JP2013147878A

JP2013147878A - Ground improvement construction machine and ground improvement method using the same

Info

Publication number: JP2013147878A
Application number: JP2012010005A
Authority: JP
Inventors: Kazuo Konishi; 一生小西; Tsuneyasu Onishi; 常康大西; Hiroshi Matsukawa; 宏志松川; Yuji Okano; 裕司岡野; Yuji Kagawa; 裕司香川; Takashi Goto; 尚後藤
Original assignee: Takenaka Doboku Co Ltd
Current assignee: Takenaka Doboku Co Ltd
Priority date: 2012-01-20
Filing date: 2012-01-20
Publication date: 2013-08-01
Anticipated expiration: 2032-01-20
Also published as: JP5204319B1

Abstract

PROBLEM TO BE SOLVED: To provide a ground improvement construction machine in which penetration accuracy of its drilling blade in a vertical direction is improved by preventing displacement and decentering caused by resistance force which the drilling blade and a drive shaft of the ground improvement construction machine receive from ground or a preceding soil improvement body, and a ground improvement method using the same.SOLUTION: A corotation prevention blade 11 is mounted to a position immediately above a ground improvement construction drilling blade 10 in a non-rotating state and in an immovable state in the axial direction, and is structured so that its main body is a frame material 11a arranged in the diameter line direction of a drill-hole 14 drilled by the drilling blade 10 and a displacement suppressing plate 11b having a circular arched curved surface with the same curvature as that of the drill-hole 14 in the circumferential direction is mounted at a position which is a tip portion of the frame material 11a and in contact with a hole wall inner surface of the drill-hole 14 drilled by the drilling blade 10. A corner part 11c protruding from the outer surface of the displacement suppressing plate 11b in the same direction as that of the frame material 11a is dug into the wall surface soil of the drill-hole 14 and keeps a non-rotating state, thus exhibiting corotation prevention action for drilled soil.

Description

この発明は、液状化防止を目的として、壁状に連続する地盤改良体を平面視が矩形等の閉鎖形状に造成し、或いは前記閉鎖形状の内部地盤を更に地盤改良壁で縦、横方向に仕切った格子形状に施工した格子状地盤改良壁を造成する地盤改良工事の施工に好適な単軸型の地盤改良施工機、及び同施工機を使用する地盤改良工法の技術分野に属し、更に云えば、地盤改良施工機の掘削翼及び駆動軸が地盤或いは先行の地盤改良体から受ける抵抗力により発生する変位や芯ブレを防止して、同掘削翼の鉛直方向の貫入精度を向上させた地盤改良施工機及び同施工機を使用する地盤改良工法の技術分野に属する。 For the purpose of preventing liquefaction, the present invention forms a ground improvement body that is continuous in a wall shape into a closed shape such as a rectangle in plan view, or the internal ground in the closed shape is further longitudinally and laterally with a ground improvement wall. It belongs to the technical field of single-axis type ground improvement construction machine suitable for construction of ground improvement work to create a grid-like ground improvement wall constructed in a partitioned lattice shape, and ground improvement construction method using the construction machine. For example, the ground excavation blade and the drive shaft of the ground improvement construction machine prevent the displacement and core blur caused by the resistance force received from the ground or the previous ground improvement body, and improve the vertical penetration accuracy of the excavation blade It belongs to the technical field of the improvement construction machine and the ground improvement method using the construction machine.

地盤の液状化防止には、例えば下記の特許文献１、２に係る特許発明で提案されたように、壁状に連続する地盤改良体を、平面視が矩形等の閉鎖形状に形成し、或いは前記閉鎖形状壁に囲まれた内部地盤を更に縦・横方向に仕切った格子状地盤改良壁を施工することの有効性が実証されており、当業者間での信頼性が高い。
例えば狭い宅地に前記格子状地盤改良壁を施工するには、１軸の掘削翼を備えた小型の地盤改良施工機で地盤改良壁を施工することが望まれる。この場合、杭状の地盤改良体を１本ずつ並列に高い鉛直精度で施工して、隣接する杭状地盤改良体相互間のラップ寸法を必要十分に確保し、もって止水構造の地盤改良壁を一枚壁状に連続する構造に施工しなければならない。
この場合に問題となるのは、地盤の土質構成が平面方向及び深度方向に多種多様で、固い部分や軟らかい部分が混在しており、掘削抵抗が多様なことである。一方、地盤改良施工機の掘削翼は、駆動軸の上部を吊り状態に支持して地中へ貫入させる構成なので、掘削翼へ地盤土壌が及ぼす抵抗の大小に応じて曲がり（芯ブレ）を生じ易く、鉛直方向の貫入精度、ひいては地盤改良体相互間のラップ寸法の精度を保つことが施工技術として難しい。特に単軸の場合は、地盤改良体を順押し状態に、又は改良体の外径相当の間隔をあけて先行造成して、更に前記間隔部へ隣り合う二つの地盤改良体を繋ぐ地盤改良体を施工する場合に同様の問題が起こり易い。
その他の原因として、空頭制限により例えば２０ｍ程度の長尺の駆動軸を使用できない場合は、１〜５ｍ程度の短尺の駆動軸を継ぎ足しする施工が行われる。この短尺駆動軸のジョイント部が剛性不足であると鉛直方向の貫入精度が保つことができない。
更に、小型施工機を使用して地盤改良工事を行う場合には、機械重量等の関係で、外径が小さく剛性の弱い駆動軸しか使用できないので、鉛直方向の貫入精度を保つことが難しい。 In order to prevent liquefaction of the ground, for example, as proposed in the patent inventions according to Patent Documents 1 and 2 below, a ground improvement body that is continuous in a wall shape is formed in a closed shape such as a rectangle in plan view, or The effectiveness of constructing a grid-like ground improvement wall in which the internal ground surrounded by the closed wall is further partitioned in the vertical and horizontal directions has been demonstrated, and the reliability among those skilled in the art is high.
For example, in order to construct the grid-like ground improvement wall on a narrow residential land, it is desired to construct the ground improvement wall with a small ground improvement construction machine having a single-axis excavation blade. In this case, pile-shaped ground improvement bodies are constructed one by one in parallel with high vertical accuracy to ensure the necessary and sufficient lap dimensions between adjacent pile-shaped ground improvement bodies, and thus a ground improvement wall with a waterproof structure. Must be constructed in a single wall-like structure.
The problem in this case is that the soil soil structure is diverse in the plane direction and the depth direction, and there are various hard and soft parts, and the excavation resistance is diverse. On the other hand, the excavation wing of the ground improvement construction machine is configured to support the upper part of the drive shaft in a suspended state and penetrate into the ground, so bending (core blurring) occurs according to the magnitude of the resistance of the soil to the excavation wing. It is easy, and it is difficult as construction technology to maintain the vertical penetration accuracy and the accuracy of the lap dimension between the ground improvement bodies. In particular, in the case of a single shaft, the ground improvement body in which the ground improvement body is pushed forward or in advance with a space corresponding to the outer diameter of the improvement body, and two adjacent ground improvement bodies are further connected to the space portion. The same problem is likely to occur when constructing.
As another cause, when a long drive shaft of about 20 m, for example, cannot be used due to the empty head limitation, a construction of adding a short drive shaft of about 1 to 5 m is performed. If the joint portion of the short drive shaft is insufficient in rigidity, the penetration accuracy in the vertical direction cannot be maintained.
Furthermore, when ground improvement work is performed using a small construction machine, it is difficult to maintain vertical penetration accuracy because only a drive shaft having a small outer diameter and weak rigidity can be used due to machine weight and the like.

上記の問題点を解決するため、例えば下記の特許文献３及び４には地盤改良を施工する地盤改良施工機の掘削翼の近傍位置に掘削土壌等の共回り防止翼を設ける技術が開示されている点が参照される。
もっとも、特許文献３の場合は、共回り防止翼を、平面的に見て直径線方向に細長い枠材（翼板）を縦向きに配置すると共に、掘削翼の外径よりも少し長い角部を形成して、両先端が掘削孔の孔壁土中へ突き刺さる構成とし、もって掘削土壌の共回り防止作用に必要な大きさの反力（固定作用力）を得る技術を開示した内容にすぎない。
また、特許文献４の場合は、共回り防止翼を平面的に見ると、直交する４方向に細長い枠材（翼板）を縦向きに配置すると共に、それぞれの先端を掘削翼の外径よりも長い角部に形成して、先端部が掘削孔の孔壁土中に突き刺さり、掘削土壌の共回り防止に必要な反力（固定力）を得る構成が開示されている。この特許文献４の場合は、共回り防止翼が攪拌翼の芯ブレ防止にも効果がある旨の記載も認められる。 In order to solve the above problems, for example, the following Patent Documents 3 and 4 disclose a technique of providing a joint rotation prevention wing such as excavated soil in the vicinity of the excavation wing of a ground improvement construction machine for performing ground improvement. Reference is made to the point.
However, in the case of Patent Document 3, the co-rotation preventing blade is arranged with a frame material (blade plate) elongated in the diameter line direction in a plan view in a plan view and a corner portion slightly longer than the outer diameter of the excavation blade. This is only a content that discloses a technique for obtaining a reaction force (fixed action force) of a size necessary for the co-rotation preventing action of excavated soil, with both ends penetrating into the hole wall soil of the excavated hole. .
In addition, in the case of Patent Document 4, when the co-rotation preventing blade is viewed in a plane, a frame material (blade plate) elongated in four orthogonal directions is arranged vertically, and each tip is formed from the outer diameter of the excavation blade. In addition, a configuration is disclosed in which a long corner portion is formed so that the tip portion pierces into the hole wall soil of the excavation hole to obtain a reaction force (fixing force) necessary to prevent the excavation soil from rotating together. In the case of this patent document 4, it is recognized that the co-rotation preventing blade is also effective in preventing the core shake of the stirring blade.

