JPH09273148A - Weak ground improving equipment - Google Patents
Weak ground improving equipmentInfo
- Publication number
- JPH09273148A JPH09273148A JP30220096A JP30220096A JPH09273148A JP H09273148 A JPH09273148 A JP H09273148A JP 30220096 A JP30220096 A JP 30220096A JP 30220096 A JP30220096 A JP 30220096A JP H09273148 A JPH09273148 A JP H09273148A
- Authority
- JP
- Japan
- Prior art keywords
- shaft
- injection
- ground
- stirring
- agent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】この発明は、地盤土壌に注入
剤を注入してこれらを撹拌混合することで地盤を改良す
る軟弱地盤改良工法及び装置に係り、特に、注入剤の注
入に伴う周辺地盤への影響を緩和しうる軟弱地盤改良工
法及び装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft ground improvement method and apparatus for improving a ground by injecting an injecting agent into ground soil and agitating and mixing the injecting agent, and particularly to a surrounding ground accompanying injection of the injecting agent. The present invention relates to a method and apparatus for improving soft ground that can mitigate the effects on the soil.
【0002】[0002]
【従来の技術】埋立地等の軟弱地盤を改良する目的で、
この地盤中にセメント系硬化剤等の注入剤を注入してこ
れらを撹拌翼で攪拌混合し、これにより地盤を硬化させ
ることで地盤改良を行う軟弱地盤改良工法が従来から知
られている。2. Description of the Related Art In order to improve soft ground such as landfills,
There has been known a soft ground improvement method in which an injectant such as a cement-based hardening agent is injected into the ground, and these are stirred and mixed by a stirring blade, thereby hardening the ground to improve the ground.
【0003】この軟弱地盤改良工法は、 改良強度(品質)の確実性及び要求に応じた強度の適
用が可能 盛土及び放置期間がないことから工期の短縮化が図れ
る ドレーン工法、コンパクション工法に比較して周辺へ
の影響が少ない 大深度(25〜30m以上)への適応が可能 比較的安価である 等の利点を有し、近年その適用範囲及び利用機械が拡充
される傾向にある。This soft ground improvement method can be applied with certainty of improved strength (quality) and strength according to requirements. Compared to the drain method and compaction method, which can shorten the construction period because there is no embankment or leaving period. It has the advantages of being relatively inexpensive and adaptable to large depths (25 to 30 m or more) with little effect on the surrounding area, and in recent years its range of application and the machines used tend to be expanded.
【0004】[0004]
【発明が解決しようとする課題】しかしながら、前述の
如き適用範囲及び利用機会の拡充に伴って、市街地又は
その周辺の軟弱地盤に前記軟弱地盤改良工法が適用され
た場合、周辺地盤に悪影響を及ぼすといった可能性が指
摘されている。すなわち、地盤中へ注入剤を注入するこ
とでこの地盤の体積が膨張することにより、地盤が盛り
上がったり又は地盤が側圧に作用して、隣接する構造物
に影響を及ぼすこともありうる、といった可能性であ
る。この発明は前記事情に鑑みてなされたもので、改良
すべき地盤の周囲への影響を可能な限り緩和しうる軟弱
地盤改良工法及び装置の提供を目的としている。However, when the above-mentioned soft ground improvement method is applied to a soft ground in or around an urban area with the expansion of the application range and utilization opportunities as described above, the surrounding ground is adversely affected. The possibility has been pointed out. In other words, by injecting the injection agent into the ground, the volume of the ground expands, so that the ground rises or the ground acts on lateral pressure, which may affect adjacent structures. Sex. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a soft ground improvement method and apparatus capable of mitigating the influence on the surroundings of the ground to be improved as much as possible.
【0005】[0005]
【課題を解決するための手段】前述した課題を解決する
ために、この発明は、以下に掲げるような手段を採用し
ている。すなわち、第1の請求項に係る発明は、外周に
スクリュー羽根が取り付けられてオーガースクリュー状
に形成された撹拌軸と、この撹拌軸先端に取り付けられ
て複数段の撹拌翼を有する注入軸とを備え、かつ、前記
注入軸の上下に注入剤吐出口が設けられた軟弱地盤改良
装置で注入剤と地盤土壌とを撹拌混合させることで地盤
改良を行う軟弱地盤改良工法を、次の各工程を具備した
ものとしたことを特徴とする。Means for Solving the Problems In order to solve the above-mentioned problems, the present invention employs the following means. That is, the invention according to the first aspect includes an agitation shaft having screw blades attached to the outer periphery and formed in an auger screw shape, and an injection shaft having a plurality of stages of agitation blades attached to the tip of the agitation shaft. Provided, and the soft ground improvement method to perform ground improvement by stirring and mixing the injection agent and the ground soil with the soft ground improvement device provided with the injection agent outlet above and below the injection axis, the following steps: It is characterized by having it.
【0006】(I)前記撹拌軸及び注入軸を回転下降させ
ることでこれらを地盤改良すべき地盤内に貫入させる工
程 (II)地盤改良目標深さから少なくとも注入剤吐出口間の
距離だけ手前の位置で下方に位置する注入剤吐出口から
注入剤を吐出させつつさらに撹拌軸及び注入軸を回転下
降させる工程 (III)前記注入軸先端が地盤改良目標深さまで到達した
後に、上方に位置する注入剤吐出口から注入剤を吐出さ
せつつ前記撹拌軸及び注入軸を回転上昇させることで、
地盤土壌と注入剤とを撹拌混合させながら余剰の土壌を
排出して地盤改良を行う工程。(I) A step of rotating and lowering the agitation shaft and the pouring shaft to penetrate them into the ground to be ground improved. (II) At least a distance between the injection outlets before the ground improvement target depth. (3) The step of further rotating and lowering the stirring shaft and the injection shaft while discharging the injection agent from the injection agent discharge port located below the position (III) The injection located above after the tip of the injection shaft reaches the ground improvement target depth By rotating the stirring shaft and the injection shaft while discharging the injection liquid from the agent discharge port,
A step of discharging the surplus soil while stirring and mixing the ground soil and the injectant to improve the ground.
【0007】また、第2の請求項に係る発明は、外周に
スクリュー羽根が取り付けられてオーガースクリュー状
に形成された中空撹拌軸と、この撹拌軸先端に所定距離
上下動自在に取り付けられ、外周に複数段の撹拌翼を有
する注入軸とを備えた軟弱地盤改良装置において、この
注入軸を軸線方向に延びる二重筒に形成すると共に、そ
の上下にそれぞれ注入剤吐出口を設け、上方に位置する
注入剤吐出口を前記二重筒の外筒内部に連通させると共
に、下方に位置する注入剤吐出口を二重筒の内筒内部に
連通させ、かつ、この注入軸に、自身の上方及び下方へ
の移動に応じてそれぞれ外筒及び内筒内部を前記撹拌軸
内部へ連通させる切換装置を設けたことを特徴とするも
のである。The invention according to the second aspect is such that a hollow stirring shaft formed into an auger screw shape with screw blades attached to the outer circumference and a vertical stirring shaft attached to the tip of the stirring shaft so as to be vertically movable. In a soft ground improvement device having an injection shaft having a plurality of stages of stirring blades, the injection shaft is formed into a double cylinder extending in the axial direction, and injection agent discharge ports are provided above and below it, respectively, and positioned above The injection agent discharge port to communicate with the inside of the outer cylinder of the double cylinder, and the injection agent discharge port located below communicates with the inside of the inner cylinder of the double cylinder. It is characterized in that a switching device is provided which connects the inside of the outer cylinder and the inside of the inner cylinder to the inside of the stirring shaft in accordance with the downward movement.
【0008】[0008]
【作用】この発明では、上方に位置する注入剤吐出口か
ら注入剤を吐出させつつ撹拌軸及び注入軸を回転上昇さ
せることで、注入剤の注入量に対応する量の余剰の土壌
を排出しつつ地盤改良を行っているので、注入剤の注入
に伴う地盤の体積膨張を抑制することができる。また、
地盤改良目標深さより少なくとも注入剤吐出口間の距離
だけ手前の位置で下方に位置する注入剤吐出口から注入
剤を吐出しているので、回転上昇時にのみ注入剤を吐出
した際に未改良として残される部分の地盤についても注
入剤を撹拌混合せしめて地盤改良を行うことができる。According to the present invention, the agitating shaft and the injection shaft are rotated upward while discharging the injection material from the injection agent discharge port located above, thereby discharging surplus soil in an amount corresponding to the injection amount of the injection material. While the ground is being improved, the volume expansion of the ground due to the injection of the injection agent can be suppressed. Also,
Since the injectant is discharged from the injectant discharge port located at the lower position at least the distance between the injectant discharge ports than the ground improvement target depth, it is not improved when the injectant is discharged only at the time of rotation rise The ground can be improved by stirring and mixing the injected material also in the remaining ground.
【0009】[0009]
【発明の実施の形態】以下、この発明の実施例について
図面を参照して説明する。図1ないし図4は、この発明
の一実施例である軟弱地盤改良装置を示す図である。こ
れら図において、符号1は改良すべき軟弱地盤(以下、
単に地盤と称する)G上に設置されたクローラ式ベース
マシーンであり、クローラ2、作業部3、及びブーム4
により垂直に保持された支柱5から概略構成されてい
る。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are views showing a soft ground improvement device according to an embodiment of the present invention. In these figures, reference numeral 1 is a soft ground to be improved (hereinafter,
It is a crawler-type base machine installed on G), and includes a crawler 2, a working unit 3, and a boom 4.
