JP2004011102A

JP2004011102A - Drilling head, drilling method and pile press-in method

Info

Publication number: JP2004011102A
Application number: JP2002161434A
Authority: JP
Inventors: Morio Kitamura; 北村　精男; Hiroaki Tauchi; 田内　宏明; Tomoya Fujita; 藤田　知也; Takakazu Hamaguchi; 濱口　貴和
Original assignee: Giken Seisakusho Co Ltd
Current assignee: Giken Seisakusho Co Ltd
Priority date: 2002-06-03
Filing date: 2002-06-03
Publication date: 2004-01-15

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the press-in resistance of a pile such as steel pipe sheet pile, in pressing the pile, by ensuring the drilling of ground for pressing in the section part of the pile, and to facilitate the recovery. <P>SOLUTION: An auger with casing 36 and a section auger 5 drill the ground for pressing in the sheet pile body 11 and section part 14 of the steel pipe sheet pile, thereby the press-in of the steel pipe sheet pile by a pile press-in means is assisted. The head 53 of the section auger 5 has a drilling blade part having a plurality of expansible and contractible blade parts 57 provided on a head body 55 to be vertically rotatable from under the head body 55, and the drilling blade part is extended to a diameter exceeding the diameter of the section part by laterally opening the expansible and contractible blade parts 57. The blade parts 57 are fixed to the head body 55 in an expanded state by a fixing pin 61. The fixing pin 61 is cut when the section auger is pulled out. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、杭及び杭のセクション用の掘削手段を有する、掘削及び杭圧入併行型の杭圧入機に備えられる掘削ヘッド、掘削方法及び杭圧入方法に関するものである。
【０００２】
【従来の技術】
従来、地盤に杭を圧入する場合、杭を圧入する地盤を掘削しつつ前記杭の圧入を補助しており、特開平１０−１９５８７２公報に示すように、杭の圧入位置をケーシング付きオーガで掘削するとともに杭を圧入することで、硬質地盤に対しても杭を圧入できる杭圧入引抜機などが開発されている。
ところで、鋼管矢板などの杭を複数地盤に連続して圧入して構造物を構築する場合、鋼管矢板のセクション部を既設の鋼管矢板のセクション部に係合させつつ、図６（ａ）に示す鋼管矢板１を挿通して配置されたケーシング付きオーガ２で掘削しながら圧入する。このケーシング付きオーガ２のオーガヘッド３の掘削範囲Ａは、図６（ｂ）に示すように、圧入する鋼管矢板１の管状の矢板本体１１の径より大きく且つ一本前に圧入した鋼管矢板１’のセクション部１２に干渉しないように、既設の鋼管矢板１’のセクション部１２との間にクリアランスａが設けられる範囲となっている。なお、このオーガヘッド３は、鋼管矢板１の圧入後引き抜く必要があるため、オーガスクリュー４の先端に接続されたヘッド本体６から左右に突出するアーム部７の先端にビットを備えた羽根部８が折り畳み自在に取り付けられ、この羽根部８を折り畳むことでその径が矢板本体１１の内径より小さくなるように構成されている。
【０００３】
【発明が解決しようとする課題】
ところで、上述した圧入方法においては、オーガヘッドの掘削範囲Ａが既設の鋼管矢板１’のセクション部１２との間のクリアランスａを考慮したものであるため、鋼管矢板１を圧入する際に、既設の鋼管矢板１’のセクション部１２に係合されるセクション部１３の先端部と、開放側のセクション部１４の先端部が掘削されていない地盤に圧入されることになり、鋼管矢板１の圧入抵抗が増大する。　この圧入抵抗の増大を減少させるべく、ケーシング付きオーガ２とともに、セクション部１２が圧入される地盤を掘削するセクションオーガを併用するとともに、セクションオーガの掘削ヘッドとしては、図７及び図８に示すように、上述した拡縮するオーガヘッド３をセクション部１２の掘削用のヘッド３０としたものが考えられる。
【０００４】
図７（ａ）や図８（ａ）に示す掘削用のヘッド３Ａ，３Ｂは、セクション部用のスクリューの先端に固定され、前記スクリューと同軸で回転するヘッド本体３０１と、ヘッド本体３０１の基端部の左右の側壁部に側方に突出して設けられた突出支持片３０２Ａ，３０２Ｂと、突出支持片３０２Ａ，３０２Ｂに回動自在に基端部が取り付けられ、且つ先端部に刃３０３ａを備える羽根部３０３とを有する。なお、両ヘッド３Ａ，３Ｂのヘッド本体３０１の下端部には、下方に突出する突出刃３０１ａが設けられている。これら両ヘッド３Ａ，３Ｂはそれぞれ羽根部３０３のヘッド本体３０１の側部における回動により掘削径が拡縮するように構成され、図７（ａ）に示すヘッド３Ａでは、杭を圧入する際の圧入抵抗により羽根部３０３がヘッド本体３０１の側部で左右に開くことで掘削径が拡径（図７（ｂ）参照）し、図８（ａ）に示すヘッド３Ｂでは、回転して地盤を掘削する際に、羽根部がヘッド本隊３０１の側部で開いて、掘削径が拡径（図８（ｂ）参照）するように構成されている。