特公平４−５４００４号公報Japanese Examined Patent Publication No. 4-54004 特許第２５６８１１５号公報（特開平２−１３２２２０号公報）Japanese Patent No. 2568115 (JP-A-2-132220) 特開昭５６−１５３０１３号公報JP-A-56-153013 特開２００９−２９３３５９号公報JP 2009-293359 A 特開平７−１５０５４５号公報JP-A-7-150545

上記特許文献３及び４は、共回り防止翼を設けた構成により、掘削土壌の共回りを防止して掘削土との攪拌効果を高めるほか、掘削地盤が掘削翼へ与える抵抗力に起因する曲がり（芯ブレ）の抑制にも効果を発揮し、鉛直方向の掘削貫入精度を高め、地盤改良体のラップ寸法の確保に寄与することが一応認められる。
しかし、特許文献３のように、共回り防止翼を構成する細長い枠材（翼板）を直径線に設け、又は特許文献４のように共回り防止翼を構成する細長い枠材（翼板）を直交する４方向に設けて、各々の先端が掘削孔の孔壁土中に突き刺さる程度の構成では、周辺地盤が掘削翼へ与える大きな抵抗力に対する変位又は芯ブレ防止の効果に多くを期待できない。
むしろ、周辺地盤が与える大きな抵抗力に負けて、共回り防止翼の先端部が孔壁を破壊して（崩して）しまい、鉛直方向の貫入精度の向上にさしたる効果を得られないとさえ考えられる。 In Patent Documents 3 and 4 described above, the structure provided with the co-rotation prevention wing prevents the co-rotation of the excavated soil to increase the stirring effect with the excavated soil, and the bending caused by the resistance force the excavation ground gives to the excavated wing It is recognized that it is effective for suppressing (core blur), improves the accuracy of excavation penetration in the vertical direction, and contributes to securing the lap size of the ground improvement body.
However, as in Patent Document 3, an elongated frame material (blade plate) constituting the co-rotation preventing wing is provided on the diameter line, or as in Patent Document 4, an elongated frame material (wing plate) constituting the co-rotation preventing wing. Are provided in four orthogonal directions, and each tip is stuck in the hole wall soil of the excavation hole, it cannot be expected to have a great effect on the displacement or the core blur prevention effect against the large resistance force that the surrounding ground exerts on the excavation blade.
Rather, it is considered that the tip of the co-rotation prevention wing destroys (breaks down) the hole wall against the large resistance force given by the surrounding ground, and the effect of improving the vertical penetration accuracy cannot be obtained. It is done.

上記の特許文献５にも、やはり共回り防止翼とストッパー翼が設けられている。しかし、共回り防止翼は、掘削翼の掘削径と同等若しくはそれよりも小径の円筒形状であり、ストッパー翼は掘削径と同等で、先端に掘削孔の内面に接する連結材が孔の深さ方向に長く設けられた構成である。従って、この特許文献５に記載された共回り防止翼とストッパー翼は、積極的に孔壁地盤に反力を取って掘削翼の変位又は芯ブレ防止効果を期待する構成になっていない。 The above-mentioned Patent Document 5 is also provided with a co-rotation prevention blade and a stopper blade. However, the co-rotation prevention wing has a cylindrical shape that is the same as or smaller than the digging diameter of the digging wing, the stopper wing is equivalent to the digging diameter, and the connecting material that contacts the inner surface of the digging hole at the tip is the depth of the hole. It is the structure provided in the direction long. Therefore, the co-rotation preventing wing and the stopper wing described in Patent Document 5 are not configured to positively take a reaction force on the hole wall ground and expect the excavation wing displacement or the core blur prevention effect.

本発明の目的は、特には狭い宅地等での施工に適する１軸の駆動軸及び掘削翼で成る単軸型の構成で、駆動軸の下部に共回り防止翼を設ける場合に、掘削土壌の共回り防止機能が奏されるだけでなく、掘削地盤が掘削翼及び駆動軸へ与える抵抗力に起因する変位又は曲がり（芯ブレ）の抑制に効果を発揮して、鉛直方向の掘削貫入精度を高め、地盤改良体のラップ寸法を確保して止水構造の地盤改良壁を一枚壁状に連続状態に施工することに寄与し、液状化防止効果に優れた地盤改良体の施工に適する地盤改良施工機および同施工機を使用する地盤改良工法を提供することである。 The object of the present invention is a single-shaft configuration comprising a uniaxial drive shaft and excavation blades that are particularly suitable for construction on a narrow residential land, etc. In addition to having a co-rotation prevention function, it is effective in suppressing displacement or bending (core shake) caused by the resistance force of the excavation ground to the excavation blades and the drive shaft. The ground is suitable for construction of ground improvement bodies that contribute to the continuous construction of a single wall-like ground improvement wall by securing a lap size of the ground improvement body and having a single wall shape and excellent liquefaction prevention effect It is to provide an improved construction machine and a ground improvement method using the construction machine.

上記した従来技術の課題を解決する手段として、請求項１に記載した発明に係る地盤改良施工機は、
走行機構部３を備えた機械本体部２の前部にリーダー４を立て、そのガイドレールに沿って昇降する回転駆動部６で駆動軸５を回転させる構成であり、同駆動軸５の下部に地盤改良施工用掘削翼１０と共回り防止翼１１及び攪拌翼１２を取り付けて成る地盤改良施工機１において、
前記共回り防止翼１１は、地盤改良施工用掘削翼１０の直上位置へ、非回転状態に、且つ軸方向へは不動の状態に取り付けられており、地盤改良施工用掘削翼１０で掘削した掘削孔１４の直径線方向に配置された枠材１１ａを主体とし、同枠材１１ａの先端部位であって地盤改良施工用掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂを取り付けて成り、前記変位抑止板１１ｂの外面から枠材１１ａと同方向へ突き出された角部１１ｃが掘削孔１４の孔壁土中へ食い込んで非回転状態を保ち掘削土の共回り防止作用を発揮する構成とされていることを特徴とする。 As means for solving the above-described problems of the prior art, the ground improvement construction machine according to the invention described in claim 1 is:
The leader 4 is set up at the front of the machine main body 2 having the traveling mechanism 3 and the drive shaft 5 is rotated by a rotary drive 6 that moves up and down along the guide rail. In the ground improvement construction machine 1 in which the excavation blade 10 for ground improvement construction, the co-rotation prevention blade 11 and the stirring blade 12 are attached,
The co-rotation prevention wing 11 is attached to a position directly above the ground improvement construction excavation blade 10 in a non-rotating state and in an axially stationary state, and excavated by the ground improvement construction excavation blade 10. Excavation is carried out at a position where the frame material 11a arranged in the diameter line direction of the hole 14 is a main body and is in contact with the inner surface of the hole wall of the excavation hole 14 excavated by the excavation blade 10 for ground improvement work at the tip portion of the frame material 11a. A displacement restraint plate 11b having an arcuate surface shape equal to the curvature of the hole 14 in the circumferential direction is attached, and a corner portion 11c protruding from the outer surface of the displacement restraint plate 11b in the same direction as the frame member 11a is formed in the excavation hole 14. It is characterized in that it is configured to cut into the perforated wall soil and maintain a non-rotating state, thereby exhibiting a joint rotation preventing action of the excavated soil.

請求項２に記載した発明に係る地盤改良施工機は、
走行機構部３を備えた機械本体部２の前部にリーダー４を立て、そのガイドレールに沿って昇降する回転駆動部６で駆動軸５を回転させる構成であり、同駆動軸５の下部に地盤改良施工用掘削翼１０と共回り防止翼１１及び攪拌翼１２を取り付けて成る地盤改良施工機１’において、
前記共回り防止翼１１は、地盤改良施工用掘削翼１０の直上位置へ、非回転状態に、且つ軸方向へは不動の状態に取り付けられており、地盤改良施工用掘削翼１０で掘削した掘削孔１４の直径線方向に配置された枠材１１ａを主体とし、同枠材１１ａは駆動軸５の上下方向へ少なくとも上下２段に配置した構成とされ、前記上下２段の枠材１１ａ、１１ａの先端部であって地盤改良施工用掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂが上下２段の枠材１１ａ、１１ａを共通に繋ぐ構成で取り付けられて成り、前記変位抑止板１１ｂの外面から枠材１１ａと同方向へ突き出された角部１１ｃが掘削孔１４の孔壁土中へ食い込んで非回転状態を保ち掘削土の共回り防止作用を発揮する構成とされていることを特徴とする。 The ground improvement construction machine according to the invention described in claim 2 is:
The leader 4 is set up at the front of the machine main body 2 having the traveling mechanism 3 and the drive shaft 5 is rotated by a rotary drive 6 that moves up and down along the guide rail. In the ground improvement construction machine 1 ′ to which the excavation blade 10 for ground improvement construction, the co-rotation prevention blade 11 and the stirring blade 12 are attached,
The co-rotation prevention wing 11 is attached to a position directly above the ground improvement construction excavation blade 10 in a non-rotating state and in an axially stationary state, and excavated by the ground improvement construction excavation blade 10. The frame member 11a is mainly arranged in the diameter line direction of the hole 14, and the frame member 11a is arranged in at least two upper and lower stages in the vertical direction of the drive shaft 5, and the upper and lower two-stage frame members 11a and 11a. Displacement restraining plate 11b having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is vertically moved at a position that is in contact with the inner wall of the excavation hole 14 excavated by the excavation blade 10 for ground improvement work. The two-stage frame members 11a and 11a are attached in a common connection structure, and the corner portion 11c protruding from the outer surface of the displacement restraining plate 11b in the same direction as the frame member 11a bites into the hole wall soil of the excavation hole 14. Keep the non-rotating state of the excavated soil Characterized in that it is configured to exhibit around preventing action.

