JP2011021374A - Sheet pile jacking method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a straight excavated hole in ground by preventing a deviation of a load and a deflection of a main shaft of excavation during the excavation of the ground. <P>SOLUTION: In an excavating tool 13, a casing 10 is externally fitted and mounted on the outer peripheral surface of the rotatively-driven main shaft 9 of excavation; a sheet pile P is arranged and supported on the outer peripheral surface of the casing 10; and a leading end of the main shaft 9 is equipped with a bit portion 15 which is evenly diameter-enlarged on the axis line O of the main shaft 9 by excavation resistance from the ground G when the main shaft 9 is rotated in the direction of excavation, and which is diameter-reduced to a size small enough not to collide with the sheet pile P, by frictional resistance to the ground G, when the main shaft 9 is rotated in a direction opposite to the direction. Excavation equipment 1 for use is fitted with the excavating tool 13 via a down-the-hole hammer 12. The excavation equipment 1 is supported in a rising attitude; the casing 10 and the sheet pile P are jacked while the ground G is excavated by the bit portion 15 of the excavating tool 13 rotatively hit in this state; after the completion of the jacking of the sheet pile P, the bit portion 15 of the excavating tool 13 is put into a diameter-reduced state; and the excavating tool 13 and the like are pulled out from the ground G. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、玉石混じりの砂礫層や岩盤、転石等が存在する硬質の地盤にＵ形の鋼製の矢板を圧入する工法に係り、特に、硬質の地盤の掘削と矢板の圧入とを同時に行うようにした矢板の圧入工法の改良に関するものである。   The present invention relates to a method of press-fitting a U-shaped steel sheet pile into a hard ground where a gravel layer mixed with cobblestones, rocks, rolling stones, etc. exist, and in particular, excavation of a hard ground and press-fitting of a sheet pile are performed simultaneously. It is related with the improvement of the press-fitting method of the sheet pile made.

従来、硬質の地盤の掘削と矢板の圧入とを同時に行う矢板の圧入工法としては、例えば、特許第２９９７４０２号公報（特許文献１）に開示された工法が知られている。   Conventionally, for example, a method disclosed in Japanese Patent No. 2997402 (Patent Document 1) is known as a sheet pile press-in method for simultaneously excavating a hard ground and press-fitting a sheet pile.

即ち、前記矢板の圧入工法は、図７に示す如く、オーガマシン３１により回転駆動される掘削主軸３２に円筒状のケーシング３３を外嵌装備すると共に、前記掘削主軸３２の先端部にダウンザホールハンマー３４を介して偏心掘削ビット３５を取り付けた掘削装置３０を用い、Ｕ形の鋼製の矢板Ｐをチャック装置３６等によりケーシング３３の外周面にケーシング３３に沿って配設支持し、オーガマシン３１により掘削主軸３２を回転駆動して偏心掘削ビット３５を回転させると共に、当該偏心掘削ビット３５をダウンザホールハンマー３４により打撃し、偏心掘削ビット３５の回転打撃作用によって地盤Ｇを掘削しながらケーシング３３及び矢板Ｐを圧入するようにし、矢板Ｐの圧入完了後に偏心掘削ビット３５を矢板Ｐと衝突しない位置に回転させ、この状態でケーシング３３及び偏心掘削ビット３５を地盤Ｇ中から引き抜くようにしたものである。   That is, as shown in FIG. 7, the press-fitting method of the sheet pile includes a cylindrical casing 33 fitted to the excavation main shaft 32 that is rotationally driven by the auger machine 31, and a down-the-hole hammer 34 at the tip of the excavation main shaft 32. A U-shaped steel sheet pile P is disposed and supported along the casing 33 on the outer peripheral surface of the casing 33 by a chuck device 36 or the like using an excavator 30 to which an eccentric excavation bit 35 is attached. The excavation main shaft 32 is rotationally driven to rotate the eccentric excavation bit 35, and the eccentric excavation bit 35 is hit by the down-the-hole hammer 34, and the casing 33 and the sheet pile P are excavated while excavating the ground G by the rotary hitting action of the eccentric excavation bit 35. The position where the eccentric excavation bit 35 does not collide with the sheet pile P after the completion of the press-fitting of the sheet pile P Rotate, in which the casing 33 and the eccentric drill bit 35 so as to pull out from in the ground G in this state.

前記矢板の圧入工法は、掘削主軸３２及びダウンザホールハンマー３４により回転打撃される偏心掘削ビット３５によって地盤Ｇを掘削し、掘削孔を形成しながら矢板Ｐを圧入するようにしているため、玉石混じりの砂礫層や岩盤等が存在する硬質の地盤Ｇの掘削が容易になると共に、硬質の地盤Ｇへの矢板Ｐの圧入を迅速且つ容易に行うことができると云う利点がある。   In the sheet pile press-in method, the ground G is excavated by the eccentric excavation bit 35 rotated by the excavation main shaft 32 and the down-the-hole hammer 34, and the sheet pile P is press-fitted while forming the excavation hole. There are advantages that excavation of the hard ground G in which a gravel layer or a rock is present is facilitated, and that the sheet pile P can be press-fitted into the hard ground G quickly and easily.

又、この矢板の圧入工法は、図８及び図９に示す如く、ビット本体３５ａ及びビット軸部３５ｂから成る偏心掘削ビット３５を用いているため、偏心掘削ビット３５を矢板Ｐに衝突することなく地盤Ｇ中から引き抜くことができると共に、掘削孔の内径を矢板Ｐの幅と同等或いはそれ以上に形成することができ、矢板Ｐの圧入をより一層容易に行えると云う利点がある。   In addition, as shown in FIGS. 8 and 9, this sheet pile press-in method uses an eccentric excavation bit 35 comprising a bit body 35a and a bit shaft portion 35b, so that the eccentric excavation bit 35 does not collide with the sheet pile P. There is an advantage that it can be pulled out from the ground G, and the inner diameter of the excavation hole can be formed equal to or larger than the width of the sheet pile P, so that the sheet pile P can be press-fitted more easily.

しかしながら、従来の矢板の圧入工法は、地盤Ｇを掘削する掘削ビットに偏心掘削ビット３５を用いているため、地盤Ｇを掘削する際に負荷が偏り、掘削主軸３２に振れが生じて真円で真っ直ぐな掘削孔を形成することができないと云う問題があった。その結果、矢板Ｐを所定の位置に正確に圧入することが困難であった。然も、地盤Ｇを掘削する際に掘削主軸３２が振れると、偏心掘削ビット３５にかかる掘削抵抗が大きくなり、掘削作業を円滑に行えないことになる。   However, the conventional sheet pile press-in method uses the eccentric excavation bit 35 for excavating the ground G, so that when the ground G is excavated, the load is biased and the excavation main shaft 32 is shaken to be a perfect circle. There was a problem that a straight excavation hole could not be formed. As a result, it was difficult to accurately press the sheet pile P into a predetermined position. However, if the excavation spindle 32 swings when excavating the ground G, the excavation resistance applied to the eccentric excavation bit 35 increases, and the excavation work cannot be performed smoothly.

又、従来の圧入工法は、偏心掘削ビット３５を掘削孔から地上へ引き抜く際に、掘削主軸３２を所定角度だけ回転させて偏心掘削ビット３５が矢板Ｐに衝突しないような位置で停止させなければならないが、偏心掘削ビット３５が掘削孔内に位置しているために偏心掘削ビット３５の向きが判り難く、偏心掘削ビット３５を矢板Ｐに衝突しないような位置で停止させるのに時間がかかり、偏心掘削ビット３５の引き抜き作業に手数がかかると云う問題があった。   Further, in the conventional press-fitting method, when the eccentric excavation bit 35 is pulled out from the excavation hole to the ground, the excavation main shaft 32 must be rotated by a predetermined angle and stopped at a position where the eccentric excavation bit 35 does not collide with the sheet pile P. However, since the eccentric excavation bit 35 is located in the excavation hole, the orientation of the eccentric excavation bit 35 is difficult to understand, and it takes time to stop the eccentric excavation bit 35 at a position where it does not collide with the sheet pile P. There has been a problem that it takes time to pull out the eccentric excavation bit 35.

更に、従来の矢板の圧入工法は、偏心掘削ビット３５の回転打撃作用により地盤Ｇを掘削するようにしているため、偏心しているビット本体３５ａの先端部分のみが大きく摩耗したり、或いは破損したりすると云う問題があった。
この場合には、偏心掘削ビット３５を交換しなければならないが、ビット本体３５ａとビット軸部３５ｂとが一体的に形成されているため、偏心掘削ビット３５全体を交換しなければならず、経済性等に極めて劣ると云う問題があった。 Furthermore, in the conventional sheet pile press-in method, since the ground G is excavated by the rotational impact action of the eccentric excavation bit 35, only the tip end portion of the eccentric bit body 35a is greatly worn or damaged. Then there was a problem.
In this case, the eccentric excavation bit 35 must be replaced. However, since the bit body 35a and the bit shaft portion 35b are integrally formed, the entire eccentric excavation bit 35 must be replaced. There was a problem that it was extremely inferior.