しかし、これらヘッド３Ａ，３Ｂの構成では、圧入時や掘削時の抵抗により拡径する構成であるため、羽根部３０３が確実に開かない場合が生じる場合がある。また、羽根部３０３は突出支持部３０２で支持しているため、突出支持片３０２の強度を大きくする必要があり、突出支持片３０２を大型化する必要が生じ、杭のセクション部を圧入する地盤を掘削するために用いた場合、拡縮した状態でもセクション部の外径より大きくなってしまい、掘削後、回収できなかったり、又回収する作業が困難となる。
【０００５】
本発明の課題は、鋼管矢板等の杭を圧入する際に、杭のセクション部が圧入される地盤の掘削に用いて、確実に地盤を掘削して、杭の圧入抵抗を低減することができるとともに、回収が容易な拡縮する掘削ヘッド、掘削方法及び杭圧入方法を提供することである。
【０００６】
【課題を解決するための手段】
以上の課題を解決するため、請求項１記載の発明は、例えば、図３に示すように、ヘッド本体５５と、前記ヘッド本体に設けられ、前記ヘッド本体の下方から左右方向に開くように回動自在の複数の掘削刃（例えば拡縮羽根５７，５７）を備えるとともに、これら複数の掘削刃を開くことにより拡径する掘削刃部と、前記複数の掘削刃を開いて前記掘削刃部を拡径した状態で前記ヘッド本体に固定する固定ピン６１とを備え、前記固定ピンは、左右に開いた状態の前記複数の掘削刃が閉じるように下方に押圧されることで切断されることを特徴とする。
【０００７】
請求項１記載の発明によれば、ヘッド本体に設けられた掘削刃部は、前記複数の掘削刃を下方から左右に開き固定ピンによりヘッド本体に固定することで、確実に拡径された掘削範囲を有する状態となるとともに、左右に開いた状態の前記複数の掘削刃が閉じるように下方に押圧されることで、固定ピンが切断されて前記複数の掘削刃が前記ヘッド本体の下方で閉じて縮径状態となり、且つ、従来と異なり掘削刃を支持する部材を大型化する必要がないので、引き抜く際に上方から外力がかかる鋼管矢板などの杭のセクション部等の断面形状が小さい地中圧入物を地盤に圧入する際の地盤の掘削に好適に用いることができ、杭のセクション部等の地中圧入物が圧入される地盤を確実に掘削して、前記地中圧入物の圧入抵抗を低減することができるとともに、セクション部等の地中圧入物の圧入後、地盤から引き抜く際に、上方から前記複数の掘削刃を閉じるように押圧するだけで縮径して引き抜き回収することができる。つまり、圧入された地中圧入物の下端部などに当接するように上方に引き上げることで容易に引き抜き回収することができる。なお、掘削ヘッドは、鋼管矢板などの杭本体等の地中圧入物を圧入する地盤を掘削する際にも用いることができる。
【０００８】
請求項２記載の発明は、例えば、図５に示すように、請求項１記載の掘削ヘッド（例えばセクションオーガヘッド５３）を、地盤に圧入される地中圧入物に沿って配置される軸部の先端に取り付けて、前記複数の掘削刃を左右に開いた状態で前記固定ピンにより前記ヘッド本体に固定し前記掘削刃部を拡径して、前記地中圧入物が圧入される地盤を掘削した後、前記地中圧入物から前記軸部を引き抜くことで、前記掘削ヘッドを上昇させて、開いた状態の前記複数の掘削刃を、前記地中圧入物の下端部により下方に閉じるように押圧させて前記固定ピンを切断し、前記掘削刃部を縮径させて前記掘削ヘッドを回収することを特徴とする。
請求項２記載の発明によれば、前記複数の掘削刃を開いた状態でヘッド本体に固定ピンで固定して前記掘削刃部が拡径された状態で、地中圧入物が圧入される地盤を確実に掘削して該地中圧入物の圧入を補助することができるとともに、前記圧入地中物が圧入される地盤を掘削した後、前記地中圧入物から軸部を引き抜くことで、掘削ヘッドは上昇し、左右に開いた前記複数の掘削刃が前記地中圧入物により閉じるように下方に押圧されて前記固定ピンが切断されることで、前記固定ピンが切断された前記複数の掘削刃は、前記ヘッド本体の上昇に伴い前記地中圧入物により下方に更に押圧されるかあるいは自重により閉じた状態となって前記掘削刃部が縮径し、縮径した前記掘削刃部はヘッド本体部とともに上方に上昇して引き抜かれて回収される。つまり、掘削後、軸部を引き抜くだけで掘削ヘッドを容易に回収することができる。
【０００９】
請求項３記載の発明は、例えば図１〜図５に示すように、長尺の杭本体１１と、該杭本体の延在方向に沿って設けられるセクション部１４とを備える杭（例えば、鋼管矢板１）を地盤に圧入する杭圧入手段（チャック部３５）と、前記杭の杭本体が圧入される地盤を掘削することで前記杭圧入手段による杭本体の圧入を補助する掘削手段３６と、前記杭のセクション部が圧入される地盤を掘削することで前記杭圧入手段による前記セクション部の圧入を補助するセクション掘削手段５とを有し、前記セクション掘削手段の、前記セクション部内に該セクション部の延在方向に沿って配置される軸部５２の先端部に請求項１記載の掘削ヘッド５３を備える杭圧入引抜機を用い、前記掘削手段により前記杭の杭本体を圧入する地盤を掘削するとともに、前記セクション部の下方で、前記掘削刃を左右に開いて前記セクション部内を挿通可能に構成された前記ヘッド本体に前記固定ピンにより固定することで、前記掘削ヘッドの前記掘削刃部を前記セクション部の内径以下の状態から該セクション部の外径を超える径まで拡径させた前記セクション掘削手段により前記杭のセクション部を圧入する地盤を掘削しながら、前記杭圧入手段により杭を圧入し、杭を圧入した後、前記軸部を前記セクション部から引き抜くように上方に移動することで、前記掘削ヘッドを上昇させて、開いた状態の前記掘削刃を前記セクション部の下端部により下方に閉じるように押圧させて前記固定ピンを切断することを特徴とする。
【００１０】
請求項３記載の発明によれば、杭本体とセクション部とをそれぞれ圧入する地盤を掘削しつつ、杭を圧入することができ、特に、前記杭のセクション部の圧入抵抗を低減することで、容易に杭を圧入することができるとともに、前記杭を圧入した後、杭のセクション部から前記セクション掘削手段の軸部を引き抜くように移動することで、該軸部先端の前記掘削ヘッドは軸部の上昇に伴い、前記セクション部内方向へと移動され、前記固定ピンにより開いた状態の複数の掘削刃の、前記セクション部の径を超えた部分が　前記セクション部の下端部に当接し、さらに上昇するヘッド本体に伴い、当接するセクション部の下端部により下方に閉じるように押圧され、前記固定ピンが切断されるので、前記複数の掘削刃は閉じられ、前記掘削刃部は前記セクション部の内径以下の縮径した状態となり、ヘッド本体ととともにセクション部内を通って引き抜かれて回収される。つまり、セクション掘削手段の掘削ヘッドは、掘削後、セクション部から引く抜くだけで、軸部とともに容易に回収することができる。
【００１１】
【発明の実施の形態】
以下、図を参照して本発明の実施の形態を詳細に説明する。
本実施の形態の掘削ヘッドは、杭圧入引抜機に備えられるものであり、まず、杭圧入引抜機の構成を説明する。
