JP2005188253A

JP2005188253A - Forepoling method for tunnel

Info

Publication number: JP2005188253A
Application number: JP2003434346A
Authority: JP
Inventors: Kunito Sakai; 酒井邦登; Atsushi Mitsuo; 満尾淳; Yukio Hirai; 平井幸雄; Hidetaka Nishimoto; 西本英高; Akira Komatsu; 小松章
Original assignee: Nippon Steel Corp; Tokyu Construction Co Ltd
Current assignee: Nippon Steel Corp; Tokyu Construction Co Ltd
Priority date: 2003-12-26
Filing date: 2003-12-26
Publication date: 2005-07-14

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forepoling method for a tunnel for facilitating driving of pipe materials in the natural ground, by arranging a spiral blade in the tip vicinity of the pipe materials. <P>SOLUTION: This forepoling method of the tunnel drives a plurality of pipe materials at an interval in the peripheral direction of the tunnel toward the natural ground 2 in front of the tunnel. The construction method covers the natural ground being an excavation object with the pipe materials with the spiral blade arranged in a predetermined range, by repeating driving work of the pipe materials with the spiral blade at a predetermined interval in the tunnel peripheral direction, by driving a hollow pipe material, that is, the pipe materials 1 with the spiral blade for arranging the spiral blade in the tip vicinity by rotating toward the natural ground in front of the tunnel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

本発明は、地山の強度が不足し、掘削によって崩壊や地表面沈下が発生するおそれのある地山にトンネルを構築する場合に実施されるトンネルの先受け工法に関するものである。
The present invention relates to a tunnel receiving method that is implemented when a tunnel is constructed in a natural ground where the strength of the natural ground is insufficient and collapse or surface subsidence may occur due to excavation.

自立性の悪い地山にトンネルを掘削する場合に、トンネル前方に向けて鋼管などをトンネルの周方向に間隔を開けて複数打設し、トンネルの外周にアーチ状の仮想屋根を構築する先受け工法が、１９９０年頃から採用され始め、現在ではトンネル補助工法の主流となっている。
特許文献１等に開示されているパイプルーフ工法は、トンネルの坑口から掘削外周面に沿ってトンネル掘進方向に鋼管を打設し、鋼管に覆われている地山を掘削していく方法である。パイプルーフ工法は、坑口に設ける鋼管の打設設備が大規模になり、トンネル掘削を開始するときの坑口対策に適用されることが多い。
また、特許文献２等に開示されているAGF工法は、トンネル掘削に使用する油圧ジャンボ削孔機によって、二重管方式で直径100mm程度の鋼管をトンネル外周にアーチ状に配置されるように打設し、打設した鋼管を使用して注入材を鋼管の周囲に注入する方法である。AGF工法は、特許文献３に開示されているような長尺鋼管フォアパイリング工法の一種であり、その他にも鋼管を専用機で地山に打設するトレビチューブ工法などがある。また、特許文献４等に開示されているように打設した有孔管を使用して地山に薬液を注入して地山の安定を図る工法もある。
トンネルの先受け工法は、一般的に継ぎ足した長さが12.5ｍになる鋼管をトンネル前方の地山に向けて斜め上方に打設する。そして、トンネル周方向にアーチ状に打設した鋼管に覆われた地山を、9ｍ掘削してトンネルを掘進させる。再び、12.5ｍになる鋼管をトンネル前方の地山に向けて斜め上方に打設すると、鋼管の前後は3.5ｍラップすることになる（図２参照）。 When excavating a tunnel in a poorly self-supporting ground, a steel bridge is placed in front of the tunnel at intervals in the circumferential direction of the tunnel to construct an arched virtual roof on the outer periphery of the tunnel The construction method began to be adopted around 1990, and is now the mainstream of the tunnel auxiliary construction method.
The pipe roof construction method disclosed in Patent Literature 1 is a method in which a steel pipe is driven in the tunnel excavation direction along the outer peripheral surface of the tunnel from the tunnel entrance, and a natural mountain covered with the steel pipe is excavated. . The pipe roof construction method is often applied to wellhead measures when starting tunnel excavation because the steel pipe placement equipment provided at the wellhead becomes large-scale.
In addition, the AGF method disclosed in Patent Document 2 is driven by a hydraulic jumbo drilling machine used for tunnel excavation so that a steel pipe having a diameter of about 100 mm is arranged in an arch shape on the outer periphery of the tunnel by a double pipe method. This is a method in which an injected material is injected around the steel pipe using the installed and cast steel pipe. The AGF method is a kind of long steel pipe fore-piling method as disclosed in Patent Document 3, and there is a Trevi tube method in which a steel pipe is driven into a natural ground with a dedicated machine. In addition, there is a method for stabilizing the natural ground by injecting a chemical into the natural ground using a perforated pipe placed as disclosed in Patent Document 4 and the like.
In the tunnel receiving method, a steel pipe with a length of 12.5m is generally placed diagonally upward toward a natural ground in front of the tunnel. Then, a tunnel is dug by excavating a natural ground covered with steel pipes that are arched in the circumferential direction of the tunnel. Again, when a steel pipe with a length of 12.5m is driven diagonally upward toward the ground in front of the tunnel, the steel pipe wraps around 3.5m (see Fig. 2).