Is roughly configured from the support column 5 held vertically.
【0010】支柱5には撹拌軸駆動装置6が図示されい
ない上下動駆動装置により上下動自在に支持され、この
撹拌軸駆動装置6には、その下端に1対の中空筒状の撹
拌軸7、7が左右(図1紙面に垂直方向)に並んで連結
されている。撹拌軸7先端には、図2に示すように、注
入軸11が所定距離上下動自在な状態で取り付けられて
いる。なお、この撹拌軸7内部には、図示されない注入
剤供給手段によりセメントスラリー等の注入剤が供給さ
れる。An agitation shaft drive device 6 is supported on the column 5 by an up-and-down drive device (not shown) so as to be vertically movable. The agitation shaft drive device 6 has a pair of hollow cylindrical agitation shafts 7 at its lower end. , 7 are connected side by side in the left-right direction (perpendicular to the plane of FIG. 1). As shown in FIG. 2, an injection shaft 11 is attached to the tip of the stirring shaft 7 so as to be vertically movable by a predetermined distance. Note that an injectant such as cement slurry is supplied to the inside of the stirring shaft 7 by an injectant supply means (not shown).
【0011】撹拌軸7は、図2に示すように、中空円筒
状の軸体8と、この軸体8外周に形成された螺旋状のス
クリュー羽根9により、全体としてオーガースクリュー
状に形成されている。なお、この実施例では、撹拌軸7
はその長手方向に複数本接続可能な構成とされている。As shown in FIG. 2, the stirring shaft 7 is formed as an auger screw as a whole by a hollow cylindrical shaft body 8 and a spiral screw blade 9 formed on the outer periphery of the shaft body 8. There is. In this embodiment, the stirring shaft 7
Are configured to be connectable in the longitudinal direction.
【0012】一方、注入軸11は、図2ないし図3に示
すように、前記撹拌軸7の軸体8と略同一径に形成され
た軸体12と、この軸体12の外周に複数段(この実施
例では3段)設けられた撹拌翼13、13、…と、軸体
12の下端部外周に形成された螺旋羽根状の掘削部14
とから概略構成されている。On the other hand, as shown in FIGS. 2 to 3, the injection shaft 11 has a shaft body 12 having a diameter substantially the same as that of the shaft body 8 of the stirring shaft 7, and a plurality of stages on the outer circumference of the shaft body 12. (In this embodiment, three stages) provided, and the spiral blade-shaped excavation portion 14 formed on the outer periphery of the lower end portion of the shaft body 12.
It is schematically composed of
【0013】撹拌軸7下端には、図2ないし図4に示す
ように、軸体8と同径の取付筒10が設けられ、これら
軸体8及び取付筒10は、それぞれの下端及び上端に形
成されたフランジ7a、10a間がボルト止めされるこ
とで互いに連結されている。取付筒10内面は横断面六
角形に形成されていると共に、前記注入軸11の軸端上
端部12aは、この取付筒10内面に嵌合する横断面六
角形状に縮径されて形成されている。As shown in FIGS. 2 to 4, a mounting cylinder 10 having the same diameter as the shaft body 8 is provided at the lower end of the stirring shaft 7, and the shaft body 8 and the mounting cylinder 10 are provided at the lower end and the upper end, respectively. The formed flanges 7a and 10a are connected to each other by bolting. The inner surface of the mounting cylinder 10 is formed in a hexagonal cross section, and the upper end 12a of the shaft end of the injection shaft 11 is formed to have a diameter reduced to a hexagonal cross section that fits into the inner surface of the mounting cylinder 10. .
【0014】取付筒10内面には、前述した六角形の一
辺に相当する長さのボス15、15が水平方向に延在さ
れて刻設される一方、前記軸体上端部12aの前記ボス
15を臨む位置には、このボス15と同一の水平長さで
かつその高さがボス15より高いボス16が刻設され、
これらボス15、16間にはピン17が嵌入されてい
る。On the inner surface of the mounting cylinder 10, bosses 15 and 15 having a length corresponding to one side of the hexagonal shape described above are engraved by extending in the horizontal direction, while the boss 15 of the shaft body upper end portion 12a is formed. A boss 16 having the same horizontal length as the boss 15 and a height higher than that of the boss 15 is engraved at a position facing
A pin 17 is fitted between the bosses 15 and 16.
【0015】従って、前記注入軸11は、取付筒10を
介して前記撹拌軸7と一体に回動すると共に、ボス16
の高さ分だけ上下動自在にこの撹拌軸7に取り付けられ
ている。なお、縮径された軸体上端部12aと軸体12
本体との間には段部12bが形成され、軸端12(すな
わち注入軸11)が最上端にまで至った際に前記取付筒
10下端が段部12bに当接するように構成されている
(図4参照)。すなわち、この段部12bは注入軸11
の上方移動の際のストッパーとして作用する。Therefore, the injection shaft 11 rotates integrally with the stirring shaft 7 via the mounting cylinder 10 and the boss 16
Is attached to the stirring shaft 7 so as to be movable up and down by the height of. In addition, the shaft body upper end portion 12a and the shaft body
A step 12b is formed between the main body and the main body, and the lower end of the mounting cylinder 10 is configured to contact the step 12b when the shaft end 12 (that is, the injection shaft 11) reaches the uppermost end ( (See FIG. 4). That is, this step 12b is
Acts as a stopper for upward movement.
【0016】軸端12は中空筒状に形成されていると共
に、この軸体12の内部には、その全長に亙る長さの供
給管18がその軸線に沿って配設されている。これによ
り、軸体12は、軸体12そのものを外筒に、また供給
管18を内筒にした二重筒構造に形成されている。供給
管18は、その上端が前記撹拌軸7と取付筒10との接
続部分付近にまで延出され、かつ、その上端開口部が閉
塞されると共に、上端部側面に貫通孔19、19、…が
穿設されている。The shaft end 12 is formed in a hollow cylindrical shape, and a supply pipe 18 having a length over its entire length is arranged inside the shaft body 12 along the axis thereof. Thus, the shaft body 12 is formed in a double cylinder structure in which the shaft body 12 itself is an outer cylinder and the supply pipe 18 is an inner cylinder. The supply pipe 18 has an upper end extending to near the connection between the stirring shaft 7 and the mounting cylinder 10, an upper end opening thereof is closed, and through holes 19, 19,. Are drilled.
【0017】また、供給管18は、軸体12上端及び最
上段の撹拌翼13の取付位置よりやや上部において、そ
れぞれリング状の固定部材20、22で軸体12内面に
固定されている。軸体12上端に位置する一方の固定部
材20は、その厚さ方向に貫通孔21、21が穿設され
ている。また、他方の固定部材22は、軸体12内面と
供給管18外面との間の間隙を閉塞するようにこの軸体
12内面に設けられている。The supply pipe 18 is fixed to the inner surface of the shaft body 12 by ring-shaped fixing members 20 and 22 at the upper end of the shaft body 12 and slightly above the mounting position of the uppermost stirring blade 13. One fixing member 20 located at the upper end of the shaft body 12 is provided with through holes 21 in the thickness direction thereof. The other fixing member 22 is provided on the inner surface of the shaft 12 so as to close a gap between the inner surface of the shaft 12 and the outer surface of the supply pipe 18.
【0018】供給管18上端にはリング状の切換部材2
3が外嵌されている。切換部材23は、前記撹拌軸7の
軸体8及び取付筒10の間に挾持された固定され、その
厚さ方向に貫通孔24、24が穿設されている。切換部
材23は、前記注入軸11の軸体12が最下端にまで至
った際にこの切換部材23により前記供給管18の貫通
孔19が閉塞されるように、その厚さが予め設定されて
いる(図5参照)。なお、切換部材23と供給管18外
面との間には軸受等が介在されることで、液密な状態で
これら供給管18と切換部材23とが相互に摺動自在と
されている。A ring-shaped switching member 2 is provided at the upper end of the supply pipe 18.
3 is externally fitted. The switching member 23 is fixedly held between the shaft body 8 of the stirring shaft 7 and the mounting cylinder 10, and has through holes 24 in the thickness direction thereof. The thickness of the switching member 23 is set in advance so that the through hole 19 of the supply pipe 18 is closed by the switching member 23 when the shaft body 12 of the injection shaft 11 reaches the lowermost end. (See FIG. 5). A bearing or the like is interposed between the switching member 23 and the outer surface of the supply pipe 18, so that the supply pipe 18 and the switching member 23 can slide relative to each other in a liquid-tight state.
