JP3834006B2

JP3834006B2 - Ground improvement device

Info

Publication number: JP3834006B2
Application number: JP2003038828A
Authority: JP
Inventors: 満生原
Original assignee: エポコラム機工株式会社
Priority date: 2003-02-17
Filing date: 2003-02-17
Publication date: 2006-10-18
Anticipated expiration: 2023-02-17
Also published as: JP2004245002A

Description

【０００１】
【発明の属する技術分野】
本発明は、地盤改良装置に関する。
【０００２】
【従来の技術】
従来、地盤改良装置の一形態として、上下方向に伸延する掘削・攪拌軸体の下部周面に相対撹拌翼部を取り付けると共に、同掘削・攪拌軸体の下端部に掘削刃体を取り付け、同掘削・攪拌軸体の下部周面に改良材吐出部を設けたものがある（例えば、特許文献１参照）。
【０００３】
そして、相対撹拌翼部は、弧状に形成した内・外側撹拌翼体を掘削・攪拌軸体に相対的に反対方向に回転するように取り付けて形成している。
【０００４】
このようにして、掘削刃体により地盤を掘削しながら相対撹拌翼部の内・外側撹拌翼体により掘削した土壌を相対撹拌すると共に、改良材吐出部より改良材を吐出して、同改良材と掘削土とを混練することにより地盤を改良するようにしている。
【０００５】
【特許文献１】
特開平３−６３３１２号公報
【０００６】
【発明が解決しようとする課題】
ところが、地盤改良作業をより一層効果的にかつ短時間にて完了させることが望まれており、かかる作業を行う地盤改良装置の改良が切望されている。
【０００７】
【課題を解決するための手段】
そこで、本発明では、地盤を掘削・撹拌しながら改良材を吐出して、同改良材と掘削土とを混練することにより地盤改良を行うようにした地盤改良装置において、上下方向に伸延する第１軸と、同第１軸の外周を囲繞する第２軸と、同第２軸の外周を囲繞する第３軸とからなる三重軸構造の掘削・攪拌軸体の下部周面に、２つの相対撹拌翼部を上下方向に隣接させて同軸的に取り付けると共に、各相対撹拌翼部は、掘削・攪拌軸体に中途部を外方へ膨出させて弧状に形成した複数の撹拌翼体を内外側に配置すると共に最内側に位置する最内側撹拌翼体を配置し、かつ、同掘削・攪拌軸体の軸線廻りに相対的に反対方向に回転するように取り付け、かつ、上下方向に隣接する各相対撹拌翼部の外側の撹拌翼体同士が相対的に反対方向に回転するように取り付け、２つの相対撹拌翼部のうち、上に位置する相対撹拌翼部の外側撹拌翼体の端部を第３軸に取り付け、外側撹拌翼体とは相対的に反対方向に回転する内側撹拌翼体の端部を第２軸に取り付け、最内側撹拌翼体を第３軸の外周面から放射状に突出させたことを特徴とする地盤改良装置を提供するものである。
【０００８】
ここで、撹拌翼体の形状である「弧状」には、角部を有しない略円弧状に限らず、角部を一つ有する略三角形弧状、角部を二つ有する略四角形弧状（本実施例に係る形状）、さらには、角部を三つ以上有する略多角形弧状等も含まれるものである。
【０００９】
また、本発明は、以下の構成にも特徴を有する。
【００１０】
（１）地盤を掘削・撹拌しながら改良材を吐出して、同改良材と掘削土とを混練することにより地盤改良を行うようにした地盤改良装置において、上下方向に伸延する第１軸と、同第１軸の外周を囲繞する第２軸と、同第２軸の外周を囲繞する第３軸とからなる三重軸構造の掘削・攪拌軸体の下部周面に、２つの相対撹拌翼部を上下方向に隣接させて同軸的に取り付けると共に、各相対撹拌翼部は、掘削・攪拌軸体の軸線廻りに内外側にて相対的に反対方向に回転する複数の撹拌翼体を具備すると共に最内側に位置する最内側撹拌翼体を配置し、上下方向に隣接する各相対撹拌翼部の外側の撹拌翼体は、それぞれ中途部を外方へ膨出させて弧状に形成し、かつ、相対的に反対方向に回転するようにし、上方に位置する外側の撹拌翼体から下方へ向けて小翼片を突設する一方、下方に隣接する外側の撹拌翼体から上方へ向けて小翼片を突設して、両小翼片を内外側方向に一部が重複状態となるように配置し、２つの相対撹拌翼部のうち、上に位置する相対撹拌翼部の外側撹拌翼体の端部を第３軸に取り付け、外側撹拌翼体とは相対的に反対方向に回転する内側撹拌翼体の端部を第２軸に取り付け、最内側撹拌翼体を第３軸の外周面から放射状に突出させたこと。
【００１１】
（２）２つの相対撹拌翼部のうち、上に位置する相対撹拌翼部の外側撹拌翼体は、掘削・攪拌軸体の半径方向に張り出し状に伸延する上下一対の上・下部横翼片と、両上・下部横翼片の外側端部間に上下方向に伸延させて介設した縦翼片とからなるものであり、第２軸の下部でかつ外側撹拌翼体の下部横翼片よりも上方位置に、改良材吐出部を設けていること。
【００１２】
（３）各相対撹拌翼部は、掘削・攪拌軸体より半径方向に伸延する棒状の撹拌翼体を具備し、同棒状の撹拌翼体は、弧状に形成した内側の撹拌翼体の内方において、外側の撹拌翼体と同一方向に回転するようにしたこと。
【００１３】
（４）掘削・攪拌軸体の近傍と外側の撹拌翼体の近傍とにそれぞれ改良材吐出部を設けたこと。
【００１４】
【発明の実施の形態】
以下に、本発明の実施の形態について説明する。
【００１５】
すなわち、本発明に係る地盤改良装置は、上下方向に伸延する掘削・攪拌軸体の下部周面に、複数の相対撹拌翼部を上下方向に隣接させて同軸的に取り付けると共に、各相対撹拌翼部は、掘削・攪拌軸体に中途部を外方へ膨出させて弧状に形成した複数の撹拌翼体を内外側に配置し、かつ、同掘削・攪拌軸体の軸線廻りに相対的に反対方向に回転するように取り付け、かつ、上下方向に隣接する各相対撹拌翼部の外側の撹拌翼体同士が相対的に反対方向に回転するように取り付けている。
【００１６】
しかも、各相対撹拌翼部は、掘削・攪拌軸体より半径方向に伸延する棒状の撹拌翼体を具備し、同棒状の撹拌翼体は、弧状に形成した内側の撹拌翼体の内方において、外側の撹拌翼体と同一方向に回転するようにしている。
【００１７】
さらには、上記のような構成において、掘削・攪拌軸体の近傍と外側の撹拌翼体の近傍とにそれぞれ改良材吐出部を設けている。
【００１８】
また、本発明に係る地盤改良装置は、上下方向に伸延する掘削・攪拌軸体の下部周面に、複数の相対撹拌翼部を上下方向に隣接させて同軸的に取り付けると共に、各相対撹拌翼部は、掘削・攪拌軸体の軸線廻りに内外側にて相対的に反対方向に回転する複数の撹拌翼体を具備し、上下方向に隣接する各相対撹拌翼部の外側の撹拌翼体は、それぞれ中途部を外方へ膨出させて弧状に形成し、かつ、相対的に反対方向に回転するようにし、上方に位置する外側の撹拌翼体から下方へ向けて小翼片を突設する一方、下方に隣接する外側の撹拌翼体から上方へ向けて小翼片を突設して、両小翼片を内外側方向に一部が重複状態となるように配置している。
【００１９】
しかも、各小翼片の横断面幅を中央部から回転方向側の端面に向けて漸次細幅に形成して、少なくとも隣接する小翼片側の側面をテーパー面となしている。
【００２０】
【実施例】
以下に、本発明の実施例を、図面を参照しながら説明する。
【００２１】
〔第１実施例〕
図1に示すＡは、本発明に係る第１実施例としての地盤改良装置であり、同地盤改良装置Ａは、ベースマシン１と改良材供給部２とを装備している。
【００２２】
ベースマシン１は、自走可能なベースマシン本体３に上下方向に伸延するリーダ４を設け、同リーダ４にモータ支持体５を昇降自在に取り付け、同モータ支持体５に駆動用モータＭを搭載し、同駆動用モータＭに上下方向に伸延する掘削・攪拌軸体６の上端部を反転歯車機構７を介して着脱自在に取り付け、同掘削・攪拌軸体６の下部周面に、複数（本実施例では二個）の相対撹拌翼部8,9を上下方向に隣接させて同軸的に取り付けると共に、同掘削・攪拌軸体６の下端部に掘削刃体10を取り付けている。
【００２３】
改良材供給部２は、改良材収容タンクと改良材供給ポンプ（図示しない）とを具備し、同改良材供給ポンプに改良材供給ホース11の基端部を接続し、同改良材供給ホース11の先端部を前記掘削・攪拌軸体６に接続している。
【００２４】
掘削・攪拌軸体６は、図２〜図４に示すように、上下方向に伸延させて形成した筒状の第１軸20と、同第１軸20の外周を囲繞する状態に上下方向に伸延させて形成した筒状の第２軸21と、同第２軸の外周を囲繞する状態に上下方向に伸延させて形成した第３軸22とから内外側三重軸構造に構成しており、これら第１〜第３軸20,21,22は、駆動用モータＭにより反転歯車機構７を介して同一軸芯廻りに回転するようにすると共に、第１・第３軸20,22に対して第２軸21は反対方向に回転するようにしている。
【００２５】
そして、第１軸20中には上下方向に伸延させて形成した筒状の改良材供給路形成体19を挿通して、同改良材供給路形成体19中に第１改良材供給路23を形成し、同改良材供給路形成体19の外周面と第１軸20の内周面との間に第２改良材供給路24を形成し、同第１軸20の外周面と第２軸21の内周面との間に第３改良材供給路25を形成している。
【００２６】
ここで、前記した改良材供給ホース11の基端部は、上記第１〜第３改良材供給路23,24,25の各上流端部に接続して、改良材供給部２より改良材供給ホース11を通して各改良材供給路23,24,25中に改良材を供給するようにしている。図２中、12,13はそれぞれスイベルジョイントである。
【００２７】
上方に配置した相対撹拌翼部８は、図２及び図３に示すように、最内側に位置する最内側撹拌翼体26と、同最内側撹拌翼体26の外周にて相対的に反対方向に回転する内側の撹拌翼体である内側撹拌翼体27と、同内側撹拌翼体27の外周にて相対的に反対方向に回転する外側の撹拌翼体である外側撹拌翼体28とを具備している。
【００２８】
そして、内側撹拌翼体27と、その外方に配置した外側撹拌翼体28は、略相似形に形成して、両撹拌翼体27,28間に形成される間隙を、両撹拌翼体27,28のほぼ全域にわたってほぼ等しい幅員となすことにより、掘削土の共回り現象を防止することができると共に、緻密な撹拌機能を発揮させることができるようにしている。
【００２９】
最内側撹拌翼体26は、第３軸22の下端部外周面より放射状に突出させて形成しており、同第３軸22の軸線対称位置に一対設けて、同第３軸22と一体的にａ方向に回転するようにしている。
【００３０】
内側撹拌翼体27は、掘削・攪拌軸体６の半径方向に張り出し状に伸延する上下一対の上・下部横翼片27a,27bと、両上・下部横翼片27a,27bの外側端部間に上下方向に伸延させて介設した縦翼片27cとから、中途部が外方に膨出する弧状に形成しており、第３軸22の外周面に回転自在に遊嵌したリング状の上部翼片支持体30に上部横翼片27aの先端部を取り付ける一方、第２軸21の外周面に下部横翼片27bの先端部を取り付けて、第２軸21と一体的にｂ方向に回転するようにしている。
【００３１】
そして、内側撹拌翼体27は、第２軸21の下部の軸線対称位置に一対設けている。31は、縦翼片27cの中途部より外方へ突出させて形成した外方突出小翼片である。
【００３２】
外側撹拌翼体28は、掘削・攪拌軸体６の半径方向に張り出し状に伸延する上下一対の上・下部横翼片28a,28bと、両上・下部横翼片28a,28bの外側端部間に上下方向に伸延させて介設した縦翼片28cとから中途部が外方に膨出する弧状に形成しており、第３軸22の下部に上部横翼片28aの先端部を取り付ける一方、第２軸21の外周面に回転自在に遊嵌したリング状の内側中間部翼片支持体34に下部横翼片28bの先端部を取り付けて、第３軸22と一体的にａ方向に回転するようにしている。