請求項３に記載した発明は、請求項２に記載した地盤改良施工機において、
駆動軸５の下端部へ取り付けた地盤改良施工用掘削翼１０の直上位置へ取り付けた共回り防止翼１１は、上下２段に配置された枠材１１ａ、１１ａの中間部位に、駆動軸５と共に回転する攪拌翼１２が設置された構成であること特徴とする。 The invention described in claim 3 is the ground improvement construction machine according to claim 2,
The co-rotation preventing wing 11 attached to the position directly above the excavation wing 10 for ground improvement construction attached to the lower end portion of the drive shaft 5 is placed together with the drive shaft 5 at an intermediate portion between the frame members 11a and 11a arranged in two stages. It is characterized in that a rotating stirring blade 12 is installed.

請求項４に記載した発明は、請求項１〜３のいずれか一に記載した地盤改良施工機において、
回転駆動部６で回転される駆動軸５は、１軸又は２軸以上の多軸で構成されており、
前記駆動軸５を２軸以上の多軸で構成した場合、共回り防止翼１１は各駆動軸５間を連結する軸間固定金具１１ｄを備えた構成であることを特徴とする。 The invention described in claim 4 is the ground improvement construction machine according to any one of claims 1 to 3,
The drive shaft 5 rotated by the rotation drive unit 6 is composed of one or two or more axes.
When the drive shaft 5 is composed of two or more multi-shafts, the co-rotation preventing wing 11 is provided with an inter-shaft fixing bracket 11d for connecting the drive shafts 5 to each other.

請求項５に記載した発明に係る地盤改良工法は、
上記請求項１〜４に記載した発明に係る地盤改良施工機を使用し、上記駆動軸５の下部に取り付けた地盤改良施工用掘削翼１０で地盤を掘削し、セメント系固化材であるスラリーを注入して掘削土と攪拌する地盤改良工法において、
前記地盤改良施工用掘削翼１０で地盤を掘削した掘削土へ固化材スラリーを注入して攪拌する際、共回り防止翼１１の変位抑止板１１ｂの外面から突き出された角部１１ｃを掘削孔１４の孔壁土中へ食い込ませて共回り防止翼１１を非回転状態に保つことにより、その枠材１１ａで攪拌効果を高めること、
及び前記変位抑止板１１ｂを掘削孔１４の内周面に接触させ、前記角部１１ｃを孔壁土中へ食い込ませた土圧抵抗により、地盤改良施工用掘削翼１０及び駆動軸５の変位又は芯ブレによる曲がり施工を防止して鉛直精度を高めることを特徴とする。 The ground improvement method according to the invention described in claim 5 is:
Using the ground improvement construction machine according to the invention described in claims 1 to 4, the ground is excavated with the ground improvement construction excavation blade 10 attached to the lower part of the drive shaft 5, and the slurry that is a cement-based solidifying material is removed. In the ground improvement method that is injected and agitated with excavated soil,
When the solidification material slurry is poured into the excavated soil excavated by the excavation blade 10 for ground improvement construction and stirred, the corner portion 11c protruding from the outer surface of the displacement restraining plate 11b of the co-rotation preventing blade 11 is formed in the excavation hole 14. To increase the stirring effect with the frame material 11a by keeping the co-rotation prevention blade 11 in a non-rotating state by biting into the pore wall soil of
And the displacement restraint plate 11b is brought into contact with the inner peripheral surface of the excavation hole 14 and the earth pressure resistance caused by the corner portion 11c being digged into the hole wall soil, the displacement or core of the excavation blade 10 and the drive shaft 5 for ground improvement work It is characterized by improving the vertical accuracy by preventing bending work due to blurring.

請求項１〜４に記載した発明に係る地盤改良施工機は、共回り防止翼１１の先端部位であって地盤改良施工用掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂを取り付けた構成なので、該変位抑止板１１ｂが掘削孔１４の孔壁内面へ強く接して大きな面圧を生じて芯ブレに抵抗する。よって、枠材１１ａの長手方向を中心とし、変位抑止板１１ｂの円弧角方向へ変位又は芯ずれ（曲がり）には強く抵抗して確実に阻止する。
また、前記変位抑止板１１ｂの外面から角部１１ｃが突き出す構成なので、該角部１１ｃが掘削孔１４の孔壁土中へ食い込んで非回転状態を保ち掘削土の共回り防止の作用を発揮する。その上、前記枠材１１ａの長手方向と直交する方向への変位又は芯ブレに強く抵抗して曲がりを確実に阻止するから鉛直方向への貫入精度の高い地盤改良体の施工に寄与する。
よって、請求項５記載の発明に係る地盤改良工法は、上記構成の施工機を用いて実施するから、特に単軸型の小型施工機で狭い宅地、空間的制約がある場所での地盤改良施工を容易に可能ならしめると共に、掘削翼１０及び駆動軸５を水平面で見た直交２次元方向への変位又は芯ブレによる曲がりは効果的に阻止され、鉛直精度の高い地盤改良施工が実現でき、その結果、隣接する地盤改良体相互間のラップ寸法は設計条件通りに良好に確保できるから、止水性能に優れて一枚壁状態の地盤改良壁を造成することができ、液状化防止効果の大きい地盤改良工事の施工が可能となる。 The ground improvement construction machine according to the invention described in claims 1 to 4 is a tip portion of the co-rotation prevention wing 11 at a position in contact with the hole wall inner surface of the excavation hole 14 excavated by the ground improvement construction excavation blade 10. Since the displacement suppression plate 11b having a circular arc surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is attached, the displacement suppression plate 11b is in strong contact with the inner surface of the hole wall of the excavation hole 14 to generate a large surface pressure. Resist blurring. Therefore, it is strongly resisted and surely prevented from displacement or misalignment (bending) in the arc angle direction of the displacement suppression plate 11b with the longitudinal direction of the frame member 11a as the center.
In addition, since the corner portion 11c protrudes from the outer surface of the displacement restraining plate 11b, the corner portion 11c bites into the hole wall soil of the excavation hole 14 and maintains the non-rotation state, thereby exerting an effect of preventing the excavation soil from rotating together. In addition, since it strongly resists displacement in the direction perpendicular to the longitudinal direction of the frame member 11a or core blur and reliably prevents bending, it contributes to the construction of a ground improvement body with high penetration accuracy in the vertical direction.
Therefore, since the ground improvement method according to the invention described in claim 5 is implemented using the construction machine having the above-described configuration, the ground improvement construction is performed particularly in a single residential type small construction machine and in a narrow residential land or a place where there is a spatial restriction. Can be easily achieved, and the displacement in the two-dimensional direction orthogonal to the excavation blade 10 and the drive shaft 5 in the horizontal plane or the bending due to the core blur can be effectively prevented, and the ground improvement construction with high vertical accuracy can be realized. As a result, the lap dimension between adjacent ground improvement bodies can be secured well according to the design conditions, so it is possible to create a single wall improvement ground wall with excellent water stopping performance, and to prevent liquefaction. Large ground improvement work can be done.

本発明に係る地盤改良施工機を示した全体図である。It is the whole figure which showed the ground improvement construction machine concerning the present invention. （Ａ）は上記地盤改良施工機の駆動軸に取り付けた共回り防止翼の実施例を示した立面図、（Ｂ）は（Ａ）に指示したｂ矢視図である。(A) is an elevation view showing an example of a co-rotation preventing wing attached to the drive shaft of the ground improvement construction machine, and (B) is a view as viewed from the arrow b instructed to (A). 共回り防止翼の変位抑止板による効果を示した説明図である。It is explanatory drawing which showed the effect by the displacement suppression board of a co-rotation prevention wing | blade. 共回り防止翼の角部による効果を示した説明図である。It is explanatory drawing which showed the effect by the corner | angular part of a co-rotation prevention wing | blade. （Ａ）は上記地盤改良施工機の駆動軸に取り付ける共回り防止翼の実施例２を示した立面図、（Ｂ）は（Ａ）に指示したｂ矢視断面図である。(A) is the elevation which showed Example 2 of the co-rotation prevention wing | blade attached to the drive shaft of the said ground improvement construction machine, (B) is b arrow sectional drawing instruct | indicated to (A). 駆動軸を２軸で構成した実施例を示した説明図である。It is explanatory drawing which showed the Example which comprised the drive shaft by 2 axes | shafts. 共回り防止翼の枠材を平面的に見て直交する２方向に配置した構成を示した説明図である。It is explanatory drawing which showed the structure which has arrange | positioned the frame material of a co-rotation prevention blade in two directions orthogonally seeing planarly. 短尺の駆動軸を切り継ぎして施工する場合の実施例を示した説明図である。It is explanatory drawing which showed the Example in the case of cut and constructing a short drive shaft. 本発明に係る地盤改良工法の一例を示した説明図である。It is explanatory drawing which showed an example of the ground improvement construction method which concerns on this invention.

本発明による地盤改良施工機は、共回り防止翼１１が地盤改良施工用掘削翼１０の直上位置へ、非回転状態に、且つ軸方向へは不動の状態に取り付けられている。前記共回り防止翼１１は、地盤改良施工用掘削翼１０で掘削した掘削孔１４の直径線方向に配置された枠材１１ａを主体とし、同枠材１１ａの先端部位であって地盤改良施工用掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂを取り付けた構成である。前記変位抑止板１１ｂの外面から枠材１１ａと同方向へ突き出された角部１１ｃが掘削孔１４の孔壁土中へ食い込んで非回転状態を保ち掘削土の共回り防止作用を発揮する構成とされ、特に云えば、狭い宅地の施工に適する単軸の小型施工機としての実施に適するが、２軸以上の多軸型としての実施も可能である。 In the ground improvement construction machine according to the present invention, the co-rotation prevention wing 11 is attached to a position directly above the ground improvement construction excavation wing 10 in a non-rotating state and in an axially stationary state. The co-rotation prevention wing 11 is mainly composed of a frame material 11a arranged in the diameter line direction of the excavation hole 14 excavated by the ground improvement construction excavation blade 10, and is a tip portion of the frame material 11a and is used for ground improvement construction. A displacement restraining plate 11b having a circular arc shape equal to the curvature in the circumferential direction of the excavation hole 14 is attached to a position in contact with the inner surface of the excavation hole 14 excavated by the excavation blade 10. The corner portion 11c protruding from the outer surface of the displacement restraining plate 11b in the same direction as the frame member 11a bites into the hole wall soil of the excavation hole 14 and maintains a non-rotating state, thereby exhibiting the joint rotation prevention action of the excavation soil. In particular, it is suitable for implementation as a single-axis small construction machine suitable for construction of a narrow residential land, but can also be implemented as a multi-axis type with two or more axes.