【0019】また、供給管18上端の前記切換部材23
下方の位置には、同様にリング状のシール部材25が外
嵌、固定されている。このシール部材25は取付筒10
内径よりやや小径に形成され、上面にゴムリング等の弾
性リング26が取り付けられている。シール部材25
は、注入軸11の軸体12が最上端にまで至った際にこ
のシール部材25により切換部材23の貫通孔24、2
4下端開口部を閉塞しうるように、その取付位置が予め
設定されている(図4参照)。Further, the switching member 23 at the upper end of the supply pipe 18
Similarly, a ring-shaped seal member 25 is externally fitted and fixed to the lower position. This sealing member 25 is
An elastic ring 26 such as a rubber ring is attached to the upper surface, and has a diameter slightly smaller than the inner diameter. Seal member 25
When the shaft 12 of the injection shaft 11 reaches the uppermost end, the sealing member 25 allows the through-holes 24, 2
4 The mounting position is set in advance so that the lower end opening can be closed (see FIG. 4).
【0020】以上述べたことから、注入軸11の軸体1
2が最上端にまで至った際には、シール部材25により
切換部材23の貫通孔24、24下端開口部が閉塞さ
れ、かつ、供給管18の上端貫通孔19、19が切換部
材23の上方に位置することで、撹拌軸7の軸体8内部
が供給管18内部に連通される(図4参照)。From the above, the shaft body 1 of the injection shaft 11 is
When 2 reaches the uppermost end, the through-holes 24 and 24 at the lower end of the switching member 23 are closed by the seal member 25, and the upper-end through-holes 19 and 19 of the supply pipe 18 are located above the switching member 23. , The inside of the shaft 8 of the stirring shaft 7 communicates with the inside of the supply pipe 18 (see FIG. 4).
【0021】同様に、注入軸11の軸体12が最下端に
まで至った際には、切換部材23により供給管18の上
端貫通孔19、19が閉塞され、かつ、シール部材25
が切換部材23下方へと移動することで、撹拌軸7の軸
体8内部が注入軸11と軸体12内部と供給管18との
間の空間に連通される(図5参照)。すなわち、切換部
材23、シール部材25は、軸体12の上下動に応じて
注入軸11の軸体12内部又は供給管18内部を撹拌軸
7の軸体8内部へ切り換えて連通させる切換装置27を
構成している。Similarly, when the shaft body 12 of the injection shaft 11 reaches the lowermost end, the switching member 23 closes the upper end through holes 19, 19 of the supply pipe 18 and the sealing member 25.
Is moved below the switching member 23, whereby the inside of the shaft 8 of the stirring shaft 7 is communicated with the space between the injection shaft 11, the inside of the shaft 12 and the supply pipe 18 (see FIG. 5). That is, the switching member 23 and the sealing member 25 switch the inside of the shaft 12 of the injection shaft 11 or the inside of the supply pipe 18 to the inside of the shaft 8 of the stirring shaft 7 to communicate with the inside of the shaft 8 of the stirring shaft 7 in accordance with the vertical movement of the shaft 12. Is composed.
【0022】また、前記固定部材22上方の軸体12に
は、この軸体12内部に連通する逆止弁を有する注入剤
吐出口28、28が設けられている。さらに、軸体12
下端部の掘削部14には、前記供給管18に連通する逆
止弁を有する注入剤吐出口29、29(図2参照)が設
けられている。すなわち、注入軸11には、その上下端
にそれぞれ注入剤吐出口(逆止弁)28、29が設けら
れている。Further, the shaft body 12 above the fixing member 22 is provided with injection agent discharge ports 28, 28 having check valves communicating with the inside of the shaft body 12. Further, the shaft 12
Injection outlets 29 and 29 (see FIG. 2) having a check valve communicating with the supply pipe 18 are provided in the excavation portion 14 at the lower end. That is, the injection shaft 11 is provided with injection agent discharge ports (check valves) 28 and 29 at its upper and lower ends, respectively.
【0023】次に、以上のような構成を有する軟弱地盤
改良装置を用いて、この発明の一実施例である軟弱地盤
改良工法を図6を参照して説明する。なお、この実施例
では、撹拌軸7、7を2対(4本)用いて地盤改良を行
う。Next, a soft ground improving method which is an embodiment of the present invention will be described with reference to FIG. 6 using the soft ground improving apparatus having the above-mentioned structure. In this embodiment, the ground improvement is performed using two pairs (four) of the stirring shafts 7, 7.
【0024】(I)貫入開始 1対の撹拌軸7、7を撹拌軸駆動装置6に連結し(図6
(a)参照)、この駆動装置6により撹拌軸7、7及び注
入軸11、11を回転下降させることで、これらを地盤
G中に貫入させる(図6(b)参照)。撹拌軸7、7が十
分に貫入した状態で、これら撹拌軸7、7上端にさらに
1対の撹拌軸7、7を連結し(図6(c)参照)、さらに
前述した貫入工程を継続する。(I) Start of penetration The pair of stirring shafts 7, 7 are connected to the stirring shaft driving device 6 (see FIG. 6).
(See (a)), the drive device 6 rotates the stirring shafts 7, 7 and the injection shafts 11, 11 to penetrate the ground G (see FIG. 6 (b)). With the stirring shafts 7, 7 fully penetrated, a pair of stirring shafts 7, 7 are further connected to the upper ends of the stirring shafts 7, 7 (see FIG. 6 (c)), and the above-described penetration process is continued. .
【0025】(II)注入開始 下方に位置する注入剤吐出口(逆止弁)29が、地盤改
良目標深さ(図6中破線)から注入剤吐出口28、29
間の間隔だけ手前の位置に至った段階で(図6(d)参
照)、図示されない注入剤供給手段により撹拌軸7の軸
体8内部に注入剤を圧入、供給する。(II) Start of injection The injection agent discharge port (check valve) 29 located below the injection agent discharge port 28, 29 from the ground improvement target depth (broken line in FIG. 6).
At a stage before reaching the position by the interval between them (see FIG. 6 (d)), the injection agent is press-fitted and supplied into the shaft body 8 of the stirring shaft 7 by the injection agent supply means (not shown).
【0026】この状態では、撹拌軸7及び注入軸11が
回転下降していることから下降抵抗による下から上への
力が働き注入軸11は最上端の位置にあり、従って、軸
体8内部は供給管18内部に連通されている。これによ
り、軸体8内部に供給された注入剤は、供給管18を通
じて下方に位置する注入剤吐出口29に至り、この吐出
口29から地盤G中に吐出される(図4矢印参照)。そ
して、さらに撹拌軸7及び注入軸11を回転下降させつ
つ注入剤を吐出させることで、地盤土壌と注入剤とを撹
拌混合して略吐出口28、29間の距離の地盤改良を行
う(図6(c)参照)。In this state, since the stirring shaft 7 and the pouring shaft 11 are rotating and descending, the force from the bottom to the top is exerted by the descending resistance, and the pouring shaft 11 is at the uppermost position. Therefore, inside the shaft body 8. Communicates with the inside of the supply pipe 18. Thereby, the injection supplied to the inside of the shaft body 8 reaches the injection discharge outlet 29 located below through the supply pipe 18 and is discharged from the discharge opening 29 into the ground G (see the arrow in FIG. 4). Then, by further rotating and lowering the stirring shaft 7 and the pouring shaft 11 to eject the infusate, the ground soil and the infusate are agitated and mixed to improve the ground in the distance between the ejection ports 28 and 29 (Fig. 6 (c)).
【0027】(III)軸引上 注入軸11先端が地盤改良目標深さにまで到達したら、
次に、撹拌軸7及び注入軸11を回転させることで回転
上昇させる(図6(f)参照)。この状態でも、前述した
注入剤供給手段からの撹拌軸7内部への注入剤供給は継
続しておく。撹拌軸7が回転上昇されている状態では、
上昇抵抗による上から下への力が働き注入軸11は最下
端の位置にあり、従って、軸体8内部は注入軸11の軸
体12と供給管18との間の空間に連通されている。こ
れにより、軸体8内部に供給された注入剤は、軸体12
を通じて上方に位置する注入剤吐出口28に至り、この
吐出口28から地盤G中に吐出される(図5矢印参
照)。そして、さらに撹拌軸7及び注入軸11を回転上
昇させつつ注入剤を吐出させることが、地盤土壌は注入
剤とを撹拌混合して地盤改良を行う。(III) Axial pull-up When the tip of the injection shaft 11 reaches the ground improvement target depth,
Next, the stirring shaft 7 and the injection shaft 11 are rotated to be rotated upward (see FIG. 6 (f)). Even in this state, the supply of the injecting agent from the above-mentioned injecting agent supplying means into the stirring shaft 7 is continued. In a state where the stirring shaft 7 is rotated and raised,
The injection shaft 11 is located at the lowermost position due to the upward-downward force caused by the rising resistance. Therefore, the inside of the shaft 8 is communicated with the space between the shaft 12 of the injection shaft 11 and the supply pipe 18. . As a result, the injection agent supplied to the inside of the shaft 8 is
Through the discharge port 28, and is discharged into the ground G from the discharge port 28 (see the arrow in FIG. 5). Then, the injection agent is discharged while the stirring shaft 7 and the injection shaft 11 are further rotated upward, whereby the ground soil is stirred and mixed with the injection agent to improve the ground.
【0028】注入剤を地盤Gに注入する際、この注入剤
の注入量に対応する量の地盤土壌は余剰になり、前述の
如く周囲地盤に悪影響を及ぼす。しかしながら、この余
剰の土壌Sは、撹拌軸7が回転上昇されていることか
ら、そのスクリュー羽根9によって地上に排出される
(図6(g)参照)。土壌S排出量は、注入剤注入量及び
土壌性状等に応じて適宜決定すれば良いが、これは撹拌
軸7回転数により調整可能である。When the injecting agent is injected into the ground G, the amount of ground soil corresponding to the injection amount of this injecting agent becomes excessive, which adversely affects the surrounding ground as described above. However, the surplus soil S is discharged to the ground by the screw blade 9 because the stirring shaft 7 is rotated up (see FIG. 6 (g)). The amount of soil S discharged may be appropriately determined in accordance with the amount of the injection agent injected, the soil properties, and the like, but this can be adjusted by the number of rotations of the stirring shaft 7.