【００３３】
そして、外側撹拌翼体28は、掘削・攪拌軸体６の下部の円周方向に一定の間隔を開けて三個設けている。35は、縦翼片28cの上部と下部にそれぞれ内方へ突出させて形成した内方突出小翼片であり、これら小翼片35,35の回転軌跡は、内側撹拌翼体27に設けた外方突出小翼片31の回転軌跡と上下方向にオーバーラップするように配置して、相対的に逆回転する内・外側撹拌翼体27,28間において、掘削土の撹拌が確実に行えるようにしている。
【００３４】
ここで、第２軸21の下部でかつ外側撹拌翼体28の下部横翼片28bよりも上方位置に第３改良材吐出部33を設けており、同第３改良材吐出部33は、第２軸21に、同第２軸21の半径方向（放射線方向）に向けて開口する円形状の第３改良材吐出孔33aを形成し、同第３改良材吐出孔33aを第３改良材供給路25に接続して、同第３改良材供給路25を通して供給される改良材を、第３改良材吐出孔33aより第２軸21の半径方向へ向けて吐出するようにしている。
【００３５】
下方に配置した相対撹拌翼部９は、図２及び図４に示すように、最内側に位置する最内側撹拌翼体26'と、同最内側撹拌翼体26'の外周にて相対的に反対方向に回転する内側の撹拌翼体である内側撹拌翼体27'と、同内側撹拌翼体27'の外周にて相対的に反対方向に回転する外側の撹拌翼体である外側撹拌翼体28'とを具備している。
【００３６】
そして、内側撹拌翼体27'と、その外方に配置した外側撹拌翼体28'は、略相似形に形成して、両撹拌翼体27',28'間に形成される間隙を、両撹拌翼体27',28'のほぼ全域にわたってほぼ等しい幅員となすことにより、掘削土の共回り現象を防止することができると共に、緻密な撹拌機能を発揮させることができるようにしている。
【００３７】
最内側撹拌翼体26'は、第２軸21の下端部外周面より放射状に突出させて形成しており、同第２軸21の軸線対称位置に一対設けて、同第２軸21と一体的にｂ方向に回転するようにしている。
【００３８】
内側撹拌翼体27'は、掘削・攪拌軸体６の半径方向に張り出し状に伸延する上下一対の上・下部横翼片27'a,27'bと、両上・下部横翼片27'a,27'bの外側端部間に上下方向に伸延させて介設した縦翼片27'cとから、中途部が外方に膨出する弧状に形成しており、第３軸22の外周面に回転自在に遊嵌したリング状の内側中間部翼片支持体34に上部横翼片27'aの先端部を取り付ける一方、第２軸21の外周面に回転自在に遊嵌したリング状の下部翼片支持体41に下部横翼片27'bの先端部を取り付けて、第３軸22と一体的にａ方向に回転するようにしている。
【００３９】
そして、内側撹拌翼体27'は、第２軸21の下部の軸線対称位置に一対設けている。31'は、縦翼片27'cの中途部より外方へ突出させて形成した外方突出小翼片である。
【００４０】
外側撹拌翼体28'は、掘削・攪拌軸体６の半径方向に張り出し状に伸延する上下一対の上・下部横翼片28'a,28'bと、両上・下部横翼片28'a,28'bの外側端部間に上下方向に伸延させて介設した縦翼片28'cとから中途部が外方に膨出する弧状に形成しており、内側中間部翼片支持体34の外周面に回転自在に遊嵌したリング状の外側中間部翼片支持体42に上部横翼片28'aの先端部を取り付ける一方、第２軸21の外周面に下部横翼片28'bの先端部を取り付けて、第２軸21と一体的にｂ方向に回転するようにしている。
【００４１】
そして、外側撹拌翼体28'は、掘削・攪拌軸体６の下部の円周方向に一定の間隔を開けて三個設けている。35'は、縦翼片28'cの上部と下部にそれぞれ内方へ突出させて形成した内方突出小翼片であり、これら内方小翼片35',35'の回転軌跡は、内側撹拌翼体27'に設けた外方突出小翼片31'の回転軌跡と上下方向にオーバーラップするように配置して、相対的に逆回転する内・外側撹拌翼体27',28'間において、掘削土の撹拌が確実に行えるようにしている。
【００４２】
ここで、第２軸21の下部でかつ外側撹拌翼体28'の下部横翼片28'bよりも上方位置に第２改良材吐出部32を設けており、同第２改良材吐出部32は、第２軸21と第１軸20に、これらの半径方向（放射線方向）に向けて開口する円形状の第２改良材吐出孔32a,32bを符合させて形成し、同第２改良材吐出孔32a,32bを第２改良材供給路24に接続して、同第２改良材供給路24を通して供給される改良材を、第２改良材吐出孔32a,32bより第２軸21の半径方向へ向けて吐出するようにしている。
【００４３】
このようにして、本実施例では、図３〜図５に示すように、相対撹拌翼部８の最内側撹拌翼体26と外側撹拌翼体28とが同一回転方向（ａ方向）に回転すると共に、内側撹拌翼体27がこれらとは反対回転方向（ｂ方向）に回転する一方、相対撹拌翼部９の最内側撹拌翼体26'と外側撹拌翼体28'とが同一回転方向（ｂ方向）に回転すると共に、内側撹拌翼体27'がこれらとは反対回転方向（ａ方向）に回転するようにしている。
【００４４】
従って、内外側の撹拌翼同士が相対撹拌すると共に、上下側の撹拌翼体同士も相対撹拌して、掘削土と改良材とを効率良く均質に撹拌・混練することができるようにしている。
【００４５】
掘削刃体10は、第１軸20の下端部に取り付けており、同掘削刃体10の回転中心部に第１改良材吐出部29を設けている。
【００４６】
そして、第１改良材吐出部29は、掘削刃体10の回転中心部に下方へ向けて開口する円形状の第１改良材吐出孔29aを形成し、同第１改良材吐出孔29aを第１改良材供給路23に接続して、同第１改良材供給路23を通して供給される改良材を、第１改良材吐出孔29aより直下方へ向けて吐出するようにしている。
【００４７】
〔地盤改良工法の説明〕
次に、上記のように構成した地盤改良装置Ａにより軟弱な地盤や汚染された土壌ないし地盤（以下「地盤Ｇ」という）を改良する工法について説明する。
【００４８】
すなわち、地盤Ｇを改良する際には、図１に示すように、地盤改良現場にベースマシン１を移動させることにより、リーダ４を建て込み、同リーダ４に沿わせて掘削・攪拌軸体６を回転させながら下降させることにより、地盤Ｇを掘削刃体10により掘削すると共に、相対撹拌翼部8,9により掘削土を撹拌する。
【００４９】
そして、改良材供給部２より改良材を改良材供給ホース11→第１・第２・第３改良材供給路23,24,25→第１・第２・第３改良材吐出部29,32,33に供給して、各改良材吐出部29,32,33より改良材を吐出させることにより、かかる改良材を相対撹拌翼部8,9により掘削土中に均一に撹拌して掘削土を改良し、図６に示すように、地盤Ｇ中に、柱状の地盤改良部ｋを築造することができ、かかる地盤改良部ｋを前後左右方向に連続して形成することにより、地盤Ｇを改良することができる。
【００５０】
この際、掘削・攪拌軸体６の下部周面に、二個の相対撹拌翼部8,9を上下方向に隣接させて同軸的に取り付けているため、上記掘削・攪拌軸体６の上下伸延方向にて広範囲に撹拌を行うことができて、地盤改良作業を効率良く短時間に完了させることができる。
【００５１】
しかも、各相対撹拌翼部8,9は、それぞれ弧状に形成した内側撹拌翼体27,27'と、その外方に配置すると共に弧状に形成した外側撹拌翼体28,28'と、内側撹拌翼体27,27'の内方に配置すると共に棒状に形成した最内側撹拌翼体26,26'とから形成して、内側撹拌翼体27,27'の回転方向に対して、外側撹拌翼体28,28'と最内側撹拌翼体26,26'の回転方向を反対方向となすことにより、これら三枚の撹拌翼体26,26',27,27',28,28'の間で相対撹拌（相対的に反対方向に回転させて行う撹拌）が行われて、掘削土に対するせん断力、特に、内側撹拌翼体27,27'と外側撹拌翼体28,28'との間に作用するせん断力が向上し、粘性土の高い掘削土に対しても共回り現象（掘削土が掘削・攪拌軸体と一体的に回転する現象）や団子化現象（掘削土が撹拌棒を包み込む形の団子状態となる現象）を起こすことなく、掘削土と改良材との撹拌・混練を均質にかつ確実に行うことができる。
【００５２】
さらには、上下方向に隣接する各相対撹拌翼部8,9の外側撹拌翼体28,28'同士が相対的に反対方向に回転するように取り付けているため、上方の外側撹拌翼体28と下方の外側撹拌翼体28'との間にもせん断力を作用させることができて、掘削・攪拌軸体６の上下伸延方向においても、広範囲に掘削土と改良材との撹拌・混練を均質にかつ確実に行うことができる。
【００５３】
なお、改良材としては、セメントミルク等の固化材に限らず、汚染土壌との有害物質を中和・消滅・浄化させて無害化する化学剤ないしは薬剤を使用することもできる。
【００５４】
〔第１実施例の変容例〕
図７及び図８は、前記した第１実施例における相対撹拌翼部8,9の変容例を示しており、同相対撹拌翼部8,9は、前記した第１実施例の相対撹拌翼部8,9と基本的構造を同じくしているが、以下の点において異なる。
【００５５】
すなわち、図７及び図８に示すように、上方に配置した相対撹拌翼部８の内側撹拌翼体27は、第３軸22の外周面に回転自在に遊嵌したリング状の上部翼片支持体30に上部横翼片27aの先端部を取り付ける一方、第３軸22の外周面に回転自在に遊嵌したリング状の内側中間部翼片支持体34に下部横翼片27bの先端部を取り付けて、第２軸21と一体的にｂ方向に回転するようにしている。
【００５６】
外側撹拌翼体28は、第３軸22の下部に上部横翼片28aの先端部を取り付ける一方、内側中間部翼片支持体34の外周面に回転自在に遊嵌したリング状の外側中間部翼片支持体42に下部横翼片28bの先端部を取り付けて、第３軸22と一体的にａ方向に回転するようにしている。
【００５７】
図７及び図８に示すように、下方に配置した相対撹拌翼部９の内側撹拌翼体27'は、第３軸22の外周面に上部横翼片27'aの先端部を取り付ける一方、第２軸21の外周面に回転自在に遊嵌したリング状の下部翼片支持体41に下部横翼片27'bの先端部を取り付けて、第３軸22と一体的にａ方向に回転するようにしている。
【００５８】
外側撹拌翼体28'は、外側中間部翼片支持体42に上部横翼片28'aの先端部を取り付ける一方、第２軸21の外周面に下部横翼片28'bの先端部を取り付けて、第２軸21と一体的にｂ方向に回転するようにしている。
【００５９】
このようにして、本実施例にかかる相対撹拌翼部8,9でも前記した第１実施例にかかる相対撹拌翼部8,9と同様に効率的に地盤改良が行えるようにしている。
【００６０】
〔第２実施例〕
図９及び図１０は、第２実施例としての相対撹拌翼部8,9を示しており、同相対撹拌翼部8,9は、前記した第１実施例としての相対撹拌翼部8,9と基本的構造を同じくしているが、上方に位置する相対撹拌翼部８の外側撹拌翼体28から下方へ向けて小翼片としての下方突出小翼片60,61を突設する一方、下方に隣接する相対撹拌翼部９の外側撹拌翼体28'から上方へ向けて小翼片としての上方突出小翼片62を突設して、両小翼片60,61,62を内外側方向に一部が重複状態となるように配置している点で異なる。
【００６１】
すなわち、図９及び図１０に示すように、上方の外側撹拌翼体28の下部横翼片28bに複数（本実施例では二枚）の下方突出小翼片60,61を内外側方向に一定の間隔を開けて配置すると共に、両下方突出小翼片60,61を下方へ向けて突出させて形成している。
【００６２】
また、下方の外側撹拌翼体28'の上部横翼片28'aに上方突出小翼片62を上方へ向けて突出させて形成すると共に、同上方突出小翼片62の先端部62aと上記下方突出小翼片60,61の先端部60a,61aとが各回転軌跡内にて内外側方向（掘削・攪拌軸体６の放射線方向）に重複するようにしている。
【００６３】