本発明による地盤改良工法は、地盤改良施工用掘削翼１０で地盤を掘削した掘削土へ固化材スラリーを注入して攪拌する際、共回り防止翼１１の変位抑止板１１ｂの外面から突き出された角部１１ｃを掘削孔１４の孔壁土中へ食い込ませて共回り防止翼１１を非回転状態に保つことにより、その枠材１１ａで攪拌効果を高める。そして、変位抑止板１１ｂを掘削孔１４の内周面に接触させ、角部１１ｃを孔壁土中へ食い込ませた土圧抵抗により、地盤改良施工用掘削翼１０及び駆動軸５の変位又は芯ブレによる曲がり施工を防止して鉛直精度を高める。 In the ground improvement method according to the present invention, when the solidifying material slurry is injected into the excavated soil excavated by the ground improvement excavation blade 10 and agitated, it is protruded from the outer surface of the displacement restraining plate 11b of the co-rotation prevention blade 11. By stirring the corner portion 11c into the hole wall soil of the excavation hole 14 and keeping the co-rotation prevention blade 11 in a non-rotating state, the stirring effect is enhanced by the frame member 11a. Then, the displacement restraining plate 11b is brought into contact with the inner peripheral surface of the excavation hole 14 and the earth pressure resistance caused by the corner portion 11c being digged into the hole wall soil is used to displace or distort the ground improvement construction excavation blade 10 and the drive shaft 5. The vertical accuracy is improved by preventing the bending construction due to.

以下に、本発明に係る地盤改良施工機を図１〜図９に示した実施例に基づいて説明する。
図１に示す地盤改良施工機１は、液状化防止を目的として、主に軟弱地盤を対象として地盤改良を行う施工機であって、特に狭隘な場所で地盤改良工事を行うことに適するように、駆動軸５を単軸とした小型で構成している。２軸以上の多軸型であると、地盤改良体を並列状態に施工して一枚の壁状に造成しようとすると、多軸の掘削翼を施工方向に配置するためには、掘削翼を支持するリーダーを施工機ごと施工方向に沿って移動させて段取り替えをするほかなく、図示したクローラの如き走行機構部では小回りが効かず、狭い宅地等での施工には不向きだからである。但し、本発明は、２軸以上の多軸型施工機を排除するものではない。
前記地盤改良施工機１の主要部分の構成は既に公知であり、上記した従来技術の主要部とほぼ同様の構成である。そこで地盤改良施工機１の構成を簡単に説明すると、走行機構部３を備えた機械本体部２の前部にリーダー４を立て、そのガイドレールに沿って昇降する回転駆動部６で駆動軸５を回転させる構成であり、同駆動軸５の下部に地盤改良施工用掘削翼１０と共回り防止翼１１及び攪拌翼１２が取り付けられており、前記リーダー４の下部には前記駆動軸５に支持して同駆動軸５の揺動を防止する下部ガイド７が設けられている。なお、前記駆動軸５の掘進力は、前記回転駆動部６に併設した油圧シリンダー６０で与えられる。 Below, the ground improvement construction machine which concerns on this invention is demonstrated based on the Example shown in FIGS.
The ground improvement construction machine 1 shown in FIG. 1 is a construction machine that performs ground improvement mainly for soft ground for the purpose of preventing liquefaction, and is particularly suitable for performing ground improvement work in a narrow place. The drive shaft 5 is a single shaft and is small. If it is a multi-axis type with two or more axes, it will be necessary to install the excavation blades in the direction of installation if the ground improvement bodies are to be constructed in parallel to create a single wall. This is because the supporting leader is moved along the construction direction along with the construction machine to change the setup, and the traveling mechanism such as the crawler shown in the figure does not work, and is not suitable for construction on a narrow residential land. However, the present invention does not exclude a multi-axis construction machine having two or more axes.
The structure of the main part of the ground improvement construction machine 1 is already known, and is substantially the same as the structure of the main part of the prior art described above. The structure of the ground improvement construction machine 1 will be briefly described below. A leader 4 is set up at the front of the machine main body 2 provided with the traveling mechanism 3, and a drive shaft 5 is driven by a rotary drive 6 that moves up and down along the guide rail. The ground improvement excavation blade 10, the co-rotation prevention blade 11, and the stirring blade 12 are attached to the lower portion of the drive shaft 5, and the drive shaft 5 is supported below the leader 4. A lower guide 7 is provided to prevent the drive shaft 5 from swinging. The digging force of the drive shaft 5 is given by a hydraulic cylinder 60 provided in the rotary drive unit 6.

上記駆動軸５の下部の構成詳細を図２（Ａ）、（Ｂ）に拡大して示した。上記駆動軸５の下端部へ攪拌翼１２が上下に二段の配置とされ、同攪拌翼１２、１２の軸１７が嵌め込み式の軸継手により同心状態に接続されている。前記攪拌翼軸１７の下部に、上下をスラスト受け板１５、１５により軸方向へ不動状態に支持された回転軸筒１８により、同攪拌翼軸１７に対しては回転自在な状態に共回り防止翼１１が取り付けられている。つまり、前記共回り防止翼１１は、掘削翼１０及び攪拌翼１２とは共回りしない状態に取り付けられている。更に、前記攪拌翼軸１７の下端部へ掘削翼１０の軸１６が、やはり嵌め込み式の軸継手により同心状態に接続されている。 Details of the configuration of the lower portion of the drive shaft 5 are shown enlarged in FIGS. 2 (A) and 2 (B). The stirrer blades 12 are vertically arranged at the lower end of the drive shaft 5 and the shafts 17 of the stirrer blades 12 and 12 are concentrically connected by fitting-type shaft couplings. A rotating shaft cylinder 18 which is supported by thrust receiving plates 15 and 15 so as to be immovable in the axial direction at the lower part of the stirring blade shaft 17 prevents the stirring blade shaft 17 from rotating in a rotatable state. Wings 11 are attached. That is, the co-rotation preventing blade 11 is attached so as not to rotate together with the excavation blade 10 and the stirring blade 12. Further, the shaft 16 of the excavating blade 10 is concentrically connected to the lower end portion of the stirring blade shaft 17 by a fitting-type shaft joint.

実施例１の地盤改良施工機１の共回り防止翼１１の主体は、上記掘削翼１０で掘削した掘削孔１４（図３を参照）の直径線方向に細長い板状の枠材１１ａで成り、同枠材１１ａの先端部であって掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、同掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂが取り付けられている。更に、前記変位抑止板１１ｂの外面から突き出された角部１１ｃが掘削孔１４の孔壁土中へ十分に深く（例えば１０ｃｍ程度）食い込んで上記の非回転状態を保つ構成とされている。 The main body of the co-rotation preventing wing 11 of the ground improvement construction machine 1 according to the first embodiment is composed of a plate-like frame member 11a elongated in the diameter line direction of the excavation hole 14 (see FIG. 3) excavated by the excavation wing 10. A displacement restraining plate 11b having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is located at the tip of the frame member 11a and in contact with the inner wall surface of the excavation hole 14 excavated by the excavation blade 10. It is attached. Further, the corner portion 11c protruding from the outer surface of the displacement restraining plate 11b bites into the hole wall soil of the excavation hole 14 sufficiently deeply (for example, about 10 cm) to keep the non-rotation state.