【0029】さらに、2本連結された撹拌軸7、7のう
ち上方の撹拌軸7が地上に出現した状態で、この撹拌軸
7を切り離し、再度、駆動装置6を撹拌軸7、7に連結
する(図6(h)参照)。そして、さらに撹拌軸7、注入
軸11を回転上昇させつつ、上方に位置する注入剤吐出
口28から注入剤を地盤G中に吐出させることで、地盤
土壌と注入剤とを撹拌混合し、かつ余剰の土壌Sをスク
リュー羽根9で地上に排出しながら地盤改良を行う)図
6(i)、(j)参照)。Further, among the two stirring shafts 7, 7, the upper stirring shaft 7 appears on the ground, the stirring shaft 7 is disconnected, and the driving device 6 is connected to the stirring shafts 7, 7 again. (See FIG. 6 (h)). Then, while further rotating the stirring shaft 7 and the injection shaft 11, the injection agent is discharged into the ground G from the injection agent discharge port 28 located above, whereby the ground soil and the injection agent are stirred and mixed, and The ground improvement is performed while discharging the surplus soil S to the ground by the screw blade 9) (see FIGS. 6 (i) and 6 (j)).
【0030】以上説明したような工法によ地盤改良を行
うことができる。ここで、この実施例では、オーガスク
リュー状に形成された撹拌軸7の先端に注入軸11を設
けた装置で地盤改良を行っているので、注入剤を地盤G
中に吐出しつつ撹拌軸7、注入軸11を回転上昇させる
ことでこれらを引き上げる際に、撹拌軸7のスクリュー
羽根9で注入剤の注入量に対応する余剰の地盤土壌を地
上に排出させることができる。これにより、従来懸念さ
れていた注入剤注入による体積膨張を抑制でき、地盤の
盛り上がりや不要な側圧の発生といった現象を可能な限
り抑え、周辺地盤への影響を十分に緩和することが可能
となる。しかも、この実施例では、注入軸11の上下に
注入剤吐出口28、29が設けられていることから、効
率の良い地盤改良が行える。The ground can be improved by the construction method described above. Here, in this embodiment, the ground is improved by a device in which the injection shaft 11 is provided at the tip of the agitating shaft 7 formed in an auger screw shape.
When the agitating shaft 7 and the pouring shaft 11 are rotated upward while being discharged, the screw blade 9 of the agitating shaft 7 discharges excess ground soil corresponding to the amount of the pouring agent to the ground. Can be. As a result, volume expansion due to the injection of the injection agent, which has been a concern in the past, can be suppressed, phenomena such as swelling of the ground and generation of unnecessary lateral pressure can be suppressed as much as possible, and the influence on the surrounding ground can be sufficiently reduced. . In addition, in this embodiment, since the injection agent discharge ports 28 and 29 are provided above and below the injection shaft 11, efficient ground improvement can be performed.
【0031】すなわち、前述の如く、この実施例では注
入剤注入に伴う不要な土壌を撹拌軸7により排出させて
いるので、地盤への注入剤注入は撹拌軸7等の引き上
げ、すなわち撹拌軸7等の回転上昇時に行うことが好ま
しい。この場合、地盤土壌と注入剤との撹拌混合効率を
向上させるためには、撹拌翼13の上方に注入剤吐出口
を設け、注入剤吐出口の上昇を撹拌翼13が追いかける
ような構成が好ましいことは言うまでもない。しかしな
がら、撹拌翼13の上方にのみ注入剤吐出口を設けたの
では、注入剤吐出を撹拌軸7等引き上げ時から開始した
場合、この時点で撹拌翼13が位置する部分の地盤には
注入剤が注入されずに未改良のまま残される。That is, as described above, in this embodiment, unnecessary soil accompanying the injection of the injecting agent is discharged by the stirring shaft 7, so that the injection of the injecting agent into the ground is raised by the stirring shaft 7, that is, the stirring shaft 7. It is preferable that the rotation is performed at the time of rotation increase. In this case, in order to improve the stirring and mixing efficiency of the ground soil and the injection, an injection outlet is provided above the stirring blade 13, and a configuration in which the stirring blade 13 follows the rise of the injection outlet is preferable. Needless to say. However, if the injection agent discharge port is provided only above the stirring blade 13, when the injection agent discharge is started from the time when the stirring shaft 7 or the like is pulled up, the injection agent is placed on the ground where the stirring blade 13 is located at this time. Are left unmodified without being injected.
【0032】しかし、この実施例では、撹拌翼13、1
3、…が設けられた注入軸11の上下にそれぞれ注入剤
吐出口28、29を設け、地盤改良目標深さから吐出口
28、29間の距離だけ手前の位置で下方に位置する吐
出口29から注入剤を吐出しつつ、撹拌軸7等を回転下
降させることで地盤改良を行っているので、前述の如く
上方にのみ吐出口を設けた場合に未改良として残される
部分の地盤にも注入剤を注入できて地盤改良を行うこと
ができる。However, in this embodiment, the stirring blades 13, 1
Dispensing agent discharge ports 28 and 29 are provided above and below the injection shaft 11 provided with 3,..., Respectively, and the discharge port 29 positioned below the distance from the ground improvement target depth by a distance between the discharge ports 28 and 29 in front thereof. The ground is improved by rotating and lowering the stirring shaft 7 etc. while discharging the injection material from the above. Therefore, when the discharge port is provided only at the upper side as described above, the ground is injected into the part of the ground which is left as unimproved. The agent can be injected to improve the ground.
【0033】しかも、下方の吐出口29から注入剤を吐
出しているので、撹拌翼13、…が吐出口29を追いか
ける構成となり、土壌と注入剤との撹拌混合効率が高く
て大変に好ましい。さらに、この実施例では、撹拌軸7
等の回転上昇時に上方に位置する注入剤吐出口28から
注入剤を吐出させて地盤改良を行っているので、この場
合にも撹拌翼13、…が吐出口28を追いかける構成と
なり、前述の如く土壌と注入剤との撹拌混合効率が非常
に高くて大変に好ましい。Moreover, since the injection agent is discharged from the lower discharge port 29, the stirring blades 13, ... Follow the discharge port 29, which is highly preferable because the mixing efficiency of the soil and the injection agent is high. Further, in this embodiment, the stirring shaft 7
When the rotation is ascended, the ground is improved by discharging the injectant from the injectant outlet 28 located above, so that the stirring blades 13,... Follow the outlet 28 in this case as well, as described above. The stirring and mixing efficiency of the soil and the injection agent is very high, which is very preferable.
【0034】以上述べたことから、この実施例によれ
ば、撹拌軸7等引き上げ時に余剰の土壌Sを撹拌軸7で
地上に排出させることで周辺地盤への影響を極力緩和
し、かつ、撹拌翼13、…及び注入剤吐出口28、29
によって地盤土壌を余すところなく撹拌混合して地盤改
良を行え、かつ、その効率も大変良好なものとすること
ができる。From the above description, according to this embodiment, the excess soil S is discharged to the ground by the stirring shaft 7 when the stirring shaft 7 and the like are pulled up, thereby mitigating the influence on the surrounding ground as much as possible, and stirring the soil. Wings 13, ... and injectant discharge ports 28, 29
Thus, ground improvement can be performed by stirring and mixing the ground soil as much as possible, and the efficiency can be made very good.
【0035】さらに、この実施例では、注入軸11が所
定距離上下動自在に撹拌軸7に取り付けられ、かつ、こ
の注入軸11の上下動に伴って、切換装置27により注
入軸11の上下に位置する注入剤吐出口28、29への
連通が切り換えられるので、注入軸11の回転上昇ある
いは下降に応じて自動的に上方の吐出口28又は下方の
吐出口29から注入剤が吐出され、何等特殊な制御機構
を設けることなく前述した工法を簡易な構成で実現する
ことができる。Further, in this embodiment, the injection shaft 11 is attached to the stirring shaft 7 so as to be vertically movable for a predetermined distance, and the vertical movement of the injection shaft 11 causes the switching device 27 to move the injection shaft 11 up and down. Since the communication with the injectant discharge ports 28, 29 located is switched, the injectant is automatically discharged from the upper discharge port 28 or the lower discharge port 29 according to the rising or lowering of the rotation of the injection shaft 11. The construction method described above can be realized with a simple configuration without providing a special control mechanism.
