JP2681511B2 - Vertical shaft structure of shield machine starting part, its construction method, and start / arrival method of shield machine using the structure - Google Patents

Description

【発明の詳細な説明】 ＜産業上の利用分野＞ この発明は、シールドトンネル工事におけるシールド
機発進部の立坑構造とその施工法、及びその構造を利用
したシールド機の発進・到達方法に関する。Description: TECHNICAL FIELD The present invention relates to a vertical shaft structure of a shield machine starting portion in shield tunnel construction, a construction method thereof, and a start / arrival method of a shield machine using the structure.

＜従来の技術＞ 今までに知られているシールド機発進部の立坑構造と
しては、土留壁を鋼矢板、地中壁等で構築し、シールド
発進（到達）部を地上からボーリングして薬液注入など
により、地盤改良を行ない、立坑を掘削して、シールド
機発進用のエントランスを設置し、発進部の土留壁を撤
去してシールド機を発進し、到達は地盤改良された到達
部にシールド機を到達させ土留壁を撤去し貫通させる地
盤改良工法がある。<Prior art> As a vertical shaft structure of the shield machine starting part known so far, the retaining wall is constructed by steel sheet pile, underground wall, etc., and the shield starting (arriving) part is bored from the ground to inject the chemical solution. As a result, the ground is improved, the shaft is excavated, the entrance for the shield machine start is installed, the earth retaining wall at the start part is removed, the shield machine is started, and the arrival is the shield machine at the arrival part where the ground is improved. There is a ground improvement method to reach the ground and remove the retaining wall to penetrate.

また、土留壁を鋼矢板、地中壁等で構築し、シールド
発進（到達）部に地上および立坑内より凍結管を設置し
冷媒を送ることにより地盤を凍結させ、シールド発進部
土留壁にエントランスを設置し土留壁を撤去してシール
ド機を発進（到達）させる凍結工法がある。In addition, the retaining wall is constructed with steel sheet piles, underground wall, etc., the freezing pipe is installed from the ground and the shaft in the shield starting (reaching) part and the refrigerant is sent to freeze the ground, and the entrance to the shield starting part is retained. There is a freezing method where the shield machine is started (reached) by installing and removing the retaining wall.

さらに、鋼矢板、地中壁等で土留壁を構築して立坑を
掘削し、立坑内にシールド機を搬入してから、立坑上部
に圧気床板を設置し、土留壁にエントランスを設置して
から発進部の土圧・水圧と同等の圧気を立坑内に加え
て、土留壁を撤去し、シールド機を発進させる立坑圧気
工法が用いられている。In addition, after constructing a retaining wall with steel sheet piles, underground walls, etc., excavating the vertical shaft, loading the shield machine into the vertical shaft, installing a pressure floor plate on the upper part of the vertical shaft, and installing an entrance on the primary retaining wall. The vertical pressure pneumatic method is used in which the pressure equivalent to the earth pressure and water pressure at the starting part is applied to the inside of the shaft, the retaining wall is removed, and the shield machine is started.

＜発明が解決しようとする課題＞ しかしながら、上記従来工法は、工区の地盤の状況に
応じてそれぞれ使い分けされ、それぞれの利点はあるも
のの、都市部などにおける工域が狭隘な場所での立坑の
構築に限度がある場合、及び工期が短期間に限られてい
る場合には必ずしも十分なものとは云えない。<Problems to be Solved by the Invention> However, although the above-mentioned conventional methods are used properly depending on the ground condition of the construction section and each has its own advantages, it is necessary to construct a shaft in a narrow area in an urban area. It is not always sufficient when there is a limit and when the construction period is limited to a short period.

特に、上記地盤改良工法は以下の問題点がある。 In particular, the above ground improvement method has the following problems.

1.立坑掘削前に地盤改良を行なう期間が必要。1. A period is required to improve the ground before excavating the shaft.

2.地盤改良後の掘削に伴ない土留壁が変形し、土留壁と
地盤改良地山が分離して、シールド発進時の出水等の事
故が多い。2. The soil retaining wall is deformed due to excavation after ground improvement, and the soil retaining wall and ground improvement ground are separated, and there are many accidents such as flooding when the shield starts.

3.地盤改良に場所と多額の費用を要する。3. Ground improvement requires a lot of space and a lot of money.

また、上記凍結工法の問題点としては、 1.凍結管の設置や、地盤の凍結に長期間を要する。 In addition, as the problems of the freezing method, 1. It takes a long time to install a freezing pipe and freeze the ground.

2.地盤の凍結（溶解）により大きな地盤沈下が発生す
る。2. Large subsidence occurs due to freezing (thawing) of the ground.

3.地盤改良に多額の費用を要する。3. A lot of cost is required for ground improvement.

ことがある。Sometimes.

さらに、圧気工法の問題点には、 1.高圧下の作業となり安全性が悪い。 In addition, the problems with the pneumatic method are: 1. The work is performed under high pressure and the safety is poor.

2.圧気設備に多額の費用を要する。2. A large amount of cost is required for the pneumatic equipment.

3.圧気設備など発進段取りに長期間を要する。3. It takes a long time to start and set up equipment such as pneumatic equipment.

等が考えられる。And so on.