特許第２９９７４０２号公報Japanese Patent No. 2997402

本発明は、このような問題点に鑑みて為されたものであり、その目的は、地盤の掘削時に負荷の偏り及び掘削主軸の振れを防止して地盤に真円で真っ直ぐな掘削孔を形成するとこができると共に、掘削工具にかかる掘削抵抗が小さくて済み、又、掘削工具等の地盤からの引き抜き作業を簡単且つ容易に行え、然も、掘削工具が摩耗・破損した場合でも、掘削工具の摩耗・破損した部分のみを交換できて経済性に優れた矢板の圧入工法を提供することにある。   The present invention has been made in view of such problems, and its purpose is to form a perfect circular and straight excavation hole in the ground by preventing load deviation and excavation of the excavation spindle during excavation of the ground. Then, the excavation tool has a small excavation resistance, and the excavation tool can be easily and easily pulled out from the ground. Even when the excavation tool is worn or damaged, the excavation tool The purpose of this invention is to provide a sheet pile press-in method that can replace only the worn / damaged portion of the sheet and is excellent in economic efficiency.

上記目的を達成するために、本発明の請求項１の発明は、オーガマシンにより回転駆動される掘削主軸に円筒状のケーシングを外嵌装備すると共に、当該ケーシングの外周面にＵ形の矢板を配設支持し、前記掘削主軸の先端部に、掘削主軸が掘削方向へ回転したときに地盤からの掘削抵抗により掘削主軸の軸線を中心にして均等に拡径し、又、掘削主軸が掘削方向と反対方向へ回転したときに地盤との摩擦抵抗により矢板に衝突しない大きさに縮径する縮拡径自在なビット部を備えた掘削工具をダウンザホールハンマーを介して取り付けた掘削装置を用い、当該掘削装置を三点式の杭打機又は静荷重型圧入機のクランプ機構部により起立姿勢で昇降自在に支持し、この状態で掘削主軸及びダウンザホールハンマーにより回転打撃される掘削工具の拡径状態のビット部によって地盤を掘削しながらケーシング及び矢板を圧入し、矢板の圧入完了後に掘削主軸を掘削方向と反対方向へ回転させて掘削工具のビット部を矢板に衝突しない縮径状態とし、この状態でケーシング及び掘削工具を地盤中から引き抜くようにしたことに特徴がある。   In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention is provided with a cylindrical casing fitted on the excavation main shaft that is rotationally driven by an auger machine, and a U-shaped sheet pile on the outer peripheral surface of the casing. When the excavation spindle is rotated in the excavation direction, the diameter of the excavation spindle is expanded uniformly around the axis of the excavation spindle by the excavation resistance from the ground. Using a drilling device with a drilling tool equipped with a bit part that can be expanded and contracted to a size that does not collide with the sheet pile due to frictional resistance with the ground when rotating in the opposite direction, via a down-the-hole hammer, The excavator is supported by a clamp mechanism of a three-point pile driver or a static load type press-fitting machine so that the excavator can be raised and lowered in a standing position, and in this state, the excavator is struck by rotation by the excavation spindle and down-the-hole hammer. The casing and sheet pile are press-fitted while excavating the ground with the bit part in the expanded diameter state, and after the press-fitting of the sheet pile is completed, the excavation spindle is rotated in the direction opposite to the excavation direction, so that the bit part of the excavation tool does not collide with the sheet pile. In this state, the casing and the excavation tool are extracted from the ground.

本発明の請求項２の発明は、請求項１の発明に於いて、掘削装置を、静荷重型圧入機のオーガ駆動部や掘削主軸、オーガスクリュー、オーガヘッド等からパイルオーガ部のオーガヘッドに替えて、ダウンザホールハンマー及び掘削工具を配設した構成の掘削装置としたことに特徴がある。   The invention of claim 2 of the present invention is the invention of claim 1, wherein the excavator is changed from an auger drive part of a static load type press-fitting machine, an excavation main shaft, an auger screw, an auger head, etc. to an auger head of a pile auger part. Thus, the excavator has a configuration in which a down-the-hole hammer and an excavation tool are provided.

本発明の請求項３の発明は、請求項１又は請求項２の発明に於いて、拡径状態のビット部の回転による最大軌跡円の直径がＵ形の矢板の幅とほぼ同じなる掘削工具を用い、Ｕ形の矢板を、その一方の継手用係合部が前記最大軌跡円の内側に位置し且つ他方の継手用係合部が前記最大軌跡円の外側に位置するようにケーシングの外周面に配設支持し、この状態で掘削工具の回転打撃作用によって地盤を掘削しながらケーシング及び矢板を圧入するようにしたことに特徴がある。   The invention according to claim 3 of the present invention is the excavation tool according to claim 1 or 2, wherein the diameter of the maximum trajectory circle due to the rotation of the expanded bit portion is substantially the same as the width of the U-shaped sheet pile. And the outer periphery of the casing such that one of the joint engaging portions is located inside the maximum locus circle and the other joint engaging portion is located outside the maximum locus circle. It is characterized in that the casing and the sheet pile are press-fitted while excavating the ground by rotating impact action of the excavating tool in this state.

本発明の請求項４の発明は、請求項１、請求項２又は請求項３の発明に於いて、前記掘削工具には、ダウンザホールハンマーの先端部に掘削主軸の軸線に合致する状態で取り付けられ、掘削主軸の回転力及びタウンザホールハンマーの打撃力を受ける円柱状のガイドデバイスと、ガイドデバイスの先端部にその円周方向に均等に配置され、ガイドデバイスの先端部に所定角度回転自在に且つ交換可能に取り付けられた複数個のビットヘッドから成る縮拡径自在なビット部とから構成した掘削工具を用いたことに特徴がある。   According to a fourth aspect of the present invention, in the first, second, or third aspect of the present invention, the excavation tool is attached to the tip of the down-the-hole hammer so as to match the axis of the excavation spindle. A cylindrical guide device that receives the rotational force of the excavation spindle and the striking force of the town the hole hammer, and is arranged evenly in the circumferential direction at the tip of the guide device, and is freely rotatable by a predetermined angle at the tip of the guide device In addition, the excavating tool is composed of a bit portion that can be expanded and contracted, and includes a plurality of bit heads that are attached in a replaceable manner.

本発明の請求項１に係る矢板の圧入工法は、掘削主軸の先端部にその軸線を中心にして縮拡径するビット部を備えた掘削工具をダウンザホールハンマーを介して取り付けた掘削装置を用い、地盤の掘削時に回転打撃される掘削工具のビット部が掘削主軸の軸線を中心にして均等に拡径した状態で地盤を掘削するため、掘削工具がバランス良く回転して負荷の偏りがなくなり、掘削工具の回転による掘削主軸の振れが防止されて地盤に真円で真っ直ぐな掘削孔を形成することができる。その結果、矢板を所定の位置に正確に圧入することができる。
又、本発明の請求項１に係る矢板の圧入工法は、地盤の掘削時に負荷の偏りをなくして掘削主軸が振れないようにしているため、掘削工具にかかる掘削抵抗が大きくならず、掘削作業を円滑に行うことができる。
更に、本発明の請求項１に係る矢板の圧入工法は、掘削主軸が掘削方向と反対方向へ回転したときに地盤との摩擦抵抗により矢板に衝突しない大きさに縮径するビット部を備えた掘削工具を用いているため、掘削工具を掘削孔から引き抜く際には掘削主軸を掘削方向と反対方向へ回転させるだけで、掘削工具のビット部を矢板に衝突しない大きさに縮径させることができ、地盤からの掘削主軸及び掘削工具等の引き抜き作業を簡単且つ容易に行える。
加えて、本発明の請求項１に係る矢板の圧入工法は、掘削主軸及びダウンザホールハンマーによる回転打撃される掘削工具により地盤を掘削しながら矢板を圧入するようにしているため、岩盤等が存在する硬質の地盤であっても、矢板の圧入を簡単且つ容易に行える。 The press-fitting method of a sheet pile according to claim 1 of the present invention uses a drilling device in which a drilling tool provided with a bit part that expands and contracts around its axis is attached to the tip of a drilling spindle via a down-the-hole hammer, Drilling the ground with the bit part of the drilling tool that is struck by rotation during excavation of the ground evenly expanding around the axis of the drilling spindle, the drilling tool rotates in a well-balanced manner, eliminating load bias and excavating The excavation spindle can be prevented from swinging due to the rotation of the tool, and a perfect circular and straight excavation hole can be formed in the ground. As a result, the sheet pile can be accurately press-fitted into a predetermined position.
Further, the sheet pile press-in method according to claim 1 of the present invention eliminates the load bias when excavating the ground so that the excavation spindle does not shake, so that the excavation resistance applied to the excavation tool does not increase, and the excavation work Can be performed smoothly.
Furthermore, the sheet pile press-in method according to claim 1 of the present invention includes a bit portion that is reduced in diameter so that it does not collide with the sheet pile due to frictional resistance with the ground when the excavation spindle rotates in the direction opposite to the excavation direction. Since the excavation tool is used, when the excavation tool is pulled out from the excavation hole, it is possible to reduce the diameter of the excavation tool bit so that it does not collide with the sheet pile by simply rotating the excavation spindle in the direction opposite to the excavation direction. It is possible to easily and easily pull out the excavation spindle and excavation tool from the ground.
In addition, since the sheet pile press-in method according to claim 1 of the present invention presses the sheet pile while excavating the ground with the excavation tool that is struck by rotation by the excavation main shaft and the down-the-hole hammer, there is a bedrock or the like. Even in a hard ground, the sheet pile can be easily and easily pressed.

