態（右側）の横断平面図、（ｂ）はその片側の縦断側面図、（ｃ）は補強リングを配置すると共にそのフランジと天井部土留めパネルを接合している状態の縦断側面図、（ｄ）は（ｃ）の正面図、（ｅ）は（ｃ）の一部を拡大して示す拡大図、（ｆ）は（ｅ）の状態からさらに補強リングと縦土留め体の下部を連結した状態の拡大図である。(A) Transverse plane in a state in which a horizontal girder is installed on the projecting side of the support beam and a ceiling retaining panel is installed (left side), and a state in which a horizontal girder is installed on the projecting side of the support beam (right side) Figure, (b) is a longitudinal side view of one side, (c) is a longitudinal side view of a state in which the reinforcing ring is arranged and the flange and the ceiling retaining panel are joined, and (d) is a view of (c). Front view, (e) is an enlarged view showing a part of (c) in an enlarged view, (f) is an enlarged view of a state in which the reinforcing ring and the lower part of the vertical soil retaining body are further connected from the state of (e). . （ａ）は拡幅部天井土留めパネル相互を連結した状態の一部の拡大図、（ｂ）は（a）の正面図、（ｃ）は（ａ）の一部の拡大図である。(A) is a partially enlarged view of the state where the widening section ceiling earth retaining panels are connected to each other, (b) is a front view of (a), and (c) is a partially enlarged view of (a). （ａ）は側壁パネルを設置した状態を示す縦断側面図、（ｂ）は（ａ）の正面図、（ｃ）は拡幅部天井土留めパネルと側壁パネルとの接合部を示す縦断正面図である。(A) is a longitudinal side view showing a state in which the side wall panel is installed, (b) is a front view of (a), and (c) is a longitudinal front view showing a joint portion between the widened portion ceiling earth retaining panel and the side wall panel. is there. （ａ）は前壁パネルを設置した状態を示す縦断側面図、（ｂ）は（ａ）の正面図、（ｃ）は拡幅部天井土留めパネルと前壁パネルとの接合部を示す縦断正面図である。(A) is a longitudinal side view showing a state in which the front wall panel is installed, (b) is a front view of (a), and (c) is a longitudinal front view showing a joint portion between the widened portion ceiling earth retaining panel and the front wall panel. FIG. （ａ）は天井用土留めパネルの係止フックに前壁パネルを吊り下げ係止して連結した状態を示す縦断正面図、（ｂ）は天井用土留めパネルにおける係止フック部付近を示す平面図、（ｃ）は前壁パネルにおける被係止孔付近の平面図である。(A) is a vertical front view showing a state in which the front wall panel is suspended and connected to the locking hook of the ceiling earth retaining panel, and (b) is a plan view showing the vicinity of the locking hook portion in the ceiling earth retaining panel. (C) is a top view of the vicinity of the locked hole in the front wall panel. 図７に示す係止フックの変形形態により天井用土留めパネルに前壁パネルを吊り下げ係止する場合を示すものであって、（ａ）は天井用土留めパネルの係止フックに前壁パネルを吊り下げ係止して連結した状態を示す縦断正面図、（ｂ）は天井用土留めパネルにおける係止フック部付近を示す平面図、（ｃ）は前壁パネルにおける被係止孔付近の平面図である。FIG. 7 shows a case where the front wall panel is suspended and locked to the ceiling earth retaining panel according to a modification of the locking hook shown in FIG. 7, and (a) shows that the front wall panel is attached to the locking hook of the ceiling earth retaining panel. A longitudinal front view showing a state of being suspended and connected, (b) is a plan view showing the vicinity of a locking hook portion in the ceiling retaining panel, (c) is a plan view of the vicinity of the locked hole in the front wall panel It is. 本発明の方法により完成した拡幅立坑を示す縦断正面図である。It is a vertical front view which shows the widening shaft completed by the method of this invention. 図９の縦断正面図である。FIG. 10 is a longitudinal front view of FIG. 9. 図９における天井用土留めパネルより下側の横断平面図である。FIG. 10 is a transverse plan view below the ceiling retaining panel in FIG. 9. 