図１に示す杭圧入引抜機３０は、既設の鋼管矢板１’…を掴むクランプ３１…を下部に備えたサドル３２、該サドル３２に対して前後にスライド移動するスライドベース３３、該スライドベース３３上で旋回する旋回部３４、該旋回部３４の前方において油圧シリンダ（図示略）により昇降可能で且つ、鋼管矢板１を把持するチャック部３５、先掘り用のケーシグ付きオーガ（掘削手段）３６、該ケーシング付きオーガ３６の油圧モータ３７、鋼管矢板１のセクション部１４が圧入される下方で地山掘削を行うためのセクションオーガ（セクション掘削手段）５、セクションオーガ５の油圧モータ５１、油圧モータ３７，５１に油圧を給油するホースが巻き取られるリール３８等とを備えたものである。そして、油圧モータ３７の下部には油圧シリンダ（図示略）が備えられ、これにより、後述するケーシング付きオーガ３６に備えられるオーガケーシング３６ａに対して、アースオーガ３６ｃを昇降させることができるようになっている。なお、鋼管矢板１は長尺の円筒状の矢板本体１１と、矢板本体１１の両側の外周面に設けられ、隣接して圧入される鋼管矢板と係合するセクション部１４を備える。セクション部１４は、矢板本体１１の延在方向に沿って延在し、断面視Ｃ字状のものであり、Ｃ字を形成する切り欠きどうしを係合可能となっている。
【００１２】
そして、チャック部３５は、内部にケーシング付きオーガ３６に備えられたオーガケーシング３６ａが挿通される鋼管矢板１を上下に延在した状態で把持し、チャック部３５に設けられる油圧シリンダの駆動により鋼管矢板１を圧入したり引き抜いたりすることができる。また、ケーシング付きオーガ３６は、鋼管矢板内に挿通される上述のような円筒状のオーガケーシング３６ａと、鋼管矢板の上端部に配置され、該鋼管矢板の上端部にオーガケーシング３６ａを取り付ける取付部３９とを備え、オーガケーシング３６ａ内には、先端にビット３６ｅを備えるオーガヘッド３６ｆを有するとともに、図２に示すように外周に沿って上下に螺旋状に設けられたスクリューを有するアースオーガ３６ｃが上記油圧モータ３７により回転可能に設けられている。
【００１３】
そして、上記オーガヘッド３６ｆは拡縮可能であり、オーガケーシング３６ａ内から突出してオーガケーシング３６ａを内包する鋼管矢板１の径より大きな径となる拡縮羽根部３６ｄが折り畳み自在に取り付けられている。つまり、掘削時は図２に示すようにオーガヘッド３６ｆを拡径状態としてオーガケーシング３６ａより広い範囲Ａを掘削できる。また、掘削時以外はオーガヘッド３６ｆを縮径状態とし、オーガヘッド３６ｆをオーガケーシング３６ａの内径より少し小さい径とし、オーガケーシング３６ａとともに鋼管矢板１の圧入後、鋼管矢板１内から引き抜き可能となっている。
また、ケーシング付きオーガ３６においては、オーガケーシング３６ａよりアースオーガ３６ｃが長くされるとともに、上述のように取付部３９を介して鋼管矢板に接続されたオーガケーシング３６ａに対して、オーガケーシング３６ａの上端部に設けた上述の図示しない油圧シリンダにより、アースオーガ３６ｃを上下動できるようになっている。これにより、チャック部３５によりケーシング付きオーガ３６と鋼管矢板１とを同時に地盤中で下降させて、掘削と同時に鋼管矢板１の圧入を行なうだけではなく、先にアースオーガ３６ｃだけを下降させて先堀させた後に鋼管矢板１を圧入することを繰り返すことができる。また、アースオーガ３６ｃで先堀させた際に、アースオーガ３６ｃを引き上げながら鋼管矢板１を圧入させて、既設の鋼管矢板１’…だけではなく、アースオーガ３６ｃから反力を取ることもできる。
【００１４】
セクションオーガ５は、アースオーガ３６ｃが鋼管矢板１の下方を掘削しつつ、チャック部３５の下降により鋼管矢板１を圧入する際に、アースオーガ３６ｃの下降に伴い、鋼管矢板のセクション部１４の下方の圧入位置の地山を掘削するものであり、上下方向に延在し、セクション部内に挿通される軸部（スクリュー部）５２と、軸部５２の先端に設けられたセクションオーガヘッド（掘削ヘッド）５３とを備える（図３参照）。
軸部５２は、上下方向に延在した状態で、オーガケーシング３６ａに設けられた支持部３６１と取付部３９に設けられた支持部３９１とで支持され、上端部に配置された駆動モータ５１により回転自在となっている。
駆動モータ５１の駆動により軸部５２が回転され、軸部の回転により先端部のセクションオーガヘッド５３は回転駆動され、セクション部の下方の地山を掘削する。
【００１５】
セクションオーガヘッド５３は、図３に示すように、軸部５２の先端に接続されたヘッド本体５５と、ヘッド本体５５に設けられ、ヘッド本体５５の下方から左右方向に開くように回動自在の複数の拡縮羽根部（掘削刃）５７，５７を備えるとともに、これら複数の拡縮羽根部５７，５７を開くことにより拡径する掘削刃部とを有する。
ヘッド本体５５の外径はセクション部１４の内径より短く、ヘッド本体５５自体がセクション部１４の内部を上下方向に移動可能となっている。
このヘッド本体５５の下端面には、２つの拡縮羽根部５７，５７が下方から左右に開いた際に、それらの上縁部５７ａが嵌合する凹部５８，５８が下方に開口した状態で形成されている。
凹部５８は、開いた状態の拡縮羽根部５７の上縁部５７ａが嵌合されるので、駆動モータ５１の駆動により軸部５２が回転されセクションオーガヘッド５３が軸心回りに回転し掘削を行う際にも、その掘削時のトルクを凹部５８の内側面で受けることができ、高トルクに耐えうる構成となっている。
これら凹部５８の外面側の側壁部５５ａのそれぞれには、先端方向に突出する突出壁部５９，５９が設けられている。
前記突出壁部５９，５９は互いに平行で同じ形状をなし、平面視してセクションオーガの軸線を挟んで離間して配置されている。そして、これら突出壁部５９，５９のそれぞれに、これら突出壁部５９のそれぞれの対向面側に隣接して、一対の拡縮羽根部５７，５７の一端部が支点ピン５６，５６を介して回動自在に取り付けられている。なお、支点ピン５６，５６は軸部５２の軸方向と直交するとともに、互いに平行となっており、ここでは略水平に並んで、それぞれ拡縮羽根部５７を軸支している。
拡縮羽根部５７，５７は、ヘッド本体５５の突出壁部５９，５９に支点ピン５６，５６を軸として、下方から上方に回動させることで重なった状態から互い違いに左右に開き、左右方向に開くことにより掘削刃部を拡径する。つまり、ヘッド５３自体の掘削範囲を拡径する。
【００１６】
また、この拡縮羽根部５７，５７は、左右に開かれ掘削刃部を拡径した状態のときに、開いた状態の拡縮羽根部５７の上縁部５７ａの上端面は、それぞれヘッド本体５５の凹部５８の底面に当接されており、この底面により拡縮羽根部自体の上方への回動を抑止されている。
図３（ｃ）には、拡縮羽根部５７を、一端部で軸支する支点ピン５６を中心に回動して、他端部をヘッド本体の下方に位置する状態から上方に移動し、ヘッド本体５５の側方に突出させて、セクション部１４の外径と略同じ径の掘削範囲となるようにした状態がハッチング部分Ｃで示されている。
そして、図３に示すように、他端部が側方に突出した状態、つまり開いた状態の拡縮羽根部５７は、支点ピン５６の軸方向と平行な軸の固定ピン６１によりそれぞれ突出壁部５９に固定されている。つまり、突出壁部５９と拡縮羽根部５７には、拡縮羽根部５７が開いた際に連通する支点ピン５６と平行に形成され、固定ピン６１が挿通される孔部がそれぞれ形成されている。