本発明の請求項２に係る矢板の圧入工法は、従前の静荷重型圧入機のパイルオーガ部を有効に活用することができ、設備費や矢板圧入工事の大幅な削減が可能になる。   The sheet pile press-in method according to claim 2 of the present invention can effectively utilize a pile auger portion of a conventional static load type press-fitting machine, and can greatly reduce equipment costs and sheet pile press-in work.

本発明の請求項３及び請求項４に係る矢板の圧入工法は、上記効果に加えて更に次のような優れた効果を奏することができる。   The sheet pile press-in method according to claims 3 and 4 of the present invention can further provide the following excellent effects in addition to the above effects.

即ち、本発明の請求項３に係る矢板の圧入工法は、拡径状態のビット部の回転による最大軌跡円の直径がＵ形の矢板の幅とほぼ同じなる掘削工具を用い、Ｕ形の矢板を、その一方の継手用係合部が前記最大軌跡円の内側に位置し且つ他方の継手用係合部が前記最大軌跡円の外側に位置するようにケーシングの外周面に配設支持し、この状態で掘削工具の回転打撃作用によって地盤を掘削しながらケーシング及び矢板を圧入するようにしているため、先に地盤に圧入した矢板に隣接して次の矢板を圧入する際、隣接する矢板の継手用係合部同士の係合が可能になると共に、掘削工具の拡径状態のビット部が先行の矢板に干渉しないようにすることができ、矢板の継手用係合部の変形や損傷を防止することができる。その結果、矢板の引き抜きを円滑に行えると共に、矢板の再使用も可能となる。   That is, the press-fitting method of a sheet pile according to claim 3 of the present invention uses a drilling tool in which the diameter of the maximum trajectory circle due to the rotation of the expanded bit portion is substantially the same as the width of the U-shaped sheet pile, Is disposed and supported on the outer peripheral surface of the casing so that one joint engaging portion is located inside the maximum locus circle and the other joint engaging portion is located outside the maximum locus circle, In this state, the casing and sheet pile are pressed in while excavating the ground by the rotary impact action of the excavating tool, so when the next sheet pile is pressed in adjacent to the sheet pile previously pressed into the ground, Engagement between the engagement parts for joints becomes possible, and the bit part in the diameter-expanded state of the excavating tool can be prevented from interfering with the preceding sheet pile. Can be prevented. As a result, the sheet pile can be pulled out smoothly and the sheet pile can be reused.

又、本発明の請求項４に係る矢板の圧入工法は、縮拡径自在なビット部がガイドデバイス部に交換可能に取り付けられた複数のビットヘッドから成る掘削工具を用いているため、地盤の掘削によりビット部が摩耗、破損した場合でも、摩耗、破損したビット部のビットヘッドのみを交換すれば良く、掘削工具全体を交換する必要がなくなり、経済性に優れたものとなる。   In addition, the sheet pile press-in method according to claim 4 of the present invention uses an excavation tool comprising a plurality of bit heads in which a diameter-adjustable bit portion is replaceably attached to a guide device portion. Even when the bit part is worn or damaged by excavation, it is only necessary to replace the bit head of the worn or damaged bit part, and it is not necessary to replace the entire excavation tool, which is excellent in economic efficiency.

本発明の矢板の圧入工法を実施するのに使用する掘削装置を三点式の杭打機で支持した状態の側面図である。It is a side view of the state which supported the excavation apparatus used to implement the press-fit method of the sheet pile of this invention with the three-point type pile driver. 掘削装置の一部分を省略した一部破断側面図である。It is the partially broken side view which abbreviate | omitted a part of excavation apparatus. 掘削装置の掘削工具を示し、一部分を省略した掘削工具の断面図ある。It is sectional drawing of the excavation tool which showed the excavation tool of the excavation apparatus and abbreviate | omitted one part. 掘削工具を示し、（Ａ）はビット部が拡径した状態の底面図、（Ｂ）はビット部が縮径した状態の底面図である。An excavation tool is shown, (A) is a bottom view in a state where a bit part has a diameter expanded, (B) is a bottom view in a state in which a bit part has a reduced diameter. 矢板の圧入工程を示す説明図である。It is explanatory drawing which shows the press-fit process of a sheet pile. 掘削装置を静荷重型圧入機のクランプ機構部で支持した状態の側面図である。It is a side view of the state which supported the excavator with the clamp mechanism part of a static load type press-fitting machine. 従来の矢板の圧入工法に使用する掘削装置の一部省略側面図である。It is a partially omitted side view of the excavator used for the conventional sheet pile press-in method. 従来の掘削装置の要部の側面図である。It is a side view of the principal part of the conventional excavation apparatus. 従来の掘削装置の偏心掘削ビットの底面図である。It is a bottom view of the eccentric excavation bit of the conventional excavator.

以下、本発明の実施の形態を図面に基づいて詳細に説明する。
図１は本発明の矢板の圧入工法を実施するのに使用する掘削装置１を三点式の杭打機２により起立状態で支持した状態を示し、前記三点式の杭打機２は、クローラ等の走行部３を有する機体本体４と、機体本体４の前部に傾倒自在に支持されたリーダ５と、リーダ５にその長手方向に沿って摺動自在に取り付けられたオーガマシン６（掘削装置１のオーガマシン６と兼用）と、リーダ５を起立状態に支持する左右一対のバックステー７及びステーシリンダ８等を備えており、従来公知のものと同様構造に構成されている。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a state in which an excavator 1 used for carrying out the sheet pile press-fitting method of the present invention is supported in a standing state by a three-point pile driver 2, and the three-point pile driver 2 is a crawler or the like. An airframe body 4 having a section 3, a reader 5 supported in a tiltable manner at the front portion of the airframe body 4, and an auger machine 6 attached to the reader 5 so as to be slidable along the longitudinal direction (of the excavator 1). An auger machine 6) and a pair of left and right back stays 7, stay cylinders 8, and the like that support the leader 5 in an upright state, and have the same structure as a conventionally known one.

本発明の矢板の圧入工法に用いる掘削装置１は、図１及び図２に示す如く、三点式の杭打機２のリーダ５に沿って昇降自在に支持されるオーガマシン６（三点式の杭打機２のオーガマシン６と兼用）と、オーガマシン６に垂下状態で連結され、オーガマシン６によって回転駆動される中空状の掘削主軸９と、オーガマシン６に垂下状態で連結され、掘削主軸９に同心状に外嵌される円筒状のケーシング１０と、オーガマシン６に設けられ、ケーシング１０を回転駆動するケーシング回転駆動手段（図示省略）と、ケーシング１０の上端部に設けられ、Ｕ形の矢板Ｐの上端部を支持するチャック装置１１と、掘削主軸９の下端部にダウンザホールハンマー１２を介して取り付けた掘削工具１３とから構成されており、オーガマシン６による掘削主軸９の回転に伴って掘削工具１３が掘削主軸９の軸線Ｏを中心にして回転すると共に、掘削主軸９の中空部に供給される圧縮エアーにより駆動するダウンザホールハンマー１２によって掘削工具１３が所定のストローク上下動して打撃するようになっている。   As shown in FIGS. 1 and 2, an excavator 1 used in the sheet pile press-fitting method of the present invention includes an auger machine 6 (three-point pile driver) supported so as to be movable up and down along a leader 5 of a three-point pile driver 2. 2 is also connected to the auger machine 6 in a suspended state and is driven to rotate by the auger machine 6, and is connected to the auger machine 6 in a suspended state. A cylindrical casing 10 that is concentrically fitted, a casing rotation driving means (not shown) that is provided in the auger machine 6 and rotationally drives the casing 10, and a U-shaped sheet pile that is provided at the upper end of the casing 10 It is composed of a chuck device 11 that supports the upper end of P, and an excavation tool 13 that is attached to the lower end of the excavation spindle 9 via a down-the-hole hammer 12. As the shaft 9 rotates, the excavation tool 13 rotates around the axis O of the excavation main shaft 9 and the down-the-hole hammer 12 driven by the compressed air supplied to the hollow portion of the excavation main shaft 9 causes the excavation tool 13 to be predetermined. Stroke up and down to hit.