なお、上記従来工法の他に二重鋼矢板工法が知られて
いるが、この工法は、鋼矢板を利用してシールド機の発
進時に鋼矢板を引抜いて掘削を開始し、軟弱地盤など地
盤条件や施工深さおよび被圧水などの条件下においてそ
の効果が発揮でき、適応範囲が限定されるというものの
他に、立坑の内壁全てを強固な連壁にし、かつシールド
機の発進部の地盤を改良する点において、基本的には先
述した地盤改良工法と変りなく、いぜん地盤改良のため
の工期の長期化やある程度の場所的な制約が必要である
という問題点があった。A double steel sheet pile construction method is known in addition to the conventional construction method, but this construction method uses steel sheet piles to pull out the steel sheet pile at the start of the shield machine to start excavation, and ground conditions such as soft ground. In addition to the effect that it can exert under conditions such as construction depth and pressured water, and the applicable range is limited, all the inner walls of the vertical shaft are solid connecting walls, and the ground of the starting part of the shield machine is In terms of improvement, there is basically no difference from the ground improvement method described above, and there has been a problem that the construction period for the improvement of the ground is still long and some positional restrictions are required.

この発明は、上記問題点を解消すべくなされたもので
あり、、その第１の目的は地盤が弱く地下水が侵入し易
いシールド機発進部において地盤改良を行なうことなく
今までより強固な地下連続壁を、まだ発進部以外は簡易
な立坑の土留を構築して、限られた立坑の平面積内で短
期間でシールド発進部の立坑構造を得んとしたものであ
る。The present invention has been made to solve the above problems, and a first object thereof is to provide a stronger underground continuation without improving the ground in a shield machine starting section where the ground is weak and groundwater easily enters. Except for the starting part of the wall, the earth retaining structure of a simple vertical shaft was constructed to obtain the vertical shaft structure of the shield starting part within a limited flat area of the vertical shaft.

この発明の他の目的は、場合によって、立坑の埋戻し
を容易にした立坑の施工法を得んとするものである。Another object of the present invention is to obtain a method of constructing a vertical shaft that facilitates backfilling of the vertical shaft in some cases.

この発明におけるさらに別の目的は、立坑の構造を簡
単にしてシールド機の発進と到達が容易なシールド機の
発進・到達方法を提供せんとする。Still another object of the present invention is to provide a method for starting and reaching a shield machine that simplifies the structure of a shaft and makes it easy to start and reach the shield machine.

＜課題を解決するための手段＞ この発明は、上記問題点に鑑みてなされたものであ
り、その要旨はシールド機を設置する立坑と、この立坑
を連続して囲繞する立坑土留芯材とから成り、この立坑
土留芯材をシールド機発進側の地下連続壁中に建込むと
共に、シールド機発進用切欠部を形成し、切欠部の周囲
にはシールド機発進用保護内壁を構築し、前記立坑土留
芯材の外側の地下連続壁中には表面に引抜き加工を施し
た発進土留芯材を前記切欠部を覆うように建込んでなる
シールド機発進部の立坑構造にある。ここで上記立坑土
留芯材は柱列式地下連続工法や壁式地下連続工法などに
よる地下連続壁中に建込めた鋼矢板、Ｈ杭、鉄筋コンク
リートなどを示し、また上記発進土留芯材としては、例
えば鋼矢板やＨ杭などが考えられる。<Means for Solving the Problems> The present invention has been made in view of the above problems, and its gist is from a shaft for installing a shield machine and a shaft earth retaining core material that continuously surrounds the shaft. It consists of this shaft underground retaining core material in the underground continuous wall on the starting side of the shield machine, and a cutout for starting the shield machine is formed, and a protective inner wall for starting the shield machine is constructed around the cutout. In the underground continuous wall outside the earth retaining core material, there is a vertical shaft structure of the shield machine starting portion in which a starting earth retaining core material whose surface is subjected to a drawing process is installed so as to cover the cutout portion. Here, the vertical shaft soil core material indicates a steel sheet pile, H pile, reinforced concrete, etc. built in an underground continuous wall by a column-row underground continuous construction method or a wall type underground continuous construction method, and as the starting soil retention core material, For example, steel sheet piles and H piles are possible.

また、他の発明の要旨は立坑構造を発進側と到達側に
用い、それぞれの立坑内にシールド機の反力壁と発進用
保護内壁の内周に沿って設けたシール材付き筒状チャン
バを設け、立坑の発進側に地山を掘削していくシールド
機を設置し、発進土留芯材を地下連続壁から立坑芯材の
切欠部上に引抜き、シールド前面の芯材のない地下連続
壁の一部を掘削しながら発進して目標地盤を掘進し、到
達側の発進土留芯材に相当する到達土留芯材を地下連続
壁から立坑土留芯材の切欠部上に引抜いてシールド機を
所定圧の人工地盤を形成した到達側の立坑内に取込み到
達するようにしたシールド機の発進・到達方法にある。Further, the gist of another invention is to use a vertical shaft structure on the starting side and the reaching side, and to provide a cylindrical chamber with a sealing material provided inside the respective vertical shafts along the inner periphery of the reaction force wall of the shield machine and the starting protective inner wall. Establish a shield machine to excavate the ground on the starting side of the shaft, pull out the starting soil retention core material from the underground continuous wall onto the cutout part of the shaft core material, of the underground continuous wall without core material in front of the shield Start while excavating a part and dig into the target ground, pull out the reaching soil core material corresponding to the starting soil core material on the arrival side from the continuous underground wall onto the cutout portion of the shaft earth retaining core material, and press the shield machine at the specified pressure. It is a method of starting and reaching a shield machine that takes in and reaches the shaft on the arrival side where the artificial ground is formed.