他方、鋼管杭の先端に螺旋状の羽根を取り付けて、地盤への貫入推進を容易にした回転埋設開端杭が特許文献５に開示されている。また、複数の羽根を螺旋状に取り付けた螺旋羽根付き鋼管杭が特許文献６に開示されている。これらの鋼管杭は、比較的小規模の構造物を支持する支持杭として地盤に鉛直に打設されることが多い。
特開平５−２９５９８０号公報特開平１０−８８７５号公報特開２０００−３４８８１号公報特開平７−２９２６５４号公報特開平１１−２６９８７５号公報特開平８−２９１５１８号公報 On the other hand, Patent Document 5 discloses a rotary embedded open end pile in which a spiral blade is attached to the tip of a steel pipe pile to facilitate penetration into the ground. Further, Patent Document 6 discloses a steel pipe pile with spiral blades in which a plurality of blades are spirally attached. These steel pipe piles are often placed vertically on the ground as support piles that support relatively small structures.
JP-A-5-295980 Japanese Patent Laid-Open No. 10-8875 JP 2000-34881 A JP-A-7-292654 JP-A-11-269875 JP-A-8-291518

前記した従来のトンネルの先受け工法にあっては、次のような問題点がある。
＜１＞パイプルーフ工法は、地山が悪くなった段階でトンネルの途中からおこなうことができない。また、打設設備が大規模になるため、工費及び工期が増加する。
＜２＞地山を打撃しながら掘削し、鋼管を押し込む長尺フォアパイリング工法では、湧水の多い地山においては鋼管の周囲の地盤が緩み、地山状態を更に悪くする場合がある。また、打撃時の騒音や振動が大きいため、市街地のトンネル工事には適さない。
＜３＞拡径ビットを用いて二重管方式で有孔鋼管を打設する長尺フォアパイリング工法では、掘削した土砂を管に沿ってトンネル内に排出することになる。このため、掘削土砂を処理する必要がある。
＜４＞薬液や注入材を注入する方法では、注入のためのプラントが必要である上に、排出された注入材を処分する必要がある。
The conventional tunnel tip receiving method described above has the following problems.
<1> The pipe roof construction method cannot be carried out from the middle of the tunnel when the ground has deteriorated. In addition, since the installation equipment becomes large-scale, the construction cost and the construction period increase.
<2> In the long fore-piling method, in which the excavation is performed while hitting the natural ground and the steel pipe is pushed in, the ground around the steel pipe is loosened in the natural ground where there is a lot of spring water, and the natural condition may be further deteriorated. In addition, the noise and vibration at the time of impact are large, so it is not suitable for urban tunnel construction.
<3> In the long fore-piling method in which a perforated steel pipe is driven by a double pipe method using a diameter expanding bit, the excavated earth and sand are discharged into the tunnel along the pipe. For this reason, it is necessary to process excavated earth and sand.
<4> In the method of injecting a chemical solution or an injection material, a plant for injection is required and it is necessary to dispose of the discharged injection material.