したがって、上記掘削翼１０が地盤の固い部分、或いは軟らかい部分を掘削する際に受ける掘削抵抗力の大小差によって駆動軸５及び掘削翼１０の回転に芯ブレを起こしそうな場合でも、上記構成の共回り防止翼１１によれば、図３に示すように、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂが、掘削孔１４の孔壁内面へ強く接して大きな面圧を生じて抵抗する。よって、枠材１１ａの長手方向を中心として変位抑止板１１ｂの円弧角方向への変位又は芯ずれ（曲がり）は確実に阻止する（スタビライザー機能を発揮）。
また、図４に示したように、例えば先行して造成した地盤改良体９ａに一部分ラップさせて地盤改良体を造成する場合において、前記枠材１１ａの長手方向と直交する方向への変位又は芯ブレによる曲がりは、上記の変位抑止板１１ｂの外面から突き出された角部１１ｃが掘削孔１４の孔壁土中へ十分深く食い込んだ状態で抵抗し阻止する。
かくして掘削翼１０及び駆動軸５を水平面で見た直交２次元方向への変位又は芯ブレによる曲がりは効果的に阻止され、鉛直精度の高い地盤改良施工が実現できる。
その結果、隣接する地盤改良体相互間のラップ寸法は設計条件通りに良好に確保できるから、止水性能に優れて一枚壁状態の地盤改良壁を造成することができ、液状化防止効果の大きい地盤改良工事の施工が可能となる。
上記の作用効果を実現する構成条件として、駆動軸５の中心を通って左右の変位抑止板１１ｂの外面を結ぶ直径線の長さは、掘削翼１０の回転円の直径Ｄ_０とほぼ等しく、これは掘削孔１４の孔径と等しい。一方、やはり攪拌翼軸１６の中心を通って、変位抑止板１１ｂの外面から突き出された左右の角部１１ｃの先端を結ぶ直径線の長さＤ_１は、掘削翼１０の回転円直径Ｄ_０よりも大きく構成している。前記角部１１ｃの突き出し長さの一例を示すと１０ｃｍ程度である。 Therefore, even when the excavation blade 10 is likely to cause core blurring in the rotation of the drive shaft 5 and the excavation blade 10 due to a difference in excavation resistance force when excavating a hard portion or a soft portion of the ground, According to the co-rotation preventing wing 11, as shown in FIG. 3, the displacement restraining plate 11 b having an arc surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is in large contact with the inner wall surface of the excavation hole 14. Resist by creating surface pressure. Therefore, displacement or misalignment (bending) of the displacement suppression plate 11b in the arc angle direction centering on the longitudinal direction of the frame member 11a is reliably prevented (exhibits a stabilizer function).
In addition, as shown in FIG. 4, for example, when a ground improvement body is formed by partially wrapping the ground improvement body 9a previously formed, the displacement or core in the direction perpendicular to the longitudinal direction of the frame member 11a is formed. Bending due to shaking resists and prevents the corner portion 11c protruding from the outer surface of the displacement restraining plate 11b from being sufficiently deeply penetrated into the hole wall soil of the excavation hole 14.
Thus, displacement in the two-dimensional direction orthogonal to the excavation blade 10 and the drive shaft 5 when viewed in the horizontal plane or bending due to core blur is effectively prevented, and ground improvement construction with high vertical accuracy can be realized.
As a result, the lap dimension between adjacent ground improvement bodies can be secured well according to the design conditions, so it is possible to create a single wall improvement ground wall with excellent water stopping performance, and to prevent liquefaction. Large ground improvement work can be done.
As a condition for realizing the effects of the above, the length of the diametrical line connecting the outer surface of the left and right displacement suppression plate 11b through the center of the drive shaft 5 is substantially equal to the diameter D ₀ of the rotational circle of the drilling blades 10, This is equal to the hole diameter of the excavation hole 14. On the other hand, the length D ₁ of the diameter line connecting the tips of the left and right corners 11c protruding from the outer surface of the displacement suppression plate 11b through the center of the stirring blade shaft 16 is the rotational circle diameter D ₀ of the excavation blade 10. It is larger than that. An example of the protruding length of the corner 11c is about 10 cm.

図５は、地盤改良施工機１’の実施例２を示す。
実施例２の地盤改良施工機１’は、対象地盤が軟弱地盤で、実施例１で説明した構成の共回り防止翼１１では十分な地盤反力を取ることができず変位抑止効果が不十分な場合に対応した構成であり、枠材１１ａを上下２段に構成し、これを繋ぐ変位抑止板１１ｂの面積を大きくして、前記変位抑止板１１ｂそのものの変形や破損を防ぐために補強効果を高めた構成を特徴としている。以下に、実施例２の地盤改良施工機１’の具体的な構成を説明する。 FIG. 5 shows Example 2 of the ground improvement construction machine 1 ′.
The ground improvement construction machine 1 ′ of the second embodiment is a soft ground, and the joint rotation preventing wing 11 having the configuration described in the first embodiment cannot take a sufficient ground reaction force and the displacement suppression effect is insufficient. The frame member 11a is configured in two upper and lower stages, and the area of the displacement restraint plate 11b connecting the frame members 11a is increased, so that the displacement restraint plate 11b itself is prevented from being deformed or damaged. It features an enhanced configuration. Below, the concrete structure of the ground improvement construction machine 1 'of Example 2 is demonstrated.

実施例２の基本構造は、上記実施例１の地盤改良施工機１との構成と多くを共通する。
即ち、駆動軸５の下端部へ相当する攪拌翼１２の軸１７が嵌め込み式の軸継手により同心状態に接続されている。この攪拌翼軸１７における攪拌翼１２の直下位置に、上下をスラスト受け板１５、１５により軸方向へは不動状態に支持され、同攪拌翼軸１７に対しては回転軸筒１８により回転自在な状態、つまり掘削翼１０及び攪拌翼１２とは共回りしない状態で防止翼１１が取り付けられている。
実施例２の場合、共回り防止翼１１の主体である細長い板状の枠材１１ａは、中間位置にもう一つの攪拌翼１２を挟んで上下２段に配置されている。この攪拌翼１２は、攪拌翼軸１７と一体的構造とされている。
更に、前記攪拌翼軸１７の下端部へ掘削翼１０の軸１６が、やはり嵌め込み式の軸継手により同心状態に接続されている。
実施例２の場合も、共回り防止翼１１の主体である上下２段の細長い板状の枠材１１ａ、１１ａはそれぞれ、上記掘削翼１０で掘削した掘削孔１４の直径線方向に配置されている。そして、同枠材１１ａ、１１ａの先端部であって、掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、同掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂが配置され、上下２段の枠材１１ａ、１１ａを共通に一体的に繋ぐ形態に取り付けられている。更に、前記変位抑止板１１ｂの外面から突き出された、上下方向に長い直線状をなす角部１１ｃが、掘削孔１４の孔壁土中へ例えば１０ｃｍ程度食い込んで前記の非回転状態を保つ構成で設けられており、この点が上記図３の実施例と異なる。 The basic structure of the second embodiment has much in common with the configuration of the ground improvement construction machine 1 of the first embodiment.
That is, the shaft 17 of the stirring blade 12 corresponding to the lower end portion of the drive shaft 5 is concentrically connected by a fitting-type shaft joint. At the position directly below the stirring blade 12 on the stirring blade shaft 17, the upper and lower sides are supported in an axially stationary state by the thrust receiving plates 15, 15, and the stirring blade shaft 17 is rotatable by the rotary shaft cylinder 18. The prevention blade 11 is attached in a state where the excavation blade 10 and the stirring blade 12 do not rotate together.
In the case of the second embodiment, the elongated plate-like frame material 11a that is the main body of the co-rotation prevention blade 11 is arranged in two upper and lower stages with another stirring blade 12 sandwiched at an intermediate position. The stirring blade 12 has an integral structure with the stirring blade shaft 17.
Further, the shaft 16 of the excavating blade 10 is concentrically connected to the lower end portion of the stirring blade shaft 17 by a fitting-type shaft joint.
Also in the second embodiment, the upper and lower two-stage elongated plate-like frame members 11a and 11a that are the main body of the co-rotation prevention blade 11 are arranged in the diameter line direction of the excavation hole 14 excavated by the excavation blade 10. Yes. And it is the tip part of the frame materials 11a and 11a, and makes the circular arc surface shape equal to the curvature of the circumference direction of the excavation hole 14 in the position which touches the hole wall inner surface of the excavation hole 14 excavated with excavation blade 10. A displacement restraining plate 11b is disposed and attached in a form that integrally connects the upper and lower two-stage frame members 11a and 11a integrally. Further, a corner portion 11c, which protrudes from the outer surface of the displacement restraining plate 11b and forms a straight line that is long in the vertical direction, is cut into the hole wall soil of the excavation hole 14 by, for example, about 10 cm to maintain the non-rotating state. This point is different from the embodiment of FIG.

実施例２の場合も、上記掘削翼１０が地盤の固い部分、或いは軟らかい部分を掘削する際に受ける掘削抵抗力の大小差によって駆動軸５及び掘削翼１０の回転に芯ブレを起こしそうな場合、上記構成の共回り防止翼１１において掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂが、図３に示したように、掘削孔１４の孔壁内面へ強く接して大きな面圧を生じて抵抗し、枠材１１ａの長手方向を中心に、変位抑止板１１ｂの円弧角の範囲では変位又は芯ブレ（曲がり）は確実に阻止する。
また、枠材１１ａの長手方向と直交する方向への変位又は芯ブレは、図４に示したように、上記の変位抑止板１１ｂの外面から突き出された角部１１ｃが掘削孔１４の孔壁土中へ十分深く食い込んだ状態で抵抗し回転方向への位置ズレを確実に阻止する。
かくして掘削翼１０及び駆動軸５を水平面で見た直交２次元方向へは、変位又は芯ブレによる曲がりは効果的に阻止され、鉛直精度の高い地盤改良施工が実現できる。
よって、隣接する地盤改良体相互間のラップ寸法は設計条件通りに良好に確保でき、止水性能に優れて一枚壁状態の地盤改良壁を造成することを可能にし、液状化防止効果の大きい地盤改良工事の施工が可能となる。
上記の作用効果を実現する構成条件として、実施例２の場合も、駆動軸５の中心を通って左右の変位抑止板１１ｂ、１１ｂの外面を結ぶ直径線の長さは、掘削翼１０の回転円の直径Ｄ_０とほぼ等しく、これは掘削孔１４の孔径と等しい。一方、同じく攪拌翼軸１７の中心を通って、変位抑止板１１ｂの外面から突き出された左右の角部１１ｃの先端を結ぶ直径線の長さＤ_２は、掘削翼１０の回転円直径Ｄ_０よりも大きく構成している。前記角部１１ｃの突き出し長さの一例を示すと１０ｃｍ程度である。 Also in the case of the second embodiment, when the excavation blade 10 is likely to cause a core blur in the rotation of the drive shaft 5 and the excavation blade 10 due to a difference in excavation resistance force when excavating a hard portion or a soft portion of the ground. As shown in FIG. 3, the displacement restraining plate 11 b having an arc surface shape equal to the curvature in the circumferential direction of the excavation hole 14 in the co-rotation prevention blade 11 having the above configuration is in strong contact with the inner surface of the hole wall of the excavation hole 14. Therefore, displacement or core blurring (bending) is reliably prevented in the range of the arc angle of the displacement restraining plate 11b around the longitudinal direction of the frame member 11a.
Further, as shown in FIG. 4, the displacement or the core blur in the direction orthogonal to the longitudinal direction of the frame member 11 a is the hole wall soil of the excavation hole 14 at the corner portion 11 c protruding from the outer surface of the displacement suppression plate 11 b. It resists in a state where it digs in deep enough, and prevents displacement in the rotational direction.
Thus, in the orthogonal two-dimensional direction when the excavating blade 10 and the drive shaft 5 are viewed in the horizontal plane, bending due to displacement or core blur is effectively prevented, and ground improvement construction with high vertical accuracy can be realized.
Therefore, the lap dimension between adjacent ground improvement bodies can be secured well according to the design conditions, it is possible to create a single wall improvement ground wall with excellent water stopping performance, and a large liquefaction prevention effect Construction of ground improvement work becomes possible.
As a configuration condition for realizing the above-described operation and effect, also in the second embodiment, the length of the diameter line connecting the outer surfaces of the left and right displacement suppression plates 11b and 11b through the center of the drive shaft 5 is the rotation of the excavating blade 10. approximately equal to the diameter D ₀ of the circle, which is equal to the pore diameter of the borehole 14. On the other hand, also through the center of the stirring blade axis 17, the length D ₂ of the diametrical line connecting the tip of the left and right corner portions 11c that protrude from the outer surface of the displacement suppression plate 11b is rotated circle diameter D ₀ of the excavation blade 10 It is larger than that. An example of the protruding length of the corner 11c is about 10 cm.