さらに、その他の発明は予定した立坑区域のシールド
機発進側に、地下連続壁工法により、表面引抜き加工し
た立坑土留芯材と発進土留芯材との二重芯材を建込んで
地下連続壁を構築する工程と、この地下連続壁中の立坑
土留芯材と連続して他の立坑内面となる立坑土留芯材と
しての立坑土留矢板を打込むと共に、囲繞した立坑土留
矢板内部を掘削する工程と、前記地下連続壁のシールド
機の発進坑口周囲に保護内壁を打設すると共に、保護内
壁の内側にあたる前記立坑土留芯材に切欠部を形成する
工程とからなる立坑発進側の地盤改良を行なわないシー
ルド発進部の立坑構造の施工法を要旨とする。Furthermore, another invention is to construct a underground core wall by installing a double core material of a shaft earth retaining core material and a starting earth retaining core material that have been surface-extracted by the underground continuous wall construction method on the shield machine starting side of the planned shaft area. A step of constructing and driving a shaft earth retaining sheet pile as a shaft earth retaining core material that becomes another shaft inner surface continuously with the shaft earth retaining core material in this underground continuous wall, and a step of excavating the surrounding shaft earth retaining sheet pile. , A step of forming a notch in the shaft earth retaining core material inside the protective inner wall while placing a protective inner wall around the start pit mouth of the shield machine of the underground continuous wall, and not performing ground improvement on the shaft starting side The gist is the construction method of the vertical shaft structure of the shield starting part.

＜作用＞ この発明の立坑構造によれば、シールド機の発進部以
外は、通常の地下土留芯材を囲繞して、土留めをし、発
進部は連壁中の発進土留芯材を一体に建込んでシールド
発進前における発進部とそれ外の土留を十分にすると同
時に、発進時において発進土留芯材を引抜いてもシール
ド切羽が地下連続壁に圧接することによって土圧を支え
ることができ、しかもシールド機を掘進しても立坑土留
芯材の切欠部において、掘削するのでスムーズに発進で
きるようにしている。<Operation> According to the vertical shaft structure of the present invention, except for the starting portion of the shield machine, the ordinary underground soil retaining core material is surrounded and earth retaining is performed, and the starting portion integrally integrates the starting soil retaining core material in the connecting wall. It is possible to support earth pressure by making the shield face face pressure against the underground continuous wall even when pulling out the starting earth retaining core material at the same time as building up and making sufficient soil retention outside the starting part before starting the shield, Moreover, even if the shield machine is driven forward, the shaft is excavated in the cutout portion of the shaft earth retaining core material so that it can be smoothly started.

また、立坑構造の発進・到達方法は、発進側と到達側
との地下連続壁中に立坑土留芯材と発進土留芯材とを二
重に建込んだ立坑を用い、シールド機を発進用保護内壁
の筒状チャンバにセットしてから発進土留芯材を引抜い
てシールド切羽と発進部地盤の圧力とを均衡させ、シー
ルド機を掘進して予定のトンネルを覆工し、到達側の到
達土留芯材を引抜き立坑に土圧や水圧など所定圧を掛け
た人口地盤中に取込むようにしている。In addition, the method of starting and reaching the shaft structure is to protect the shield machine from starting by using a shaft that double-builds the shaft retaining core material and the starting soil retaining core material in the underground continuous wall between the starting side and the reaching side. After setting it in the cylindrical chamber of the inner wall, pull out the starting earth retaining core material to balance the pressure of the shield face and the starting area ground, dig the shield machine and cover the planned tunnel, and reach the reaching earth retaining core. The material is pulled out and taken into the artificial ground where a predetermined pressure such as earth pressure or water pressure is applied to the vertical shaft.

さらに、立坑の施工は発進部以外は立坑土留矢板を予
定立坑の面積に沿って地中に打ち込み、矢板内に腹おこ
しや切梁などの公知の手段によって立坑を掘削し、前記
発進側には発進部以外の立坑土留矢板と、発進土留矢板
とを同時に地下連壁中に建込んで二重芯材を簡単に仕上
げる。また、前記土留矢板の発進部のシールド機の発進
坑口（エントランス）周囲には保護内壁を打設すると共
に、内壁内の土留矢板を切欠いてシールドの発進を容易
にする。このようにして、通常の立坑の構造の他に、地
盤を強固にしなければならない発進側を地下連続壁中に
発進土留芯材を建込んで補強し、シールド発進時には掘
進に邪魔にならないように引抜くことができる。Furthermore, the construction of the vertical shaft is driven into the ground along the area of the planned vertical shaft with the vertical shaft earth retaining sheet except for the starting part, and the vertical shaft is excavated by known means such as bellows and cutting beams in the vertical plate, and on the starting side. Shaft pile retaining sheet piles other than the starting part and starting pile retaining sheet piles are simultaneously installed in the underground wall to finish the double core material easily. In addition, a protective inner wall is placed around the start pit (entrance) of the shield machine at the starting portion of the earth retaining sheet pile, and the earth retaining sheet in the inner wall is cut out to facilitate the start of the shield. In this way, in addition to the structure of the normal shaft, the starting side that must strengthen the ground is reinforced by building the starting earth retaining core material in the underground continuous wall so that it does not interfere with the excavation when starting the shield. Can be pulled out.

＜実施例＞ 以下にこの発明の一実施例を説明する。<Example> An example of the present invention will be described below.