このようにして、上下方向に隣接する外側撹拌翼体28,28'を相対撹拌させることにより、両撹拌翼体28,28'に上下方向に突設した内外側の下方突出小翼片60,61と上方突出小翼片62との間に位置する掘削土にせん断力を作用させることができて、上下方向に隣接する外側撹拌翼体28の下部横翼片28bと外側撹拌翼体28'の上部横翼片28'aとの間においても、掘削土と改良材との撹拌・混練を確実に行うことができる。
【００６４】
その結果、上下方向に隣接する相対撹拌翼部8,9により、掘削土と改良材との撹拌・混練を確実に行うことができると共に、上下方向に隣接する相対撹拌翼部8,9の間においても掘削土と改良材との撹拌・混練を確実に行うことができて、掘削・攪拌軸体６の上下伸延方向の広範囲において、地盤改良作業を効率良く短時間に完了させることができる。
【００６５】
しかも、各小翼片60,61,62の横断面幅を中央部60b,61b,62bから回転方向側の端面60c,61c,62cに向けて漸次細幅に形成して、少なくとも隣接する小翼片側の側面をテーパー面60d,60e,61d,61e,61f,61g,62d,62e,62f,62gとなしている。
【００６６】
すなわち、外側の下方突出小翼片60には、内側面にテーパー面60d,60eを形成しており、また、内側の下方突出小翼片61には、内外側面にそれぞれテーパー面61d,61e,61f,61gを形成しており、また、上方突出小翼片62には、内外側面にそれぞれテーパー面62d,62e,62f,62gを形成している。
【００６７】
このようにして、各小翼片60,61,62により掘削土を撹拌すると共に、掘削土をテーパー面60d,60e,61d,61e,61f,61g,62d,62e,62f,62gに沿わせて隣接する小翼片側へスムーズに案内して、掘削土と改良材とを円滑かつ確実に撹拌することができるようにしている。c,d,e,f,gは、それぞれ回転方向側のテーパー面60d,61d,61e,62d,62eに沿って流動する掘削土の流動方向を示している。
【００６８】
その結果、上下方向に隣接する外側撹拌翼体28,28'の間における掘削土と改良材との撹拌・混練をより一層確実に行うことができて、掘削・攪拌軸体６の上下伸延方向の広範囲において、地盤改良作業をより一層効率良く短時間に完了させることができる。
【００６９】
〔第３実施例〕
図１１及び図１２は、第３実施例としての相対撹拌翼部8,9を示しており、同相対撹拌翼部8,9は、前記した第１実施例としての相対撹拌翼部8,9と基本的構造を同じくしているが、内側撹拌翼体27,27'の下部横翼片27b,27'bと外側撹拌翼体28,28'の下部横翼片28b,28'bとに、それぞれ下方へ向けて複数（本実施例では二枚）の下方突出案内翼片70,70',71,71'を突設している点において異なる。
【００７０】
すなわち、各下方突出案内翼片70,70',71,71'は、回転軌跡に対して回転方向側の端面70a,70'a,71a,71'aがやや内方に位置するように傾斜姿勢となして、各下方突出案内翼片70,70',71,71'の側面に沿って掘削土が外方（掘削・攪拌軸体６から離隔する方向）に案内されるようにしている。h,iは、それぞれ掘削土が各下方突出案内翼片70,70',71,71'の側面に案内される方向を示している。
【００７１】
このようにして、内側撹拌翼体27,27'の下部横翼片27b,27'bと外側撹拌翼体28,28'の下部横翼片28b,28'bとに、それぞれ下方突出案内翼片70,70',71,71'を突設して、各下方突出案内翼片70,70',71,71'の側面に沿って掘削土が外方に案内されるようにしているいるため、内側撹拌翼体27,27'の下部横翼片27b,27'bと外側撹拌翼体28,28'の下部横翼片28b,28'bの近傍に配設した第２・第３改良材吐出部32,33から吐出される改良材を、外側撹拌翼体28,28'の縦翼片28c,28'cの近傍までスムーズに案内することができて、同改良材と掘削土を効率良く均質に混練することができる。
【００７２】
〔第４実施例〕
図１３及び図１４は、第４実施例としての相対撹拌翼部8,9を示しており、同相対撹拌翼部8,9は、前記した第１実施例としての相対撹拌翼部8,9と基本的構造を同じくしているが、外側撹拌翼体28,28'の近傍にそれぞれ第４・第５改良材吐出部50,51を設けている点で異なる。
【００７３】
すなわち、第４改良材吐出部50は、外側撹拌翼体28の縦翼片28cの背面（回転方向側の面とは反対側の面）に上下方向に伸延する第４改良材吐出孔50aを形成しており、同第４改良材吐出孔50aは、縦翼片28cと下部横翼片28bと外側中間部翼片支持体42と第２軸21とにわたって形成した改良材導入路52を通して第３改良材供給路25に接続して、第４改良材吐出孔50aより改良材を縦翼片28cが描く回転軌跡の接線方向に吐出させるようにしている。ｊは、改良材吐出方向を示している。
【００７４】
ここで、第３改良材吐出部33の第３改良材吐出孔33aには加圧開放弁53を設けて、同加圧開放弁53が所定の圧力以上に加圧された場合に開弁して改良材が吐出されるようにしている。
【００７５】
このようにして、第４改良材吐出部50よりも上流側において第３改良材供給路25に接続している第３改良材吐出部33からだけ改良材が吐出されて、第４改良材吐出部50からは改良材が吐出されないという不具合を解消すると共に、両吐出部33,50からそれぞれ所要量の改良材が吐出されるようにしている。
【００７６】
また、第５改良材吐出部51は、外側撹拌翼体28'の縦翼片28'cの背面（回転方向側の面とは反対側の面）に上下方向に伸延する第５改良材吐出孔51aを形成しており、同第５改良材吐出孔51aは、縦翼片28'cと下部横翼片28'bと第２軸21と第１軸20とにわたって形成した改良材導入路54を通して第２改良材供給路24に接続して、第５改良材吐出孔51aより改良材を縦翼片28'cが描く回転軌跡の接線方向に吐出させるようにしている。
【００７７】
ここで、第２改良材吐出部32の第２改良材吐出孔32aには加圧開放弁55を設けて、同加圧開放弁55が所定の圧力以上に加圧された場合に開弁して改良材が吐出されるようにしている。
【００７８】
このようにして、第５改良材吐出部51よりも上流側において第２改良材供給路24に接続している第２改良材吐出部32からだけ改良材が吐出されて、第５改良材吐出部51からは改良材が吐出されないという不具合を解消すると共に、両吐出部32,51からそれぞれ所要量の改良材が吐出されるようにしている。
【００７９】
従って、本実施例では、掘削・攪拌軸体６の下部周面に取り付けた各相対撹拌翼部8,9により掘削土を撹拌しながら、掘削・攪拌軸体６に設けた第２・第３改良材吐出部32,33と外側撹拌翼体28,28'の縦翼片28c,28'cに設けた第４・第５改良材吐出部50,51とからそれぞれ改良材を吐出することにより、掘削・攪拌軸体６と外側撹拌翼体28,28'との間で撹拌される掘削土と改良材とを、短時間に効率良く均質に混練することができる。
【００８０】
また、本実施例に係る外側撹拌翼体28,28'の近傍にそれぞれ第４・第５改良材吐出部50,51を設ける構造は、前記した第１実施例の変容例や第２・第３実施例に適用することにより、掘削・攪拌軸体６と外側撹拌翼体28,28'との間で撹拌される掘削土と改良材とを、より一層短時間に効率良く均質に混練することもできる。
【００８１】
【発明の効果】
（１）請求項１記載の本発明では、地盤を掘削・撹拌しながら改良材を吐出して、同改良材と掘削土とを混練することにより地盤改良を行うようにした地盤改良装置において、上下方向に伸延する第１軸と、同第１軸の外周を囲繞する第２軸と、同第２軸の外周を囲繞する第３軸とからなる三重軸構造の掘削・攪拌軸体の下部周面に、２つの相対撹拌翼部を上下方向に隣接させて同軸的に取り付けると共に、各相対撹拌翼部は、掘削・攪拌軸体に中途部を外方へ膨出させて弧状に形成した複数の撹拌翼体を内外側に配置すると共に最内側に位置する最内側撹拌翼体を配置し、かつ、同掘削・攪拌軸体の軸線廻りに相対的に反対方向に回転するように取り付け、かつ、上下方向に隣接する各相対撹拌翼部の外側の撹拌翼体同士が相対的に反対方向に回転するように取り付け、２つの相対撹拌翼部のうち、上に位置する相対撹拌翼部の外側撹拌翼体の端部を第３軸に取り付け、外側撹拌翼体とは相対的に反対方向に回転する内側撹拌翼体の端部を第２軸に取り付け、最内側撹拌翼体を第３軸の外周面から放射状に突出させている。
【００８２】
このようにして、掘削・攪拌軸体の下部周面に、複数の相対撹拌翼部を上下方向に隣接させて同軸的に取り付けているため、上記掘削・攪拌軸体の上下伸延方向にて広範囲に撹拌を行うことができて、地盤改良作業を効率良く短時間に完了させることができる。
【００８３】
この際、各相対撹拌翼部を形成する複数の撹拌翼体は、中途部が外方へ膨出する弧状に形成して掘削・攪拌軸体に内外側に配置し、かつ、同掘削・攪拌軸体の軸線廻りに相対的に反対方向に回転するように取り付けているため、かかる複数の撹拌翼体を相対撹拌（相対的に反対方向に回転させて行う撹拌）させることにより、掘削土に対するせん断力、特に、内側の撹拌翼体と外側の撹拌翼体との間に作用するせん断力が向上し、粘性土の高い掘削土に対しても共回り現象（掘削土が掘削・攪拌軸体と一体的に回転する現象）や団子化現象（掘削土が撹拌棒を包み込む形の団子状態となる現象）を起こすことなく、掘削土と改良材との撹拌・混練を確実に行うことができる。
【００８４】
しかも、上下方向に隣接する各相対撹拌翼部の外側の撹拌翼体同士が相対的に反対方向に回転するように取り付けているため、上方の撹拌翼体と下方の撹拌翼体との間にせん断力を作用させることができて、掘削・攪拌軸体の上下伸延方向においても、広範囲に掘削土と改良材との撹拌・混練を確実に行うことができる。
【００８５】
（２）請求項２記載の本発明では、地盤を掘削・撹拌しながら改良材を吐出して、同改良材と掘削土とを混練することにより地盤改良を行うようにした地盤改良装置において、上下方向に伸延する第１軸と、同第１軸の外周を囲繞する第２軸と、同第２軸の外周を囲繞する第３軸とからなる三重軸構造の掘削・攪拌軸体の下部周面に、２つの相対撹拌翼部を上下方向に隣接させて同軸的に取り付けると共に、各相対撹拌翼部は、掘削・攪拌軸体の軸線廻りに内外側にて相対的に反対方向に回転する複数の撹拌翼体を具備すると共に最内側に位置する最内側撹拌翼体を配置し、上下方向に隣接する各相対撹拌翼部の外側の撹拌翼体は、それぞれ中途部を外方へ膨出させて弧状に形成し、かつ、相対的に反対方向に回転するようにし、上方に位置する外側の撹拌翼体から下方へ向けて小翼片を突設する一方、下方に隣接する外側の撹拌翼体から上方へ向けて小翼片を突設して、両小翼片を内外側方向に一部が重複状態となるように配置し、２つの相対撹拌翼部のうち、上に位置する相対撹拌翼部の外側撹拌翼体の端部を第３軸に取り付け、外側撹拌翼体とは相対的に反対方向に回転する内側撹拌翼体の端部を第２軸に取り付け、最内側撹拌翼体を第３軸の外周面から放射状に突出させている。
【００８６】
このようにして、上方に位置する外側の撹拌翼体から下方へ向けて小翼片を突設する一方、下方に隣接する外側の撹拌翼体から上方へ向けて小翼片を突設して、両小翼片を内外側方向に一部が重複状態となるように配置しているため、上下方向に隣接する外側の撹拌翼体を相対撹拌させることにより、両撹拌翼体に上下方向に突設した内外側の小翼片の間に位置する掘削土にせん断力を作用させることができて、上下方向に隣接する外側の撹拌翼体の間においても、掘削土と改良材との撹拌・混練を確実に行うことができる。
【００８７】
その結果、上下方向に隣接する複数の相対撹拌翼部により、掘削土と改良材との撹拌・混練を確実に行うことができると共に、上下方向に隣接する複数の相対撹拌翼部の間においても掘削土と改良材との撹拌・混練を確実に行うことができて、掘削・攪拌軸体の上下伸延方向の広範囲において、地盤改良作業を効率良く短時間に完了させることができる。