【0036】なお、この発明の軟弱地盤改良工法及び装
置は、その細部が前記実施例に限定されることなく、種
々の変形例が可能である。一例として、前記注入剤吐出
口28、29の切り替えは、注入軸11の上下動による
ものだけでなく、従来の二重管による地盤改良剤の注入
時における流路切り換え手段など種々の手段が採用でき
る。また、注入剤吐出口28、29は撹拌翼13、1
3、…と別体に設けられる必要はなく、翼13、…内部
を中空としてその先端に吐出口を設けたような構成であ
っても良い。また、前記実施例では撹拌軸7を上下に2
本連結して地盤改良を行っていたが、撹拌軸7の連結本
数あるいは連結の有無については改良すべき地盤の深さ
に応じて適宜選択されればよいことは勿論である。さら
に、前記実施例では、地盤改良目標深さから吐出口2
8、29間の距離だけ手前に注入剤の吐出を開始してい
たが、これより以前で注入剤の吐出を開始しても良いこ
とは言うまでもない。The soft ground improvement method and apparatus of the present invention are not limited to the details of the embodiment, and various modifications are possible. As an example, the switching of the injection agent discharge ports 28 and 29 is not limited to the vertical movement of the injection shaft 11, but various means such as a flow path switching means at the time of injecting the soil improvement agent by a conventional double pipe are adopted. it can. Further, the injectant discharge ports 28 and 29 are provided with the stirring blades 13 and 1, respectively.
It is not necessary to provide it separately from 3, ..., and the inside of the blades 13 ... may be hollow and a discharge port may be provided at its tip. Further, in the above embodiment, the stirring shaft 7 is vertically
Although the ground has been connected to improve the ground, it goes without saying that the number of connected stirring shafts 7 or the presence or absence of connection may be appropriately selected according to the depth of the ground to be improved. Further, in the above-described embodiment, the discharge port 2 is changed from the ground improvement target depth.
Although the ejection of the infusate was started before the distance between 8 and 29, it goes without saying that the ejection of the infusate may be started before this.
【0037】[0037]
【発明の効果】以上詳細に説明したように、この発明に
よれば、上方に位置する注入剤吐出口から注入剤を吐出
させつつ撹拌軸及び注入軸を回転上昇させることで、撹
拌軸のスクリュー羽根により注入剤の注入量に対応する
量の余剰の土壌を地上に排出しつつ、注入軸に設けられ
た撹拌翼で地盤土壌と注入剤とを撹拌混合することで地
盤改良を行っているので、従来懸念されていた注入剤の
注入に伴う地盤の体積膨張を抑制することができる。こ
れにより、地盤の盛り上がりや不要な側圧の発生といっ
た現象を可能な限り抑え、周辺地盤への影響を十分に緩
和することが可能となる。As described above in detail, according to the present invention, the stirring shaft and the injection shaft are rotated and raised while discharging the injecting agent from the injecting agent discharge port located above, whereby the screw of the stirring shaft is rotated. The ground is improved by stirring and mixing the ground soil and the pouring agent with the stirring blades provided on the pouring shaft, while discharging the surplus soil corresponding to the pouring amount of the pouring agent to the ground with the blades. It is possible to suppress the volume expansion of the ground due to the injection of the injection agent, which has been a concern in the past. As a result, it is possible to suppress phenomena such as swelling of the ground and generation of unnecessary lateral pressure as much as possible, and to sufficiently mitigate the influence on the surrounding ground.
【0038】また、地盤改良目標深さより少なくとも注
入剤吐出口間の距離だけ手前の位置で下方に位置する注
入剤吐出口から注入剤を吐出しているので、回転上昇時
にのみ注入剤を吐出した際に未改良として残される部分
の地盤についても注入剤を撹拌混合せしめて地盤改良を
行うことができる。しかも、撹拌軸等を回転下降させる
時には下方の吐出口から注入剤を吐出し、かつ、撹拌軸
等を回転上昇させる時には上方の吐出口から注入剤を吐
出しているので、注入軸に設けられた撹拌翼が吐出口を
追いかける構成となり、土壌と注入剤との撹拌混合効率
が高くて大変に好ましい。Further, since the injectant is discharged from the injectant discharge port located below the ground improvement target depth by at least the distance between the injectant discharge ports, the injectant is discharged only when the rotation is increased. At this time, the ground can be improved by stirring and mixing the injecting agent with respect to the ground that remains unimproved. Moreover, when the stirring shaft or the like is rotated and lowered, the injectant is discharged from the lower discharge port, and when the stirring shaft or the like is rotated and raised, the injectant is discharged from the upper discharge port. Since the stirring blade follows the discharge port, the stirring and mixing efficiency of the soil and the infusate is high, which is very preferable.
【0039】よって、この発明によれば、撹拌軸等引き
上げ時に余剰の土壌を撹拌軸のスクリュー羽根で地上に
排出させることで周辺地盤への影響を極力緩和し、か
つ、撹拌翼及び注入剤吐出口によって地盤土壌を余すと
ころなく撹拌混合して地盤改良を行え、かつ、その効率
も大変良好なものとすることができる。Therefore, according to the present invention, the excess soil is discharged to the ground by the screw blades of the stirring shaft when the stirring shaft and the like are pulled up, and the influence on the surrounding ground is mitigated as much as possible, and the stirring blade and the injection agent are discharged. Through the outlet, the ground soil can be thoroughly mixed with stirring to improve the ground, and its efficiency can be made very good.
【0040】さらに、この発明では、注入軸が所定距離
上下動自在に撹拌軸に取り付けられ、かつ、この注入軸
の上下動に伴って、切換装置により注入軸の上下に位置
する注入剤吐出口への連通が切り換えられる装置を用い
ているので、注入軸の回転上昇あるいは下降に応じて自
動的に上方の吐出口又は下方の吐出口から注入剤が吐出
され、何等特殊な制御機構を設けることなく前述した工
法を簡易な構成で実現することができる。Further, according to the present invention, the injection shaft is attached to the stirring shaft so as to be vertically movable for a predetermined distance, and the injecting agent discharge port positioned above and below the injection shaft is moved by the switching device as the injection shaft moves up and down. Since a device that can switch the communication with the injection port is used, the injection agent is automatically discharged from the upper discharge port or the lower discharge port in response to the rotation rise or fall of the injection shaft, and any special control mechanism must be provided. Without this, the above-mentioned construction method can be realized with a simple configuration.
【図1】 請求項2の発明の一実施例を示すための軟弱
地盤改良装置の全体構成を示す正面図である。FIG. 1 is a front view showing an overall configuration of a soft ground improvement device for showing an embodiment of the invention of claim 2.
【図2】 図1のII円内を拡大視して示した正面図であ
る。FIG. 2 is an enlarged front view showing the inside of a circle II in FIG. 1;
【図3】 図3は注入軸のみを取り出して示した正面図
である。FIG. 3 is a front view showing only an injection shaft.
【図4】 図4は、注入軸が最上端に至った状態の縦断
面図である。FIG. 4 is a vertical cross-sectional view showing a state where the injection shaft reaches the uppermost end.
【図5】 図5は、注入軸が最下端に至った状態の縦断
面図である。FIG. 5 is a vertical cross-sectional view showing a state where the injection shaft reaches the lowermost end.
【図6】 図6は、請求項1の軟弱地盤改良工法につい
ての発明の一実施例を説明するための工程図である。FIG. 6 is a process drawing for explaining one embodiment of the invention regarding the soft ground improvement method of claim 1.
G 地盤 S 地盤土壌 6 撹拌軸駆動装置 7 撹拌軸 9 スクリュー羽根 11 注入軸 13 撹拌翼 18 供給管 27 切換装置 28、29 注入剤吐出口 G Ground S Ground soil 6 Stirring shaft drive device 7 Stirring shaft 9 Screw blade 11 Injection shaft 13 Stirring blade 18 Supply pipe 27 Switching device 28, 29 Injectant discharge port
─────────────────────────────────────────────────────
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【手続補正書】[Procedure amendment]
【提出日】平成8年12月11日[Submission date] December 11, 1996
【手続補正1】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】全文[Correction target item name] Full text
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【書類名】 明細書[Document Name] Statement
【発明の名称】 軟弱地盤改良装置Title: Soft ground improvement device
【特許請求の範囲】[Claims]
【発明の詳細な説明】Detailed Description of the Invention
【0001】[0001]
【発明の属する技術分野】この発明は、地盤土壌に注入
剤を注入してこれらを撹拌混合することで地盤を改良す
る軟弱地盤改良装置に係り、特に、所定半径内におい
て、確実に土壌と注入剤との撹拌混合効果が高まる軟弱
地盤改良装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft ground improvement apparatus for improving the ground by injecting an injecting agent into the ground soil and stirring and mixing them, and particularly, to reliably inject the soil into the soil within a predetermined radius. The present invention relates to a soft ground improvement device with which the effect of stirring and mixing with an agent is enhanced.
【0002】[0002]
【従来の技術】埋立地等の軟弱地盤を改良するための装
置として、地盤中にセメント系硬化剤等の注入剤を注入
してこれらを撹拌翼で攪拌混合し、これにより地盤を硬
化させることで地盤改良を行う軟弱地盤改良装置は従来
から知られている。2. Description of the Related Art As a device for improving soft ground such as landfills, an injection agent such as a cement-based hardening agent is injected into the ground, and these are agitated and mixed by a stirring blade to harden the ground. Conventionally, a soft ground improvement device for improving ground is known.