第１図はこの発明のシールド機発進時の立坑構造の要
部を示すものであり、これを図に従って説明すると、１
はシールド発進側のソイルモルタルルを使用した柱列式
又は泥水固化した壁式などの地下連続壁であり、この連
続壁中には立坑土留芯材としての内側土留矢板２とこれ
から所定間隔を置いた発進土留芯材としての外側土留矢
板３が建込んでいる。そしてこの地下連続壁１の外部は
地盤改良がされていない地盤４であって、図示していな
いが前記内側土留矢板２に継手等で接続した発進側以外
の３壁面にも土留矢板２があり、これらが腹おこしや切
梁によって立坑を構築している。５は上記のように形成
した立坑の一部壁面に接するように設けられた前後のフ
ランジ部5a,5bを有する円筒チャンバで、全体として筒
状の鋼材からなり、この円筒チャンバの設置後に、これ
の外周に、地中壁１に内接するように内壁６が打設され
る。なお、上記円筒チャンバ５の中央付近と後端部付近
の内側には、所定幅のリング状弾性の第１のシール材６
と第２のシール材７とが固着され、第２のシール材７は
ヒンジ式のシール押えなどでその内端部が前方に傾斜す
るようになっている。８は泥水タンク９からの圧力調整
パイプであり、バルブ10を介して泥水・グラウト供給パ
イプ11に接続し、これの出水端が円筒チャンバ５の上下
から内部に開口して、シールド機20の前面と内側土留矢
板２にシールド機発進用として円形に切欠いた切欠部12
間に泥水が圧入されるように配設している。この泥水・
グラウト供給パイプ11は、バルブ13を介して途中から、
グラウト注入パイプ14を接続し、後述するように、シー
ルド機20により地下連続壁１を貫通後にセグメント背面
の空隙部にグラウトを注入するパイプとして利用するも
のである。また、15は裏込注入用パイプで、これの出口
がバルブ16を介して円筒チャンバ２とシールド機20のス
キンプレート17間において90゜ごとの間隔で室内にそれ
ぞれ開口するように設けられている。20はこのような円
筒チャンバ２内に設置されるシールド機であり、これの
発進ひ当っては、カッタービット18の先端に圧接すると
ともに、シールド機20のスキンプレート17と円筒チャン
バ５ならびにシール材６および７で囲まれる空間19に裏
込材などによるシールを行なう。さらに、必要に応じて
シールド機20の前面に前記泥水タンク９からの泥水を満
たす。この場合圧力調整パイプ８側のバルブ10を開いて
泥水タンク９の水位を設定泥水圧に保持して地山の圧力
に対抗させることができる。シールド機20に対向する部
位の地下連続壁１中の内側土留矢板２を、シールド機20
の掘削と貫入を可能にするだけの大きさで切欠いて切欠
部12を形成し、続いて表面を引抜き容易にワックス加工
した内側土留矢板２を上向き（矢印）に引抜いてシール
ド機20で掘削しながら発進させる。FIG. 1 shows a main part of a vertical shaft structure when the shield machine of the present invention is started.
Is an underground continuous wall such as a column type or a mud-solidified wall type that uses soil mortar on the shield starting side. Inside this continuous wall, the inner earth retaining sheet pile 2 as a shaft earth retaining core material and a predetermined interval from this are placed. An outer earth retaining sheet pile 3 as a starting earth retaining core material is installed. The outside of the continuous underground wall 1 is the ground 4 which has not been improved, and although not shown, there are also the earth retaining sheet piles 2 on the three wall surfaces other than the starting side which are connected to the inner soil retaining sheet pile 2 by a joint or the like. , These construct the shaft by the belly up and the beam. Reference numeral 5 denotes a cylindrical chamber having front and rear flange portions 5a and 5b provided so as to be in contact with a part of the wall of the vertical shaft formed as described above, which is made of a tubular steel material as a whole, and is installed after the installation of the cylindrical chamber. An inner wall 6 is placed on the outer periphery of the inner wall 6 so as to be inscribed in the underground wall 1. A ring-shaped elastic first seal member 6 having a predetermined width is provided inside the center of the cylindrical chamber 5 and near the rear end.
And the second seal member 7 are fixed to each other, and the second seal member 7 is configured such that the inner end portion of the second seal member 7 is inclined forward by a hinge type seal retainer or the like. Reference numeral 8 denotes a pressure adjusting pipe from the muddy water tank 9, which is connected to a muddy water / grout supply pipe 11 via a valve 10 and a water outlet end of which is opened from above and below the cylindrical chamber 5 to the front of the shield machine 20. And a notch 12 that is a circular notch for starting the shield machine on the inner soil retaining sheet pile 2.
It is arranged so that muddy water is pressed in between. This muddy water
From the middle of the grout supply pipe 11 via the valve 13,
The grout injection pipe 14 is connected and used as a pipe for injecting grout into the void portion on the back surface of the segment after passing through the underground continuous wall 1 by the shield machine 20 as described later. Reference numeral 15 is a back-filling injection pipe, and its outlet is provided via a valve 16 between the cylindrical chamber 2 and the skin plate 17 of the shield machine 20 at intervals of 90 ° to open in the room. . Reference numeral 20 is a shield machine installed in such a cylindrical chamber 2. When the shield machine 20 starts and hits the tip of the cutter bit 18, the skin plate 17 of the shield machine 20, the cylindrical chamber 5 and the sealing material are pressed. A space 19 surrounded by 6 and 7 is sealed with a backing material or the like. Further, if necessary, the front surface of the shield machine 20 is filled with muddy water from the muddy water tank 9. In this case, the valve 10 on the pressure adjusting pipe 8 side can be opened to maintain the water level of the mud tank 9 at the set mud pressure to counteract the natural pressure. Shield machine 20 with the inner soil retaining sheet pile 2 in the continuous underground wall 1 facing the shield machine 20.
The notch 12 is formed with a size large enough to enable the excavation and penetration of the inside, and then the surface is easily extracted and the wax-coated inner soil retaining sheet pile 2 is extracted upward (arrow) and excavated by the shield machine 20. While starting.