なお、連通する孔部に挿入された固定ピン６１は、後述するがセクションオーガヘッド５３を引き抜く際に、開いた状態の拡縮羽根部５７の突出部分がセクション部の下端縁により下方に押圧されることで切断されるものである。
そして、これら拡縮羽根部５７，５７は、固定ピン６１が切断されることで、それぞれ自重により支点ピン５６，５６を中心に下方に回動して閉じて重ねられた状態に折り畳まれ、折り畳まれることによりセクション部１４内を挿通可能となっている。
【００１７】
次に、上述したようなセクションオーガヘッド５３を有する杭圧入引抜機３０により、鋼管矢板１（１’）を地盤に圧入して矢板壁を形成する方法とともに、セクションオーガヘッド５３の掘削方法を説明する。
杭圧入引抜機３０は、既設の鋼管矢板１’をクランプ３１により掴むことにで、これら既設の鋼管矢板１’から反力を取っている。そして、上述のように、チャック部３５が鋼管矢板１を掴ませるとともに、鋼管矢板１の上端部に取付部３９を介してケーシング付きオーガ３６、セクションオーガ５を取り付ける。
このときセクションオーガ５は、鋼管矢板１のセクション部に上方から挿通させ、下端部から軸部５２の先端部、つまりセクションオーガヘッド５３を突出させる（図４（ａ）参照）。そして、突出することでセクション部１４の下方に配置されたセクションオーガヘッド５３では、図４（ｂ）に示すように、拡縮羽根部５７，５７を開くことで、拡縮羽根部５７の先端部を軸方向と直交する方向に突出させ、先端部間の長さが、セクション部の外径よりも大きな径を有する状態にする。このとき拡縮羽根部５７は凹部５８の底面に当接することで上方への移動は抑止されているとともに、凹部５８の側壁部分により挟まれた状態となる。そして、この状態で拡縮羽根部５７を固定ピン６１によりヘッド本体５５の突出壁部５９に固定する。
【００１８】
そして、ケーシング付きオーガ３６、セクションオーガ５を取り付けた状態で、アースオーガ３６ｃ、セクションオーガ５を作動させるとともにチャック部３５を下降させることにより、オーガケーシング３６ａ下及び鋼管矢板１のセクション部下をスクリューの回転駆動により、オーガヘッド３６ｆのビットで地盤を掘削しながら鋼管矢板１を圧入していく。
このとき、セクションオーガの掘削は、図１に示すように、アースオーガの掘削位置よりも高い位置で行う。
そして、上述したように、掘削時の拡径オーガヘッド３６ｆはオーガケーシング３６ａ径に対して大径であることに加えて、開放側のセクション部下部が掘削されることになり、開放側のセクション部１４が圧入抵抗を受けることなく鋼管矢板を圧入することができる（図２（ｂ）参照）。
また、地盤を先掘りし鋼管矢板１の圧入を行う場合でも、ケーシング付きオーガ３６のオーガケーシング３６ａと鋼管矢板１を上述のように固定した状態で、アースオーガ３６ｃに加えてセクションオーガ５を作動させることにより、アースオーガ３６ｃを下降させて地盤を掘削してから、次いで鋼管矢板１を地盤に圧入することができる。
そして、鋼管矢板の圧入後、図５に示すように、ケーシング付きオーガとともにセクションオーガ５を引き抜く。
セクションオーガ５を上げてセクション部から引き抜く際には、このとき、図５（ａ）に示すセクションオーガヘッド５３は、軸部５２を上昇させることで上方に移動し、図５（ｂ）に示すように、拡縮羽根部５７が開いた状態、つまり拡径された状態のまま上昇し、セクション部の下端に当接する。
そして、更にセクションオーガヘッド５３は上昇することで、固定ピン６１が切断、詳細には剪断されて、図５（ｃ）に示すように、拡縮羽根部５７は自重により折り畳まれて閉じ、セクション部１４内を移動する。これによりセクションオーガヘッド５３は、セクション部４から引き抜かれて回収される。
このようにセクションオーガ５はセクション部が圧入される地盤を掘削することでセクション部を備える鋼管矢板の圧入抵抗の低減化を図ることができるともに、その先端に設けられたオーガヘッド５３を容易に回収することができる。なお、上記実施の形態の杭圧入引抜機３０は、上記鋼管矢板１を圧入するものに限定されるものではなく、他の各種杭にも応用することができる。また、杭本体が圧入される地盤を掘削するアースオーガは、実施の形態で用いたようなオーガケーシングを備えたものではなくてもよい。
【００１９】
【発明の効果】
本発明によれば、杭のセクション部の圧入抵抗を低減して容易に杭を圧入することができるとともに、地盤を掘削した後で、容易に回収することができる。
【図面の簡単な説明】
【図１】本発明を適用した一実施の形態の杭圧入引抜機の構成を示す図である。
【図２】図１の杭圧入引抜機により圧入される鋼管矢板の下端部分と、杭圧入引抜機より圧入される鋼管矢板を示す図であり、（ａ）はケーシング付きオーガ及びセクションオーガの先端部分の要部拡大図、（ｂ）はケーシング付きオーガ及びセクションオーガにより掘削された範囲を示す地盤に圧入された鋼管矢板の概略平面図である。
【図３】本発明を適用した杭圧入引抜機の備えるセクションオーガのオーガヘッド部を示す図であり、（ａ）はセクションオーガヘッド部の拡大正面図、（ｂ）は同セクションオーガ部の要部側断面図、（ｃ）はセクションオーガヘッド部による掘削範囲を示す図である。
【図４】地盤を掘削する前のセクションオーガヘッド部の状態を示す図である。
【図５】鋼管矢板圧入後、セクションオーガヘッド部が引き抜かれる状態を示す図である。
【図６】従来の杭圧入引抜機により圧入される鋼管矢板の下端部分と、杭圧入引抜機より圧入される鋼管矢板を示す図であり、（ａ）はケーシング付きオーガ及びセクションオーガの先端部分の要部拡大図、（ｂ）はケーシング付きオーガ及びセクションオーガにより掘削された範囲を示す地盤に圧入された鋼管矢板の概略平面図である。
【図７】矢板本体の圧入する地盤掘削に用いられるオーガヘッドをセクション部用のオーガヘッドとした場合のヘッドを示す図であり、（ａ）は概略側面図、（ｂ）は（ａ）により掘削される範囲を示す図である。
【図８】矢板本体の圧入する地盤掘削に用いられるオーガヘッドをセクション部用のオーガヘッドとした場合のヘッドを示す図であり、（ａ）は概略側面図、（ｂ）は（ａ）により掘削される範囲を示す図である。
【符号の説明】
１　　鋼管矢板（杭，地中圧入物）
５　　セクションオーガ（セクション掘削手段）
１１　矢板本体（杭本体）
１４　セクション部
３５　チャック部
１６　ケーシング付きオーガ（掘削手段）
５３　セクションオーガヘッド（掘削ヘッド）
５７　拡縮羽根部（掘削刃）
６１　固定ピン[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drilling head, a drilling method, and a pile press-fitting method provided in a pile and pile press-fitting type pile press having a drill and a pile section for drilling.