前記掘削装置１の掘削工具１３は、図２乃至図４に示す如く、ダウンザホールハンマー１２の先端部に掘削主軸９の軸線Ｏに合致する状態で取り付けられ、掘削主軸９の回転力及びタウンザホールハンマー１２の打撃力を受ける円柱状のガイドデバイス１４と、ガイドデバイス１４の先端部にその円周方向に均等に配置され、ガイドデバイス１４の先端部に所定角度回転自在に且つ交換可能に取り付けられた複数個のビットヘッド１５′から成る縮拡径自在なビット部１５と、ビット部１５の各ビットヘッド１５′をガイドデバイス１４に着脱自在に取り付けるための複数本の抜け止めピン１６とから構成されており、掘削主軸９が掘削方向へ回転したときには、ビット部１５の各ビットヘッド１５′が地盤Ｇからの掘削抵抗により掘削主軸９の軸線Ｏを中心にして拡径する方向へ回転し、又、掘削主軸９が前記と反対方向へ回転したときには、ビット部１５の各ビットヘッド１５′が地盤Ｇとの摩擦抵抗により矢板Ｐに衝突しない大きさに縮径する方向へ回転するようになっている。   The excavation tool 13 of the excavator 1 is attached to the tip of the down-the-hole hammer 12 so as to match the axis O of the excavation main shaft 9 as shown in FIGS. A cylindrical guide device 14 that receives the striking force of the hammer 12, and the guide device 14 is evenly arranged in the circumferential direction at the distal end portion of the guide device 14, and is attached to the distal end portion of the guide device 14 so as to be rotatable and exchangeable by a predetermined angle. And a plurality of bit heads 15 ', each of which has a plurality of bit heads 15', and a plurality of retaining pins 16 for detachably attaching each bit head 15 'of the bit portion 15 to the guide device 14. When the excavation spindle 9 rotates in the excavation direction, each bit head 15 ′ of the bit portion 15 causes the excavation spindle by the excavation resistance from the ground G. When the excavation main shaft 9 rotates in the opposite direction to the above, the bit heads 15 'of the bit portion 15 are turned to the sheet pile P by frictional resistance with the ground G. It rotates in the direction to reduce the diameter so that it does not collide.

具体的には、ガイドデバイス１４は、先端部側（図３の下端部側）が後端部側（図３の上端部側）よりも大径となる多段円柱状に形成されており、小径の後端部側がダウンザホールハンマー１２に連結され、その軸線回りに回転力を受けると共に、軸線方向先端側に打撃力を受けるようになっている。   Specifically, the guide device 14 is formed in a multistage columnar shape in which the tip end side (lower end portion side in FIG. 3) has a larger diameter than the rear end portion side (upper end portion side in FIG. 3), and has a small diameter. The rear end portion side is connected to the down-the-hole hammer 12 so as to receive a rotational force around its axis and to receive a striking force on the front end side in the axial direction.

このガイドデバイス１４の先端部には、ガイドデバイス１４の先端面側及び外周面側に開口する凹部１４ａがガイドデバイス１４の円周方向に等角度で形成されている。この実施の形態では、凹部１４ａは、ガイドデバイス１４の先端部に１２０度間隔で三つ形成されており、各凹部１４ａの底面には、ビットヘッド１５′を着脱自在に取り付けるための軸孔１４ｂが形成されている。   A concave portion 14 a that opens to the distal end surface side and the outer circumferential surface side of the guide device 14 is formed at an equal angle in the circumferential direction of the guide device 14 at the distal end portion of the guide device 14. In this embodiment, three recesses 14a are formed at the front end portion of the guide device 14 at intervals of 120 degrees, and a shaft hole 14b for detachably attaching a bit head 15 'to the bottom surface of each recess 14a. Is formed.

又、ガイドデバイス１４の先端部には、その外周面から軸線方向へ向かうピン孔１４ｃがガイドデバイス１４の円周方向に１２０度間隔で三つ形成されており、各ピン孔１４ｃは、軸孔１４ｂの内周面にその接線方向に接する状態で開口させられている。   In addition, three pin holes 14c extending in the axial direction from the outer peripheral surface of the guide device 14 are formed at intervals of 120 degrees in the circumferential direction of the guide device 14, and each pin hole 14c has a shaft hole. It is opened in the state which touches the inner peripheral surface of 14b in the tangential direction.

更に、ガイドデバイス１４内には、ダウンザホールハンマー１２からの圧縮エアーをガイドデバイス１４の先端部に形成した各凹部１４ａ内及びガイドデバイス１４の先端面に形成したすり鉢状の窪み部１４ｄ内へそれぞれ供給する空気孔１４ｅが形成されている。この空気孔１４ｅは、その下流側部分が分岐して各凹部１４ａの底面及び窪み部１４ｄの底面に於いて開口しており、各凹部１４ａの底面及び窪み部１４ｄの底面から圧縮エアーを噴出するようになっている。これによって、岩盤等の掘削時にその掘削粉等が空気孔１４ｅから噴出される圧縮エアーにより掘削孔２７とケーシング１０との隙間を通って地上へ吹き上げられることになる。   Further, in the guide device 14, the compressed air from the down-the-hole hammer 12 is supplied into each concave portion 14 a formed at the distal end portion of the guide device 14 and into a mortar-shaped recess portion 14 d formed at the distal end surface of the guide device 14. An air hole 14e is formed. The air hole 14e is branched at its downstream side and opens at the bottom of each recess 14a and the bottom of the recess 14d. The compressed air is ejected from the bottom of each recess 14a and the bottom of the recess 14d. It is like that. As a result, when excavating the bedrock or the like, the excavated powder or the like is blown up to the ground through the gap between the excavation hole 27 and the casing 10 by the compressed air ejected from the air hole 14e.

一方、ビット部１５を構成する各ビットヘッド１５′は、ガイドデバイス１４の凹部１４ａに収容される厚肉のブロック状のビット本体部１５ａと、ビット本体部１５ａの後端面に垂直に連設されて凹部１４ａの底面に形成した軸孔１４ｂに回転自在且つ抜き差し自在に嵌合される円柱状のビット軸部１５ｂとから構成されており、ビット本体部１５ａの先端面には、ダウンザホールハンマー１２からの衝撃力を岩盤へ伝えて岩盤を破壊切削する超硬合金等の硬質材料から成る突起１７が多数植設されている。   On the other hand, each bit head 15 ′ constituting the bit portion 15 is vertically connected to the thick block-shaped bit body portion 15 a housed in the recess 14 a of the guide device 14 and the rear end face of the bit body portion 15 a. And a cylindrical bit shaft portion 15b that is rotatably and removably fitted into a shaft hole 14b formed in the bottom surface of the recess portion 14a. A large number of protrusions 17 made of a hard material such as a cemented carbide that transmits the impact force of the rock to the rock and breaks and cuts the rock are implanted.

又、各ビットヘッド１５′のビット軸部１５ｂの外周面には、断面が半円形状の環状溝１５ｃが形成されている。この環状溝１５ｃは、ビット軸部１５ｂを軸孔１４ｂに嵌合してビット本体部１５ａの後端面を凹部１４ａの底面に当接させたときにピン孔１４ｃに合致するように形成されている。   Further, an annular groove 15c having a semicircular cross section is formed on the outer peripheral surface of the bit shaft portion 15b of each bit head 15 '. The annular groove 15c is formed to match the pin hole 14c when the bit shaft portion 15b is fitted into the shaft hole 14b and the rear end surface of the bit body portion 15a is brought into contact with the bottom surface of the recess 14a. .

そして、各ビットヘッド１５′は、ビット軸部１５ｂをガイドデバイス１４の軸孔１４ｂに嵌合し、ガイドデバイス１４のピン孔１４ｃに抜け止めピン１６を嵌合して抜け止めピン１６の一部分をビット軸部１５ｂの環状溝１５ｃに係合させ、この状態で抜け止めピン１６をスナップリング１８で抜け止めすることによって、ガイドデバイス１４の先端部に抜け止めされた状態でビット軸部１５ｂの軸線を中心にして回転可能に支持され、又、スナップリング１８を外して抜け止めピン１６をピン孔１４ｃから抜き取ることによって、ガイドデバイス１４から取り外すことができるようになっている。   Each bit head 15 ′ fits the bit shaft portion 15 b into the shaft hole 14 b of the guide device 14, and fits the retaining pin 16 into the pin hole 14 c of the guide device 14 so that a part of the retaining pin 16 is inserted. By engaging with the annular groove 15c of the bit shaft portion 15b and retaining the retaining pin 16 with the snap ring 18 in this state, the axis of the bit shaft portion 15b is retained in the distal end portion of the guide device 14. Further, the guide device 14 can be detached from the guide device 14 by removing the snap ring 18 and extracting the retaining pin 16 from the pin hole 14c.

上述した掘削工具１３は、掘削主軸９が掘削方向へ回転したときには、ビット部１５の各ビットヘッド１５′が地盤Ｇからの掘削抵抗によりビット軸部１５ｂの軸線を中心してガイドデバイス１４の外方へ拡がるように回転し、ビット本体部１５ａの先端部分がガイドデバイス１４の外周面から外方へ突出し且つビット本体部１５ａが凹部１４ａの壁面１４ａ′に当接して位置決された状態で回転される。即ち、掘削工具１３は、地盤Ｇの掘削時にそのビット部１５が掘削主軸９の軸線Ｏを中心にして均等に拡径した状態で掘削方向（図４（Ａ）の矢印方向）へ回転されることになる。   In the excavating tool 13 described above, when the excavating main shaft 9 rotates in the excavating direction, each bit head 15 ′ of the bit portion 15 moves outwardly of the guide device 14 around the axis of the bit shaft portion 15 b due to excavation resistance from the ground G. The bit body portion 15a is rotated in a state where the tip portion of the bit body portion 15a protrudes outward from the outer peripheral surface of the guide device 14 and the bit body portion 15a is positioned in contact with the wall surface 14a 'of the recess portion 14a. The That is, when excavating the ground G, the excavation tool 13 is rotated in the excavation direction (the arrow direction in FIG. 4A) in a state where the bit portion 15 is uniformly expanded in diameter around the axis O of the excavation main shaft 9. It will be.