【００８８】
（３）請求項３記載の本発明では、２つの相対撹拌翼部のうち、上に位置する相対撹拌翼部の外側撹拌翼体は、掘削・攪拌軸体の半径方向に張り出し状に伸延する上下一対の上・下部横翼片と、両上・下部横翼片の外側端部間に上下方向に伸延させて介設した縦翼片とからなるものであり、第２軸の下部でかつ外側撹拌翼体の下部横翼片よりも上方位置に、改良材吐出部を設けている。
【００８９】
このようにして、各小翼片により掘削土を撹拌すると共に、掘削土をテーパー面に沿わせて隣接する小翼片側へスムーズに案内して、掘削土と改良材とを円滑かつ確実に撹拌することができるようにしている。
【００９０】
その結果、上下方向に隣接する複数の相対撹拌翼部の間における掘削土と改良材との撹拌・混練をより一層確実に行うことができて、掘削・攪拌軸体の上下伸延方向の広範囲において、地盤改良作業をより一層効率良く短時間に完了させることができる。
【００９１】
（４）請求項４記載の本発明では、各相対撹拌翼部は、掘削・攪拌軸体より半径方向に伸延する棒状の撹拌翼体を具備し、同棒状の撹拌翼体は、弧状に形成した内側の撹拌翼体の内方において、外側の撹拌翼体と同一方向に回転するようにしている。
【００９２】
このようにして、各相対撹拌翼部を、弧状に形成した内側の撹拌翼体と、その外方に配置すると共に弧状に形成した外側の撹拌翼体と、内側の撹拌翼体の内方に配置すると共に棒状に形成した撹拌翼体とから形成して、内側の撹拌翼体の回転方向に対して、外側の撹拌翼体と棒状の撹拌翼体の回転方向を反対方向となすことにより、これら三枚の撹拌翼体の間で相対撹拌がなされるようにしている。
【００９３】
その結果、各相対撹拌翼部における掘削土と改良材との撹拌・混練を、より一層確実に行うことができて、地盤改良作業をより一層効率良く短時間に完了させることができる。
【００９４】
（５）請求項５記載の本発明では、掘削・攪拌軸体の近傍と外側の撹拌翼体の近傍とにそれぞれ改良材吐出部を設けている。
【００９５】
このようにして、掘削・攪拌軸体の下部周面に取り付けた各相対撹拌翼部により掘削土を撹拌しながら、掘削・攪拌軸体の近傍に設けた改良材吐出部と外側の撹拌翼体の近傍に設けた改良材吐出部とからそれぞれ改良材を吐出することにより、掘削・攪拌軸体と外側撹拌翼体との間で撹拌される掘削土と改良材とを、短時間に効率良く均質に混練することができる。
【図面の簡単な説明】
【図１】本発明に係る地盤改良装置の側面説明図。
【図２】掘削・攪拌軸体と相対撹拌翼部の一部切欠側面図。
【図３】同掘削・攪拌軸体と相対撹拌翼部の断面底面説明図。
【図４】同掘削・攪拌軸体と相対撹拌翼部の底面説明図。
【図５】同掘削・攪拌軸体と相対撹拌翼部の断面側面説明図。
【図６】地盤改良説明図。
【図７】第１実施例の変容例としての掘削・攪拌軸体と相対撹拌翼部の一部切欠側面図。
【図８】同掘削・攪拌軸体と相対撹拌翼部の断面側面説明図。
【図９】第２実施例としての掘削・攪拌軸体と相対撹拌翼部の一部切欠側面図。
【図１０】図９のＩ-Ｉ線断面平面説明図。
【図１１】第３実施例としての掘削・攪拌軸体と相対撹拌翼部の一部切欠側面図。
【図１２】図１１のII-II線断面平面説明図。
【図１３】第４実施例としての掘削・攪拌軸体と相対撹拌翼部の一部切欠側面図。
【図１４】同掘削・攪拌軸体と相対撹拌翼部の断面平面説明図。
【符号の説明】
Ａ地盤改良装置
１ベースマシン
２改良材供給部
３ベースマシン本体
４リーダ
５モータ支持体
６掘削・攪拌軸体
７反転歯車機構
８相対撹拌翼部
９相対撹拌翼部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ground improvement device.
[0002]
[Prior art]
Conventionally, as one form of ground improvement device, a relative stirring blade is attached to the lower peripheral surface of a drilling / stirring shaft extending in the vertical direction, and a drilling blade is attached to the lower end of the drilling / stirring shaft. There is one in which an improved material discharge part is provided on the lower peripheral surface of the excavation / stirring shaft (for example, see Patent Document 1).
[0003]
The relative stirring blade portion is formed by attaching inner and outer stirring blade bodies formed in an arc shape to the excavation / stirring shaft body so as to rotate relatively in the opposite directions.
[0004]
In this way, while excavating the ground with the excavating blade body, the soil excavated by the inner and outer agitating blade bodies of the relative agitating blade part is relatively agitated, and the improving material is discharged from the improving material discharging part. And the ground is improved by kneading with excavated soil.
[0005]
[Patent Document 1]
JP-A-3-63312
[0006]
[Problems to be solved by the invention]
However, it is desired to complete the ground improvement work more effectively and in a short time, and improvement of the ground improvement apparatus that performs such work is desired.
[0007]
[Means for Solving the Problems]
Therefore, in the present invention, in the ground improvement device in which the ground improvement is performed by discharging the improvement material while excavating and stirring the ground and kneading the improvement material and the excavated soil, the vertical extension is performed.A triple-axis structure comprising a first axis, a second axis that surrounds the outer periphery of the first axis, and a third axis that surrounds the outer periphery of the second axisOn the lower peripheral surface of the drilling and stirring shaft body,TwoA plurality of stirring blade bodies formed in an arc shape with the relative stirring blade portions being coaxially attached adjacent to each other in the vertical direction, and each of the relative stirring blade portions bulging the midway portion outwardly on the excavation / stirring shaft body Inside and outsideThe innermost stirring wing that is positioned and located on the innermost side.Placed and mounted so as to rotate in opposite directions around the axis of the excavation / stirring shaft, and the stirrer blades outside the relative stirrer blades adjacent in the vertical direction are relatively Install to rotate in the opposite direction,Of the two relative agitation blades, the inner agitation blade body is attached to the third shaft at the end of the outer agitation blade body of the upper relative agitation blade part and rotates in a direction opposite to the outer agitation blade body. The end of the shaft is attached to the second shaft, and the innermost stirring blade is projected radially from the outer peripheral surface of the third shaft.The ground improvement apparatus characterized by the above is provided.
[0008]
Here, the “arc shape” which is the shape of the stirring blade body is not limited to a substantially arc shape having no corners, but is substantially a triangle arc shape having one corner, and a substantially square arc shape having two corners (this embodiment) The shape according to the example), and a substantially polygonal arc shape having three or more corners are also included.