【0003】この従来から知られている軟弱地盤改良装
置は、 注入口の位置の関係から、注入剤が注入されない未改
良区域が残ってしまう。 注入剤が吐出されると同時に撹拌されるので、注入剤
が注入口から離れた位置まで到達せず、所定半径範囲に
確実に注入されない場合が生じ、改良強度(品質)が確
実に得られない。 注入剤の撹拌に斑が生じ、均一な強度の地盤改良区域
が得られない。 等の欠点を有し、適用範囲が制限されているのが現状で
ある。[0003] In this conventionally known soft ground improvement device, an unimproved area where the injection agent is not injected remains due to the position of the inlet. Since the injectate is agitated at the same time as it is discharged, the injectate may not reach a position away from the injection port and may not be reliably injected into a predetermined radius range, and improved strength (quality) cannot be reliably obtained. . Stirring of the injection agent causes unevenness, and a ground improvement area with uniform strength cannot be obtained. At present, it has drawbacks such as the above, and its application range is limited.
【0004】[0004]
【発明が解決しようとする課題】この発明は前記事情に
鑑みてなされたもので、所定半径範囲に確実に注入さ
れ、改良強度(品質)が確実に得られ、かつ、注入剤の
撹拌に斑がなく、均一な強度の地盤改良区域が得られる
軟弱地盤改良装置の提供を目的としている。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to reliably inject into a predetermined radius range, to reliably obtain improved strength (quality), and to improve the agitation of the injection agent. It is an object of the present invention to provide a soft ground improvement apparatus that can obtain a ground improvement area having uniform strength.
【0005】[0005]
【課題を解決するための手段】前述した課題を解決する
ために、本願発明は、以下に掲げるような構成を採用し
ている。すなわち、請求項1に係る発明は、外周にスク
リュー羽根が取り付けられてオーガースクリュー状に形
成された撹拌軸と、この撹拌軸先端に取り付けられて複
数段の撹拌翼を有する注入軸とを備え、かつ、前記注入
軸の上下に注入剤吐出口が設けられた軟弱地盤改良装置
であって、さらに、次の構成を具備することを特徴とし
た注入剤と地盤土壌とを撹拌混合させることで地盤改良
を行う軟弱地盤改良装置である。In order to solve the above-mentioned problems, the present invention adopts the following constitutions. That is, the invention according to claim 1 comprises a stirring shaft formed into an auger screw shape with screw blades attached to the outer periphery, and an injection shaft having a plurality of stages of stirring blades attached to the tip of the stirring shaft, And a soft ground improvement device having an injectant discharge port provided above and below the injection shaft, further comprising a following composition, by stirring and mixing the injectant and the ground soil, the ground It is a soft ground improvement device for improvement.
【0006】(i)注入軸は軸線方向に延びる二重筒に形
成されている (ii)注入軸に備えられた複数段の撹拌翼の最上位のもの
よりさらに上位に上方注入剤吐出口が設けられ、さら
に、該撹拌翼の最下位のものよりさらに下位に下方注入
剤吐出口が設けられている (iii)上方注入剤吐出口は前記二重筒の外筒内部に連通
されていると共に、下方注 入剤吐出口は二重筒の内筒
内部に連通されている(I) The injection shaft is formed in a double cylinder extending in the axial direction. (Ii) The upper injection agent discharge port is located higher than the uppermost one of a plurality of stages of stirring blades provided on the injection shaft. Further, a lower injection agent discharge port is provided below the lowermost one of the stirring blades. (Iii) The upper injection agent discharge port is communicated with the inside of the outer cylinder of the double cylinder. The lower injection agent outlet is connected to the inside of the double cylinder
【0007】[0007]
【作用】本願発明では、撹拌軸及び注入軸を対象地盤中
に貫入させ、下方注入剤吐出口の位置が地盤改良目標深
さより少なくとも上下の注入剤吐出口間の距離だけ手前
の位置にきたら、下方注入剤吐出口からのみ注入剤を吐
出させつつそこから吐出された注入剤を撹拌しながら目
標深さまで貫入させる。その後、撹拌軸及び注入軸を目
的深さから上昇させる際には、上方注入剤吐出口からの
み注入剤を吐出させ、この注入剤を撹拌しながら上昇さ
せる。これにより、目的とする深さ方向の改良区間全域
に渡って注入剤が連続的に注入されることになるし、改
良区間の土中に、注入剤が先行して注入された後に撹拌
翼により撹拌されることになるので、所定半径範囲全体
に注入剤が注入されると共に、均一な混合ができる。In the present invention, when the stirring shaft and the injection shaft are penetrated into the target ground, and the position of the lower injection agent discharge port is at a position at least a distance between the injection agent discharge ports above and below the ground improvement target depth, While injecting the injectant only from the lower injectant ejecting port, the injectant ejected from the injecting agent is allowed to penetrate to the target depth while stirring. After that, when the stirring shaft and the injection shaft are raised from the target depth, the injection agent is discharged only from the upper injection agent discharge port, and the injection agent is raised while being stirred. Accordingly, to so that infusate over the improvement section throughout the depth direction of interest is continuously injected, Kai
Since the injecting agent is first injected into the soil in the good section and is then agitated by the agitating blade, the injecting agent is injected over the entire predetermined radius range and uniform mixing is possible.
【0008】[0008]
【発明の実施形態】以下、本願請求項1及び2の発明の
実施例について図面を参照して説明する。図1ないし図
5は、これら発明の一実施例である軟弱地盤改良装置を
示す図である。これらの図において、符号1は改良すべ
き軟弱地盤(以下、単に地盤と称する)G上に設置され
たクローラ式ベースマシーンであり、クローラ2、作業
部3、及びブーム4により垂直に保持された支柱5から
概略構成されている。DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing a soft ground improvement device which is one embodiment of the present invention. In these drawings, reference numeral 1 is a crawler type base machine installed on a soft ground (hereinafter, simply referred to as ground) G to be improved, and is vertically held by a crawler 2, a working unit 3 and a boom 4. The pillar 5 is roughly configured.
【0009】支柱5には撹拌軸駆動装置6が図示されて
いない上下動駆動装置により上下動自在に支持され、こ
の撹拌軸駆動装置6には、その下端に1対の中空筒状の
撹拌軸7、7が左右(図1紙面に垂直方向)に並んで連
結されている。撹拌軸7先端には、図2に示すように、
注入軸11が所定距離上下動自在な状態で取り付けられ
ている。なお、この撹拌軸7内部には、図示されない注
入剤供給手段によりセメントスラリー等の注入剤が供給
される。A stirring shaft driving device 6 is supported on the support column 5 by a vertical movement driving device (not shown) so as to be vertically movable. The stirring shaft driving device 6 has a pair of hollow cylindrical stirring shafts at its lower end. 7 and 7 are connected side by side (perpendicular to the plane of FIG. 1). At the tip of the stirring shaft 7, as shown in FIG.
The injection shaft 11 is attached so as to be vertically movable for a predetermined distance. Note that an injectant such as cement slurry is supplied to the inside of the stirring shaft 7 by an injectant supply means (not shown).
【0010】撹拌軸7は、図2に示すように、中空円筒
状の軸体8と、この軸体8外周に形成された螺旋状のス
クリュー羽根9により、全体としてオーガースクリュー
状に形成されている。なお、この実施例では、撹拌軸7
はその長手方向に複数本接続可能な構成とされている。As shown in FIG. 2, the stirring shaft 7 is formed into an auger screw shape as a whole by a hollow cylindrical shaft 8 and a spiral screw blade 9 formed on the outer periphery of the shaft 8. I have. In this embodiment, the stirring shaft 7
Are configured to be connectable in the longitudinal direction.
【0011】一方、注入軸11は、図2ないし図3に示
すように、前記撹拌軸7の軸体8と略同一径に形成され
た軸体12と、この軸体12の外周に複数段(この実施
例では3段)設けられた撹拌翼13、13、…と、軸体
12の下端部外周に形成された螺旋羽根状の掘削部14
とから概略構成されている。On the other hand, as shown in FIGS. 2 and 3, the injection shaft 11 has a shaft 12 having substantially the same diameter as the shaft 8 of the stirring shaft 7, and a plurality of steps around the shaft 12. (Three stages in this embodiment) provided, and a spiral blade-shaped excavation portion 14 formed on the outer periphery of the lower end portion of the shaft 12.
It is schematically composed of
【0012】撹拌軸7下端には、図2ないし図4に示す
ように、軸体8と同径の取付筒10が設けられ、これら
軸体8及び取付筒10は、それぞれの下端及び上端に形
成されたフランジ7a、10a間がボルト止めされるこ
とで互いに連結されている。取付筒10内面は横断面六
角形に形成されていると共に、前記注入軸11の軸端上
端部12aは、この取付筒10内面に嵌合する横断面六
角形状に縮径されて形成されている。At the lower end of the stirring shaft 7, as shown in FIGS. 2 to 4, a mounting cylinder 10 having the same diameter as the shaft body 8 is provided. The formed flanges 7a and 10a are connected to each other by being bolted. The inner surface of the mounting cylinder 10 is formed in a hexagonal cross section, and the upper end 12a of the shaft end of the injection shaft 11 is formed to have a diameter reduced to a hexagonal cross section that fits into the inner surface of the mounting cylinder 10. .
【0013】取付筒10内面には、前述した六角形の一
辺に相当する長さのボス15、15が水平方向に延在さ
れて刻設される一方、前記軸体上端部12aの前記ボス
15を臨む位置には、このボス15と同一の水平長さで
かつその高さがボス15より高いボス16が刻設され、
これらボス15、16間にはピン17が嵌入されてい
る。On the inner surface of the mounting cylinder 10, bosses 15, 15 having a length corresponding to one side of the above-mentioned hexagon are engraved so as to extend in the horizontal direction, while the bosses 15 of the shaft upper end 12a are provided. A boss 16 having the same horizontal length as the boss 15 and a height higher than the boss 15 is engraved at a position facing
A pin 17 is fitted between the bosses 15 and 16.