なお、図１〜４に基づいて説明した実施例１の地盤改良施工機１、及び図３〜５に基づいて説明した実施例２の地盤改良施工機１’は、狭隘な場所での施工を考慮して駆動軸５を単軸とした構成であるが、図６で示すように、２軸とした構成でも同様に実施することができるし、図示することは省略したが、３軸以上の多軸型の構成で実施することもできる。但し、前記駆動軸５を２軸以上の多軸型で構成する場合には、隣合う駆動軸５、５の回転軸筒１８を軸間固定金具１１ｄで連結して拘束する必要がある。かく構成とすると、地盤掘削中において隣接する掘削翼１０、１０、及び駆動軸５、５の変位や芯ブレを基本的に防止して共回り防止翼１１、１１はスタビライザー機能を発揮するものとなる。 In addition, the ground improvement construction machine 1 of Example 1 demonstrated based on FIGS. 1-4 and the ground improvement construction machine 1 'of Example 2 demonstrated based on FIGS. 3-5 perform construction in a narrow place. In consideration of the configuration in which the drive shaft 5 is a single axis in consideration, as shown in FIG. 6, the configuration can be similarly implemented with a configuration in which the drive shaft 5 is a two-axis. It can also be implemented in a multi-axis configuration. However, when the drive shaft 5 is composed of two or more multi-shaft types, it is necessary to connect and constrain the rotating shaft cylinders 18 of the adjacent drive shafts 5 and 5 with the inter-shaft fixing bracket 11d. With this configuration, the excavation blades 10 and 10 and the drive shafts 5 and 5 that are adjacent to each other during ground excavation are basically prevented from displacing and running out of the core, and the joint rotation prevention blades 11 and 11 exhibit a stabilizer function. Become.

また、前記共回り防止翼１１の基本形態は、図２及び５に示した実施例のように、直径線の１方向に細長い板状の枠材１１ａで構成するほか、図７に示したように、枠材１１ｂを平面的に見て直交する２方向に配置した構成とし、各共回り防止翼１１、１１の先端部位に上述した変位抑止板１１ｂを取り付けた構成で実施することもできる。
なお、図７で示した実施例では、前記枠材１１ｂ、１１ｂを平面的に見てＸ状に配置した構成を示しているが、その有用性は次のように説明できる。例えば図９に示したように、地盤改良体の外径相当の間隔を開けて先行造成した二つの地盤改良体９ｂ、９ｃ間へ両者を連結する地盤改良体９を造成する場合、角部１１ｃ、１１ｃが先行造成した地盤改良体９ｂ、９ｃへ食い込むことを避ける必要がある。つまり、固化が進行中の地盤改良体９ｂ、９ｃへは角部１１ｃが貫入し難いので、図７のような態様で実施することが望まれる。勿論、隣接する地盤改良体が存在しない場合には、枠材１１ｂ、１１ｂを、平面的に見て十字状に配置した構成で実施しても良い。 Further, the basic form of the co-rotation preventing wing 11 is constituted by a plate-like frame member 11a elongated in one direction of the diameter line as in the embodiment shown in FIGS. 2 and 5, and as shown in FIG. In addition, the frame member 11b may be arranged in two directions orthogonal to each other when seen in a plan view, and the above-described displacement suppression plate 11b may be attached to the tip portion of each of the co-rotation preventing blades 11 and 11.
7 shows a configuration in which the frame members 11b and 11b are arranged in an X shape when seen in a plan view, the usefulness thereof can be explained as follows. For example, as shown in FIG. 9, when the ground improvement body 9 that connects the two ground improvement bodies 9b and 9c that are formed in advance with a space corresponding to the outer diameter of the ground improvement body is formed, the corner portion 11c is formed. , 11c needs to avoid biting into the ground improvement bodies 9b and 9c that have been created in advance. That is, since the corner portion 11c is difficult to penetrate into the ground improvement bodies 9b and 9c in which solidification is in progress, it is desirable to implement the embodiment as shown in FIG. Of course, when there is no adjacent ground improvement body, the frame members 11b and 11b may be arranged in a cross shape when seen in a plan view.

更に、空頭制限により長尺の駆動軸（約２０ｍ程度）を使用できない場合には、例えば１〜５ｍ程度の短尺の駆動軸５０、５０を継ぎ足して施工することになる。この場合には、図８に示したように、各駆動軸５０の適所に、上述した共回り防止翼１１と同様な構成のスタビライザー１１’（つまり攪拌作用を要しない）を設けることにより、短尺駆動軸５０のジョイント部５０ａの剛性不足に起因する駆動軸５の変位又は芯ブレを解消して、鉛直方向の貫入精度が保つ実施例が好ましい。 Furthermore, when a long drive shaft (about 20 m) cannot be used due to the empty head limitation, for example, the short drive shafts 50 and 50 of about 1 to 5 m are added for construction. In this case, as shown in FIG. 8, a stabilizer 11 ′ having the same configuration as that of the above-described co-rotation preventing blade 11 (that is, no stirring action) is provided at an appropriate position of each drive shaft 50, thereby shortening the length. An embodiment in which the displacement of the drive shaft 5 or the core blur due to insufficient rigidity of the joint portion 50a of the drive shaft 50 is eliminated and the penetration accuracy in the vertical direction is maintained is preferable.

次に、上述した地盤改良施工機（１又は１’）を使用した請求項５に記載した発明に係る地盤改良工法について説明する。
本発明に係る地盤改良工法も、従来の地盤改良工法と同様、走行機構部３で機械本体部２を施工位置へ移動させ、回転駆動部６で駆動軸５を回転駆動させつつ同回転駆動部６をガイドレール４に沿って下降させて、前記駆動軸５の下部に取り付けた地盤改良施工用掘削翼１０で地盤を掘削しつつセメント系固化材であるスラリーを注入し、攪拌翼１２で攪拌して施工する構成である。 Next, the ground improvement construction method according to the invention described in claim 5 using the ground improvement construction machine (1 or 1 ') described above will be described.
Similarly to the conventional ground improvement method, the ground improvement method according to the present invention also moves the machine main body 2 to the construction position by the traveling mechanism unit 3 and rotates the drive shaft 5 by the rotation drive unit 6 while rotating the same. 6 is lowered along the guide rail 4, and a slurry, which is a cement-based solidified material, is injected while excavating the ground with the ground improvement excavation blade 10 attached to the lower portion of the drive shaft 5, and stirred with the stirring blade 12. It is the composition to be constructed.