拡幅部側の親杭を撤去する場合の工程を示すものであって、（ａ）は底部コンクリートを打設して支持梁先端側に短尺支柱を設けた状態を示す縦断正面図、（ｂ）は平面図、（ｃ）は拡幅側の親杭を切断し、切断した親杭および中間部の支持梁を撤去した状態を示す縦断正面図、（ｄ）は（ｃ）の平面図である。The process in the case of removing the main pile on the widened portion side is shown, and (a) is a longitudinal front view showing a state in which the bottom concrete is placed and a short column is provided on the support beam tip side, (b) Is a plan view, (c) is a longitudinal front view showing a state where the parent pile on the widened side is cut, and the cut parent pile and the intermediate support beam are removed, and (d) is a plan view of (c). 本発明の拡幅立坑の施工方法の第２実施形態の工程説明図であって、（ａ）は受け桁を敷設した状態の平面図、（ｂ）は（ａ）の縦断側面図、（ｃ）は縦孔を掘削した状態を示す平面図、（ｄ）は（ｃ）の縦断側面図である。It is process explanatory drawing of 2nd Embodiment of the construction method of the widening shaft of this invention, Comprising: (a) is a top view in the state which laid the receiving beam, (b) is a vertical side view of (a), (c). Is a plan view showing a state in which a vertical hole has been excavated, (d) is a vertical side view of (c). （ａ）および（ｂ）は縦土留め体構築した状態のそれぞれ平面図と縦断側面図、（ｃ）はおよび（ｄ）は縦梁を設置した状態の平面図と縦断側面図である。(A) And (b) is a top view and a longitudinal side view, respectively, in a state in which a vertical earth retaining body is constructed, and (c) and (d) are a plan view and a longitudinal side view in a state in which a longitudinal beam is installed. （ａ）および（ｂ）は、縦土留め体下部の拡幅天井部を奥部に向かってつぼ掘りしている状態のそれぞれ横断平面図と縦断側面図、（ｃ）および（ｄ）は、支持梁を架設している状態のそれぞれ横断平面図と縦断側面図である。(A) and (b) are a cross-sectional plan view and a longitudinal side view, respectively, in a state where the widened ceiling portion at the bottom of the vertical earth retaining body is dug toward the back, and (c) and (d) are supporting It is a cross-sectional plan view and a longitudinal side view, respectively, in a state where beams are installed. （ａ）および（ｂ）は、中間部および端部に縦梁を設置すると共に中間部の縦梁に支持梁を架設している状態のそれぞれ平面図と縦断側面図である。(A) And (b) is each a top view and a vertical side view of the state which installed the support beam to the vertical beam of the intermediate part while installing the vertical beam in the intermediate part and the edge part. （ａ）および（ｂ）は支持梁上に短尺横桁を挿入している状態のそれぞれ平面図と縦断側面図、（ｃ）および（ｄ）は支持梁上に複数の短尺横桁を架設している状態のそれぞれ横断平面図と縦断側面図である。(A) and (b) are a plan view and a longitudinal side view of a state in which a short cross beam is inserted on the support beam, respectively, and (c) and (d) are a plurality of short cross beams installed on the support beam. It is a cross-sectional top view and a vertical side view, respectively. （ａ）および（ｂ）は、短尺横桁上に拡幅部天井用土留めパネルを挿入している状態のそれぞれ横断平面図と縦断側面図、（ｃ）および（ｄ）は複数の短尺横桁上に拡幅部天井用土留めパネルを設置した状態のそれぞれ横断平面図と縦断側面図である。(A) and (b) are respectively a cross-sectional plan view and a longitudinal side view of a state in which the widening section ceiling retaining panel is inserted on a short cross beam, and (c) and (d) are on a plurality of short cross beams. It is a cross-sectional plan view and a longitudinal side view, respectively, in a state where the earth retaining panel for the widened portion ceiling is installed. （ａ）および（ｂ）は、他端側をつぼ掘りして支持梁を架設している状態のそれぞれ横断平面図と縦断側面図、（ｃ）および（ｄ）はつぼ掘り空間部間の地山を掘削した状態のそれぞれ横断平面図と縦断側面図である。(A) and (b) are a cross-sectional plan view and a longitudinal side view, respectively, in a state in which the other end side is dug up and a support beam is installed, and (c) and (d) are the ground between the crucible spaces. It is a cross-sectional plan view and a longitudinal side view, respectively, in a state where a mountain is excavated. （ａ）および（ｂ）は支持梁上に長尺横桁を挿入している状態のそれぞれ横断平面図と縦断側面図、（ｃ）および（ｄ）は支持梁上に複数の長尺横桁を設置した状態のそれぞれ横断平面図と縦断側面図である。