なお、芯材の引抜きに際しては、あらかじめ芯材に配
設した注入パイプ（図示せず）により、芯材先端に発生
するボイド部に必要に応じてグラウト材の注入を行う。
シールド機20が地下連続壁１を掘削・開口して円筒チャ
ンバ５内をトンネル覆工用のセグメントで置き換えられ
た時点で泥水・グラウト供給パイプ11からグラウト注入
を行い、確実な止水を行う。When the core material is pulled out, grout material is injected into a void portion generated at the tip of the core material as needed using an injection pipe (not shown) provided in the core material in advance.
When the shield machine 20 excavates and opens the underground continuous wall 1 and replaces the inside of the cylindrical chamber 5 with a segment for tunnel lining, grout is injected from the muddy water / grout supply pipe 11 to reliably stop the water.

つぎに、この発明である上記第１図におけるシールド
機を立坑に設置するまでのシールド機発進部の立坑構造
とその施工法を第２図乃至第７図により説明し、この立
坑構造を用いたシールド機の発進・到達方法を第７図乃
至第12図により順を追って説明する。Next, the vertical shaft structure of the shield machine starting portion and its construction method until the shield machine shown in FIG. 1 according to the present invention is installed in the vertical shaft will be described with reference to FIGS. 2 to 7, and this vertical shaft structure was used. The starting and reaching methods of the shield machine will be described in order with reference to FIGS. 7 to 12.

土留芯材建込部 まず、初めに、予定した立坑区域21のうちシールド機
20の発進側を地盤の性状に応じて、壁式地下連続壁工法
により、後述する立坑土留芯材と発進土留芯材である土
留矢板を例えば40cmの間隔を置いて二重芯材として建込
めるように仮設土留構築ラインに沿って地下連続壁22を
構築する（第２図a,b）。掘削は、泥水により立坑壁を
保護するようにする。Soil core material building section First of all, the shield machine in the planned shaft area 21
Depending on the nature of the ground, the starting side of 20 can be built as a double core material with a shaft underground retaining core material and the earth retaining sheet pile, which is the starting soil retaining core material, at a distance of 40 cm, for example, by the underground underground continuous wall construction method. In this way, the underground continuous wall 22 is constructed along the temporary earth retaining construction line (Fig. 2 a, b). Drilling should protect the shaft wall with muddy water.

なお、芯材としてＨ鋼を用いることもできる。 Note that H steel can also be used as the core material.

土留芯材建込み及び泥水固化 ついで、泥水の充填した連続壁22に、以下に述べるよ
うに事前加工された立坑土留芯材23と発進土留芯材24と
をそれぞれ内外二重に精度良く建込む。精度良く建込む
理由は、立坑の土留めや矢板の打撃による精度劣化を防
止し、発進土留芯材24に表面加工したワックスを保護す
るためである。泥水は、壁式地下連続工法のためセメン
トにより自然固化するが、泥水固化の代わりにソイルモ
ルタルの打込み又は薬液注入を行なってもよい（第３図
a,b）。Soil retention core material installation and muddy water solidification Next, on the continuous wall 22 filled with muddy water, the shaft soil retention core material 23 and the starting soil retention core material 24, which have been pre-processed as described below, are accurately installed both inside and outside. . The reason for installing with high accuracy is to prevent the accuracy deterioration due to earth retaining of the vertical shaft and impact of the sheet pile, and to protect the wax surface-treated on the starting earth retaining core material 24. Muddy water naturally solidifies with cement due to the wall-type underground continuous construction method, but instead of solidifying muddy water, soil mortar may be driven in or chemical liquid injection (Fig. 3).
a, b).

上記の芯材の事前加工とは、外側の矢板である発進土
留芯材24には後に述べる引抜きを容易にするため全表面
をワックス加工し、内側の立坑土留矢板23には上記発進
土留矢板24を引抜く際に矢板同志の接触による引抜き抵
抗を小さくし、外部から後述する立坑土留矢板23の切欠
部からの涌水防止のために、建込み方向にパイプスペー
サー25を溶接することである。The pre-processing of the core material means that the outer surface of the starting earth retaining core material 24, which is the outer sheet pile, is waxed on the entire surface in order to facilitate the later-described extraction, and the inner shaft piercing earth retaining sheet pile 23 includes the starting earth retaining sheet pile 24 The pipe spacer 25 is welded in the build-up direction in order to reduce the pull-out resistance due to the contact between the sheet piles when pulling out the sheet, and to prevent the flooding from the notch of the vertical shaft retaining sheet pile 23 described later from the outside.

土留矢板施工完了及び立坑掘削 地下連続壁22を構築した後に、前記立坑予定区域に立
坑内面となる立坑土留矢板25を打込んで、土留壁を設置
し、囲繞された内部を支保工26を架設しながら最終掘削
予定面31まで掘削して立坑を構築する。上記立坑土留矢
板25と前記立坑土留芯材23とは、継手等により連続する
ことで浸水を防止する（第４図a,b）。Earth retaining sheet pile construction completed and shaft excavation After constructing the underground continuous wall 22, drive the shaft underground retaining sheet pile 25, which will be the inner surface of the shaft, into the planned area of the shaft, install the retaining wall, and install the support 26 inside the enclosed interior. At the same time, the vertical shaft is constructed by excavating to the final planned surface 31. The shaft earth retaining sheet pile 25 and the shaft earth retaining core material 23 are connected by a joint or the like to prevent water infiltration (FIGS. 4A and 4B).