本発明に係る地盤改良工法の特徴は、地盤改良施工用掘削翼１０で地盤を掘削した掘削土へ固化材スラリーを注入して攪拌翼１２で攪拌する際に、共回り防止翼１１の先端部に取り付けた変位抑止板１１ｂの外面から突き出された角部１１ｃを掘削孔１４の孔壁土中へ食い込ませて共回り防止翼１１を非回転状態に保つことにより、その枠材１１ａで攪拌効果を高め、更に前記変位抑止板１１ｂを掘削孔１４の内周面に接触させ、前記角部１１ｃを孔壁土中へ食い込ませた土圧抵抗により、掘削翼１０及び駆動軸５の変位又は芯ブレによる曲がり施工を防止するスタビライザー機能を発揮して鉛直精度を高めることである。
一般に、単軸型の地盤改良施工機１を使用して地盤改良壁を造成する場合には、地盤改良体を順押し状態に造成する手順で行ったり、或いは図９に示すように、地盤改良体の外径相当の間隔を開けて先行造成した二つの地盤改良体９ｂ、９ｃ間へ両者を連結する地盤改良体９を造成する手順で行われる。
前記地盤改良体を順押し状態で造成する施工法は、先行造成した地盤改良体の固化が進行中の場合、前記掘削翼１０及び駆動軸５が、前記地盤改良体と原地盤のうち、軟らかい方へ向かって変位又は芯ブレする問題が発生する。
また、図９に示す施工法は、先行造成した地盤改良体９ｂ、９ｃの固化が進行中で、該地盤改良体が原地盤よりも軟らかい場合、掘削翼１０及び駆動軸５が、前記地盤改良体９ｂ、９ｃのうち後から造成した軟らかい地盤改良体９ｃへ向かって変位又は芯ブレする。一方、先行造成した地盤改良体９ｂ、９ｃの固化が進み、原地盤より固くなった場合には、掘削翼１０及び駆動軸５は、原地盤へ向かって変位又は芯ブレする問題が発生する。
そこで、図３に示したように、掘削孔１４の内周面に接触させた変位抑止板１１ｂで地盤改良施工用掘削翼１０へ与える抵抗力に起因する曲がりを抑制して、枠材１１ａの長手方向を中心として変位抑止板１１ｂの円弧角方向への変位又は芯ブレ（曲がり）による曲がり施工を確実にして阻止して鉛直精度を高めることができる。
また、枠材１１ａの長手方向と直交する方向への変位又は芯ブレによる曲がりは、図４に示したように、上記の変位抑止板１１ｂの外面から突き出された角部１１ｃが掘削孔１４の孔壁土中へ十分深く食い込んだ状態で抵抗し阻止する。
よって、隣接する地盤改良体相互間のラップ寸法は設計条件通りに良好に確保できるから、止水性能に優れて一枚壁状態の地盤改良壁を造成することができ、液状化防止効果の大きい地盤改良工事の施工が可能となる。 The ground improvement method according to the present invention is characterized in that when the solidifying material slurry is injected into the excavated soil excavated by the ground improvement construction excavating blade 10 and stirred by the stirring blade 12, the tip portion of the co-rotation preventing blade 11 The corner member 11c protruding from the outer surface of the displacement restraining plate 11b attached to the pierced bite into the hole wall soil of the excavation hole 14 to keep the co-rotation preventing wing 11 in a non-rotating state, thereby providing a stirring effect with the frame member 11a. Further, the displacement suppression plate 11b is brought into contact with the inner peripheral surface of the excavation hole 14 and the earth pressure resistance caused by the corner portion 11c being digged into the hole wall soil is caused by displacement of the excavation blade 10 and the drive shaft 5 or core blurring. It is to improve the vertical accuracy by exhibiting a stabilizer function to prevent bending construction.
In general, when the ground improvement wall is created using the single shaft type ground improvement construction machine 1, the ground improvement body is formed in a forward pushing state, or as shown in FIG. This is carried out by a procedure for creating a ground improvement body 9 that connects the two ground improvement bodies 9b, 9c, which have been created in advance with an interval corresponding to the outer diameter of the body.
The construction method for constructing the ground improvement body in a forward-pressed state is that the excavation blade 10 and the drive shaft 5 are softer of the ground improvement body and the original ground when solidification of the previously created ground improvement body is in progress. There arises a problem of displacement or runout in the direction.
In the construction method shown in FIG. 9, when solidification of the ground improvement bodies 9b and 9c formed in advance is in progress, and the ground improvement body is softer than the original ground, the excavation blade 10 and the drive shaft 5 are provided with the ground improvement. The body 9b, 9c is displaced or shakes toward the soft ground improvement body 9c formed later. On the other hand, when solidification of the ground improvement bodies 9b and 9c formed in advance advances and becomes harder than the original ground, there arises a problem that the excavating blade 10 and the drive shaft 5 are displaced or run out toward the original ground.
Therefore, as shown in FIG. 3, the displacement restraining plate 11 b brought into contact with the inner peripheral surface of the excavation hole 14 suppresses bending caused by the resistance force applied to the excavation blade 10 for ground improvement construction, and the frame material 11 a The vertical accuracy can be improved by reliably preventing the displacement restraining plate 11b from being displaced in the direction of the arc angle or bending due to core blurring (bending) around the longitudinal direction.
Further, as shown in FIG. 4, the bending in the direction orthogonal to the longitudinal direction of the frame member 11 a or the bending of the core is caused by the corner portion 11 c protruding from the outer surface of the displacement suppressing plate 11 b of the excavation hole 14. Resist and block in a state where it has penetrated deeply into the pore wall soil.
Therefore, since the lap dimension between adjacent ground improvement bodies can be ensured well according to the design conditions, it is possible to create a single wall improvement ground wall with excellent water stopping performance, and a large liquefaction prevention effect Construction of ground improvement work becomes possible.

以上に本発明を図示した実施例に基づいて説明したが、本発明は上記実施例に限定されるものではない。本発明の要旨、及び技術思想を逸脱しない範囲で、当業者が必要に応じて行う設計変更や応用、変形として種々な態様で実施できることを、ここに念のため申し添える。 Although the present invention has been described above based on the illustrated embodiment, the present invention is not limited to the above-described embodiment. It should be noted here that the present invention can be implemented in various modes as design changes, applications, and modifications as required by those skilled in the art without departing from the spirit and technical idea of the present invention.

１、１’ 地盤改良施工機
１０地盤改良施工用掘削翼
１１共回り防止翼
１１ａ枠材
１１ｂ変位抑止板
１１ｃ角部
１１ｄ軸間固定金具
１２攪拌翼
２機械本体部
３走行機構部
４リーダー
５駆動軸
６回転駆動部 DESCRIPTION OF SYMBOLS 1, 1 'Ground improvement construction machine 10 Excavation blade 11 for ground improvement construction Joint rotation prevention blade 11a Frame material 11b Displacement suppression plate 11c Corner | angular part 11d Interaxial fixing bracket 12 Stirring blade 2 Machine body part 3 Traveling mechanism part 4 Leader 5 Drive Shaft 6 Rotation drive part

上記した従来技術の課題を解決する手段として、請求項１に記載した発明に係る地盤改良施工機は、
走行機構部３を備えた機械本体部２の前部にリーダー４を立て、そのガイドレールに沿って昇降する回転駆動部６で駆動軸５を回転させる構成であり、同駆動軸５の下部に地盤改良施工用掘削翼１０と共回り防止翼１１及び攪拌翼１２を取り付けて成る地盤改良施工機１において、
前記共回り防止翼１１は、地盤改良施工用掘削翼１０の直上位置へ、非回転状態に、且つ軸方向へは不動の状態に取り付けられており、地盤改良施工用掘削翼１０で掘削した掘削孔１４の直径線方向に配置された枠材１１ａを主体とし、同枠材１１ａの先端部位であって地盤改良施工用掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂを取り付けて成り、前記変位抑止板１１ｂの外面から半径方向外向きに突き出され、両側面を鉛直に形成された角部１１ｃが、掘削孔１４の孔壁土中へ食い込んで非回転状態を保ち掘削土の共回り防止作用を発揮し、且つ鉛直方向への貫入精度の高い地盤改良体の施工を可能とする構成であることを特徴とする。 As means for solving the above-described problems of the prior art, the ground improvement construction machine according to the invention described in claim 1 is:
The leader 4 is set up at the front of the machine main body 2 having the traveling mechanism 3 and the drive shaft 5 is rotated by a rotary drive 6 that moves up and down along the guide rail. In the ground improvement construction machine 1 in which the excavation blade 10 for ground improvement construction, the co-rotation prevention blade 11 and the stirring blade 12 are attached,
The co-rotation prevention wing 11 is attached to a position directly above the ground improvement construction excavation blade 10 in a non-rotating state and in an axially stationary state, and excavated by the ground improvement construction excavation blade 10. Excavation is carried out at a position where the frame material 11a arranged in the diameter line direction of the hole 14 is a main body and is in contact with the inner surface of the hole wall of the excavation hole 14 excavated by the excavation blade 10 for ground improvement work at the tip portion of the frame material 11a. A corner portion formed by attaching a displacement restraining plate 11b having an arcuate surface shape equal to the curvature of the hole 14 in the circumferential direction , projecting radially outward from the outer surface of the displacement restraining plate 11b , and having both side surfaces formed vertically. 11c is configured der to exert co-rotation preventing action of the excavated soil maintaining the non-rotating state bite into the hole plaster borehole 14, and to allow construction of penetration accurate soil improvement material in the vertical direction It is characterized by that.

請求項２に記載した発明に係る地盤改良施工機は、
走行機構部３を備えた機械本体部２の前部にリーダー４を立て、そのガイドレールに沿って昇降する回転駆動部６で駆動軸５を回転させる構成であり、同駆動軸５の下部に地盤改良施工用掘削翼１０と共回り防止翼１１及び攪拌翼１２を取り付けて成る地盤改良施工機１’において、
前記共回り防止翼１１は、地盤改良施工用掘削翼１０の直上位置へ、非回転状態に、且つ軸方向へは不動の状態に取り付けられており、地盤改良施工用掘削翼１０で掘削した掘削孔１４の直径線方向に配置された枠材１１ａを主体とし、同枠材１１ａは駆動軸５の上下方向へ少なくとも上下２段に配置した構成とされ、前記上下２段の枠材１１ａ、１１ａの先端部であって地盤改良施工用掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂが上下２段の枠材１１ａ、１１ａを共通に繋ぐ構成で取り付けられて成り、前記変位抑止板１１ｂの外面から半径方向外向きに突き出され、両側面を鉛直に形成された角部１１ｃが、掘削孔１４の孔壁土中へ食い込んで非回転状態を保ち掘削土の共回り防止作用を発揮し、且つ鉛直方向への貫入精度の高い地盤改良体の施工を可能とする構成であることを特徴とする。 The ground improvement construction machine according to the invention described in claim 2 is:
The leader 4 is set up at the front of the machine main body 2 having the traveling mechanism 3 and the drive shaft 5 is rotated by a rotary drive 6 that moves up and down along the guide rail. In the ground improvement construction machine 1 ′ to which the excavation blade 10 for ground improvement construction, the co-rotation prevention blade 11 and the stirring blade 12 are attached,
The co-rotation prevention wing 11 is attached to a position directly above the ground improvement construction excavation blade 10 in a non-rotating state and in an axially stationary state, and excavated by the ground improvement construction excavation blade 10. The frame member 11a is mainly arranged in the diameter line direction of the hole 14, and the frame member 11a is arranged in at least two upper and lower stages in the vertical direction of the drive shaft 5, and the upper and lower two-stage frame members 11a and 11a. Displacement restraining plate 11b having an arcuate surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is vertically moved at a position that is in contact with the inner wall of the excavation hole 14 excavated by the excavation blade 10 for ground improvement work. 2-stage of the frame member 11a, made installed in a configuration that connects 11a in common, protrudes radially outward from the outer surface of the displacement suppression plate 11b, the corner portion 11c of the both side surfaces are vertically formed, borehole 14 hole wall soil Rolling state exhibits a co-rotation preventing action of the excavated soil keeping, characterized configuration der Rukoto that enables and construction of penetration accurate soil improvement material in the vertical direction.