(A) and (b) are respectively a cross-sectional plan view and a longitudinal side view of a state in which a long cross beam is inserted on the support beam, and (c) and (d) are a plurality of long cross beams on the support beam. It is a cross-sectional plan view and a longitudinal side view, respectively, in a state in which the is installed. （ａ）および（ｂ）は、複数の長尺横桁上に天井用土留めパネルを挿入している状態のそれぞれ横断平面図と縦断側面図、（ｃ）および（ｄ）は複数の横桁上に天井用土留めパネルを設置した状態のそれぞれ横断平面図と縦断側面図である。(A) and (b) are respectively a cross-sectional plan view and a longitudinal side view of a state in which a ceiling retaining panel is inserted on a plurality of long cross beams, and (c) and (d) are a plurality of cross beams. It is a cross-sectional plan view and a longitudinal side view, respectively, in a state where a ceiling earth retaining panel is installed. （ａ）および（ｂ）は、拡幅部天井空間部の下側の地山を掘削孔して前壁パネル等を設けている状態のそれぞれ横断平面図と縦断側面図、（ｃ）および（ｄ）はさらに下方に掘削孔して前壁パネル等を設置した状態のそれぞれ横断平面図と縦断側面図である。(A) And (b) is a cross-sectional plan view and a longitudinal side view, respectively, in a state where a front wall panel or the like is provided by excavating a natural ground below the widened portion ceiling space portion, (c) and (d) ) Are a cross-sectional plan view and a longitudinal side view, respectively, in a state in which a front wall panel and the like are installed by drilling holes further downward. （ａ）および（ｂ）は基礎コンクリートを打設している状態のそれぞれ横断平面図と縦断側面図、（ｃ）および（ｄ）は支持梁先端側の下に短尺支柱を配置した状態のそれぞれ横断平面図と縦断側面図である。(A) and (b) are a cross-sectional plan view and a longitudinal side view, respectively, in a state in which foundation concrete is placed, and (c) and (d) are each in a state in which a short column is disposed under the support beam tip side. It is a transverse plan view and a longitudinal side view. （ａ）および（ｂ）は、中間部の支持梁を撤去した状態のそれぞれ横断平面図と縦断側面図である。(A) And (b) is each a cross-sectional top view and a vertical side view of the state which removed the support beam of the intermediate part. 受け桁を縦土留め体の内側に敷設して縦梁を支持する形態の平面図である。It is a top view of the form which lays a receiving girder inside a vertical earth retaining body and supports a vertical beam. 図２５の縦断側面図である。It is a vertical side view of FIG. 仮屋根材を押込み配置する形態を示すものであって、（ａ）は縦土留め体の下部に仮屋根材を押込む直前の状態を示す縦断側面図、（ｂ）は（ａ）における仮屋根材付近を拡大して示す縦断側面図、（ｃ）は仮屋根材を押込んでいる状態を示す縦断側面図である。It shows a form in which the temporary roofing material is pushed in, and (a) is a vertical side view showing a state immediately before the temporary roofing material is pushed into the lower part of the vertical earth retaining body, and (b) is a temporary drawing in (a). The longitudinal side view which expands and shows the roof material vicinity, (c) is a longitudinal side view which shows the state which has pushed in the temporary roof material. （ａ）は仮屋根材を押込み配置した状態を示す縦断側面図、（ｂ）は縦梁および支持梁並びに補強リングを配置した状態を示す縦断側面図、（ｃ）は仮屋根材と補強リングとの隙間を調整している状態を示す縦断側面図である。(A) is a longitudinal side view showing a state where the temporary roofing material is pushed in, (b) is a longitudinal side view showing a state where the longitudinal beam, the supporting beam and the reinforcing ring are arranged, and (c) is a temporary roofing material and the reinforcing ring. It is a vertical side view which shows the state which is adjusting the clearance gap between.