発進坑口工 ついで、シールド発進部（シールド発進予定位置）の
周囲（坑口）を鋼材又はコンクリートにより補強して保
護内壁27を設置する。この保護内壁27の内側には、第１
のシール材28と第２のシール材29を備えてシールド機20
を密封状態に設置する筒状チャンバ30をセットする（第
５図a,b）。Next, a protective inner wall 27 will be installed by reinforcing the periphery (hole) around the shield starting portion (scheduled starting position) with steel or concrete. Inside the protective inner wall 27, the first
Shielding machine 20 equipped with the sealing material 28 and the second sealing material 29
Then, the cylindrical chamber 30 for setting the above in a sealed state is set (FIGS. 5A and 5B).

立坑土留芯材坑口部の切断 立坑内にシールド発進に必要な反力壁、架台、仮組セ
グメントなどの仮設を投入、据付けなどを行なって発進
準備を終了し、つぎに立坑土留芯材である内側土留矢板
23のうち保護内壁27の内側を切断して切欠部32を設けて
坑口部の鏡開きを行なう。なお、立坑土留芯材23には矢
板、Ｈ鋼の他に鉄筋の場合も考えられる。Vertical shaft earth retaining core material Cutting of the mouth of the shaft Introducing temporary installation of reaction wall, frame, temporary assembly segment, etc., necessary for starting the shield into the vertical shaft, performing installation, etc. to complete preparation for start, and then the vertical shaft soil retaining core material Inner Dome sheet pile
Of the 23, the inside of the protective inner wall 27 is cut to provide a notch 32 to open the mirror at the wellhead. In addition to the sheet pile and the H steel, the shaft retaining iron core material 23 may be a reinforcing bar.

立坑土留芯材に切欠部32を設けても地山の安定を確保
する理由は、ａ…地下連続壁22中に発進土留芯材24が存
在すること。ｂ…内外の芯材23,24間に地下連続壁22の
一部固化体が存在し、これらがあたかも段ボール状に一
体結合していること。ｃ…パイプスペーサ25によって発
進土留芯材24から内側への出水を防水する。この場合地
下連続壁22の固化体を不透水性のものにすればより効果
が生じる。The reason for ensuring the stability of the ground even if the cutout portion 32 is provided in the shaft earth retaining core material is that a starting soil retaining core material 24 exists in the underground continuous wall 22. b ... A partially solidified body of the underground continuous wall 22 exists between the inner and outer core members 23 and 24, and these are integrally joined as if they were cardboard. c ... The pipe spacer 25 waterproofs the water from the starting soil core material 24 to the inside. In this case, if the solidified body of the continuous underground wall 22 is made impermeable, the effect will be further enhanced.

以上述べたことにより、この発明の立坑構造が出来上
がるが、これらは従来行なった地盤改良工程を省き、シ
ールド発進部のみを補強して他を一般の土留壁と同程度
に簡易構造としたので、工期が短縮されるだけでなく、
立坑構築用の平面積が最少で済むために都心部での利用
に有効である。また、立坑をマンホールとして使用する
場合、又は埋め戻す場合にも地盤を現状復帰させること
が容易である。From the above, the vertical shaft structure of the present invention is completed, but these omit the conventional ground improvement process, and only the shield starting part is reinforced and the other has a simple structure to the same extent as a general retaining wall, Not only the construction period is shortened,
It is effective for use in the center of the city because the flat area for constructing a vertical shaft is minimal. Further, when the shaft is used as a manhole or when it is backfilled, it is easy to restore the ground.

シールド発進 シールド機を設置するには、筒状チャンバ30中にシー
ルド機の先端を押付ける。ついでバルブ10を開にして泥
水タンク９からシールド機20の前面と地下連続壁22との
間に泥水を注入し、シールド機先部のカッターに掘削運
転時と同程度の地山に対抗できる圧力を保持する。この
ようにしてシールド機20と地盤４側の圧力を保持してお
き、発進土留芯材24をワックス効果によってスムーズに
引抜く。この場合芯材24を全て引き抜いてもよいが、シ
ールド機の発進に必要な中央部を所定の高さまで引抜く
方がシールド発進部の土留めを確実にする上で有利であ
る（第７図a,b）。Shield Start To install the shield machine, press the tip of the shield machine into the cylindrical chamber 30. Then, open the valve 10 and inject muddy water from the mud tank 9 between the front of the shield machine 20 and the continuous underground wall 22, and the cutter at the tip of the shield machine has a pressure to withstand the same level of rock formation as during excavation operation. Hold. In this way, the pressure on the shield machine 20 and the ground 4 side is held, and the starting earth retaining core material 24 is smoothly pulled out by the wax effect. In this case, all of the core material 24 may be pulled out, but it is advantageous to pull out the center portion required for starting the shield machine to a predetermined height in order to secure earth retaining of the shield starting portion (Fig. 7). a, b).

発進土留芯材24の引抜きと同時にシールド機を前進さ
せて行くが、発進坑口である切欠部32の止水にはセグメ
ント組立て後に裏込め注入を行なって坑口の隙間の止水
を行うと共に、必要によりバルブ16を開にして裏込注入
用パイプ15から第１と第２のシール材6,7間に止水グラ
ウトを行うこともできる。The shield machine is advanced at the same time as the starting earth retaining core material 24 is pulled out, but for the water stop of the notch 32 which is the start wellhead, backfill injection is performed after segment assembly to stop the water in the gap of the wellhead, and it is necessary. Thus, the valve 16 can be opened to perform the water-stopping grout between the backfill injection pipe 15 and the first and second sealing members 6 and 7.

到達側立坑の準備工 到達側も発進側と対称構造の立坑を構築しておく。Preparatory work for the shaft on the arrival side The shaft on the arrival side should also have a symmetrical structure with the starting side.