上記のような課題を解決するために、本発明のトンネルの先受け工法は、トンネル前方の地山に向けて複数の管材をトンネルの周方向に間隔を開けて打ち込むトンネルの先受け工法において、中空の管材であって、先端付近に螺旋翼を設けた螺旋翼付き管材をトンネル前方の地山に向けて回転させることによって打ち込み、トンネル周方向に所定の間隔を開けて前記螺旋翼付き管材の打ち込み作業を繰り返し、掘削対象となる地山を所定の範囲に配置した前記螺旋翼付き管材によって覆う工法である。ここで、前記螺旋翼付き管材の後端に中空管材を接合して、さらに地山の深部に向けて管材を打ち込むことができる。また、前記螺旋翼付き管材の管材の外径を70〜300mm、螺旋翼の外径を90〜450mmとすることができる。
さらに、上記したいずれかに記載のトンネルの先受け工法において、前記螺旋翼付き管材のトンネル前方の地山に向けての打ち込みに加えて、例えばトンネルの一次支保工の両端部から前記螺旋翼付き管材を、トンネル掘進方向に略直交、かつ下方向あるいは水平方向に向けて打ち込むこともできる。
In order to solve the above-mentioned problems, the tunnel tip receiving method of the present invention is a tunnel tip receiving method in which a plurality of pipe materials are driven at intervals in the circumferential direction of the tunnel toward the ground in front of the tunnel. It is a hollow pipe, driven by rotating a pipe with a spiral wing provided with a spiral wing in the vicinity of the tip toward a natural ground in front of the tunnel, and with a predetermined interval in the circumferential direction of the tunnel, This is a construction method in which the driving operation is repeated and a natural ground to be excavated is covered with the pipe member with the spiral blade disposed in a predetermined range. Here, a hollow tube material can be joined to the rear end of the tube material with spiral wings, and the tube material can be driven further toward the deep part of the natural ground. Moreover, the outer diameter of the pipe of the pipe member with the spiral blade can be set to 70 to 300 mm, and the outer diameter of the spiral blade can be set to 90 to 450 mm.
Further, in the above-mentioned tunnel tip receiving method according to any one of the above, in addition to driving the pipe member with the spiral blade toward the ground in front of the tunnel, for example, with the spiral blade from both ends of the primary support of the tunnel It is also possible to drive the pipe material substantially perpendicular to the tunnel excavation direction and downward or horizontally.

本発明のトンネルの先受け工法は、上記した課題を解決するための手段により、次のような効果の少なくとも一つを得ることができる。
＜１＞管材の先端付近に螺旋翼を設けたことにより、管材の地山への打ち込みが容易になる。また、回転力によって打ち込みをおこなうため、騒音や振動がほとんど発生せず、市街地のトンネル工事にも適用できる。
＜２＞地山を打撃したり、削孔水を使用したりしないため、地山を緩めることがない。また、掘削した土砂は、中空管材の内部に取り込まれたり、地山に押し付けられたりするので、ほとんどトンネル内部に排出されることはない。また、押し付けられた掘削土によって管材の周囲の地山が補強される。
＜３＞回転力によって管材を地山に打ち込むことができるので、管材を打ち込むための大型の機械を必要としない。また、削孔水等を使用しないため、スラリープラントなどの給水、排土処理設備が不要である。
The tunnel tip receiving method of the present invention can obtain at least one of the following effects by means for solving the above-described problems.
<1> By providing the spiral blade near the tip of the pipe material, it becomes easy to drive the pipe material into the natural ground. In addition, since driving is performed by rotational force, noise and vibration are hardly generated, and it can be applied to tunnel construction in an urban area.
<2> The natural ground is not loosened because it does not hit the natural ground or use drilling water. In addition, the excavated earth and sand is taken into the hollow tube material or pressed against the natural ground, so it is hardly discharged into the tunnel. Moreover, the natural ground around the pipe material is reinforced by the pressed excavated soil.
<3> Since the pipe material can be driven into the natural ground by the rotational force, a large machine for driving the pipe material is not required. In addition, since no drilling water or the like is used, water supply and soil removal treatment facilities such as a slurry plant are unnecessary.