[0002]
[Prior art]
Conventionally, when a pile is pressed into the ground, the press-fitting of the pile is assisted while excavating the ground into which the pile is pressed. As shown in JP-A-10-195873, the press-fitting position of the pile is excavated by an auger with a casing. At the same time, a pile press-in / pull-out machine that can press a pile into hard ground by pressing a pile into it has been developed.
By the way, when a structure such as a steel pipe sheet pile is continuously pressed into a plurality of grounds to construct a structure, a section of the steel pipe sheet pile is engaged with a section of an existing steel pipe sheet pile, and the structure shown in FIG. It is press-fitted while excavating with an auger 2 with a casing arranged so as to penetrate a steel pipe sheet pile 1. As shown in FIG. 6B, the excavation range A of the auger head 3 of the auger 2 with the casing is larger than the diameter of the tubular sheet pile main body 11 of the steel pipe sheet pile 1 to be press-fitted and the steel pipe sheet pile 1 press-fitted immediately before. The clearance a is provided between the section 12 of the existing steel pipe sheet pile 1 'so as not to interfere with the section 12 of the existing steel pipe sheet pile 1'. Since the auger head 3 needs to be pulled out after press-fitting the steel pipe sheet pile 1, the blade part 8 having a bit at the tip of an arm part 7 protruding left and right from the head body 6 connected to the tip of the auger screw 4. Is mounted so as to be freely foldable, and is configured such that its diameter becomes smaller than the inner diameter of the sheet pile body 11 by folding the wing portion 8.
[0003]
[Problems to be solved by the invention]
In the press-fitting method described above, the excavation range A of the auger head takes into account the clearance a between the section 12 of the existing steel pipe sheet pile 1 ′. The tip of the section 13 engaged with the section 12 of the steel pipe sheet pile 1 'and the tip of the open section 14 are pressed into the unexcavated ground. The resistance increases. In order to reduce the increase of the press-in resistance, a section auger for excavating the ground into which the section 12 is press-fitted is used together with the auger 2 with the casing, and a section auger excavating head is shown in FIGS. 7 and 8. In addition, it is conceivable that the above-described auger head 3 which expands and contracts is used as the excavating head 30 of the section 12.
[0004]
The excavating heads 3A and 3B shown in FIG. 7A and FIG. 8A are fixed to the tip of a section screw and rotate coaxially with the screw. Protruding support pieces 302A, 302B protruding laterally from the left and right side walls of the end, and a base end rotatably attached to the protruding support pieces 302A, 302B, and a blade 303a at a distal end. And a blade portion 303. A protruding blade 301a that protrudes downward is provided at the lower end of the head main body 301 of each of the heads 3A and 3B. These two heads 3A and 3B are configured such that the excavation diameter is expanded and contracted by the rotation of the blade portion 303 on the side of the head body 301, and the head 3A shown in FIG. When the blade 303 opens right and left on the side of the head body 301 due to resistance, the excavation diameter increases (see FIG. 7B), and the head 3B shown in FIG. 8A rotates and excavates the ground. At this time, the wings are opened at the side of the head main body 301, and the excavation diameter is configured to be enlarged (see FIG. 8B).
However, in the configuration of these heads 3A and 3B, since the diameter is increased by resistance during press-fitting and excavation, there may be cases where the blade portion 303 cannot be opened reliably. Further, since the blades 303 are supported by the protruding support portions 302, the strength of the protruding support pieces 302 needs to be increased, so that the protruding support pieces 302 need to be increased in size. When it is used for excavation, it becomes larger than the outer diameter of the section even in the expanded and contracted state, so that it cannot be recovered after the excavation, or the recovery operation becomes difficult.
[0005]
An object of the present invention is to press-fit a pile such as a steel pipe sheet pile or the like, and to excavate the ground in which a section of the pile is press-fitted, thereby reliably excavating the ground and reducing the press-fit resistance of the pile. In addition, an object of the present invention is to provide a digging head, a digging method, and a pile press-fitting method that can be easily recovered and expanded.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, for example, as shown in FIG. 3, the invention according to claim 1 is provided on a head main body 55, and is provided on the head main body, and is rotated from the lower side of the head main body so as to open in the left-right direction. A plurality of movable digging blades (for example, expanding / contracting blades 57, 57) are provided, and a digging blade portion whose diameter is expanded by opening the plurality of digging blades, and a digging blade portion which is opened by opening the plurality of digging blades. A fixing pin 61 that is fixed to the head main body in a diameter state, wherein the fixing pin is cut by being pressed downward so as to close the plurality of digging blades that are open left and right. And
[0007]
According to the first aspect of the present invention, the digging blade portion provided on the head main body opens the plurality of digging blades from left to right from the bottom and fixes the digging blade to the head main body with the fixing pin, so that the digging blade is reliably expanded in diameter. While being in a state having a range, the plurality of digging blades which are open left and right are pressed downward so as to close, so that a fixing pin is cut and the plurality of digging blades are closed below the head main body. Since it is not necessary to increase the size of the member that supports the excavation blade, unlike in the past, it is not necessary to increase the size of the member. It can be suitably used for excavation of the ground at the time of injecting the injecting material into the ground, and reliably excavate the ground into which the underground injecting material such as the section of the pile is to be injected, and press-in resistance of the underground injecting material Can be reduced Rutotomoni, was injected in the ground press-fitting of such section portion, when pulled from the ground, can be withdrawal recovered diameter by simply pressing to close the plurality of cutting blades from above. In other words, it can be easily pulled out and collected by pulling it upward so as to contact the lower end portion or the like of the press-fitted underground press-fit. The excavation head can also be used when excavating the ground into which an underground injection material such as a pile body such as a steel pipe sheet pile is injected.
[0008]
According to a second aspect of the present invention, for example, as shown in FIG. 5, the excavating head (for example, the section auger head 53) according to the first aspect is provided with a shaft portion which is arranged along with an underground press-fitted material that is pressed into the ground. With the plurality of digging blades opened to the left and right, fixed to the head body with the fixing pins and expanding the digging blade portion to excavate the ground into which the underground press-fit is pressed. After that, by pulling out the shaft portion from the underground press-in, the excavating head is raised, so that the plurality of open excavating blades are closed downward by the lower end of the underground press-in. The fixing pin is cut by being pressed, and the diameter of the excavating blade is reduced to collect the excavating head.