この他に、到達側の立坑内にはシールド機が内部に侵
入する大きさで筒状仮組セグメント33を保護内壁27′内
にセットする。この仮組セグメント33中には、土砂を詰
め込み人工地盤34を造成する（第８図a,b）。In addition to this, a cylindrical temporary assembly segment 33 is set in the protection inner wall 27 'in such a size that the shield machine can penetrate into the shaft on the arrival side. The artificial ground 34 is constructed by filling the temporary assembly segment 33 with earth and sand (FIGS. 8A and 8B).

人工地盤への加圧 仮組セグメント33内に人工地盤34が構築されると、予
め仮組セグメント33にセットしている注入パイプ35で給
水槽36から泥水を注入して、（到達）土留芯材24を引抜
いてシールド機20を導き入れる際の地山作用圧に人工地
盤34が充分に抵抗できるようにする。Pressurization to artificial ground When artificial ground 34 is built in temporary assembly segment 33, muddy water is injected from water tank 36 by injection pipe 35 set in temporary assembly segment 33 in advance, and (arrival) soil core The artificial ground (34) can sufficiently resist the natural working pressure when the material (24) is pulled out and the shield machine (20) is introduced.

なお、注入時には注入が容易になるようにエア抜きパ
イプ37を数カ所設け、これを利用して内部圧力を確認す
るようにすることもできる（第９図a,b）。At the time of injection, it is possible to provide several air bleeding pipes 37 to facilitate the injection, and use this to check the internal pressure (Figs. 9a and 9b).

シールド機到達と土留芯材引抜き シールド機が暗渠を掘削しながら立坑に到達した時点
で到達土留芯材としての土留矢板24を無理なく引抜く
（第10図a,b）。無理なく引抜ける理由は、表面のワッ
クス加工と、強制打込みによらない精度良い建込み及び
パイプスペーサーによる内側土留矢板23との接触抵抗を
軽減したことによる。なお、外側の土留矢板の引抜きに
よる鏡の安定は、人工地盤の加圧調整により作用圧とバ
ランスさせて行ない、人工地盤の加圧調整は仮組セグメ
ント33に予め設けた圧力ゲージ38により給水量を調整し
て行なう。Arrival of shield machine and removal of earth retaining core material When the shield machine reaches the vertical shaft while excavating the underdrain, the earth retaining sheet pile 24 as the arrival earth retaining core material is pulled out without difficulty (Figs. 10a and 10b). The reason why it can be pulled out without difficulty is that the surface is waxed, and the contact resistance with the inner soil retaining sheet pile 23 by the pipe spacer is increased and the installation is performed with high accuracy. In addition, the stability of the mirror by pulling out the earth retaining sheet pile on the outside is balanced with the working pressure by the pressure adjustment of the artificial ground, and the pressure adjustment of the artificial ground is adjusted by the pressure gauge 38 previously provided in the temporary assembly segment 33. Adjust and perform.

シールド機の立坑内への導入及び止水 シールド機20は、仮組セグメント33内を掘削しながら
前進して全体を立坑内に導入する。ここで、仮組セグメ
ント33の後方外周に仮止めしておいた止水板38をくさび
状に打込みセグメント全周を密閉する。また、止水板38
の外側には、予め設けておいたグラウトパイプを使用し
て地山側の空隙部にグラウトを注入して止水を完全なも
のにする（第11図a,b）。Introduction of Shield Machine into Vertical Shaft and Water Stop The shield machine 20 moves forward while excavating the temporary assembly segment 33 and introduces the whole into the vertical shaft. Here, the water blocking plate 38 temporarily fixed to the rear outer periphery of the temporary assembly segment 33 is driven in a wedge shape to seal the entire circumference of the segment. Also, the water stop plate 38
On the outside of, the grout pipe that was previously provided is used to inject the grout into the void on the ground side to complete the water stop (Fig. 11 a, b).

仮組セグメントの取外しとシード機の取出し 最後に、仮組セグメントを取外すには、排水パイプを
開いてセグメント内部の圧力水を抜き開口の後、シール
ド機を立坑外に引き上げ、立坑内を片付けて作業を終了
する（第12図a,b）。Removal of the temporary assembly segment and removal of the seed machineFinally, to remove the temporary assembly segment, open the drainage pipe, drain the pressure water inside the segment, open the shield machine, pull the shield machine out of the shaft, and clean up the shaft. Finish the work (Fig. 12 a, b).

＜発明の効果＞ 以上述べてきたように、この発明の立坑構造はシール
ド機発進側のみ立坑と発進の土留芯材を二重にして地下
連続壁中に建込み、他の立坑側壁を通常の立坑土留芯材
としているので、構造が極めて簡単で工期が短かくてす
む。また、立坑外の地盤改良をしないので小さなスペー
スでシールド発進部を構築できる。さらに、立坑周囲に
おける通常の土留芯材はもちろん地下連続壁も簡単に撤
去できるので土地の現状復帰のための工事が簡単であ
る。<Effects of the Invention> As described above, in the shaft structure of the present invention, only the shield machine starting side is built in the underground continuous wall by duplicating the shaft and the earth retaining core material of the starting, and the other side walls of the shaft are normal. Since it is made of vertical shaft soil core material, the structure is extremely simple and the construction period is short. In addition, since the ground is not improved outside the shaft, the shield starting part can be constructed in a small space. Furthermore, not only ordinary earth retaining cores around the shaft but also the continuous underground wall can be easily removed, so construction work to restore the current state of the land is easy.

また、上記立坑構造を発進側と到達側に配することに
より、シールドの発進も到達も発進（到達）土留芯材の
引抜きと、到達側の人工地盤の形成によってトンネルの
覆工を容易に行うことができる。Also, by arranging the above-mentioned shaft structure on the starting side and the reaching side, the starting and reaching of the shield can also be started (reaching). Pulling out the soil retaining core material and forming the artificial ground on the reaching side facilitates the lining of the tunnel. be able to.