[0009]
The present invention is also characterized by the following configuration.
[0010]
(1) In a ground improvement device that performs ground improvement by discharging the improved material while excavating and stirring the ground, and kneading the improved material and the excavated soil, it extends vertically.A triple-axis structure comprising a first axis, a second axis that surrounds the outer periphery of the first axis, and a third axis that surrounds the outer periphery of the second axisOn the lower peripheral surface of the drilling and stirring shaft body,TwoThe relative agitation blades are coaxially mounted adjacent to each other in the vertical direction, and each of the agitation blades rotates in the opposite direction around the axis of the excavation and agitation shaft body in the opposite direction. BodyAnd the innermost stirring blade located on the innermost sideThe stirring blade bodies outside the relative stirring blade portions adjacent to each other in the vertical direction are formed in an arc shape with the middle portions bulging outward, and are rotated in the opposite directions. The winglet piece protrudes downward from the outer stirring wing body located at the lower side, while the winglet piece protrudes upward from the outer stirring wing body adjacent to the lower side, Arrange so that part is overlapped in the inner and outer direction,Of the two relative agitation blades, the inner agitation blade body is attached to the third shaft at the end of the outer agitation blade body of the upper relative agitation blade part and rotates in a direction opposite to the outer agitation blade body. The end of the shaft is attached to the second shaft, and the innermost stirring blade is projected radially from the outer peripheral surface of the third shaft.Was it.
[0011]
(2)Out of the two relative agitating blades, the outer agitating blade body of the upper relative agitating blade portion includes a pair of upper and lower horizontal wing pieces extending in the radial direction of the excavating and agitating shaft body, It consists of a vertical wing piece that extends vertically between the outer end portions of the upper and lower horizontal wing pieces, above the lower horizontal wing piece at the lower part of the second shaft and on the outer stirring blade body. The improved material discharge part is provided at the position.thing.
[0012]
(3) Each of the relative stirring blades has a rod-shaped stirring blade extending radially from the excavation / stirring shaft, and the rod-shaped stirring blade is inward of the inner stirring blade formed in an arc shape. In the same direction as the outer stirring blade body.
[0013]
(4) Improved material discharge portions are provided in the vicinity of the excavation / stirring shaft body and in the vicinity of the outer stirring blade body.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0015]
That is, the ground improvement device according to the present invention has a plurality of relative stirring blades coaxially attached to the lower peripheral surface of the excavation / stirring shaft body extending in the vertical direction, adjacent to each other in the vertical direction, and each relative stirring blade. The excavating / stirring shaft body has a plurality of stirring blades that are formed in an arc shape by expanding the middle part outwardly, and relatively around the axis of the excavating / stirring shaft body The rotating blades are attached so as to rotate in opposite directions, and are attached so that the stirring blade bodies outside the relative stirring blade portions adjacent to each other in the vertical direction relatively rotate in opposite directions.
[0016]
In addition, each of the relative stirring blades includes a rod-shaped stirring blade extending in the radial direction from the excavation / stirring shaft body, and the rod-shaped stirring blade is formed inward of the inner stirring blade formed in an arc shape. The outer stirring blade body rotates in the same direction.
[0017]
Further, in the configuration as described above, improvement material discharge portions are provided in the vicinity of the excavation / stirring shaft body and the vicinity of the outer stirring blade body, respectively.
[0018]
Further, the ground improvement device according to the present invention includes a plurality of relative stirring blades which are coaxially attached to the lower peripheral surface of the excavation / stirring shaft body extending in the vertical direction so as to be adjacent to each other in the vertical direction. The section includes a plurality of stirring blades that rotate in opposite directions on the inner and outer sides around the axis of the excavation / stirring shaft body, and the stirring blade bodies outside the relative stirring blade portions adjacent in the vertical direction are In each case, the middle part bulges outward to form an arc shape, and rotates relatively in the opposite direction, and a small blade piece protrudes downward from the outer stirring blade body located above On the other hand, a small blade piece protrudes upward from an outer stirring blade body adjacent to the lower side, and both small blade pieces are arranged so as to be partially overlapped in the inner and outer directions.
[0019]
In addition, the cross-sectional width of each winglet piece is gradually narrowed from the central portion toward the end surface on the rotation direction side, and at least the side surface on the side of the adjacent winglet piece is a tapered surface.
[0020]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0021]
[First embodiment]
A shown in FIG. 1 is a ground improvement device as a first embodiment according to the present invention, and the ground improvement device A is equipped with a base machine 1 and an improvement material supply unit 2.
[0022]
The base machine 1 includes a self-propelled base machine body 3 provided with a leader 4 extending in the vertical direction. A motor support 5 is attached to the leader 4 so as to be movable up and down, and a driving motor M is mounted on the motor support 5. Then, an upper end portion of the excavation / stirring shaft body 6 extending in the vertical direction is detachably attached to the driving motor M via the reverse gear mechanism 7, and a plurality ( In this embodiment, two) relative agitation blades 8 and 9 are coaxially attached adjacent to each other in the vertical direction, and an excavation blade body 10 is attached to the lower end of the excavation and agitation shaft body 6.
[0023]
The improvement material supply unit 2 includes an improvement material storage tank and an improvement material supply pump (not shown), and connects the base end portion of the improvement material supply hose 11 to the improvement material supply pump. Are connected to the excavation / stirring shaft body 6.
[0024]
As shown in FIGS. 2 to 4, the excavation / stirring shaft body 6 is formed in a vertical direction so as to surround a cylindrical first shaft 20 formed by extending in the vertical direction and an outer periphery of the first shaft 20. A cylindrical second shaft 21 formed by extension and a third shaft 22 formed by extending in the vertical direction so as to surround the outer periphery of the second shaft constitute an inner / outer triple axis structure, The first to third shafts 20, 21, and 22 are rotated about the same axis by the drive motor M via the reversing gear mechanism 7 and to the first and third shafts 20, 22. The second shaft 21 rotates in the opposite direction.
[0025]
A cylindrical improvement material supply path forming body 19 formed by extending in the vertical direction is inserted into the first shaft 20, and a first improvement material supply path 23 is inserted into the improvement material supply path formation body 19. The second improved material supply path 24 is formed between the outer peripheral surface of the improved material supply path forming body 19 and the inner peripheral surface of the first shaft 20, and the outer peripheral surface of the first shaft 20 and the second shaft are formed. A third improved material supply path 25 is formed between the inner peripheral surface of 21.
[0026]
Here, the base end portion of the improved material supply hose 11 is connected to the upstream end portions of the first to third improved material supply paths 23, 24, 25, and the improved material supply unit 2 supplies the improved material. The improvement material is supplied into the respective improvement material supply paths 23, 24, and 25 through the hose 11. In FIG. 2, 12 and 13 are swivel joints.
[0027]
As shown in FIGS. 2 and 3, the relative stirring blade portion 8 disposed above is relatively opposite to the innermost stirring blade body 26 located on the innermost side and the outer periphery of the innermost stirring blade body 26. An inner stirring blade body 27 that is an inner stirring blade body that rotates in the same direction, and an outer stirring blade body 28 that is an outer stirring blade body that rotates in the opposite direction on the outer periphery of the inner stirring blade body 27. is doing.
[0028]
The inner agitating blade body 27 and the outer agitating blade body 28 arranged outside the inner agitating blade body 27 are formed in a substantially similar shape, and a gap formed between the both agitating blade bodies 27, 28 is formed between the two agitating blade bodies 27. , 28, the jointing phenomenon of the excavated soil can be prevented and a precise stirring function can be exhibited.
[0029]
The innermost agitating blade body 26 is formed so as to protrude radially from the outer peripheral surface of the lower end portion of the third shaft 22, and is provided in a pair at symmetrical positions with respect to the third shaft 22 so as to be integrated with the third shaft 22. To rotate in the direction a.
[0030]
The inner stirring blade body 27 includes a pair of upper and lower lateral blade pieces 27a and 27b extending in a radial manner extending in the radial direction of the excavation and stirring shaft body 6, and outer end portions of both upper and lower lateral blade pieces 27a and 27b. A ring shape in which a midway part is formed in an arc shape that bulges outward from a vertical wing piece 27c that is vertically extended in between, and is freely loosely fitted on the outer peripheral surface of the third shaft 22. The tip of the upper horizontal wing piece 27a is attached to the upper wing piece support 30 of the upper side, while the tip of the lower horizontal wing piece 27b is attached to the outer peripheral surface of the second shaft 21 so as to be integrated with the second shaft 21 in the b direction. To rotate.
[0031]
A pair of inner stirring blade bodies 27 are provided at positions symmetrical with respect to the axis below the second shaft 21. Reference numeral 31 denotes an outwardly projecting small blade piece that protrudes outward from the middle portion of the vertical blade piece 27c.
[0032]
The outer agitating blade body 28 includes a pair of upper and lower horizontal wing pieces 28a and 28b extending in the radial direction of the excavating and agitating shaft body 6, and outer end portions of both upper and lower horizontal wing pieces 28a and 28b. An intermediate part is formed in an arc shape that bulges outward from a vertical blade piece 28c that is vertically extended between them, and the tip of the upper horizontal blade piece 28a is attached to the lower part of the third shaft 22 On the other hand, the tip of the lower horizontal wing piece 28b is attached to the ring-shaped inner intermediate wing piece support 34 that is freely loosely fitted on the outer peripheral surface of the second shaft 21, and the a direction is integrated with the third shaft 22 in the a direction. To rotate.
[0033]
Three outer stirring blade bodies 28 are provided at regular intervals in the circumferential direction below the excavation / stirring shaft body 6. 35 is an inwardly projecting small blade piece formed by projecting inward at the upper and lower portions of the vertical blade piece 28c, and the rotation trajectory of these small blade pieces 35 and 35 is provided on the inner stirring blade body 27. Arranged so as to overlap the rotation trajectory of the outwardly projecting small blade piece 31 in the vertical direction so that the excavated soil can be reliably stirred between the inner and outer stirring blade bodies 27 and 28 that rotate in the opposite directions. I have to.
[0034]
Here, the third improvement material discharge part 33 is provided at a position below the second shaft 21 and above the lower horizontal blade piece 28b of the outer stirring blade body 28. A circular third improvement material discharge hole 33a that opens in the radial direction (radiation direction) of the second shaft 21 is formed in the two shafts 21, and the third improvement material discharge holes 33a are supplied to the third improvement material. The improvement material that is connected to the passage 25 and supplied through the third improvement material supply passage 25 is discharged in the radial direction of the second shaft 21 from the third improvement material discharge hole 33a.
[0035]
As shown in FIGS. 2 and 4, the relative stirring blade portion 9 disposed below is relatively positioned on the innermost stirring blade body 26 ′ located on the innermost side and on the outer periphery of the innermost stirring blade body 26 ′. An inner stirring blade body 27 ′ that is an inner stirring blade body that rotates in the opposite direction and an outer stirring blade body that is an outer stirring blade body that rotates in the opposite direction on the outer periphery of the inner stirring blade body 27 ′. 28 '.