According to the invention as set forth in claim 2, the ground into which the underground press-fit is press-fitted in a state where the plurality of digging blades are opened and fixed to the head body with the fixing pins and the digging blade portion is expanded in diameter. Can be reliably excavated to assist in the press-fitting of the underground press-fit, and after excavating the ground into which the press-filled press-fit is pressed, the shaft portion is pulled out from the underground press-fit, thereby excavating. The head is raised, and the plurality of digging blades, which are cut off the fixing pins, are pressed downward so that the plurality of digging blades opened right and left are closed by the underground press-fitting and cut the fixing pins. The blade is further pressed downward by the underground press-fit with the rise of the head main body or is closed by its own weight, and the digging blade portion is reduced in diameter. Ascends upward with the main unit and is pulled out It is. That is, after the excavation, the excavating head can be easily collected only by pulling out the shaft.
[0009]
The invention according to claim 3 is a pile (for example, a steel pipe) provided with a long pile main body 11 and a section portion 14 provided along the extending direction of the pile main body, as shown in FIGS. A pile press-in means (chuck portion 35) for press-fitting the sheet pile 1) into the ground, and an excavating means 36 for assisting press-fitting of the pile main body by the pile press-in means by excavating the ground into which the pile main body of the pile is pressed. Section excavating means 5 for assisting the press-fitting of the section by the pile press-fitting means by excavating the ground into which the section of the pile is press-fitted. When excavating the ground into which the pile main body of the pile is press-fitted by the excavation means, using a pile press-in and pull-out machine provided with the excavation head 53 according to claim 1 at the tip end of the shaft portion 52 arranged along the extending direction of the pile. When Below the section, the digging blade is opened to the left and right and fixed to the head body configured to be able to pass through the section by the fixing pin, so that the digging blade of the digging head is While excavating the ground for press-fitting the section of the pile by the section excavating means expanded from the state of being equal to or less than the inner diameter of the section to the diameter exceeding the outer diameter of the section, the pile is press-fitted by the pile press-fitting means. After press-fitting the stake, the shaft is moved upward so as to be pulled out from the section, thereby raising the drilling head, and moving the drilling blade in an open state downward by the lower end of the section. It is characterized in that the fixing pin is cut by pressing so as to close.
[0010]
According to the invention as set forth in claim 3, the pile can be press-fitted while excavating the ground for press-fitting the pile body and the section, respectively. In particular, by reducing the press-fit resistance of the section of the pile, The pile can be easily press-fitted, and after the pile is press-fitted, by moving the section of the section excavating means so as to pull out the shaft from the section of the pile, the excavation head at the tip of the shaft is shaved. With the rise of the plurality of excavating blades, which are moved inward in the section and are opened by the fixing pins, the portions exceeding the diameter of the section abut against the lower end of the section, and further rise. With the head body to be pressed, the lower end of the abutting section is pressed so as to close downward, and the fixing pin is cut, so that the plurality of digging blades are closed, and the digging blade is The diameter of the section becomes smaller than the inner diameter of the section, and the section is pulled out and collected together with the head main body through the section. In other words, the excavating head of the section excavating means can be easily collected together with the shaft simply by pulling it out of the section after excavation.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The excavating head according to the present embodiment is provided in a pile press-in / pull-out machine. First, the configuration of the pile press-in / pull-out machine will be described.
A pile press-in / pull-out machine 30 shown in FIG. 1 includes a saddle 32 provided at its lower part with a clamp 31 for gripping an existing steel pipe sheet pile 1 ′, a slide base 33 that slides back and forth with respect to the saddle 32, and the slide base 33. A turning part 34 that turns upward, a chuck part 35 that can be moved up and down by a hydraulic cylinder (not shown) in front of the turning part 34, and that grips the steel pipe sheet pile 1; an auger (digging means) 36 with a predigging casing; The hydraulic motor 37 of the auger 36 with the casing, the section auger (section excavating means) 5 for performing ground excavation below the section 14 of the steel pipe sheet pile 1 which is press-fitted, the hydraulic motor 51 of the section auger 5 and the hydraulic motor 37 , 51 and a reel 38 on which a hose for supplying oil pressure is wound up. A hydraulic cylinder (not shown) is provided below the hydraulic motor 37, so that the earth auger 36c can be moved up and down with respect to an auger casing 36a provided in an auger 36 with a casing described later. ing. The steel pipe sheet pile 1 includes a long cylindrical sheet pile main body 11 and a section 14 provided on the outer peripheral surface on both sides of the sheet pile main body 11 and engaging with a steel pipe sheet pile which is press-fitted adjacently. The section 14 extends in the direction in which the sheet pile main body 11 extends, has a C-shaped cross section, and is capable of engaging notches forming a C-shape.
[0012]
Then, the chuck portion 35 grips the steel pipe sheet pile 1 in which the auger casing 36 a provided in the auger 36 with the casing is inserted in a vertically extended state, and drives the steel pipe by driving a hydraulic cylinder provided in the chuck portion 35. The sheet pile 1 can be pressed in or pulled out. Further, the auger 36 with a casing is provided with the above-described cylindrical auger casing 36a to be inserted into the steel pipe sheet pile and the upper end of the steel pipe sheet pile, and a mounting part for attaching the auger casing 36a to the upper end of the steel pipe sheet pile. In the auger casing 36a, there is provided an auger head 36f having a bit 36e at a tip thereof, and an earth auger 36c having a screw provided vertically spirally along the outer periphery as shown in FIG. The hydraulic motor 37 is provided so as to be rotatable.
[0013]
The auger head 36f is expandable and contractable, and an expandable and contractible blade portion 36d which protrudes from the auger casing 36a and has a diameter larger than the diameter of the steel pipe sheet pile 1 enclosing the auger casing 36a is foldably attached. That is, at the time of excavation, as shown in FIG. 2, the auger head 36f can be excavated in a wider range A than the auger casing 36a by setting the diameter of the auger head 36f to an expanded state. Except during excavation, the auger head 36f is reduced in diameter, and the auger head 36f is slightly smaller than the inner diameter of the auger casing 36a. After the steel pipe sheet pile 1 is pressed into the auger casing 36a together with the auger casing 36a, the auger head 36f can be pulled out of the steel pipe sheet pile 1. ing.