符号の説明Explanation of symbols

１地盤
２縦孔
３土留めパネル
４天井用拡幅土留め体
５縦土留め体
６親杭
７つぼ状空間部
８ハンド式オーガー
９支持用ロッド
１０ブラケット
１１支持梁
１２横桁
１２ａ短尺横桁
１２ｂ長尺横桁
１３補強リング
１４ボルト・ナット
１５継手板
１６縦板
１７側壁パネル
１８接合用プレート
１９前壁パネル
２０傾斜面
２１係止フック
２２広幅透孔
２３狭幅透孔
２４被係止用透孔
２５下部拡幅土留め体
２６拡幅立坑
２７短尺柱
２８基礎コンクリート
３０受け桁
３１縦梁
３２連結部材
３３天井用パネル
３４天井空間
３５地山
３６継ぎ梁
３７埋設管
３９仮屋根材
４０支持台
４１支承フレーム
４２高さ調整部材
４３仮屋根材
４４反力受け
４５ジャッキ
４６挟み込み治具
４７ピース
４８仮屋根部
４９支承板
DESCRIPTION OF SYMBOLS 1 Ground 2 Vertical hole 3 Earth retaining panel 4 Widening earth retaining body 5 Ceiling retaining body 6 Parent pile 7 Vase-like space part 8 Hand type auger 9 Supporting rod 10 Bracket 11 Support beam 12 Cross beam 12a Short cross beam 12b Long transverse girder 13 Reinforcement ring 14 Bolt / nut 15 Joint plate 16 Vertical plate 17 Side wall panel 18 Joining plate 19 Front wall panel 20 Inclined surface 21 Locking hook 22 Wide through hole 23 Narrow through hole 24 Locking through Hole 25 Lower widening retaining body 26 Widening shaft 27 Short column 28 Foundation concrete 30 Girder 31 Vertical beam 32 Connecting member 33 Ceiling panel 34 Ceiling space 35 Ground 36 Joint beam 37 Temporary roof material 40 Temporary roof material 40 Support base 41 Frame 42 Height adjusting member 43 Temporary roof material 44 Reaction force receiver 45 Jack 46 Clamping jig 47 Piece 48 Temporary roof 49 Support plate

Claims

縦方向に配置された縦土留め体と、縦土留め体に横方向に接続された拡幅土留め体とにより内壁面を土留めして立坑を形成する拡幅立坑の施工方法において、地表より地中縦方向に掘削し縦土留め体を配置し、次に、縦土留め体下部より横方向に拡幅土留め体の奥行き長さを掘削して奥行き方向に天井土留め体が挿入できる空間部を形成し、その奥行き方向の空間部に天井用拡幅土留め体を配置し、さらに、天井用拡幅土留め体が配置された前記空間部の下側を縦方向に掘削して下部拡幅空間を形成し、その下部拡幅空間の側壁部に、下部拡幅縦土留め体を配置し、親杭または縦梁からなる縦支持部材に取り付けられた支持梁を、前記奥行き方向の空間部に張り出すように配置し、間隔をおいて隣り合う前記支持梁の張り出し部に支持させるように複数の桁を架設し、その桁に天井用拡幅土留め体を架設して支持させることを特徴とする拡幅立坑の施工方法。 In the construction method of the widening shaft, the vertical wall is placed vertically and the widening retaining body is connected to the vertical soiling body in the lateral direction to hold the inner wall surface to form the shaft. A space that allows excavation in the mid-longitudinal direction and placement of vertical earth retaining bodies, and then excavation of the depth length of the wide earth retaining body in the lateral direction from the lower part of the vertical earth retaining body to insert the ceiling earth retaining body in the depth direction. The ceiling widening retaining body is disposed in the space portion in the depth direction, and further, the lower widening space is formed by excavating the lower side of the space portion where the ceiling widening retaining body is disposed in the vertical direction. Forming and placing a lower widened vertical earth retaining body on a side wall portion of the lower widened space, and extending a support beam attached to a vertical support member made of a parent pile or a vertical beam to the space portion in the depth direction And is supported by the projecting portion of the support beam adjacent to each other with a gap Uni bridged multiple digits, the construction method of widening shafts, characterized in that to support and bridged the ceiling widening earth retaining member on the digit.