以下、図面を参照しながら本発明の実施の形態について説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

＜１＞螺旋翼付き管材
螺旋翼付き管材１は、中空の管材の先端付近に螺旋翼１１を取り付けた管材である。螺旋翼１１の始端は、管材の先端であっても、先端から所定の間隔を開けた位置であってもよい。管材の先端には必要に応じて公知の削孔ビットを設けてもよい。
螺旋翼付き管材１を構成する中空の管材には、例えば外径がφ70〜300mm、好ましくはφ110〜220mmの鋼管が使用できる。また、鋼管の肉厚は4〜6mm程度が好ましい。螺旋翼１１の外径は、管材の外径の1.3〜1.5倍程度が好ましいため、φ90〜450mm、好ましくはφ170〜325mmとする。
螺旋翼１１は、一枚の板材を螺旋状に成形して製作することができる（図１参照）。また、複数の板材を螺旋状に配置することによって成形してもよい（特許文献６参照）。
螺旋翼付き管材１は、後方から回転力と圧力を加えると、木ネジが木材中を推進するように容易に推進していく。特に、地盤が軟らかい場合はその推進力は顕著になり、ほとんど回転力だけで地山に螺旋翼付き管材１を打ち込むことができる。このため、管材の打ち込みに伴って地山を緩めることがなく、騒音や振動もほとんど発生しない。また、削孔水を使用する必要がないため、スラリープラントが不要で、ドライな環境で打ち込み作業を行うことができる。
また、螺旋翼付き管材１は先端が開口されており、内部が中空であるため、地山や掘削した土砂を管材の内部に取り込むことができる。さらに、取り込みきらない土砂は管外の周辺地山に押し付けられるので、地山強度が増大する。このため、掘削土砂が排出されることがない。
<1> Tubular material with spiral wings The tubular material 1 with spiral wings is a tubular material in which a spiral blade 11 is attached in the vicinity of the tip of a hollow tubular material. The starting end of the spiral blade 11 may be the tip of the pipe material or a position spaced a predetermined distance from the tip. You may provide a well-known drill bit at the front-end | tip of a pipe material as needed.
As the hollow tube material constituting the tube member 1 with a spiral blade, for example, a steel tube having an outer diameter of φ70 to 300 mm, preferably φ110 to 220 mm can be used. Further, the thickness of the steel pipe is preferably about 4 to 6 mm. Since the outer diameter of the spiral blade 11 is preferably about 1.3 to 1.5 times the outer diameter of the pipe material, it is set to φ90 to 450 mm, preferably φ170 to 325 mm.
The spiral blade 11 can be manufactured by forming a single plate material into a spiral shape (see FIG. 1). Moreover, you may shape | mold by arrange | positioning several board | plate materials helically (refer patent document 6).
When the rotational force and pressure are applied from the rear, the spiral winged tube material 1 is easily propelled so that the wood screw is propelled in the wood. In particular, when the ground is soft, the propulsive force becomes remarkable, and the pipe member 1 with a spiral wing can be driven into the natural ground with almost only rotational force. For this reason, the natural ground is not loosened with the driving of the pipe material, and noise and vibration are hardly generated. In addition, since it is not necessary to use drilling water, a slurry plant is unnecessary, and the driving operation can be performed in a dry environment.
Moreover, since the pipe material 1 with a spiral wing has an open end and is hollow inside, a natural ground or excavated earth and sand can be taken into the pipe material. Furthermore, since the earth and sand which cannot be taken in are pressed against the surrounding natural ground outside the pipe, the natural ground strength increases. For this reason, excavation earth and sand are not discharged.

＜２＞中空管材
一般にトンネルの構内は狭く、取り扱いや打ち込み機による制限から長尺の鋼管をそのまま使用することは難しい。このため、螺旋翼付き管材１も後方に中空管材１２を継ぎ足すことによって長尺の先受け用管材にすることが多い。
すなわち、最初に3〜4ｍ程度の長さの螺旋翼付き管材１を地山に向けて打ち込んだ後に、螺旋翼付き管材１の後端に中空管材１２を接合する。接合方法には、ネジ式、溶接式、継手管によるカップリング式等がある。
<2> Hollow tube material Generally, the tunnel is narrow and it is difficult to use a long steel pipe as it is because of limitations due to handling and driving equipment. For this reason, the tubular member 1 with a spiral wing is also often made into a long receiving tube by adding a hollow tubular member 12 to the rear.
That is, after the tube member 1 with a spiral wing having a length of about 3 to 4 m is first driven toward the ground, the hollow tube member 12 is joined to the rear end of the tube member 1 with the spiral wing. As a joining method, there are a screw method, a welding method, a coupling method using a joint pipe, and the like.