又、掘削工具１３は、掘削主軸９が前記と反対方向へ回転したときには、ビット部１５の各ビットヘッド１５′が地盤Ｇとの摩擦抵抗によりビット軸部１５ｂの軸線を中心してガイドデバイス１４の内方へ縮まるように回転し、ビット本体部１５ａが凹部１４ａ内に収容された状態で回転される。即ち、掘削工具１３は、ビット部１５が縮径した状態で掘削方向と反対方向（図４（Ｂ）の矢印方向）へ回転されることになる。   Further, when the excavation main shaft 9 rotates in the opposite direction, the excavation tool 13 has the bit head 15 'of the bit portion 15 centered on the axis of the bit shaft portion 15b due to frictional resistance with the ground G. The bit body portion 15a is rotated so as to be contracted inward, and is rotated while being accommodated in the recess portion 14a. That is, the excavation tool 13 is rotated in the direction opposite to the excavation direction (the arrow direction in FIG. 4B) with the bit portion 15 having a reduced diameter.

尚、この実施の形態に於いては、掘削工具１３には、拡径状態に於けるビット部１５の回転による最大軌跡円Ｓの直径がＵ形の矢板Ｐの幅Ｗとほぼ同じなる掘削工具１３が使用されている。   In this embodiment, the excavation tool 13 includes an excavation tool in which the diameter of the maximum trajectory circle S due to the rotation of the bit portion 15 in the expanded state is substantially the same as the width W of the U-shaped sheet pile P. 13 is used.

次に、上述した構成の掘削装置１及び三点式の杭打機２を用いたＵ形の矢板Ｐの圧入工法について説明する。   Next, a method for press-fitting the U-shaped sheet pile P using the excavator 1 and the three-point pile driver 2 having the above-described configuration will be described.

先ず、三点式の杭打機２により掘削装置１を地上の所定個所に起立姿勢で支持し、一番目の矢板Ｐ（図５の右端の矢板Ｐ）を、図５に示すようにその幅方向中心Ｃが掘削主軸９の軸線Ｏに対して矢板Ｐの各継手用係合部Ｐａ，Ｐｂの幅にほぼ相当する長さだけずらした状態でケーシング１０の外周面に配設支持する。
即ち、一番目の矢板Ｐを、その一方の継手用係合部Ｐａが拡径状態に於けるビット部１５の回転による最大軌跡円Ｓの内側に位置し且つ他方の継手用係合部Ｐｂが前記最大軌跡円Ｓの外側に位置するようにケーシング１０の外周面にその長手方向に沿って配設支持する。 First, the excavator 1 is supported in a standing position at a predetermined position on the ground by a three-point pile driver 2, and the first sheet pile P (the sheet pile P at the right end in FIG. 5) is centered in the width direction as shown in FIG. C is disposed and supported on the outer peripheral surface of the casing 10 while being shifted from the axis O of the excavation main shaft 9 by a length substantially corresponding to the width of the joint engaging portions Pa and Pb of the sheet pile P.
That is, the first sheet pile P is positioned inside the maximum trajectory circle S due to the rotation of the bit portion 15 when one of the joint engaging portions Pa is in an expanded state, and the other joint engaging portion Pb is The casing 10 is arranged and supported along the longitudinal direction on the outer peripheral surface of the casing 10 so as to be positioned outside the maximum locus circle S.

このとき、矢板Ｐの上端部は、チャック装置１１によってケーシング１０に支持され、矢板Ｐの下端部は、ケーシング１０側に設けた差し込み金具（図示省略）を矢板Ｐ側に設けた受け金具（図示省略）に差し込むことによって、ケーシング１０に支持される。
又、掘削工具１３は、ケーシング１０の先端（下端）から突出した状態となっている。 At this time, the upper end portion of the sheet pile P is supported by the casing 10 by the chuck device 11, and the lower end portion of the sheet pile P is a receiving metal fitting (not shown) provided on the sheet pile P side with an insertion fitting (not shown) provided on the casing 10 side. It is supported by the casing 10 by being inserted into (omitted).
Further, the excavation tool 13 is in a state of protruding from the tip (lower end) of the casing 10.

そして、オーガマシン６により掘削主軸９を掘削方向へ回転駆動して掘削工具１３を掘削方向へ回転させると共に、この掘削工具１３をダウンザホールハンマー１２によって打撃し、掘削工具１３の回転打撃作用により地盤Ｇを掘削しながら、一番目の矢板Ｐをケーシング１０と一緒に地盤Ｇの所定の深さまで圧入する。   The auger machine 6 rotates the excavating spindle 9 in the excavating direction to rotate the excavating tool 13 in the excavating direction, and the excavating tool 13 is hit with the down-the-hole hammer 12. The first sheet pile P is press-fitted together with the casing 10 to a predetermined depth of the ground G.

このとき、掘削工具１３のビット部１５が掘削主軸９の軸線Ｏを中心にして均等に拡径した状態で地盤Ｇを掘削するから、負荷の偏りがなくなり、掘削工具１３の回転による掘削主軸９の振れが防止されることになる。その結果、地盤Ｇに真円で真っ直ぐな掘削孔２７を形成することができると共に、掘削工具１３にかかる掘削抵抗が大きくならず、掘削作業を円滑に行うことができる。従って、矢板Ｐを所定の位置に正確に圧入することができる。
又、地盤Ｇの掘削時には、各ビットヘッド１５′のビット本体部１５ａがガイドデバイス１４の凹部１４ａの壁面１４ａ′に当接し、各ビットヘッド１５′が拡径した状態で位置決めされるので、ビットヘッド１５′に作用する掘削負荷の大部分が凹部１４ａの壁面１４ａ′によって受け止められることになり、そのため掘削負荷がビットヘッド１５′のビット軸部１５ｂに集中すると云うことがなく、ビット軸部１５ｂの損傷や破損を防止することができる。
更に、地盤Ｇの掘削時には、ガイドデバイス１４に形成した空気孔１４ｅから圧縮エアーが噴出されているため、掘削の際に発生する掘削粉等が圧縮エアーにより掘削孔２７とケーシング１０との隙間を通って地上へ吹き上げられる。 At this time, since the ground G is excavated in a state where the bit portion 15 of the excavation tool 13 is uniformly expanded in diameter with the axis O of the excavation main shaft 9 as the center, there is no load bias, and the excavation main shaft 9 due to the rotation of the excavation tool 13 is eliminated. Will be prevented. As a result, the excavation hole 27 that is straight and straight can be formed in the ground G, and the excavation resistance applied to the excavation tool 13 is not increased, so that excavation work can be performed smoothly. Therefore, the sheet pile P can be accurately press-fitted into a predetermined position.
Further, when excavating the ground G, the bit body 15a of each bit head 15 'abuts against the wall surface 14a' of the recess 14a of the guide device 14, and each bit head 15 'is positioned in an expanded state. Most of the excavation load acting on the head 15 'is received by the wall surface 14a' of the recess 14a. Therefore, the excavation load is not concentrated on the bit shaft portion 15b of the bit head 15 ', and the bit shaft portion 15b. Can be prevented from being damaged or broken.
Furthermore, when the ground G is excavated, compressed air is ejected from the air holes 14e formed in the guide device 14, so that excavated powder or the like generated during excavation creates a gap between the excavated hole 27 and the casing 10 by the compressed air. It is blown up to the ground through.

一番目の矢板Ｐの圧入が完了したら、掘削主軸９を掘削方向と反対方向へ回転させる。そうすると、掘削工具１３のビット部１５が地盤Ｇとの摩擦抵抗により拡径状態から矢板Ｐに衝突しない縮径状態に縮径する。この状態で掘削装置１を地上に引き上げることによって、ケーシング１０、掘削工具１３、ダウンザホールハンマー１２及び掘削主軸９を一番目の矢板Ｐに沿って地盤Ｇ中から引き抜くことができる。   When the press-fitting of the first sheet pile P is completed, the excavation spindle 9 is rotated in the direction opposite to the excavation direction. If it does so, the bit part 15 of the excavation tool 13 will reduce in diameter from the diameter-expanded state by the frictional resistance with the ground G to the diameter-reduced state which does not collide with the sheet pile P. In this state, the casing 10, the excavating tool 13, the down-the-hole hammer 12, and the excavation main shaft 9 can be extracted from the ground G along the first sheet pile P by pulling up the excavator 1 to the ground.

このとき、掘削主軸９を掘削方向と反対方向へ回転させるだけで、掘削工具１３のビット部１５を矢板Ｐの先端に衝突しない縮径状態とすることができるため、掘削装置１の引き抜き作業を簡単且つ容易に行うことができる。   At this time, the bit portion 15 of the excavation tool 13 can be brought into a reduced diameter state that does not collide with the tip of the sheet pile P by simply rotating the excavation spindle 9 in the direction opposite to the excavation direction. It can be done easily and easily.