【0014】従って、前記注入軸11は、取付筒10を
介して前記撹拌軸7と一体に回動すると共に、ボス16
の高さ分だけ上下動自在にこの撹拌軸7に取り付けられ
ている。なお、縮径された軸体上端部12aと軸体12
本体との間には段部12bが形成され、軸端12(すな
わち注入軸11)が最上端にまで至った際に前記取付筒
10下端が段部12bに当接するように構成されている
(図4参照)。すなわち、この段部12bは注入軸11
の上方移動の際のストッパーとして作用する。Accordingly, the injection shaft 11 rotates integrally with the stirring shaft 7 via the mounting cylinder 10 and the boss 16
Is attached to the stirring shaft 7 so as to be movable up and down by the height of. In addition, the shaft body upper end portion 12a and the shaft body
A step 12b is formed between the main body and the main body, and the lower end of the mounting cylinder 10 is configured to contact the step 12b when the shaft end 12 (that is, the injection shaft 11) reaches the uppermost end ( (See FIG. 4). That is, this step 12b is
Acts as a stopper for upward movement.
【0015】軸端12は中空筒状に形成されていると共
に、この軸体12の内部には、その全長に亙る長さの供
給管18がその軸線に沿って配設されている。これによ
り、軸体12は、軸体12そのものを外筒に、また供給
管18を内筒にした二重筒構造に形成されている。供給
管18は、その上端が前記撹拌軸7と取付筒10との接
続部分付近にまで延出され、かつ、その上端開口部が閉
塞されると共に、上端部側面に貫通孔19、19、…が
穿設されている。The shaft end 12 is formed in a hollow cylindrical shape, and a supply pipe 18 having a length extending over the entire length thereof is arranged inside the shaft body 12 along the axis thereof. Thus, the shaft body 12 is formed in a double cylinder structure in which the shaft body 12 itself is an outer cylinder and the supply pipe 18 is an inner cylinder. The supply pipe 18 has an upper end extending to near the connection between the stirring shaft 7 and the mounting cylinder 10, an upper end opening thereof is closed, and through holes 19, 19,. Are drilled.
【0016】また、供給管18は、軸体12上端及び最
上段の撹拌翼13の取付位置よりやや上部において、そ
れぞれリング状の固定部材20、22で軸体12内面に
固定されている。軸体12上端に位置する一方の固定部
材20は、その厚さ方向に貫通孔21、21が穿設され
ている。また、他方の固定部材22は、軸体12内面と
供給管18外面との間の間隙を閉塞するようにこの軸体
12内面に設けられている。The supply pipe 18 is fixed to the inner surface of the shaft 12 by ring-shaped fixing members 20 and 22, respectively, at the upper end of the shaft 12 and slightly above the mounting position of the uppermost stirring blade 13. One fixing member 20 located at the upper end of the shaft body 12 is provided with through holes 21 in the thickness direction thereof. The other fixing member 22 is provided on the inner surface of the shaft 12 so as to close a gap between the inner surface of the shaft 12 and the outer surface of the supply pipe 18.
【0017】供給管18上端にはリング状の切換部材2
3が外嵌されている。切換部材23は、前記撹拌軸7の
軸体8及び取付筒10の間に挾持された固定され、その
厚さ方向に貫通孔24、24が穿設されている。切換部
材23は、前記注入軸11の軸体12が最下端にまで至
った際にこの切換部材23により前記供給管18の貫通
孔19が閉塞されるように、その厚さが予め設定されて
いる(図5参照)。なお、切換部材23と供給管18外
面との間には軸受等が介在されることで、液密な状態で
これら供給管18と切換部材23とが相互に摺動自在と
されている。A ring-shaped switching member 2 is provided at the upper end of the supply pipe 18.
3 is externally fitted. The switching member 23 is fixedly held between the shaft body 8 of the stirring shaft 7 and the mounting cylinder 10, and has through holes 24 in the thickness direction thereof. The thickness of the switching member 23 is set in advance so that the through hole 19 of the supply pipe 18 is closed by the switching member 23 when the shaft body 12 of the injection shaft 11 reaches the lowermost end. (See FIG. 5). A bearing or the like is interposed between the switching member 23 and the outer surface of the supply pipe 18, so that the supply pipe 18 and the switching member 23 can slide relative to each other in a liquid-tight state.
【0018】また、供給管18上端の前記切換部材23
下方の位置には、同様にリング状のシール部材25が外
嵌、固定されている。このシール部材25は取付筒10
内径よりやや小径に形成され、上面にゴムリング等の弾
性リング26が取り付けられている。シール部材25
は、注入軸11の軸体12が最上端にまで至った際にこ
のシール部材25により切換部材23の貫通孔24、2
4下端開口部を閉塞しうるように、その取付位置が予め
設定されている(図4参照)。The switching member 23 at the upper end of the supply pipe 18
Similarly, a ring-shaped seal member 25 is externally fitted and fixed to the lower position. This sealing member 25 is
An elastic ring 26 such as a rubber ring is attached to the upper surface, and has a diameter slightly smaller than the inner diameter. Seal member 25
When the shaft 12 of the injection shaft 11 reaches the uppermost end, the sealing member 25 allows the through-holes 24, 2
4 The mounting position is set in advance so that the lower end opening can be closed (see FIG. 4).
【0019】以上述べたことから、注入軸11の軸体1
2が最上端にまで至った際には、シール部材25により
切換部材23の貫通孔24、24下端開口部が閉塞さ
れ、かつ、供給管18の上端貫通孔19、19が切換部
材23の上方に位置することで、撹拌軸7の軸体8内部
が供給管18内部に連通される(図4参照)。As described above, the shaft 1 of the injection shaft 11
When 2 reaches the uppermost end, the through-holes 24 and 24 at the lower end of the switching member 23 are closed by the seal member 25, and the upper-end through-holes 19 and 19 of the supply pipe 18 are located above the switching member 23. , The inside of the shaft 8 of the stirring shaft 7 communicates with the inside of the supply pipe 18 (see FIG. 4).
【0020】同様に、注入軸11の軸体12が最下端に
まで至った際には、切換部材23により供給管18の上
端貫通孔19、19が閉塞され、かつ、シール部材25
が切換部材23下方へと移動することで、撹拌軸7の軸
体8内部が注入軸11と軸体12内部と供給管18との
間の空間に連通される(図5参照)。すなわち、切換部
材23、シール部材25は、軸体12の上下動に応じて
注入軸11の軸体12内部又は供給管18内部を撹拌軸
7の軸体8内部へ切り換えて連通させる切換手段27を
構成している。Similarly, when the shaft body 12 of the injection shaft 11 reaches the lowermost end, the switching member 23 closes the upper end through holes 19 of the supply pipe 18 and the sealing member 25.
Is moved below the switching member 23, whereby the inside of the shaft 8 of the stirring shaft 7 is communicated with the space between the injection shaft 11, the inside of the shaft 12 and the supply pipe 18 (see FIG. 5). That is, the switching member 23 and the sealing member 25 switch the inside of the shaft body 12 of the injection shaft 11 or the inside of the supply pipe 18 to the inside of the shaft body 8 of the agitation shaft 7 in accordance with the vertical movement of the shaft body 12 to communicate with each other. Are configured.
【0021】また、前記固定部材22上方の軸体12に
は、この軸体12内部に連通する逆止弁を有する注入剤
吐出口28、28が設けられている。さらに、軸体12
下端部の掘削部14には、前記供給管18に連通する逆
止弁を有する注入剤吐出口29、29(図2参照)が設
けられている。すなわち、注入軸11には、その上下端
にそれぞれ注入剤吐出口28、29が設けられており、
その吐出口には逆止弁が設けられている。The shaft 12 above the fixing member 22 is provided with injecting agent discharge ports 28 having a check valve communicating with the inside of the shaft 12. Further, the shaft 12
Injection outlets 29 and 29 (see FIG. 2) having a check valve communicating with the supply pipe 18 are provided in the excavation portion 14 at the lower end. That is, the injection shaft 11 is provided with injection agent discharge ports 28 and 29 at the upper and lower ends thereof,
A check valve is provided at the discharge port.
【0022】次に、以上のような構成を有する本願発明
の軟弱地盤改良装置を使用した軟弱地盤改良工法の一態
様を図6を参照して説明する。なお、この施工例では、
撹拌軸7、7を2対(4本)用いて地盤改良を行う例を
示す。Next, one mode of the soft ground improvement method using the soft ground improving apparatus of the present invention having the above-mentioned structure will be described with reference to FIG. In addition, in this construction example,
An example of performing ground improvement using two pairs (four) of stirring shafts 7 and 7 will be shown.
【0023】(i)貫入開始 1対の撹拌軸7、7を撹拌軸駆動装置6に連結し(図6
(a)参照)、この駆動装置6により撹拌軸7、7及び注
入軸11、11を回転下降させることで、これらを地盤
G中に貫入させる(図6(b)参照)。撹拌軸7、7が十
分に貫入した状態で、これら撹拌軸7、7上端にさらに
1対の撹拌軸7、7を連結し(図6(c)参照)、さらに
前述した貫入工程を継続する。(I) Start of Penetration A pair of stirring shafts 7, 7 are connected to a stirring shaft driving device 6 (FIG. 6).