＜３＞回転圧入機（図４）
回転圧入機４は、螺旋翼付き管材１を地山に打ち込むための機械である。例えば、管材に回転力を与える回転モータ４１と、圧入用の反力を確保するための反力ジャッキ４２と、管材を推進させるためのスライド架台４３で構成する。
スライド架台４３は、管材の打ち込み角度に合わせて任意の角度に設定できるように支持させる。スライド架台４３は、管材の単位長さ以上の範囲を直線的に前後できる装置を使用する。
スライド架台４３に設置した回転モータ４１は、螺旋翼付き管材１又は中空管材１２の後端を把持して管材に回転力を与える装置である。回転モータ４１に螺旋翼付き管材１をセットし、反力ジャッキ４２を一次支保工３で覆工したトンネルの内周面に押し当て、管材を回転させながらスライド架台４３をトンネルの前方に向けて押し出すことで、螺旋翼付き管材１を地山に打ち込む。
<3> Rotary press-fitting machine (Fig. 4)
The rotary press machine 4 is a machine for driving the pipe member 1 with a spiral wing into a natural ground. For example, it comprises a rotary motor 41 that applies a rotational force to the pipe material, a reaction force jack 42 for securing a reaction force for press-fitting, and a slide frame 43 for propelling the pipe material.
The slide mount 43 is supported so that it can be set to an arbitrary angle according to the driving angle of the pipe material. The slide mount 43 uses a device that can linearly move back and forth in the range of the unit length or more of the pipe material.
The rotation motor 41 installed on the slide mount 43 is a device that grips the rear end of the spiral winged tube material 1 or the hollow tube material 12 and applies a rotational force to the tube material. The pipe member 1 with a spiral blade is set on the rotary motor 41, the reaction force jack 42 is pressed against the inner peripheral surface of the tunnel covered with the primary support 3, and the slide base 43 is directed forward of the tunnel while rotating the pipe member. By pushing, the tube material 1 with spiral wings is driven into a natural ground.

＜４＞脚部補強
地山の状態が悪く、地耐力が不足する場合は、アーチ状に形成した支保工の脚部付近が沈下し、トンネルの変形を誘発することがある。このようなおそれがある地山では、支保工の脚部周辺の例えば掘削底盤２２より下方に向けて細径杭を打設して脚部補強をおこなっていた（図２，３参照）。脚部補強は支保工の両端部あるいは側面から水平方向に向けて行うこともある。特に、先受け工法を行う場合は、地山に打設した管材が受けた地山の荷重が脚部に集中するため、脚部の沈下が増加するおそれがある。
そこで、アーチ状の一次支保工３の両端部から螺旋翼付き管材１を、トンネル掘進方向に略直交する方向であって、下方向あるいは水平方向に向けて打ち込んで脚部を補強することができる。螺旋翼付き管材１は下方や水平方向に向けて打ち込む場合も、回転力を付与するだけで容易に推進させることができる。
<4> Leg part reinforcement When the ground is in poor condition and the earth strength is insufficient, the vicinity of the leg part of the supporting structure formed in an arch shape may sink and induce deformation of the tunnel. In such a natural ground, the reinforcement of the leg was performed by driving a small-diameter pile around, for example, the bottom of the excavation bottom plate 22 around the leg of the support work (see FIGS. 2 and 3). Leg reinforcement may be performed horizontally from both ends or sides of the support. In particular, when the prior receiving method is used, the load of the natural ground received by the pipe material placed on the natural ground is concentrated on the leg, and there is a possibility that the settlement of the leg increases.
Thus, the leg portion can be reinforced by driving the pipe member 1 with the spiral wing from both ends of the arch-shaped primary support work 3 in a direction substantially perpendicular to the tunnel excavation direction and downward or in the horizontal direction. . Even when the spiral winged tube material 1 is driven downward or horizontally, it can be easily propelled only by applying a rotational force.

＜１＞適用地盤
トンネルの先受け工法は、地山の状態が比較的悪く、掘削後に切羽（掘削面）が崩壊したり、トンネル直上の地表面が沈下したりするおそれがある場合に適用される。
表１に本発明のトンネルの先受け工法を適用できる地盤を示す。 <1> Applicable ground The tunnel receiving method is applied when the condition of the ground is relatively bad and the face (excavation surface) may collapse after excavation or the ground surface directly above the tunnel may sink. The
Table 1 shows the ground to which the tunnel tip receiving method of the present invention can be applied.