[0036]
The inner stirring blade body 27 ′ and the outer stirring blade body 28 ′ disposed outside the inner stirring blade body 27 ′ are formed in a substantially similar shape so that a gap formed between the two stirring blade bodies 27 ′ and 28 ′ By making the width almost equal over almost the entire area of the stirring blades 27 'and 28', the co-rotation phenomenon of the excavated soil can be prevented and a precise stirring function can be exhibited.
[0037]
The innermost stirring blade body 26 ′ is formed so as to protrude radially from the outer peripheral surface of the lower end portion of the second shaft 21. A pair of the innermost stirring blade bodies 26 ′ are provided at symmetrical positions with respect to the second shaft 21, and are integrated with the second shaft 21. In general, it rotates in the b direction.
[0038]
The inner stirring blade body 27 ′ includes a pair of upper and lower horizontal blade pieces 27′a and 27′b extending in the radial direction of the excavation and stirring shaft body 6, and both upper and lower horizontal blade pieces 27 ′. From the vertical wing piece 27'c that is vertically extended between the outer end portions of a and 27'b, an intermediate portion is formed in an arc shape that bulges outward, and the third shaft 22 The tip of the upper horizontal wing piece 27'a is attached to the ring-shaped inner intermediate wing piece support 34 that is freely loosely fitted to the outer peripheral surface, and the ring that is freely loosely fitted to the outer peripheral surface of the second shaft 21 A tip portion of the lower horizontal wing piece 27 ′ b is attached to the lower wing piece support body 41, and rotates integrally with the third shaft 22 in the direction a.
[0039]
A pair of inner agitating blade bodies 27 ′ are provided at symmetrical positions on the lower axis of the second shaft 21. 31 ′ is an outwardly projecting small blade formed by projecting outward from the midway part of the vertical blade 27′c.
[0040]
The outer agitating blade body 28 'includes a pair of upper and lower lateral blade pieces 28'a, 28'b extending in the radial direction of the excavation / stirring shaft body 6, and both upper and lower transverse blade pieces 28'. It is formed in an arc shape in which the middle part bulges outward from the vertical wing piece 28'c that is extended vertically between the outer ends of a and 28'b, and supports the inner middle wing piece The tip of the upper horizontal wing piece 28'a is attached to the ring-shaped outer intermediate wing piece support 42 that is freely loosely fitted to the outer circumferential surface of the body 34, while the lower horizontal wing piece is attached to the outer circumferential surface of the second shaft 21. A tip end portion of 28'b is attached to rotate integrally with the second shaft 21 in the b direction.
[0041]
Three outer stirring blade bodies 28 ′ are provided at regular intervals in the circumferential direction below the excavation / stirring shaft body 6. 35 ′ is an inwardly protruding winglet formed by projecting inwardly at the upper and lower portions of the vertical wing piece 28′c. The rotation trajectory of these inner winglet pieces 35 ′ and 35 ′ Between the inner and outer agitating blade bodies 27 ', 28', which are arranged so as to overlap in the vertical direction with the rotation trajectory of the outwardly projecting small blade piece 31 'provided on the body 27', It ensures that the excavated soil can be agitated.
[0042]
Here, the second improvement material discharge section 32 is provided below the second shaft 21 and above the lower horizontal blade piece 28'b of the outer stirring blade body 28 '. Are formed by matching the second shaft 21 and the first shaft 20 with circular second improvement material discharge holes 32a and 32b that open in the radial direction (radiation direction). The discharge holes 32a and 32b are connected to the second improvement material supply path 24, and the improvement material supplied through the second improvement material supply path 24 is sent to the radius of the second shaft 21 from the second improvement material discharge holes 32a and 32b. It discharges in the direction.
[0043]
Thus, in this embodiment, as shown in FIGS. 3 to 5, the innermost stirring blade body 26 and the outer stirring blade body 28 of the relative stirring blade portion 8 rotate in the same rotational direction (direction a). At the same time, the inner stirring blade body 27 rotates in the opposite rotational direction (direction b), while the innermost stirring blade body 26 'and the outer stirring blade body 28' of the relative stirring blade portion 9 have the same rotational direction (b). The inner stirring blade body 27 'rotates in the opposite rotation direction (direction a).
[0044]
Therefore, the inner and outer stirring blades are relatively stirred together, and the upper and lower stirring blade bodies are also relatively stirred, so that the excavated soil and the improved material can be stirred and kneaded efficiently and uniformly.
[0045]
The excavation blade body 10 is attached to the lower end portion of the first shaft 20, and a first improvement material discharge portion 29 is provided at the rotation center portion of the excavation blade body 10.
[0046]
And the 1st improvement material discharge part 29 forms the circular 1st improvement material discharge hole 29a opened toward the downward direction in the rotation center part of the excavation blade 10, and the 1st improvement material discharge hole 29a is made into 1st. The 1st improvement material supply path 23 is connected, and the improvement material supplied through the said 1st improvement material supply path 23 is discharged toward the directly downward direction from the 1st improvement material discharge hole 29a.
[0047]
[Description of ground improvement method]
Next, a method for improving soft ground or contaminated soil or ground (hereinafter referred to as “ground G”) by the ground improvement device A configured as described above will be described.
[0048]
That is, when the ground G is improved, as shown in FIG. 1, the leader 4 is built by moving the base machine 1 to the ground improvement site, and the excavation / stirring shaft body 6 is moved along the leader 4. The ground G is excavated by the excavating blade body 10 and the excavated soil is agitated by the relative agitating blade portions 8 and 9.
[0049]
Then, the improvement material is supplied from the improvement material supply unit 2 to the improvement material supply hose 11 → first, second, and third improvement material supply paths 23, 24, 25 → first, second, and third improvement material discharge units 29, 32. , 33 and discharging the improved material from each of the improved material discharge portions 29, 32, 33, the improved material is uniformly stirred into the excavated soil by the relative agitating blade portions 8, 9, and the excavated soil is removed. As shown in FIG. 6, a columnar ground improvement portion k can be built in the ground G, and the ground G is improved by continuously forming the ground improvement portion k in the front-rear and left-right directions. can do.
[0050]
At this time, since the two relative stirring blade portions 8 and 9 are coaxially attached to the lower peripheral surface of the excavation / stirring shaft body 6 so as to be adjacent to each other in the vertical direction, the vertical excavation of the excavation / stirring shaft body 6 is performed. Stirring can be performed in a wide range in the direction, and the ground improvement work can be completed efficiently and in a short time.
[0051]
Moreover, each of the relative stirring blade portions 8 and 9 has an inner stirring blade body 27 and 27 ′ formed in an arc shape, and an outer stirring blade body 28 and 28 ′ disposed outside the arc stirring portion and an inner stirring blade body 27 and 27 ′. The inner stirrer blades 26 and 26 'are arranged inside the blade bodies 27 and 27' and formed in a rod shape, and the outer stirrer blades with respect to the rotation direction of the inner stirrer blade bodies 27 and 27 '. Between the three stirring blade bodies 26, 26 ', 27, 27', 28, 28 'by rotating the rotational directions of the body 28, 28' and the innermost stirring blade bodies 26, 26 'in opposite directions. Relative agitation (agitation performed by rotating in opposite directions) is performed, and the shearing force on the excavated soil, in particular, acts between the inner agitation blade bodies 27 and 27 'and the outer agitation blade bodies 28 and 28'. The shearing force to be improved improves the co-rotation phenomenon (a phenomenon in which the excavated soil rotates integrally with the excavating / stirring shaft) and the dumpling phenomenon (the excavated soil wraps around the stirring rod). The current dumpling state ) Without causing, it can be uniformly and reliably perform agitation and kneading of the material and the modifying material and the excavated soil.
[0052]
Further, since the outer stirring blade bodies 28, 28 'of the relative stirring blade portions 8, 9 adjacent to each other in the vertical direction are attached so as to rotate in opposite directions, the upper outer stirring blade body 28 and A shearing force can also be applied between the lower outer stirring blade body 28 'and the stirring and kneading of the excavated soil and the improving material is homogeneous over a wide range even in the vertical extension direction of the excavating and stirring shaft body 6. This can be done reliably and reliably.
[0053]
The improving material is not limited to a solidified material such as cement milk, and a chemical agent or a chemical agent that neutralizes, eliminates, and purifies harmful substances from contaminated soil can be used.
[0054]
[Modification of the first embodiment]
7 and 8 show a modification of the relative stirring blade portions 8 and 9 in the first embodiment described above, and the relative stirring blade portions 8 and 9 are the relative stirring blade portions in the first embodiment described above. The basic structure is the same as 8,9, but differs in the following points.
[0055]
That is, as shown in FIGS. 7 and 8, the inner stirring blade body 27 of the relative stirring blade portion 8 disposed above is supported by a ring-shaped upper blade piece that is freely loosely fitted on the outer peripheral surface of the third shaft 22. While attaching the tip of the upper horizontal wing piece 27a to the body 30, the tip of the lower horizontal wing piece 27b is attached to the ring-shaped inner intermediate wing piece support 34 that is freely loosely fitted to the outer peripheral surface of the third shaft 22. It is attached so as to rotate integrally with the second shaft 21 in the b direction.
[0056]
The outer agitating blade body 28 has a ring-shaped outer intermediate portion rotatably fitted on the outer peripheral surface of the inner intermediate blade piece support 34 while the tip portion of the upper horizontal blade piece 28a is attached to the lower portion of the third shaft 22. The tip of the lower horizontal wing piece 28b is attached to the wing piece support 42 so as to rotate integrally with the third shaft 22 in the direction a.
[0057]
As shown in FIGS. 7 and 8, the inner stirring blade body 27 ′ of the relative stirring blade portion 9 disposed below is attached to the outer peripheral surface of the third shaft 22 with the tip of the upper horizontal blade piece 27 ′ a, The tip of the lower lateral wing piece 27'b is attached to the ring-shaped lower wing piece support 41 that is freely loosely fitted to the outer peripheral surface of the second shaft 21, and rotates in the direction a integrally with the third shaft 22. Like to do.
[0058]
The outer agitating blade body 28 ′ is attached to the outer middle blade member support 42 with the tip of the upper blade member 28 ′ a, while the tip of the lower blade member 28 ′ b is attached to the outer peripheral surface of the second shaft 21. It is attached so as to rotate integrally with the second shaft 21 in the b direction.
[0059]
In this way, the relative stirring blade portions 8 and 9 according to this embodiment can efficiently improve the ground as in the case of the relative stirring blade portions 8 and 9 according to the first embodiment.
[0060]
[Second Embodiment]
9 and 10 show the relative stirring blade portions 8 and 9 as the second embodiment, and the relative stirring blade portions 8 and 9 are the relative stirring blade portions 8 and 9 as the first embodiment described above. The basic structure is the same as the above, but downward projecting small blade pieces 60, 61 as small blade pieces project downward from the outer stirring blade body 28 of the relative stirring blade portion 8 positioned above, An upward projecting winglet piece 62 as a winglet piece protrudes upward from the outer agitating wing body 28 'of the relative agitating wing section 9 adjacent to the lower side, and both winglet pieces 60, 61, 62 are connected to the inside and outside. It differs in that it is arranged so that part of it is overlapped in the direction.