In the auger 36 with a casing, the earth auger 36c is longer than the auger casing 36a, and the upper end of the auger casing 36a is connected to the auger casing 36a connected to the steel pipe sheet pile through the mounting portion 39 as described above. The earth auger 36c can be moved up and down by the above-mentioned hydraulic cylinder (not shown) provided in the section. Thereby, the auger 36 with the casing and the steel pipe sheet pile 1 are simultaneously lowered in the ground by the chuck portion 35, and not only the steel pipe sheet pile 1 is press-fitted simultaneously with excavation, but also only the earth auger 36c is lowered first. After the excavation, the press-fitting of the steel pipe sheet pile 1 can be repeated. Further, when pre-drilled by the earth auger 36c, the steel pipe sheet pile 1 can be press-fitted while pulling up the earth auger 36c, and a reaction force can be taken not only from the existing steel pipe sheet piles 1 '... but also from the earth auger 36c.
[0014]
When the earth auger 36c excavates below the steel pipe sheet pile 1 and press-fits the steel pipe sheet pile 1 by the lowering of the chuck portion 35, the section auger 36c moves below the section part 14 of the steel pipe sheet pile with the lowering of the earth auger 36c. A shaft portion (screw portion) 52 extending in the up-down direction and inserted into the section portion, and a section auger head (digging head) provided at the tip of the shaft portion 52. ) 53 (see FIG. 3).
The shaft portion 52 is supported by a support portion 361 provided on the auger casing 36a and a support portion 391 provided on the mounting portion 39 while extending in the up-down direction, and is driven by the drive motor 51 disposed at the upper end portion. It is freely rotatable.
The shaft 52 is rotated by the driving of the drive motor 51, and the section auger head 53 at the distal end is rotated by the rotation of the shaft to excavate the ground below the section.
[0015]
As shown in FIG. 3, the section auger head 53 is provided on the head main body 55 connected to the tip of the shaft 52, and is provided on the head main body 55, and is rotatable so as to open in the left-right direction from below the head main body 55. It has a plurality of expanding / contracting blades (digging blades) 57, 57, and an excavating blade for expanding the diameter by opening the plurality of expanding / contracting blades 57, 57.
The outer diameter of the head main body 55 is shorter than the inner diameter of the section 14, and the head main body 55 itself can move up and down inside the section 14.
When the two expanding and contracting blade portions 57, 57 open left and right from below, the concave portions 58, 58 into which the upper edge portions 57a are fitted are formed on the lower end surface of the head main body 55 so as to open downward. Have been.
The concave portion 58 is fitted with the upper edge portion 57a of the expanding and contracting blade portion 57 in the opened state, so that the shaft portion 52 is rotated by the drive of the drive motor 51, and the section auger head 53 rotates around the axis to perform excavation. Also in this case, the torque at the time of the excavation can be received on the inner surface of the concave portion 58, so that the configuration can withstand high torque.
Protruding wall portions 59, 59 protruding in the distal end direction are provided on each of the side wall portions 55a on the outer surface side of these concave portions 58.
The protruding wall portions 59, 59 are parallel to each other and have the same shape, and are spaced apart from each other across the axis of the section auger in plan view. One end of each of the pair of expanding / contracting blades 57, 57 is turned via the fulcrum pin 56, 56, adjacent to each of the protruding wall portions 59, 59, adjacent to the respective opposing surfaces of the protruding wall portions 59. It is movably mounted. The fulcrum pins 56, 56 are orthogonal to the axial direction of the shaft portion 52 and are parallel to each other. Here, they are arranged substantially horizontally, and respectively support the expanding / contracting blade portions 57.
The expanding / contracting blades 57, 57 are alternately opened left and right from a state of being overlapped with the projecting wall portions 59, 59 of the head main body 55 by being pivoted upward from below with the fulcrum pins 56 as axes. The diameter of the excavation blade is expanded by opening. That is, the excavation range of the head 53 itself is increased.
[0016]
Further, when the expanding / contracting blades 57 and 57 are opened to the left and right and the diameter of the excavating blade is expanded, the upper end surfaces of the upper edges 57 a of the expanding / contracting blades 57 in the opened state are respectively connected to the head body 55. It is in contact with the bottom surface of the concave portion 58, and the upward rotation of the expanding / contracting blade portion itself is suppressed by this bottom surface.
In FIG. 3C, the expanding / contracting blade portion 57 is pivoted about a fulcrum pin 56 pivotally supported at one end, and the other end is moved upward from a state located below the head main body. Hatched portion C shows a state in which it is projected to the side of main body 55 so as to have an excavation area having substantially the same diameter as the outer diameter of section portion 14.
As shown in FIG. 3, the expanding / contracting blade portion 57 in a state where the other end protrudes sideward, that is, in an open state, is respectively protruded by a fixing pin 61 having an axis parallel to the axial direction of the fulcrum pin 56. 59. That is, the protruding wall portion 59 and the expanding / contracting blade portion 57 are formed in parallel with the fulcrum pin 56 communicating when the expanding / contracting blade portion 57 is opened, and are formed with holes through which the fixing pins 61 are inserted.
When the section auger head 53 is pulled out, the fixing pin 61 inserted into the communicating hole is pressed downward by the lower end edge of the section when the section auger head 53 is pulled out. It is cut by the thing.
When the fixing pin 61 is cut, the expanding / contracting blade portions 57, 57 are turned downward around the fulcrum pins 56, 56 by their own weights, and are folded and folded in a closed state. This allows the section 14 to be inserted.
[0017]
Next, a method of press-fitting the steel pipe sheet pile 1 (1 ') into the ground to form a sheet pile wall and a method of excavating the section auger head 53 by the pile press-in and pull-out machine 30 having the section auger head 53 as described above will be described. I do.
The pile press-in / pull-out machine 30 takes a reaction force from the existing steel pipe sheet piles 1 'by gripping the existing steel pipe sheet piles 1' with the clamps 31. Then, as described above, the chuck portion 35 causes the steel pipe sheet pile 1 to be gripped, and the auger 36 with the casing and the section auger 5 are attached to the upper end portion of the steel pipe sheet pile 1 via the attachment portion 39.
At this time, the section auger 5 is inserted into the section of the steel pipe sheet pile 1 from above, and the tip of the shaft 52, that is, the section auger head 53, is projected from the lower end (see FIG. 4A). Then, in the section auger head 53 disposed below the section 14 by protruding, as shown in FIG. 4B, the tip of the expanding / contracting blade 57 is opened by opening the expanding / contracting blades 57, 57. It is made to protrude in the direction orthogonal to the axial direction, and the length between the tip portions is set to a state having a diameter larger than the outer diameter of the section portion. At this time, the expansion and contraction blade portion 57 is in contact with the bottom surface of the concave portion 58, so that the upward movement is suppressed, and the expanding / contracting blade portion 57 is sandwiched by the side wall portion of the concave portion 58. Then, in this state, the expansion / contraction blade portion 57 is fixed to the protruding wall portion 59 of the head main body 55 by the fixing pin 61.