本発明による地盤改良施工機は、共回り防止翼１１が地盤改良施工用掘削翼１０の直上位置へ、非回転状態に、且つ軸方向へは不動の状態に取り付けられている。前記共回り防止翼１１は、地盤改良施工用掘削翼１０で掘削した掘削孔１４の直径線方向に配置された枠材１１ａを主体とし、同枠材１１ａの先端部位であって地盤改良施工用掘削翼１０で掘削した掘削孔１４の孔壁内面へ接する位置に、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂを取り付けた構成である。前記変位抑止板１１ｂの外面から半径方向外向きに突き出され、両側面を鉛直に形成された角部１１ｃが、掘削孔１４の孔壁土中へ食い込んで非回転状態を保ち掘削土の共回り防止作用を発揮し、且つ鉛直方向への貫入精度の高い地盤改良体の施工を可能とする構成であり、特に云えば、狭い宅地の施工に適する単軸の小型施工機としての実施に適するが、２軸以上の多軸型としての実施も可能である。 In the ground improvement construction machine according to the present invention, the co-rotation prevention wing 11 is attached to a position directly above the ground improvement construction excavation wing 10 in a non-rotating state and in an axially stationary state. The co-rotation prevention wing 11 is mainly composed of a frame material 11a arranged in the diameter line direction of the excavation hole 14 excavated by the ground improvement construction excavation blade 10, and is a tip portion of the frame material 11a and is used for ground improvement construction. A displacement restraining plate 11b having a circular arc shape equal to the curvature in the circumferential direction of the excavation hole 14 is attached to a position in contact with the inner surface of the excavation hole 14 excavated by the excavation blade 10. The corners 11c protruding outward in the radial direction from the outer surface of the displacement restraining plate 11b and vertically formed on both side surfaces thereof bite into the hole wall soil of the excavation hole 14 to maintain the non-rotation state and prevent the excavation soil from rotating together. It is a configuration that enables the construction of a ground improvement body that exerts its action and has high penetration accuracy in the vertical direction, and is particularly suitable for implementation as a single-axis small construction machine suitable for construction of narrow residential land, Implementation as a multi-axis type with two or more axes is also possible.

したがって、上記掘削翼１０が地盤の固い部分、或いは軟らかい部分を掘削する際に受ける掘削抵抗力の大小差によって駆動軸５及び掘削翼１０の回転に芯ブレを起こしそうな場合でも、上記構成の共回り防止翼１１によれば、図３に示すように、掘削孔１４の円周方向の曲率と等しい円弧面状をなす変位抑止板１１ｂが、掘削孔１４の孔壁内面へ強く接して大きな面圧を生じて抵抗する。よって、枠材１１ａの長手方向の変位又は芯ずれ（曲がり）は確実に阻止する（スタビライザー機能を発揮）。
また、図４に示したように、例えば先行して造成した地盤改良体９ａに一部分ラップさせて地盤改良体を造成する場合において、上記の変位抑止板１１ｂの外面から突き出された角部１１ｃが掘削孔１４の孔壁土中へ十分深く食い込んだ状態で抵抗し、前記枠材１１ａの長手方向と直交する方向への変位又は芯ブレによる曲がりを阻止する。
かくして掘削翼１０及び駆動軸５を水平面で見た直交２次元方向への変位又は芯ブレによる曲がりは効果的に阻止され、鉛直精度の高い地盤改良施工が実現できる。
その結果、隣接する地盤改良体相互間のラップ寸法は設計条件通りに良好に確保できるから、止水性能に優れて一枚壁状態の地盤改良壁を造成することができ、液状化防止効果の大きい地盤改良工事の施工が可能となる。
上記の作用効果を実現する構成条件として、駆動軸５の中心を通って左右の変位抑止板１１ｂの外面を結ぶ直径線の長さは、掘削翼１０の回転円の直径Ｄ_０とほぼ等しく、これは掘削孔１４の孔径と等しい。一方、やはり攪拌翼軸１６の中心を通って、変位抑止板１１ｂの外面から突き出された左右の角部１１ｃの先端を結ぶ直径線の長さＤ_１は、掘削翼１０の回転円直径Ｄ_０よりも大きく構成している。前記角部１１ｃの突き出し長さの一例を示すと１０ｃｍ程度である。 Therefore, even when the excavation blade 10 is likely to cause core blurring in the rotation of the drive shaft 5 and the excavation blade 10 due to a difference in excavation resistance force when excavating a hard portion or a soft portion of the ground, According to the co-rotation preventing wing 11, as shown in FIG. 3, the displacement restraining plate 11 b having an arc surface shape equal to the curvature in the circumferential direction of the excavation hole 14 is in large contact with the inner wall surface of the excavation hole 14. Resist by creating surface pressure. Therefore, displacement or misalignment of the longitudinal Direction of the frame member 11a (bending) is reliably prevented (exhibit stabilizer function).
Further, as shown in FIG. 4, for example prior to when it is partially wrapped to construct a ground improvement body ground improvement body 9a which was constructed, the upper Symbol corner 11c that protrude from the outer surface of the displacement suppression plate 11b of Resists in a state where it has penetrated deeply into the hole wall soil of the excavation hole 14 and prevents displacement in the direction perpendicular to the longitudinal direction of the frame member 11a or bending due to core blurring .
Thus, displacement in the two-dimensional direction orthogonal to the excavation blade 10 and the drive shaft 5 when viewed in the horizontal plane or bending due to core blur is effectively prevented, and ground improvement construction with high vertical accuracy can be realized.
As a result, the lap dimension between adjacent ground improvement bodies can be secured well according to the design conditions, so it is possible to create a single wall improvement ground wall with excellent water stopping performance, and to prevent liquefaction. Large ground improvement work can be done.
As a condition for realizing the effects of the above, the length of the diametrical line connecting the outer surface of the left and right displacement suppression plate 11b through the center of the drive shaft 5 is substantially equal to the diameter D ₀ of the rotational circle of the drilling blades 10, This is equal to the hole diameter of the excavation hole 14. On the other hand, the length D ₁ of the diameter line connecting the tips of the left and right corners 11c protruding from the outer surface of the displacement suppression plate 11b through the center of the stirring blade shaft 16 is the rotational circle diameter D ₀ of the excavation blade 10. It is larger than that. An example of the protruding length of the corner 11c is about 10 cm.

Claims

A leader is set up at the front of the machine body with the traveling mechanism, and the drive shaft is rotated by a rotary drive that moves up and down along the guide rail. In the ground improvement construction machine that is equipped with the anti-rotation blade and the stirring blade,
The co-rotation prevention wing is attached to a position directly above the excavation wing for ground improvement construction, in a non-rotating state, and in an immovable state in the axial direction, and the diameter of the excavation hole excavated by the excavation wing for ground improvement construction It is mainly composed of a frame material arranged in the line direction, and the circumferential curvature of the excavation hole is located at the tip portion of the frame material and in contact with the inner wall surface of the excavation hole excavated by the excavation blade for ground improvement work. A displacement restraining plate having an equal arc surface shape is attached, and a corner portion protruding in the same direction as the frame material from the outer surface of the displacement restraining plate bites into the hole wall soil of the excavation hole and keeps the non-rotating state, A ground improvement construction machine characterized in that it is configured to exhibit a co-rotation preventing action.

A leader is set up at the front of the machine body with the traveling mechanism, and the drive shaft is rotated by a rotary drive that moves up and down along the guide rail. In the ground improvement construction machine that is equipped with the anti-rotation blade and the stirring blade,
The co-rotation prevention wing is attached to a position directly above the excavation wing for ground improvement construction, in a non-rotating state, and in an immovable state in the axial direction, and the diameter of the excavation hole excavated by the excavation wing for ground improvement construction The frame material is mainly arranged in the line direction, and the frame material is arranged in at least two levels in the vertical direction of the drive shaft. A displacement restraining plate having an arc surface shape equal to the curvature of the circumferential direction of the excavation hole is attached to a position in contact with the inner wall of the excavation hole excavated with the excavation blade in a configuration that commonly connects the upper and lower frame members. The corner portion protruding in the same direction as the frame material from the outer surface of the displacement restraining plate bites into the hole wall soil of the excavation hole and maintains a non-rotating state and exhibits a joint rotation preventing action of the excavation soil. A ground improvement construction machine characterized by that.

The co-rotation prevention blade attached to the position directly above the excavation blade for ground improvement work attached to the lower end of the drive shaft has a stirring blade that rotates with the drive shaft in the middle part of the frame material arranged in two stages above and below The ground improvement construction machine according to claim 2, wherein the ground improvement construction machine is a structure.

The drive shaft that is rotated by the rotary drive unit is composed of one or two or more axes.
4. The structure according to claim 1, wherein, when the drive shaft is composed of two or more multi-shafts, the co-rotation preventing wing includes an inter-shaft fixing bracket that connects the drive shafts. Ground improvement construction machine described in Kaichi.

Using the ground improvement construction machine according to the invention described in claims 1 to 4 above, the ground is excavated with a ground improvement construction excavating blade attached to the lower part of the drive shaft, and a slurry which is a cement-based solidifying material is injected. In the ground improvement method of mixing with excavated soil,
When the solidified material slurry is injected into the excavated soil excavated by the excavating blade for ground improvement construction and agitated, the corner protruding from the outer surface of the displacement restraining plate of the co-rotation preventing vane into the hole wall soil of the excavating hole Enhancing the stirring effect with the frame material by keeping the co-rotation prevention blade in a non-rotating state by biting in,
And the displacement restraining plate is brought into contact with the inner peripheral surface of the excavation hole, and the earth pressure resistance caused by the corner portion being digged into the hole wall soil, the excavation blade for ground improvement construction and the bending work by the displacement of the drive shaft or the core shake are performed. A ground improvement method characterized by preventing and increasing vertical accuracy.