[0061]
That is, as shown in FIGS. 9 and 10, a plurality of (two in the present embodiment) lower projecting small blade pieces 60, 61 are fixed in the inner and outer directions on the lower horizontal blade piece 28b of the upper outer stirring blade body 28. Are arranged with a gap therebetween, and both downward projecting small blade pieces 60 and 61 are formed to project downward.
[0062]
Further, an upper protruding wing piece 62 is formed to protrude upward on the upper horizontal wing piece 28'a of the lower outer agitating wing body 28 ', and the tip 62a of the upper protruding wing piece 62 and the above-mentioned The tip portions 60a and 61a of the downward projecting small blade pieces 60 and 61 overlap each other in the inner and outer directions (radiation direction of the excavation / stirring shaft body 6) in each rotation locus.
[0063]
In this way, by causing the outer stirring blade bodies 28 and 28 'adjacent in the vertical direction to relatively stir, the inner and outer downward projecting small blade pieces 60 projecting in the vertical direction on both stirring blade bodies 28 and 28', A shear force can be applied to the excavated soil located between the upper projecting small blade piece 61 and the upper projecting small blade piece 62, and the lower horizontal blade piece 28b and the outer stirring blade body 28 'of the outer stirring blade body 28 adjacent to each other in the vertical direction. Also between the upper horizontal blade piece 28'a, the excavated soil and the improved material can be reliably stirred and kneaded.
[0064]
As a result, the excavated soil and the improved material can be reliably stirred and kneaded by the relative stirring blade portions 8 and 9 adjacent in the vertical direction, and between the relative stirring blade portions 8 and 9 adjacent in the vertical direction. In addition, the excavation soil and the improved material can be reliably agitated and kneaded, and the ground improvement work can be efficiently completed in a short time in a wide range of the excavation and agitation shaft body 6 in the vertical extension direction.
[0065]
Moreover, at least adjacent winglets are formed by gradually reducing the cross-sectional width of each winglet piece 60, 61, 62 from the central portion 60b, 61b, 62b toward the end surfaces 60c, 61c, 62c on the rotation direction side. One side surface has tapered surfaces 60d, 60e, 61d, 61e, 61f, 61g, 62d, 62e, 62f and 62g.
[0066]
That is, the outer downward projecting winglet piece 60 is formed with tapered surfaces 60d, 60e on the inner surface, and the inner lower projecting winglet piece 61 is tapered on the inner and outer surfaces, respectively. 61f and 61g are formed, and the upward projecting winglet pieces 62 are formed with tapered surfaces 62d, 62e, 62f and 62g on the inner and outer surfaces, respectively.
[0067]
In this way, the excavated soil is agitated by the small blade pieces 60, 61, 62, and the excavated soil is aligned along the tapered surfaces 60d, 60e, 61d, 61e, 61f, 61g, 62d, 62e, 62f, 62g. It smoothly guides to one side of the adjacent small blade so that the excavated soil and the improved material can be stirred smoothly and reliably. “c”, “d”, “e”, “f”, and “g” indicate the flow directions of the excavated soil flowing along the tapered surfaces 60d, 61d, 61e, 62d, and 62e on the rotation direction side, respectively.
[0068]
As a result, it is possible to more reliably perform the agitation and kneading of the excavated soil and the improved material between the outer agitating blade bodies 28 and 28 'adjacent in the vertical direction, and the vertical extension direction of the excavation and agitation shaft body 6 The ground improvement work can be completed more efficiently and in a short time in a wide area.
[0069]
[Third embodiment]
11 and 12 show the relative stirring blade portions 8 and 9 as the third embodiment, and the relative stirring blade portions 8 and 9 are the relative stirring blade portions 8 and 9 as the first embodiment described above. The basic structure is the same, but the lower side blade pieces 27b, 27'b of the inner stirring blade bodies 27, 27 'and the lower side blade pieces 28b, 28'b of the outer stirring blade bodies 28, 28' They are different in that a plurality (two in this embodiment) of downward projecting guide blade pieces 70, 70 ′, 71, 71 ′ are provided to project downward.
[0070]
That is, the downward projecting guide blade pieces 70, 70 ′, 71, 71 ′ are inclined so that the end surfaces 70a, 70′a, 71a, 71′a on the rotational direction side are located slightly inward with respect to the rotation locus. In this posture, the excavated soil is guided outward (in the direction away from the excavation / stirring shaft body 6) along the side surfaces of the downward projecting guide blade pieces 70, 70 ', 71, 71'. . h and i indicate directions in which excavated soil is guided to the side surfaces of the downward projecting guide blade pieces 70, 70 ', 71, 71', respectively.
[0071]
In this way, the lower lateral blade pieces 27b, 27'b of the inner stirring blade bodies 27, 27 'and the lower lateral blade pieces 28b, 28'b of the outer stirring blade bodies 28, 28' are respectively projected downwardly projecting guide blades. The pieces 70, 70 ', 71, 71' are projected so that the excavated soil is guided outward along the side surfaces of the respective downward projecting guide blade pieces 70, 70 ', 71, 71'. Therefore, the second and third lower wing pieces 27b and 27'b of the inner stirring blade bodies 27 and 27 'and the second and third blades 28b and 28'b arranged in the vicinity of the lower stirring blade bodies 28 and 28' of the outer stirring blade bodies 28 and 28 'are provided. The improved material discharged from the improved material discharge sections 32, 33 can be smoothly guided to the vicinity of the longitudinal blade pieces 28c, 28'c of the outer stirring blade bodies 28, 28 '. Can be efficiently and uniformly kneaded.
[0072]
[Fourth embodiment]
13 and 14 show the relative stirring blade portions 8 and 9 as the fourth embodiment, and the relative stirring blade portions 8 and 9 are the relative stirring blade portions 8 and 9 as the first embodiment described above. The basic structure is the same, except that fourth and fifth improvement material discharge sections 50 and 51 are provided in the vicinity of the outer stirring blade bodies 28 and 28 ', respectively.
[0073]
In other words, the fourth improvement material discharge section 50 has a fourth improvement material discharge hole 50a extending in the vertical direction on the back surface (surface opposite to the rotation direction surface) of the vertical blade piece 28c of the outer stirring blade body 28. The fourth improved material discharge hole 50a is formed through the improved material introduction path 52 formed across the vertical blade piece 28c, the lower horizontal blade piece 28b, the outer intermediate blade piece support 42 and the second shaft 21. 3. Connected to the improved material supply path 25, the improved material is discharged from the fourth improved material discharge hole 50a in the tangential direction of the rotation locus drawn by the vertical blade piece 28c. j indicates the improvement material discharge direction.
[0074]
Here, a pressure release valve 53 is provided in the third improvement material discharge hole 33a of the third improvement material discharge portion 33, and the valve is opened when the pressure release valve 53 is pressurized to a predetermined pressure or higher. The improved material is discharged.
[0075]
In this way, the improvement material is discharged only from the third improvement material discharge section 33 connected to the third improvement material supply path 25 on the upstream side of the fourth improvement material discharge section 50, and the fourth improvement material discharge is performed. The problem that the improvement material is not discharged from the portion 50 is solved, and a required amount of the improvement material is discharged from the discharge portions 33 and 50, respectively.
[0076]
In addition, the fifth improvement material discharge part 51 extends in the vertical direction to the back surface (surface opposite to the rotation direction surface) of the longitudinal blade piece 28'c of the outer stirring blade body 28 '. The fifth improved material discharge hole 51a is formed through the vertical blade piece 28'c, the lower horizontal blade piece 28'b, the second shaft 21 and the first shaft 20, and has a hole 51a. 54 is connected to the second improved material supply path 24, and the improved material is discharged from the fifth improved material discharge hole 51a in the tangential direction of the rotation locus drawn by the vertical blade piece 28'c.
[0077]
Here, a pressurization release valve 55 is provided in the second improvement material discharge hole 32a of the second improvement material discharge part 32, and the valve is opened when the pressure release valve 55 is pressurized to a predetermined pressure or more. The improved material is discharged.
[0078]
In this way, the improvement material is discharged only from the second improvement material discharge section 32 connected to the second improvement material supply path 24 on the upstream side of the fifth improvement material discharge section 51, and the fifth improvement material discharge is performed. The problem that the improvement material is not discharged from the portion 51 is solved, and a required amount of the improvement material is discharged from the discharge portions 32 and 51, respectively.
[0079]
Therefore, in this embodiment, the second and third shafts 6 provided on the excavation / stirring shaft 6 are stirred while the excavated soil is stirred by the relative stirring blades 8 and 9 attached to the lower peripheral surface of the excavation / stirring shaft 6. By discharging the improved material from the improved material discharge sections 32 and 33 and the fourth and fifth improved material discharge sections 50 and 51 provided on the vertical blade pieces 28c and 28'c of the outer stirring blade bodies 28 and 28 ', respectively. The excavated soil and the improved material agitated between the excavation / stirring shaft body 6 and the outer agitating blade bodies 28 and 28 'can be kneaded efficiently and uniformly in a short time.
[0080]
In addition, the structure in which the fourth and fifth improvement material discharge portions 50 and 51 are provided in the vicinity of the outer agitating blade bodies 28 and 28 'according to the present embodiment, respectively, is a modification of the first embodiment and the second and second embodiments. By applying to the third embodiment, the excavated soil and the improved material agitated between the excavation / stirring shaft body 6 and the outer stirring blade bodies 28 and 28 'are kneaded efficiently and uniformly in a shorter time. You can also.
[0081]
【The invention's effect】
(1) In the present invention described in claim 1, in the ground improvement device which performs ground improvement by discharging the improvement material while excavating and stirring the ground, and kneading the improvement material and excavated soil, Stretch verticallyA triple-axis structure comprising a first axis, a second axis that surrounds the outer periphery of the first axis, and a third axis that surrounds the outer periphery of the second axisOn the lower peripheral surface of the drilling and stirring shaft body,TwoA plurality of stirring blade bodies formed in an arc shape with the relative stirring blade portions being coaxially attached adjacent to each other in the vertical direction, and each of the relative stirring blade portions bulging the midway portion outwardly on the excavation / stirring shaft body Inside and outsideThe innermost stirring wing that is positioned and located on the innermost side.Placed and mounted so as to rotate in opposite directions around the axis of the excavation / stirring shaft, and the stirrer blades outside the relative stirrer blades adjacent in the vertical direction are relatively Install to rotate in the opposite direction,Of the two relative agitation blades, the inner agitation blade body is attached to the third shaft at the end of the outer agitation blade body of the upper relative agitation blade part and rotates in a direction opposite to the outer agitation blade body. Is attached to the second shaft, and the innermost stirring blade is radially projected from the outer peripheral surface of the third shaft.
[0082]
In this way, a plurality of relative stirring blades are coaxially attached to the lower peripheral surface of the excavation / stirring shaft body so as to be adjacent to each other in the vertical direction. The ground improvement work can be completed efficiently and in a short time.