[0018]
Then, with the casing auger 36 and the section auger 5 attached, the earth auger 36c and the section auger 5 are operated and the chuck portion 35 is lowered, so that the lower part of the auger casing 36a and the lower part of the section of the steel pipe sheet pile 1 are screwed. By rotating, the steel sheet pile 1 is pressed into the ground while excavating the ground with the bit of the auger head 36f.
At this time, excavation of the section auger is performed at a position higher than the excavation position of the earth auger, as shown in FIG.
As described above, the enlarged diameter auger head 36f during excavation has a larger diameter than the auger casing 36a, and in addition, the lower portion of the open-side section is excavated, so that the open-side section is excavated. The section 14 can press-fit a steel sheet pile without receiving press-fitting resistance (see FIG. 2B).
Even when the ground is first dug and the steel pipe sheet pile 1 is press-fitted, the section auger 5 is operated in addition to the earth auger 36c in a state where the auger casing 36a of the auger 36 with the casing and the steel pipe sheet pile 1 are fixed as described above. By doing so, the earth auger 36c is lowered to excavate the ground, and then the steel pipe sheet pile 1 can be pressed into the ground.
Then, after press-fitting the steel pipe sheet pile, as shown in FIG. 5, the section auger 5 is pulled out together with the auger with the casing.
When the section auger 5 is lifted and pulled out of the section, the section auger head 53 shown in FIG. 5 (a) moves upward by raising the shaft 52, as shown in FIG. 5 (b). As described above, the expanding / contracting blade portion 57 rises in an open state, that is, an expanded state, and abuts on the lower end of the section portion.
When the section auger head 53 is further raised, the fixing pin 61 is cut and specifically sheared, and as shown in FIG. 5C, the expanding / contracting blade portion 57 is folded and closed by its own weight, and the section portion is closed. Move within 14. As a result, the section auger head 53 is pulled out from the section 4 and collected.
As described above, the section auger 5 can reduce the press-in resistance of the steel pipe sheet pile having the section by excavating the ground into which the section is press-fitted, and can easily mount the auger head 53 provided at the tip thereof. Can be recovered. In addition, the pile press-in / pull-out machine 30 of the above embodiment is not limited to the one that presses the steel pipe sheet pile 1 but can be applied to other various piles. Further, the earth auger for excavating the ground into which the pile body is press-fitted may not be provided with the auger casing as used in the embodiment.
[0019]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, while the press-in resistance of the section part of a pile is reduced and a pile can be press-fitted easily, it can collect | recover easily after excavating the ground.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a pile press-in and pull-out machine according to an embodiment to which the present invention is applied.
FIG. 2 is a view showing a lower end portion of a steel pipe sheet pile pressed by the pile press-in / draw-out machine of FIG. 1 and a steel pipe sheet pile pressed by the pile press-in / pull-out machine; FIG. 2 (a) is a tip of an auger with a casing and a section auger; FIG. 3B is a schematic plan view of a steel pipe sheet pile pressed into the ground showing an area excavated by the auger with casing and the section auger.
3A and 3B are diagrams showing an auger head of a section auger provided in a pile press-in / pull-out machine to which the present invention is applied, wherein FIG. 3A is an enlarged front view of the section auger, and FIG. FIG. 3C is a sectional view of a part, and FIG.
FIG. 4 is a diagram showing a state of a section auger head before excavating the ground.
FIG. 5 is a diagram showing a state in which a section auger head is pulled out after press-fitting a steel pipe sheet pile.
FIG. 6 is a view showing a lower end portion of a steel pipe sheet pile pressed by a conventional pile press-in / pull-out machine, and a steel pipe sheet pile pressed into by a pile press-in / pull-out machine; FIG. (B) is a schematic plan view of a steel pipe sheet pile pressed into the ground showing an area excavated by an auger with a casing and a section auger.
FIGS. 7A and 7B are diagrams showing a head in a case where an auger head used for excavation of the ground into which a sheet pile body is pressed is used as an auger head for a section, where FIG. 7A is a schematic side view, and FIG. It is a figure which shows the range which is excavated.
FIGS. 8A and 8B are diagrams showing a head in a case where an auger head used for excavating the ground into which a sheet pile body is press-fitted is used as an auger head for a section, where FIG. 8A is a schematic side view, and FIG. It is a figure which shows the range which is excavated.
[Explanation of symbols]
1 Steel sheet piles (pile, underground press-fit)
5 section auger (section excavation means)
11 sheet pile body (pile body)
14 Section 35 Chuck 16 Auger with casing (digging means)
53 Section Auger Head (Drilling Head)
57 Expanding and contracting blades (drilling blades)
61 Fixing pin

Claims

The head body,
An excavation blade portion provided on the head body, comprising a plurality of excavation blades rotatable to open in the left-right direction from below the head body, and expanding the diameter by opening the plurality of excavation blades,
A fixing pin that opens the plurality of digging blades and fixes the digging blade portion to the head body in a state where the diameter of the digging blade portion is expanded,
The excavating head is characterized in that the fixing pin is cut by being pressed downward so as to close the plurality of excavating blades that are open left and right.

The excavating head according to claim 1, which is attached to a tip of a shaft portion disposed along an underground press-fitting object to be pressed into the ground, and wherein the plurality of excavating blades are opened to the left and right by the fixing pin. After excavating the ground to which the underground press-fit is fixed by expanding the excavation blade portion fixed to the main body, by pulling out the shaft portion from the underground press-fit, the excavating head is raised. The plurality of excavating blades in an open state are pressed so as to be closed downward by a lower end portion of the underground press-in, the fixing pin is cut, and the excavating head is collected by reducing the diameter of the excavating blade. A drilling method characterized by performing.

Pile press-fitting means for press-fitting a pile comprising a long pile main body and a section provided along the extending direction of the pile main body into the ground,
Excavating means for assisting press-fitting of the pile main body by the pile press-fitting means by digging a ground into which the pile main body of the pile is press-fitted, and excavating the ground into which the section of the pile is press-fitted; And a section excavating means for assisting press-fitting of the section by the section excavating means, wherein the section excavating means is provided at a tip end of a shaft portion arranged in the section along the extending direction of the section. Using a pile press-in / pull-out machine provided with a digging head, digging the ground for press-fitting the pile main body of the pile with the digging means, and opening the digging blade to the left and right below the section, thereby opening the inside of the section. Is fixed to the head main body, which is configured to be able to be inserted, by the fixing pin, so that the digging blade portion of the digging head is moved from a state of an inner diameter or less of the section portion to the section. While drilling ground press-fitting the section portion of the pile by the section excavating means is expanded to a diameter greater than the outer diameter of Deployment unit, pile was pressed by the pile press-fitting means,
After press-fitting the stake, the excavating head is raised by moving the shaft portion upward so as to be pulled out from the section portion, and the open excavating blade is closed downward by the lower end portion of the section portion. The fixing pin is cut by pressing as described above, and the diameter of the excavating blade portion is reduced and pulled out.