さらに、この立坑構造の施工は、通常の地下連続壁工
法と同じか、それ以下の作業で出来、しかも連続壁内の
二重の芯材をそれぞれの使用に応じて使い分けることに
より、シールド機の発進前はもちろん、発進後において
も十分に地山の崩壊を防止することができる。Furthermore, the construction of this shaft structure can be done by the same or less work as the normal underground continuous wall construction method, and moreover, by using the double core material in the continuous wall properly according to each use, It is possible to prevent the ground from collapsing sufficiently not only before starting but also after starting.

【図面の簡単な説明】[Brief description of the drawings]

第１図はこの発明にかかるシールド機の発進部施工構造
を示す断面図、第２図乃至第12図まではこの発明である
立坑構造の施工法とシールド機の発進・到達方法を順に
記載したものであり、各図の（ａ）は平面図、（ｂ）は
側面図である。 １（22）……地下連続壁、２（23）……立坑土留芯材、
３（24）……発進土留芯材、４……地盤、５……筒状チ
ャンバ、12（32）……切欠部、20……シールド機。FIG. 1 is a cross-sectional view showing a starting part construction structure of a shield machine according to the present invention, and FIGS. 2 to 12 sequentially show a construction method of a shaft structure according to the present invention and a start-up / arrival method of a shield machine. In each figure, (a) is a plan view and (b) is a side view. 1 (22) …… Continuous underground wall, 2 (23) …… Shaft retaining core material,
3 (24) …… Starting soil core material, 4 …… Soil, 5 …… Cylindrical chamber, 12 (32) …… Notch, 20 …… Shield machine.

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】シールド機を設置する立坑と、この立坑を
連続して囲繞する立坑土留芯材とから成り、 この立坑土留芯材をシールド機発進側の地下連続壁中に
建込むと共に、シールド機発進用切欠部を形成し、 切欠部の周囲にはシールド機発進用保護内壁を構築し、 前記立坑土留芯材の外側の地下連続壁中には表面に引抜
き加工を施した発進土留芯材を前記切欠部を覆うように
建込んでなる、 シールド機発進部の立坑構造。1. A vertical shaft for installing a shield machine and a vertical shaft earth retaining core material surrounding the vertical shaft. The vertical shaft earth retaining core material is installed in an underground continuous wall on the starting side of the shielding machine, and the shield is installed. A notch for machine start is formed, a protective inner wall for shield machine start is constructed around the notch, and a start earth core material with a surface drawn in the underground continuous wall outside the shaft earth core material The vertical shaft structure of the shield machine starting section, which is constructed so as to cover the notch. 【請求項２】請求項１の立坑構造を発進側と到達側に用
い、それぞれの立坑内にシールド機の反力壁と発進用保
護内壁の内周に沿って設けたシール材付き筒状チャンバ
を設け、 立坑の発進側に地山を掘削していくシールド機を設置
し、発進土留芯材を地下連続壁から立坑土留芯材の切欠
部上に引抜き、シールド前面に芯材のない地下連続壁の
一部を掘削しながら発進して目標地盤を掘進し、 到達側の発進土留芯材に相当する到達土留芯材を地下連
続壁から立坑土留芯材の切欠部上に引抜いてシールド機
を所定圧の人工地盤を形成した到達側の立坑内に取込み
到達するようにした、 シールド機の発進・到達方法。2. A tubular chamber with a sealing material, wherein the vertical shaft structure according to claim 1 is used on the starting side and the reaching side, and provided inside the respective vertical shafts along the inner circumferences of the reaction force wall and the starting protective inner wall of the shield machine. We installed a shield machine to excavate the ground on the starting side of the shaft, pull out the starting soil retention core material from the underground continuous wall onto the notch of the vertical shaft soil retention core material, and continue underground without a core material in front of the shield. Start while excavating a part of the wall to excavate the target ground, pull out the arrival soil core material equivalent to the starting soil retention core material on the arrival side from the underground continuous wall onto the notch of the shaft soil retention core material, and use the shield machine. A method of starting and reaching a shield machine that takes in and reaches the shaft on the arrival side where artificial ground of a predetermined pressure is formed. 【請求項３】予定した立坑区域のシールド機発進側に、
地下連続壁工法により、表面引抜き加工した立坑土留芯
材と発進土留芯材との二重芯材を建込んで地下連続壁を
構築する工程と、 この地下連続壁中の立坑土留芯材と連続して他の立坑内
面となる立坑土留芯材としての立坑土留矢板を打込むと
共に、囲繞した立坑土留矢板内部を掘削する工程と、 前記地下連続壁のシールド機の発進坑口周囲に保護内壁
を設けると共に、保護内壁の内側にあたる前記立坑土留
芯材に切欠部を形成する工程と、 からなる立坑発進側の地盤改良を行なわないシールド発
進部の立坑構造の施工法。3. A shield machine starting side in a planned shaft area,
By the underground continuous wall method, a process of constructing an underground continuous wall by building a double core material of a vertical shaft soil core material and a starting soil core material that have been subjected to surface drawing, and a continuous process with the vertical shaft metal core material in this underground continuous wall. Then, while driving the shaft earth retaining sheet pile as a shaft earth retaining core material to be the inner surface of the other shaft, excavating the surrounding shaft earth retaining sheet pile, and providing a protective inner wall around the starting hole mouth of the shield machine of the underground continuous wall In addition, a step of forming a notch in the shaft retaining core material inside the protective inner wall, and a method of constructing a shaft structure of a shield starting part that does not improve the ground on the shaft starting side.