[0083]
At this time, the plurality of stirring blade bodies forming the respective relative stirring blade portions are formed in an arc shape in which the middle portion bulges outward, and are arranged on the inner and outer sides of the excavation / stirring shaft body, and Since it is attached so as to rotate in the opposite direction around the axis of the shaft body, the plurality of stirring blade bodies can be relatively stirred (stirring by rotating in the relatively opposite direction) to The shearing force, especially the shearing force acting between the inner stirring blade body and the outer stirring blade body, is improved, and the phenomenon of co-rotation even with excavated soil with high viscosity soil (excavated soil is excavated and stirred shaft body) The mixing and excavation of the excavated soil and the improved material can be carried out reliably without causing the phenomenon of rotating in an integrated manner) and the dumpling phenomenon (a phenomenon in which the excavated soil wraps around the stirring rod). .
[0084]
Moreover, since the outer stirring blade bodies of the relative stirring blade portions adjacent to each other in the vertical direction are mounted so as to rotate in the opposite directions, the upper stirring blade body and the lower stirring blade body are interposed between them. A shearing force can be applied, and the excavation soil and the improved material can be reliably agitated and kneaded in a wide range in the vertical extension direction of the excavation / agitation shaft body.
[0085]
(2) In the present invention described in claim 2, in the ground improvement device in which ground improvement is performed by discharging the improvement material while excavating and stirring the ground, and kneading the improvement material and the excavation soil. Stretch verticallyA triple-axis structure comprising a first axis, a second axis that surrounds the outer periphery of the first axis, and a third axis that surrounds the outer periphery of the second axisOn the lower peripheral surface of the drilling and stirring shaft body,TwoThe relative agitation blades are coaxially mounted adjacent to each other in the vertical direction, and each of the agitation blades rotates in the opposite direction around the axis of the excavation and agitation shaft body in the opposite direction. BodyAnd the innermost stirring blade located on the innermost sideThe stirring blade bodies outside the relative stirring blade portions adjacent to each other in the vertical direction are formed in an arc shape with the middle portions bulging outward, and are rotated in the opposite directions. The winglet piece protrudes downward from the outer stirring wing body located at the lower side, while the winglet piece protrudes upward from the outer stirring wing body adjacent to the lower side, Arrange so that part is overlapped in the inner and outer direction,Of the two relative agitation blades, the inner agitation blade body is attached to the third shaft at the end of the outer agitation blade body of the upper relative agitation blade part and rotates in a direction opposite to the outer agitation blade body. The end of the shaft is attached to the second shaft, and the innermost stirring blade is projected radially from the outer peripheral surface of the third shaft.ing.
[0086]
In this manner, the small blade piece protrudes downward from the outer stirring blade body located above, while the small blade piece protrudes upward from the outer stirring blade body adjacent to the lower portion. Since both small blades are arranged so as to be partially overlapped in the inner and outer directions, the outer stirring blades adjacent to each other in the vertical direction are relatively agitated to cause both stirring blades to move in the vertical direction. Shear force can be applied to the excavated soil located between the projecting inner and outer small blade pieces, and the excavated soil and the improvement material are agitated also between the outer agitating blade bodies adjacent in the vertical direction. -Kneading can be performed reliably.
[0087]
As a result, it is possible to reliably perform the agitation and kneading of the excavated soil and the improved material by the plurality of relative stirring blade portions adjacent in the vertical direction, and also between the plurality of relative stirring blade portions adjacent in the vertical direction. The excavation soil and the improved material can be reliably agitated and kneaded, and the ground improvement work can be completed efficiently and in a short time in a wide range in the vertical extension direction of the excavation / agitation shaft body.
[0088]
(3) In the present invention described in claim 3,Out of the two relative agitating blades, the outer agitating blade body of the upper relative agitating blade portion includes a pair of upper and lower horizontal wing pieces extending in the radial direction of the excavating and agitating shaft body, It consists of a vertical wing piece that extends vertically between the outer end portions of the upper and lower horizontal wing pieces, above the lower horizontal wing piece at the lower part of the second shaft and on the outer stirring blade body. The improved material discharge part is installed at the position.ing.
[0089]
In this way, the excavated soil is agitated by each winglet piece, and the excavated soil is smoothly guided to the adjacent winglet side along the taper surface to smoothly and reliably agitate the excavated soil and the improved material. To be able to.
[0090]
As a result, it is possible to more reliably perform the agitation and kneading of the excavated soil and the improved material between a plurality of adjacent agitating blade portions adjacent in the vertical direction, and in a wide range of the vertical direction of the excavation and agitation shaft body. The ground improvement work can be completed more efficiently and in a short time.
[0091]
(4) In the present invention according to claim 4, each relative stirring blade portion includes a rod-shaped stirring blade body extending in a radial direction from the excavation / stirring shaft body, and the rod-shaped stirring blade body is formed in an arc shape. The inner stirring blade body is rotated in the same direction as the outer stirring blade body.
[0092]
In this way, each of the relative stirring blades is arranged in an arc shape on the inner stirring blade body, on the outer side of the inner stirring blade body, and on the inner side of the inner stirring blade body. It is formed from a stirring blade body that is arranged and formed into a rod shape, and the rotation direction of the outer stirring blade body and the rod-shaped stirring blade body is opposite to the rotation direction of the inner stirring blade body, Relative stirring is performed between these three stirring blades.
[0093]
As a result, the agitation and kneading of the excavated soil and the improving material in each relative agitating blade can be performed more reliably, and the ground improvement operation can be completed more efficiently and in a short time.
[0094]
(5) In the present invention described in claim 5, improvement material discharge portions are provided in the vicinity of the excavation / stirring shaft body and in the vicinity of the outer stirring blade body, respectively.
[0095]
In this way, while the excavated soil is agitated by the respective relative agitating blades attached to the lower peripheral surface of the excavation / stirring shaft body, the improved material discharge part provided in the vicinity of the excavating / stirring shaft body and the outer stirring blade body The improvement material is discharged from the improvement material discharge section provided in the vicinity of each other, so that the excavated soil and the improved material that are agitated between the excavation / stirring shaft body and the outer stirring blade body can be efficiently removed in a short time. It can be homogeneously kneaded.
[Brief description of the drawings]
FIG. 1 is an explanatory side view of a ground improvement device according to the present invention.
FIG. 2 is a partially cutaway side view of an excavation / stirring shaft body and a relative stirring blade portion.
FIG. 3 is a cross-sectional bottom view of the excavation / stirring shaft body and a relative stirring blade part.
FIG. 4 is an explanatory bottom view of the excavation / stirring shaft body and a relative stirring blade portion.
FIG. 5 is a sectional side view of the excavation / stirring shaft body and a relative stirring blade part.
FIG. 6 is an explanatory diagram of ground improvement.
FIG. 7 is a partially cutaway side view of an excavation / stirring shaft body and a relative stirring blade portion as a modified example of the first embodiment.
FIG. 8 is a sectional side view of the excavation / stirring shaft body and a relative stirring blade part.
FIG. 9 is a partially cutaway side view of an excavation / stirring shaft body and a relative stirring blade portion as a second embodiment.
10 is a cross-sectional plan view taken along the line II of FIG. 9;
FIG. 11 is a partially cutaway side view of a digging / stirring shaft body and a relative stirring blade portion as a third embodiment.
12 is a cross-sectional plan view taken along a line II-II in FIG.
FIG. 13 is a partially cutaway side view of an excavation / stirring shaft body and a relative stirring blade portion as a fourth embodiment.
FIG. 14 is a sectional plan view of the excavation / stirring shaft body and a relative stirring blade part.
[Explanation of symbols]
A Ground improvement device
1 Base machine
2 Improvement material supply department
3 Base machine body
4 leader
5 Motor support
6 Drilling and stirring shaft body
7 Reverse gear mechanism
8 Relative stirring blade
9 Relative stirring blade

Claims

In the ground improvement device which improves the ground by discharging the improved material while excavating and stirring the ground and kneading the improved material and the excavated soil, the first shaft extending in the vertical direction and the same Two relative stirring blades are provided on the lower peripheral surface of a triple-shaft excavation / stirring shaft body composed of a second shaft surrounding the outer periphery of one shaft and a third shaft surrounding the outer periphery of the second shaft. Attached coaxially adjacent to each other in the vertical direction, each of the relative stirring blades has a plurality of stirring blades formed in an arc shape by bulging the midway part of the excavation / stirring shaft body outwardly . In addition, the innermost stirring blade body located at the innermost side is disposed, and the relative stirring blades are mounted so as to rotate in the opposite directions around the excavation / stirring shaft body and are adjacent to each other in the vertical direction. mounting as stirring blade bodies of the outer parts are rotated relatively opposite directions, 2 The end of the outer stirring blade body of the relative stirring blade portion located above is attached to the third shaft, and the inner stirring blade body rotating in the opposite direction to the outer stirring blade body. A ground improvement device characterized in that an end is attached to the second shaft, and the innermost stirring blade is protruded radially from the outer peripheral surface of the third shaft .

In the ground improvement device which improves the ground by discharging the improved material while excavating and stirring the ground and kneading the improved material and the excavated soil, the first shaft extending in the vertical direction and the same Two relative stirring blades are provided on the lower peripheral surface of a triple-shaft excavation / stirring shaft body composed of a second shaft surrounding the outer periphery of one shaft and a third shaft surrounding the outer periphery of the second shaft. adjacent to the vertical direction together with the coaxially attaching, with each relative agitating blade unit comprises a plurality of stirring blades body rotating relatively opposite directions at the inner and outer side around an axis of excavation and stirring shaft body top Arrange the innermost stirring blade located inside ,
The stirrer blades outside the relative stirrer blades adjacent to each other in the vertical direction are formed in an arc shape with their mid-sections bulging outward, and are rotated in opposite directions to be positioned above. The winglet piece protrudes downward from the outer stirring wing body, while the winglet piece protrudes upward from the outer stirring wing body adjacent to the lower side, and both winglet pieces are connected to the inner and outer sides. Arrange so that part of it overlaps in the direction,
Of the two relative agitation blades, the inner agitation blade body is attached to the third shaft at the end of the outer agitation blade body of the upper relative agitation blade part and rotates in a direction opposite to the outer agitation blade body. The ground improvement device is characterized in that the end of this is attached to the second shaft, and the innermost stirring blade is protruded radially from the outer peripheral surface of the third shaft .

Out of the two relative agitating blades, the outer agitating blade body of the upper relative agitating blade portion includes a pair of upper and lower horizontal wing pieces extending in the radial direction of the excavating and agitating shaft body, It consists of a vertical wing piece that extends vertically between the outer end portions of the upper and lower horizontal wing pieces, above the lower horizontal wing piece at the lower part of the second shaft and on the outer stirring blade body. The ground improvement apparatus of Claim 1 or Claim 2 which has provided the improvement material discharge part in the position .

Each of the relative stirring blades is provided with a rod-shaped stirring blade extending radially from the excavation / stirring shaft body, and the rod-shaped stirring blade body is formed on the outer side of the inner stirring blade body formed in an arc shape. The ground improvement device according to any one of claims 1 to 3, wherein the ground improvement device rotates in the same direction as the stirring blade body.

The ground improvement device according to any one of claims 1 to 4, wherein an improvement material discharge portion is provided in the vicinity of the excavation / stirring shaft body and in the vicinity of the outer stirring blade body.