次に、地上に引き上げた掘削装置１を三点式の杭打機２により矢板Ｐの幅Ｗだけ移動させた後、二番目の矢板Ｐ（図５の真中の矢板Ｐ）を一番目の矢板Ｐと逆向きにケーシング１０の外周面に配設支持すると共に、二番目の矢板Ｐの一方の継手用係合部Ｐｂを前記最大軌跡円Ｓの外側に位置させて掘削孔２７内に位置する一番目の矢板Ｐの継手用係合部Ｐａに係合させ且つ二番目の矢板Ｐの他方の継手用係合部Ｐａを前記最大軌跡円Ｓの内側に位置させた状態で、一番目の矢板Ｐの場合と同様に掘削工具１３の回転打撃作用によって地盤Ｇを掘削しながら二番目の矢板Ｐを圧入し、二番目の矢板Ｐを一番目の矢板Ｐと接合する。   Next, after the excavator 1 lifted to the ground is moved by the width W of the sheet pile P by the three-point pile driver 2, the second sheet pile P (the sheet pile P in the middle of FIG. 5) is replaced with the first sheet pile P. The first is located in the excavation hole 27 with the joint engaging portion Pb of the second sheet pile P positioned outside the maximum trajectory circle S while being arranged and supported on the outer peripheral surface of the casing 10 in the opposite direction. The first sheet pile P is engaged with the joint engaging portion Pa of the second sheet pile P and the other joint engaging portion Pa of the second sheet pile P is positioned inside the maximum trajectory circle S. Similarly to the case, the second sheet pile P is press-fitted while excavating the ground G by the rotary impact action of the excavation tool 13, and the second sheet pile P is joined to the first sheet pile P.

このとき、拡径状態のビット部１５の回転による最大軌跡円Ｓの直径が矢板Ｐの幅Ｗとほぼ同じなる掘削工具１３を用いて地盤Ｇを掘削しながら矢板Ｐを圧入して行くため、既に圧入された一番目の矢板Ｐに対して二番目の矢板Ｐの圧入を行う際、隣接する矢板Ｐの継手用係合部Ｐａ，Ｐｂ同士の係合が可能になると共に、掘削工具１３の拡径状態のビット部１５が一番目の矢板Ｐに干渉しないようにすることができる。その結果、矢板Ｐの継手用係合部Ｐａの変形や損傷を防止することができ、矢板Ｐを地盤Ｇから引き抜く際にその引き抜き作業を容易に行えるうえ、矢板Ｐの再使用が可能となる。   At this time, in order to press-fit the sheet pile P while excavating the ground G using the excavation tool 13 in which the diameter of the maximum trajectory circle S due to the rotation of the bit portion 15 in the expanded state is substantially the same as the width W of the sheet pile P, When the second sheet pile P is pressed into the first sheet pile P that has already been press-fitted, the joint engaging portions Pa and Pb of the adjacent sheet pile P can be engaged with each other, and the excavation tool 13 The expanded bit portion 15 can be prevented from interfering with the first sheet pile P. As a result, deformation and damage of the joint engaging portion Pa of the sheet pile P can be prevented, and when the sheet pile P is pulled out from the ground G, the drawing work can be easily performed, and the sheet pile P can be reused. .

二番目の矢板Ｐの圧入が完了したら、掘削主軸９を掘削方向と反対方向へ回転させ、掘削工具１３のビット部１５を矢板Ｐの先端へ衝突しない縮径状態とした後、この状態で掘削装置１を地上へ引き上げてケーシング及び掘削工具１３等を二番目の矢板Ｐに沿って地盤Ｇ中から引き抜く。   When the press-fitting of the second sheet pile P is completed, the excavation main shaft 9 is rotated in the direction opposite to the excavation direction, and the bit portion 15 of the excavation tool 13 is reduced in diameter so that it does not collide with the tip of the sheet pile P. The apparatus 1 is pulled up to the ground, and the casing, the excavation tool 13 and the like are pulled out from the ground G along the second sheet pile P.

引き続き、掘削装置１を三点式の杭打機２により矢板Ｐの幅Ｗだけ更に移動させた後、三番目の矢板Ｐ（図５の左端の矢板Ｐ）を二番目の矢板Ｐと逆向きにケーシング１０の外周面に配設支持すると共に、三番目の矢板Ｐの一方の継手用係合部Ｐｂを前記最大軌跡円Ｓの外側に位置させて二番目の掘削孔２７内に位置する二番目の矢板Ｐの継手用係合部Ｐａに係合させ且つ三番目の矢板Ｐの他方の継手用係合部Ｐａを前記最大軌跡円Ｓの内側に位置させた状態で、前記と同様に掘削工具１３の回転打撃作用によって地盤Ｇを掘削しながら三番目の矢板Ｐを圧入し、三番目の矢板Ｐを二番目の矢板Ｐと接合する。   Subsequently, after the excavator 1 is further moved by the width W of the sheet pile P by the three-point pile driver 2, the third sheet pile P (the leftmost sheet pile P in FIG. 5) is casing in the direction opposite to the second sheet pile P. The second engagement position Pb is located in the second excavation hole 27 with one joint engaging portion Pb of the third sheet pile P positioned outside the maximum trajectory circle S. The excavation tool 13 is engaged in the same manner as described above in a state where the joint engaging portion Pa of the sheet pile P is engaged and the other joint engaging portion Pa of the third sheet pile P is positioned inside the maximum trajectory circle S. The third sheet pile P is pressed into the ground G while excavating the ground G by the rotary impact action of, and the third sheet pile P is joined to the second sheet pile P.

三番目の矢板Ｐの圧入が完了したら、掘削主軸９を掘削方向と反対方向へ回転させ、掘削工具１３のビット部１５を矢板Ｐの先端へ衝突しない縮径状態とした後、この状態で掘削装置１を地上へ引き上げてケーシング１０及び掘削工具１３等を三番目の矢板Ｐに沿って地盤Ｇ中から引き抜く。
以下、同様にして四番目の矢板Ｐ、五番目の矢板Ｐ等を順次地盤Ｇへ圧入して行く。 After the press-fitting of the third sheet pile P is completed, the excavation spindle 9 is rotated in the direction opposite to the excavation direction, and the bit portion 15 of the excavation tool 13 is reduced in diameter so that it does not collide with the tip of the sheet pile P. The apparatus 1 is pulled up to the ground, and the casing 10 and the excavation tool 13 are pulled out from the ground G along the third sheet pile P.
In the same manner, the fourth sheet pile P, the fifth sheet pile P, and the like are sequentially pressed into the ground G.

このような矢板Ｐの圧入に於いては、掘削主軸９及びダウンザホールハンマー１２により回転打撃される掘削工具１３の回転打撃作用によって、地盤Ｇを掘削して掘削孔２７を形成しながら矢板Ｐを圧入するから、岩盤や転石等の存在する硬質の地盤Ｇの掘削が容易になると共に、そのような地盤Ｇへの矢板Ｐの圧入を迅速且つ容易に行うことができる。特に、ビットヘッド１５′に突起１７を植設しているため、岩盤の掘削には特に有効である。
更に、掘削時には、ビットヘッド１５′が拡径して矢板Ｐの幅Ｗと同一の掘削孔２７を形成し、又、地盤Ｇ中からの引き抜き時には、ビットヘッド１５′が縮径して矢板Ｐに衝突しないような掘削工具１３を用いているため、掘削孔２７の内径を十分大きく形成することができ、従って矢板Ｐの圧入を容易に行えると共に、掘削孔２７の直進性を維持して矢板Ｐを所定位置に正確に圧入することができる。 In such press-fitting of the sheet pile P, the sheet pile P is press-fitted while forming the excavation hole 27 by excavating the ground G by the rotary impact action of the excavation tool 13 which is impacted by the excavation main shaft 9 and the down-the-hole hammer 12. Therefore, excavation of the hard ground G in which rock, rocks, and the like are present is facilitated, and the sheet pile P can be pressed into the ground G quickly and easily. In particular, since the protrusion 17 is implanted in the bit head 15 ', it is particularly effective for excavation of the rock mass.
Further, during excavation, the bit head 15 ′ expands to form the excavation hole 27 having the same width W as the sheet pile P. When the bit head 15 ′ is pulled out from the ground G, the bit head 15 ′ decreases in diameter and the sheet pile P Since the excavating tool 13 that does not collide with the excavation hole is used, the inner diameter of the excavation hole 27 can be formed sufficiently large, so that the sheet pile P can be easily press-fitted and the straightness of the excavation hole 27 is maintained and the sheet pile is maintained. P can be accurately press-fitted into a predetermined position.