玉石混じりの砂礫層や玉石層は、螺旋翼付き管材１を回転・圧入することが難しいため適用できない。また、シルト・粘土のように地盤が軟弱すぎると、管材と管材の間から地山が抜け落ちてしまうため、先受け工法の効果があまり期待できない。しかし、これ以外の地盤には広く適用できる。
A gravel layer or a cobblestone layer mixed with cobblestones cannot be applied because it is difficult to rotate and press-fit the pipe member 1 with a spiral wing. In addition, if the ground is too soft like silt or clay, the ground will fall out between the pipes, so that the effect of the prior construction method cannot be expected. However, it can be widely applied to other grounds.

＜２＞トンネルの掘削
トンネルを所定の長さ掘削して、トンネル周方向の掘削面にＨ形鋼材や吹付けコンクリート等の一次支保工３を施す。トンネル前方の掘削面（切羽）にもコンクリートを吹付け、必要に応じて鏡ボルトを打ち込む。
<2> Excavation of tunnel The tunnel is excavated for a predetermined length, and primary support work 3 such as H-shaped steel or shotcrete is applied to the excavation surface in the circumferential direction of the tunnel. Concrete is sprayed on the excavation surface (face) in front of the tunnel, and mirror bolts are driven in if necessary.

＜３＞管材の打ち込み
回転圧入機４に螺旋翼付き管材１を設置し、管材のスライド方向を地山への打ち込み方向に合わせる。通常、斜め上方に向けて螺旋翼付き管材１を打ち込むため、打ち込み角度も斜め上方に向けて設定する。反力ジャッキ４２は、一次支保工３に押し当てて圧入時の反力を確保する。
螺旋翼付き管材１の先端を切羽の外周２１付近に押し当て、管材を回転させる。螺旋翼付き管材１が回転し、地山に打ち込まれる量に伴ってスライド架台４３をトンネル前方に向けて進める。
螺旋翼付き管材１によって掘削した土砂は、管材の内部に取り込まれたり、地山に押し付けられたりするので、ほとんどトンネル内部に排出されることはない。また、押し付けられた掘削土によって管材の周囲の地山が補強される。
螺旋翼付き管材１の後端付近まで打ち込んだ後に、一旦、回転モータ４１と管材を切り離し、スライド架台４３を後方の所定の位置に戻す。そして、地山に打ち込まれた管材の後端と回転モータ４１との間に中空管材１２を配置し、管材間を接合する。一般的に継ぎ足した長さが12.5ｍになるまで管材をトンネル前方の地山に向けて打ち込む。 <3> Tubing of pipe material The pipe material 1 with a spiral blade is installed in the rotary press-fitting machine 4, and the sliding direction of the pipe material is adjusted to the driving direction to the natural ground. Usually, since the spirally winged tube material 1 is driven obliquely upward, the driving angle is also set obliquely upward. The reaction force jack 42 is pressed against the primary support 3 to ensure a reaction force during press-fitting.
The tip of the tube member 1 with a spiral wing is pressed against the vicinity of the outer periphery 21 of the face, and the tube member is rotated. The pipe member 1 with the spiral wing rotates and advances the slide frame 43 toward the front of the tunnel according to the amount driven into the natural ground.
Since the earth and sand excavated by the pipe member 1 with the spiral wing is taken into the pipe member or pressed against the natural ground, it is hardly discharged into the tunnel. Moreover, the natural ground around the pipe material is reinforced by the pressed excavated soil.
After driving to the vicinity of the rear end of the pipe member 1 with the spiral blade, the rotary motor 41 and the pipe member are once separated, and the slide mount 43 is returned to a predetermined position on the rear side. And the hollow pipe material 12 is arrange | positioned between the rear end of the pipe material driven into the natural ground, and the rotation motor 41, and pipe materials are joined. Generally, the pipe material is driven toward the natural ground in front of the tunnel until the length of addition is 12.5 m.