縦方向に配置された縦土留め体と、縦土留め体に横方向に接続された拡幅土留め体とにより内壁面を土留めして立坑を形成する拡幅立坑の施工方法において、地中に埋設されている埋設物近傍の地表より地中縦方向に掘削して縦土留め体を配置し、次に、前記埋設された埋設物の下側を、縦土留め体下部より横方向に拡幅土留め体の奥行き長さを掘削して奥行き方向に天井用拡幅土留め体が挿入できる空間部を形成し、その奥行き方向の空間部に天井用拡幅土留め体を配置し、さらに天井用拡幅土留め体が配置された前記空間部の下側を縦方向に掘削して下部拡幅空間を形成し、その下部拡幅空間の側壁部に、下部拡幅土留め体を配置し、親杭または縦梁からなる縦支持部材に取り付けられた支持梁を、前記奥行き方向の空間部に張り出すように配置し、間隔をおいて隣り合う前記支持梁の張り出し部に支持させるように複数の桁を架設し、その桁に天井用拡幅土留め体を架設して支持させることを特徴とする拡幅立坑の施工方法。 In the construction method of the widening shaft, in which the vertical wall retaining body arranged in the vertical direction and the widening retaining body laterally connected to the vertical soil retaining body are fixed to the inner wall surface to form the shaft, Excavation from the ground surface near the buried object is placed in the vertical direction in the ground, and the vertical soil retaining body is arranged.Then, the lower side of the embedded buried object is widened laterally from the lower part of the vertical soil retaining body. Excavating the depth of the earth retaining body to form a space where the ceiling wide earth retaining body can be inserted in the depth direction, placing the ceiling wide earth retaining body in the space in the depth direction, and further widening the ceiling A lower widened space is formed by vertically excavating the lower side of the space where the earth retaining body is arranged, and a lower widened earth retaining body is arranged on a side wall portion of the lower widened space, and a parent pile or a longitudinal beam The support beam attached to the vertical support member consisting of Placed, widening pit, characterized in that bridged the plurality of digits so as to support the overhanging portion of the support beam adjacent at intervals, it is supported by bridging the ceiling widening earth retaining member on the digit Construction method.

地表より地中縦方向に掘削して縦土留め体を配置し、次に、縦土留め体下部より横方向に仮屋根材を土中に押込んで配置し、さらに、土中に配置された仮屋根材の下部を横方向に拡幅土留め体の奥行き長さを掘削して奥行き方向に前記支持梁の張り出し部に架設の桁上に架設される天井用土留め体が挿入できる空間部を形成することを特徴とする請求項１又は２に記載の拡幅立坑の施工方法。 Excavated from the surface of the earth in the vertical direction, placed the vertical earth retaining body, then pushed the temporary roofing material into the ground in the horizontal direction from the lower part of the vertical earth retaining body, and further placed in the soil Excavation of the depth of the widening retaining body in the horizontal direction at the lower part of the temporary roofing material to form a space part in which the ceiling retaining body can be inserted in the extending direction of the support beam in the depth direction. The construction method of the widening shaft of Claim 1 or 2 characterized by the above-mentioned.

土留め体がライナープレートの組立て体であることを特徴とする請求項１〜３のいずれか1項に記載の拡幅立坑の施工方法。 Construction method for widening the vertical shaft according to any one of claims 1 to 3, wherein the earth retaining body is a assembly of the liner plate.