上記の実施の形態に於いては、掘削装置１を三点式の杭打機２により起立姿勢で支持し、この状態で掘削装置１により矢板Ｐを地盤Ｇに圧入するようにしたが、他の実施の形態に於いては、図６に示すように、掘削装置１を従前の静荷重型圧入機（例えば、株式会社技研製作所のスーパークラッシュパイラー）のクランプ機構部１９を用いて起立姿勢で支持し、この状態で掘削装置１により矢板Ｐを地盤Ｇに圧入するようにしても良い。
尚、従前の静荷重型圧入機（スーパークラッシュパイラー）のクランプ機構部１９を用いる場合には、当該静荷重型圧入機のオーガ駆動部や掘削主軸、ケーシング、オーガスクリュー、オーガヘッド等から成るパイルオーガ部（図示省略）に改良を加え、そのオーガスクリュー及びオーガヘッドに替えてダウンザホールハンマー１２及び掘削工具１３を組み付けすることにより、これを前記掘削装置１として利用するようにしても良い。 In the above embodiment, the excavator 1 is supported in a standing posture by the three-point pile driver 2, and the sheet pile P is press-fitted into the ground G by the excavator 1 in this state. In this embodiment, as shown in FIG. 6, the excavator 1 is supported in a standing posture by using a clamp mechanism portion 19 of a conventional static load type press-fitting machine (for example, Super Crush Piler of Giken Co., Ltd.). In this state, the sheet pile P may be pressed into the ground G by the excavator 1.
In the case of using the clamp mechanism 19 of the conventional static load type press-fitting machine (Super Crush Piler), a pile auger comprising the auger drive part, excavation main shaft, casing, auger screw, auger head, etc. of the static load type press-fitting machine. The part (not shown) may be improved, and the down-the-hole hammer 12 and the excavation tool 13 may be assembled in place of the auger screw and auger head, and used as the excavator 1.

前記静荷重型圧入機のクランプ機構部１９は、地上に設置した反力架台（図示省略）又は既に地盤Ｇに圧入したＵ形の矢板Ｐを掴むクランプ２０を下部に備えたサドル２１と、サドル２１の上面に設けられ、サドル２１に対して前後にスライド移動するスライドベース２２と、スライドベース２２に立設され、スライドベース２２上で旋回可能なリーダマスト２３と、リーダマスト２３の前部に昇降可能に支持され、油圧シリンダ２４により昇降する昇降フレーム２５と、昇降フレーム２５に旋回可能に設けられ、Ｕ形の矢板Ｐ及び掘削装置１のケーシング１０を掴むチャック部２６等から成り、地上に設置した反力架台又は既に地盤Ｇに圧入したＵ形の矢板Ｐをクランプ２０で掴み、反力架台又は既設の矢板Ｐから反力を取った状態でチャック部２６に保持された掘削装置１を用いて矢板Ｐを地盤Ｇに圧入するようにしたものである。
この静荷重型圧入機のクランプ機構部１９は、従来公知のものと同様構造に構成されているため、ここではその詳細な説明を省略する。
又、掘削装置１は、前述の通り静荷重型圧入機のパイルオーガ部を構成するケーシングの内部のオーガスクリュー及びオーガヘッドに替えて、ダウンザホールハンマー１２及び掘削工具１３等を配設することにより、形成するようにしても良い。
尚、静荷重型圧入機のクランプ機構部１９は、掘削装置１のケーシング１０及び矢板Ｐを起立姿勢で掴むチャック部２６を備えているため、掘削装置１のチャック装置１１を省略している。 The clamp mechanism 19 of the static load type press-fitting machine includes a saddle 21 having a clamp 20 for holding a reaction force stand (not shown) installed on the ground or a U-shaped sheet pile P already press-fitted into the ground G, and a saddle. A slide base 22 that slides back and forth with respect to the saddle 21, a leader mast 23 that is erected on the slide base 22 and that can turn on the slide base 22, and a front portion of the leader mast 23. A lifting frame 25 supported up and down by a hydraulic cylinder 24, a swing frame 25 provided on the lifting frame 25, and a chuck portion 26 for gripping the casing 10 of the excavator 1 and the like. The U-shaped sheet pile P that has already been press-fitted into the ground G is gripped by the clamp 20 and the reaction force is removed from the reaction force rack or the existing sheet pile P. The sheet pile P using drilling device 1 held by the click portion 26 is obtained so as to press-fitted into the ground G.
Since the clamp mechanism 19 of the static load type press-fitting machine has a structure similar to that of a conventionally known one, detailed description thereof is omitted here.
The excavator 1 is formed by disposing the down-the-hole hammer 12 and the excavating tool 13 in place of the auger screw and auger head inside the casing constituting the pile auger portion of the static load type press-fitting machine as described above. You may make it do.
In addition, since the clamp mechanism part 19 of the static load type press-fitting machine includes the chuck part 26 that holds the casing 10 and the sheet pile P of the excavation apparatus 1 in an upright posture, the chuck apparatus 11 of the excavation apparatus 1 is omitted.

而して、前記静荷重型圧入機のクランプ機構部１９によれば、地上に設置した反力架台又は既に地盤Ｇに圧入したＵ形の矢板Ｐをクランプ２０で掴んでから、チャック部２６により矢板Ｐと掘削装置１のケーシング１０を起立姿勢で強固に掴み、この状態で掘削装置１のオーガマシン６及び静荷重型圧入機のクランプ機構部１９の油圧シリンダ２４を作動させ、掘削装置１により地盤Ｇを掘削しながら油圧シリンダ２４により昇降フレーム２５及びチャック部２６を下降させて矢板Ｐの圧入を行う。   Thus, according to the clamp mechanism portion 19 of the static load type press-fitting machine, the reaction force frame installed on the ground or the U-shaped sheet pile P already press-fitted into the ground G is gripped by the clamp 20, and then the chuck portion 26 The sheet pile P and the casing 10 of the excavator 1 are firmly held in an upright posture. In this state, the auger machine 6 of the excavator 1 and the hydraulic cylinder 24 of the clamp mechanism 19 of the static load type press-fitting machine are operated. While excavating the ground G, the lifting frame 25 and the chuck part 26 are lowered by the hydraulic cylinder 24 to press-fit the sheet pile P.

矢板Ｐが油圧シリンダ２４のストローク分だけ圧入されたら、地盤Ｇの掘削及び矢板Ｐの圧入を停止すると共に、チャック部２６を操作して矢板Ｐ及び掘削装置１のケーシング１０を解放し、昇降フレーム２５及びチャック部２６を油圧シリンダ２４により上昇させた後、チャック部２６により矢板Ｐと掘削装置１のケーシング１０を再び掴み、この状態で再度掘削装置１により地盤Ｇの掘削を掘削しながら油圧シリンダ２４により昇降フレーム２５及びチャック部２６を下降させて矢板Ｐの圧入を行う。
以下、同様の動作を繰り返し行うことにより矢板Ｐを所定の深さまで圧入する。 When the sheet pile P is press-fitted for the stroke of the hydraulic cylinder 24, the excavation of the ground G and the press-fitting of the sheet pile P are stopped, and the chuck portion 26 is operated to release the sheet pile P and the casing 10 of the excavator 1, and the lifting frame 25 and the chuck part 26 are lifted by the hydraulic cylinder 24, and then the sheet pile P and the casing 10 of the excavator 1 are gripped again by the chuck part 26. In this state, the excavator 1 excavates the ground G again and the hydraulic cylinder 24, the elevating frame 25 and the chuck portion 26 are lowered to press-fit the sheet pile P.
Thereafter, the sheet pile P is press-fitted to a predetermined depth by repeatedly performing the same operation.

そして、矢板Ｐの圧入が完了したら、掘削装置１の掘削主軸９を掘削方向と反対方向へ回転させて掘削工具１３のビット部１５を縮径状態とすると共に、チャック部２６を操作して矢板Ｐのみを解放し、この状態で昇降フレーム２５及びチャック部２６を油圧シリンダ２４により上昇させ、掘削装置１を引き上げる。   Then, when the press-fitting of the sheet pile P is completed, the excavation main shaft 9 of the excavator 1 is rotated in the direction opposite to the excavation direction so that the bit portion 15 of the excavation tool 13 is reduced in diameter, and the chuck portion 26 is operated to operate the sheet pile. Only P is released, and in this state, the lifting frame 25 and the chuck portion 26 are raised by the hydraulic cylinder 24, and the excavator 1 is pulled up.

掘削装置１が油圧シリンダ２４のストローク分だけ引き上げられたら、チャック部２６を操作して掘削装置１のケーシング１０を解放し、昇降フレーム２５及びチャック部２６を油圧シリンダ２４により下降させた後、チャック部２６により掘削装置１のケーシング１０を掴み、この状態で再度昇降フレーム２５及びチャック部２６を油圧シリンダ２４により上昇させ、掘削装置１を引き上げる。
以下、同様の動作を繰り返し行うことにより掘削装置１を矢板Ｐに沿って地盤Ｇ中から引き抜くことができる。 When the excavator 1 is lifted by the stroke of the hydraulic cylinder 24, the chuck portion 26 is operated to release the casing 10 of the excavator 1, the lifting frame 25 and the chuck portion 26 are lowered by the hydraulic cylinder 24, and then the chuck The casing 10 of the excavator 1 is gripped by the portion 26, and in this state, the elevating frame 25 and the chuck portion 26 are raised again by the hydraulic cylinder 24, and the excavator 1 is pulled up.
Thereafter, the excavator 1 can be pulled out from the ground G along the sheet pile P by repeatedly performing the same operation.