管材を所定の長さ地山に打ち込んだ後に、トンネル周方向に所定の間隔を開けて次の螺旋翼付き管材１の打ち込み作業をおこなう。この作業を所定の範囲で繰り返すことによって、トンネル前方の掘削面にアーチ状に管材が配置される。
また、一次支保工３の側面または脚部から、水平または掘削底盤２２よりも下方に向けて螺旋翼付き管材１を打ち込むことによって脚部補強をおこなうことができる。 After the tube material is driven into the ground for a predetermined length, the next tube material 1 with a spiral blade is driven at a predetermined interval in the circumferential direction of the tunnel. By repeating this operation within a predetermined range, the pipe material is arranged in an arch shape on the excavation surface in front of the tunnel.
Moreover, the leg portion can be reinforced by driving the pipe member 1 with the spiral blade from the side surface or the leg portion of the primary support 3 toward the horizontal or the bottom of the excavation bottom plate 22.

所定の範囲に複数の螺旋翼付き管材１を配置して掘削対象となる地山を覆うと、安全な地山掘削環境が提供されることになる。この状態で、管材に覆われた地山２３を掘削する（図３参照）。例えばトンネルの掘進方向に向けて9ｍ掘削する。9ｍ掘削した後に、再び12.5ｍになる管材をトンネル前方の地山に向けて斜め上方に打設すると、管材の前後は3.5ｍラップすることになる（図２参照）。
When a plurality of pipes 1 with spiral wings are arranged in a predetermined range to cover a natural ground to be excavated, a safe natural ground excavation environment is provided. In this state, the natural ground 23 covered with the pipe material is excavated (see FIG. 3). For example, excavate 9m toward the tunnel direction. After excavating 9m, if the pipe material that becomes 12.5m again is driven diagonally upward toward the ground in front of the tunnel, the pipe material will wrap around 3.5m (see Fig. 2).

本発明のトンネルの先受け工法の実施例の説明図。Explanatory drawing of the Example of the tip receiving construction method of the tunnel of this invention. トンネルの先受け工法の実施例の縦断面図。The longitudinal cross-sectional view of the Example of the point receiving construction method of a tunnel. トンネルの先受け工法の実施例の横断面図。The cross-sectional view of the Example of the point receiving construction method of a tunnel. 回転圧入機の実施例の説明図。Explanatory drawing of the Example of a rotary press-fitting machine.

Explanation of symbols

１・・・螺旋翼付き管材
１１・・螺旋翼
１２・・中空管材
２・・・地山 DESCRIPTION OF SYMBOLS 1 ... Tube material 11 with a spiral wing ... Spiral wing 12 ... Hollow tube material 2 ... Ground

Claims

In the tunnel tip receiving method, in which multiple pipes are driven at intervals in the circumferential direction of the tunnel toward the natural ground in front of the tunnel,
It is a hollow pipe, and it is driven by rotating a pipe with a spiral wing provided with a spiral wing near the tip toward a natural ground in front of the tunnel,
Repeat the driving operation of the pipe member with the spiral wing with a predetermined interval in the circumferential direction of the tunnel,
Covering the natural ground to be excavated with the spiral winged tube material arranged in a predetermined range,
The tunnel construction method.

In the tunnel tip receiving method, in which multiple pipes are driven at intervals in the circumferential direction of the tunnel toward the natural ground in front of the tunnel,
It is a hollow pipe, and it is driven by rotating a pipe with a spiral wing provided with a spiral wing near the tip toward a natural ground in front of the tunnel,
Joining the hollow pipe to the rear end of the pipe that has been driven into the natural ground, and then driving the pipe toward the deep part of the natural ground,
Repeat the operation of driving the pipe with the spiral wing and the hollow pipe at a predetermined interval in the circumferential direction of the tunnel,
Cover the natural mountain to be excavated with the spiral winged tube material and the hollow tube material arranged in a predetermined range,
The tunnel construction method.

In the prior receiving method of the tunnel according to claim 1 or 2,
The outer diameter of the pipe material of the pipe member with the spiral wing is 70 to 300 mm, the outer diameter of the spiral wing is 90 to 450 mm,
The tunnel construction method.

In the point receiving construction method of the tunnel according to any one of claims 1 to 3,
In addition to driving the pipe with spiral wing toward the ground in front of the tunnel, the pipe with spiral wing is driven from both ends of the tunnel support work substantially perpendicular to the tunnel excavation direction and downward or horizontally. It is characterized by
The tunnel construction method.