掘削装置１及び静荷重型の圧入機１９を用いた矢板Ｐの圧入工法も、三点式の杭打機２を用い矢板Ｐの圧入工法と同様の作用効果を奏することができる。   The press-fitting method of the sheet pile P using the excavator 1 and the static load type press-fitting machine 19 can also exhibit the same effects as the press-fitting method of the sheet pile P using the three-point pile driver 2.

尚、上記の実施の形態に於いては、ダウンザホールハンマー１２は、エアー圧によって駆動されるようにしたが、他の実施の形態に於いては、ダウンザホールハンマー１２として油圧で駆動されるものを使用しても良い。   In the above-described embodiment, the down-the-hole hammer 12 is driven by air pressure. However, in the other embodiments, the down-the-hole hammer 12 is driven by hydraulic pressure. You may do it.

又、上記の実施の形態に於いては、掘削工具１３には、ビット部１５を三つのビットヘッド１５′から構成した掘削工具１３を用いたが、他の実施の形態に於いては、掘削工具１３に、ビット部１５を二つのビットヘッド１５′又は四つのビットヘッド１５′から構成した掘削工具１３を用いても良い。   In the above embodiment, the excavating tool 13 is the excavating tool 13 in which the bit portion 15 is composed of three bit heads 15 ′. In other embodiments, the excavating tool 13 is excavated. The tool 13 may be an excavation tool 13 in which the bit portion 15 is composed of two bit heads 15 ′ or four bit heads 15 ′.

１は掘削装置、２は三点式の杭打機、６はオーガマシン、９は掘削主軸、１０はケーシング、１２はダウンザホールハンマー、１３は掘削工具、１４はガイドデバイス、１５はビット部、１５′はビットヘッド、１９は静荷重型圧入機のクランプ機構部、Ｇは地盤、Ｏは掘削主軸の軸線、ＰはＵ形の矢板、Ｐａは矢板の一方の継手用係合部、Ｐｂは矢板の他方の継手用係合部、Ｓは拡径状態に於けるビット部の回転による最大軌跡円、Ｗは矢板の幅。   1 is a drilling device, 2 is a three-point pile driver, 6 is an auger machine, 9 is a drilling spindle, 10 is a casing, 12 is a down-the-hole hammer, 13 is a drilling tool, 14 is a guide device, 15 is a bit part, 15 'is Bit head, 19 is a clamp mechanism of a static load type press-fitting machine, G is the ground, O is the axis of the main excavation shaft, P is a U-shaped sheet pile, Pa is one of the joint engaging sections of the sheet pile, and Pb is the other of the sheet pile The engagement portion for the joint, S is the maximum trajectory circle due to the rotation of the bit portion in the expanded diameter state, and W is the width of the sheet pile.

Claims (4)

オーガマシン（６）により回転駆動される掘削主軸（９）に円筒状のケーシング（１０）を外嵌装備すると共に、当該ケーシング（１０）の外周面にＵ形の矢板（Ｐ）を配設支持し、前記掘削主軸（９）の先端部に、掘削主軸（９）が掘削方向へ回転したときに地盤（Ｇ）からの掘削抵抗により掘削主軸（９）の軸線（Ｏ）を中心にして均等に拡径し、又、掘削主軸（９）が掘削方向と反対方向へ回転したときに地盤（Ｇ）との摩擦抵抗により矢板（Ｐ）に衝突しない大きさに縮径する縮拡径自在なビット部（１５）を備えた掘削工具（１３）をダウンザホールハンマー（１２）を介して取り付けた掘削装置（１）を用い、当該掘削装置（１）を三点式の杭打機（２）又は静荷重型圧入機のクランプ機構部（１９）により起立姿勢で昇降自在に支持し、この状態で掘削主軸（９）及びダウンザホールハンマー（１２）により回転打撃される掘削工具（１３）の拡径状態のビット部（１５）によって地盤（Ｇ）を掘削しながらケーシング（１０）及び矢板（Ｐ）を圧入し、矢板（Ｐ）の圧入完了後に掘削主軸（９）を掘削方向と反対方向へ回転させて掘削工具（１３）のビット部（１５）を矢板（Ｐ）に衝突しない縮径状態とし、この状態でケーシング（１０）及び掘削工具（１３）を地盤（Ｇ）中から引き抜くようにしたことを特徴とする矢板の圧入工法。   A cylindrical casing (10) is externally fitted to the excavation spindle (9) that is rotationally driven by the auger machine (6), and a U-shaped sheet pile (P) is disposed and supported on the outer peripheral surface of the casing (10). And, when the excavation spindle (9) rotates in the excavation direction, the tip of the excavation spindle (9) is evenly centered on the axis (O) of the excavation spindle (9) due to excavation resistance from the ground (G). The diameter can be reduced to a size that does not collide with the sheet pile (P) due to frictional resistance with the ground (G) when the excavation spindle (9) rotates in the direction opposite to the excavation direction. Using the excavator (1) to which the excavation tool (13) provided with the bit part (15) is attached via the down-the-hole hammer (12), the excavator (1) is a three-point pile driver (2) or a static load. Can be moved up and down in a standing posture by the clamping mechanism (19) of the die press The casing (10) while excavating the ground (G) by the expanded bit portion (15) of the excavating tool (13) supported and rotated by the excavation spindle (9) and the down-the-hole hammer (12) in this state. And press the sheet pile (P), and after the press of the sheet pile (P) is completed, the excavation spindle (9) is rotated in the direction opposite to the excavation direction and the bit part (15) of the excavation tool (13) collides with the sheet pile (P). The sheet pile press-in method is characterized in that the casing (10) and the excavation tool (13) are pulled out from the ground (G) in this state. 掘削装置（１）を、静荷重型圧入機のオーガ駆動部や掘削主軸、オーガスクリュー、オーガヘッド等からパイルオーガ部のオーガヘッドに替えて、ダウンザホールハンマー（１２）及び掘削工具（１３）を配設した構成の掘削装置（１）としたことを特徴とする請求項１に記載の矢板の圧入工法。   Change the excavator (1) from the auger drive part of the static load type press-fitting machine, excavation spindle, auger screw, auger head, etc. to the auger head of the pile auger part, and arrange the down-the-hole hammer (12) and excavation tool (13). The sheet pile press-in method according to claim 1, wherein the excavator (1) is configured as described above. 拡径状態のビット部（１５）の回転による最大軌跡円（Ｓ）の直径がＵ形の矢板（Ｐ）の幅（Ｗ）とほぼ同じなる掘削工具（１３）を用い、Ｕ形の矢板（Ｐ）を、その一方の継手用係合部（Ｐａ）が前記最大軌跡円（Ｓ）の内側に位置し且つ他方の継手用係合部（Ｐｂ）が前記最大軌跡円（Ｓ）の外側に位置するようにケーシング（１０）の外周面に配設支持し、この状態で掘削工具（１３）の回転打撃作用によって地盤（Ｇ）を掘削しながらケーシング（１０）及び矢板（Ｐ）を圧入するようにしたことを特徴とする請求項１又は請求項２に記載の矢板の圧入工法。   Using the excavation tool (13), the diameter of the maximum trajectory circle (S) due to the rotation of the expanded bit portion (15) is substantially the same as the width (W) of the U-shaped sheet pile (P). P) with one joint engaging portion (Pa) positioned inside the maximum trajectory circle (S) and the other joint engaging portion (Pb) outside the maximum trajectory circle (S). In this state, the casing (10) and the sheet pile (P) are press-fitted while excavating the ground (G) by the rotary hammering action of the excavating tool (13). The press-fitting method for a sheet pile according to claim 1 or 2, characterized in that it is configured as described above. 前記掘削工具（１３）には、ダウンザホールハンマー（１２）の先端部に掘削主軸（９）の軸線（Ｏ）に合致する状態で取り付けられ、掘削主軸（９）の回転力及びタウンザホールハンマー（１２）の打撃力を受ける円柱状のガイドデバイス（１４）と、ガイドデバイス（１４）の先端部にその円周方向に均等に配置され、ガイドデバイス（１４）の先端部に所定角度回転自在に且つ交換可能に取り付けられた複数個のビットヘッド（１５′）から成る縮拡径自在なビット部（１５）とから構成した掘削工具（１３）を用いたことを特徴とする請求項１、請求項２又は請求項３に記載の矢板の圧入工法。   The excavation tool (13) is attached to the tip of the down-the-hole hammer (12) so as to coincide with the axis (O) of the excavation spindle (9), and the rotational force of the excavation spindle (9) and the town the hole hammer ( 12) The cylindrical guide device (14) that receives the impact force of 12) and the guide device (14) are evenly arranged in the circumferential direction at the tip of the guide device (14), and are freely rotatable by a predetermined angle at the tip of the guide device (14). An excavation tool (13) comprising a bit section (15) having a plurality of bit heads (15 '), which are exchangeably mounted and can be expanded and contracted, is used. The press-fitting method of the sheet pile of Claim 2 or Claim 3.

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