(See (a)), the drive device 6 rotates the stirring shafts 7, 7 and the injection shafts 11, 11 to penetrate the ground G (see FIG. 6 (b)). With the stirring shafts 7, 7 fully penetrated, a pair of stirring shafts 7, 7 are further connected to the upper ends of the stirring shafts 7, 7 (see FIG. 6 (c)), and the above-described penetration process is continued. .
【0024】(ii)注入開始 下方注入剤吐出口29が、地盤改良目標深さ(図6中破
線)から注入剤吐出口28、29間の間隔だけ手前の位
置に至った段階で(図6(d)参照)、図示されない注入
剤供給手段により撹拌軸7の軸体8内部に注入剤を圧
入、供給する。(Ii) Start of injection When the lower injection agent discharge port 29 reaches a position just before the ground improvement target depth (broken line in FIG. 6) by a distance between the injection agent discharge ports 28 and 29 (FIG. 6). (See (d)), the injection agent is press-fitted and supplied into the shaft body 8 of the stirring shaft 7 by an injection agent supply means (not shown).
【0025】この状態では、撹拌軸7及び注入軸11が
回転下降していることから下降抵抗による下から上への
力が働き注入軸11は最上端の位置にあり、従って、軸
体8内部は供給管18内部に連通されている。これによ
り、軸体8内部に供給された注入剤は、供給管18を通
じて下方注入剤吐出口29に至り、この吐出口29から
地盤G中に吐出される(図4矢印参照)。そして、さら
に撹拌軸7及び注入軸11を回転下降させつつ注入剤を
吐出させることで、地盤土壌と注入剤とを撹拌混合して
略吐出口28、29間の距離の地盤改良を行う(図6
(c)参照)。In this state, since the stirring shaft 7 and the injection shaft 11 are rotating and descending, a downward-to-upward force is exerted by the downward resistance, and the injection shaft 11 is at the uppermost position. Is connected to the inside of the supply pipe 18. As a result, the infusate supplied to the inside of the shaft body 8 reaches the lower infusate discharge port 29 through the supply pipe 18, and is discharged into the ground G from this discharge port 29 (see the arrow in FIG. 4). Then, by further rotating and lowering the stirring shaft 7 and the pouring shaft 11 to eject the infusate, the ground soil and the infusate are agitated and mixed to improve the ground in the distance between the ejection ports 28 and 29 (Fig. 6
(c)).
【0026】(iii)軸引上 注入軸11先端が地盤改良目標深さにまで到達したら、
次に、撹拌軸7及び注入軸11を回転させることで回転
上昇させる(図6(f)参照)。この状態でも、前述した
注入剤供給手段からの撹拌軸7内部への注入剤供給は継
続しておく。撹拌軸7が回転上昇されている状態では、
上昇抵抗による上から下への力が働き注入軸11は最下
端の位置にあり、従って、軸体8内部は注入軸11の軸
体12と供給管18との間の空間に連通されている。こ
れにより、軸体8内部に供給された注入剤は、軸体12
を通じて上方注入剤吐出口28に至り、この吐出口28
から地盤G中に吐出される(図5矢印参照)。そして、
さらに撹拌軸7及び注入軸11を回転上昇させつつ注入
剤を吐出させることが、地盤土壌は注入剤とを撹拌混合
して地盤改良を行う。(Iii) Pulling up the shaft When the tip of the injection shaft 11 reaches the ground improvement target depth,
Next, the stirring shaft 7 and the injection shaft 11 are rotated to be rotated upward (see FIG. 6 (f)). Even in this state, the supply of the injecting agent from the above-mentioned injecting agent supplying means into the stirring shaft 7 is continued. In a state where the stirring shaft 7 is rotated and raised,
The injection shaft 11 is located at the lowermost position due to the upward-downward force caused by the rising resistance. Therefore, the inside of the shaft 8 is communicated with the space between the shaft 12 of the injection shaft 11 and the supply pipe 18. . As a result, the injection agent supplied to the inside of the shaft 8 is
Through to the upper injection agent discharge port 28, and the discharge port 28
Is discharged into the ground G (see the arrow in FIG. 5). And
Further, the injecting agent is discharged while the stirring shaft 7 and the injecting shaft 11 are rotated and raised, and the ground soil is stirred and mixed with the injecting agent to improve the ground.
【0027】注入剤を地盤Gに注入する際、この注入剤
の注入量に対応する量の地盤土壌は余剰になり、前述の
如く周囲地盤に悪影響を及ぼす。しかしながら、この余
剰の土壌Sは、撹拌軸7が回転上昇されていることか
ら、そのスクリュー羽根9によって地上に排出される
(図6(g)参照)。土壌S排出量は、注入剤注入量及び
土壌性状等に応じて適宜決定すれば良いが、これは撹拌
軸7回転数により調整可能である。When the injection is injected into the ground G, the amount of ground soil corresponding to the injection amount of the injection becomes excessive and adversely affects the surrounding ground as described above. However, the surplus soil S is discharged to the ground by the screw blade 9 because the stirring shaft 7 is rotated up (see FIG. 6 (g)). The amount of soil S discharged may be appropriately determined in accordance with the amount of the injection agent injected, the soil properties, and the like, but this can be adjusted by the number of rotations of the stirring shaft 7.
【0028】さらに、2本連結された撹拌軸7、7のう
ち上方の撹拌軸7が地上に出現した状態で、この撹拌軸
7を切り離し、再度、駆動装置6を撹拌軸7、7に連結
する(図6(h)参照)。そして、さらに撹拌軸7、注入
軸11を回転上昇させつつ、上方に位置する注入剤吐出
口28から注入剤を地盤G中に吐出させることで、地盤
土壌と注入剤とを撹拌混合し、かつ余剰の土壌Sをスク
リュー羽根9で地上に排出しながら地盤改良を行う)図
6(i)、(j)参照)。Further, with the upper stirring shaft 7 of the two connected stirring shafts 7 and 7 appearing on the ground, the stirring shaft 7 is disconnected, and the driving device 6 is connected to the stirring shafts 7 and 7 again. (See FIG. 6 (h)). Then, while further rotating the stirring shaft 7 and the injection shaft 11, the injection agent is discharged into the ground G from the injection agent discharge port 28 located above, whereby the ground soil and the injection agent are stirred and mixed, and The ground improvement is performed while discharging the surplus soil S to the ground by the screw blade 9) (see FIGS. 6 (i) and 6 (j)).
【0029】以上説明したような施工法により地盤改良
を行うことができるが、このような施工例で使用される
本願発明に係る軟弱地盤改良装置は、オーガスクリュー
状に形成された撹拌軸7の先端に注入軸11を設けた装
置であるから、注入剤を地盤G中に吐出しつつ撹拌軸
7、注入軸11を回転上昇させることでこれらを引き上
げる際に、撹拌軸7のスクリュー羽根9で注入剤の注入
量に対応する余剰の地盤土壌を地上に排出させることが
できる。これにより、従来懸念されていた注入剤注入に
よる体積膨張を抑制でき、地盤の盛り上がりや不要な側
圧の発生といった現象を可能な限り抑え、周辺地盤への
影響を十分に緩和することが可能となる。The ground can be improved by the construction method as described above. However, the soft ground improvement apparatus according to the present invention used in such a construction example has a stirring shaft 7 formed in an auger screw shape. Since the device is provided with the injection shaft 11 at the tip, when the injecting agent is discharged into the ground G and the stirring shaft 7 and the injection shaft 11 are rotated and raised to pull them up, the screw blade 9 of the stirring shaft 7 is used. It is possible to discharge the surplus ground soil corresponding to the injection amount of the injection agent to the ground. As a result, volume expansion due to the injection of the injection agent, which has been a concern in the past, can be suppressed, phenomena such as swelling of the ground and generation of unnecessary lateral pressure can be suppressed as much as possible, and the influence on the surrounding ground can be sufficiently reduced. .
【0030】さらに、上記本願発明の実施例では、撹拌
翼13、13、…が設けられた注入軸11の撹拌翼が設
けられている高さ位置よりもさらに上下位にそれぞれ注
入剤吐出口28、29を設けているので、地盤改良目標
深さから吐出口28、29間の距離だけ手前の位置で下
方注入剤吐出口29から注入剤を吐出しつつ、撹拌軸7
等を回転下降させることで地盤改良を行うことができる
ので、前述の如く上方にのみ吐出口が設けられている装
置と比べた場合、未改良として残される部分の地盤にも
注入剤を注入できる。Furthermore, in the embodiment of the present invention, the stirring blades 13 and 13, the stirring blade is set in the injection shaft 11 ... it is provided
Since the injecting agent discharge ports 28 and 29 are provided above and below the height position where the ink is removed, the injecting agent discharge ports 28 and 29 are positioned below the injecting agent discharge holes 28 and 29 from the ground improvement target depth. While discharging the injection agent from the outlet 29, the stirring shaft 7
Since the ground can be improved by rotating and lowering etc., injecting agent can be injected also into the ground left unmodified as compared with the device in which the discharge port is provided only above as described above. .
【0031】しかも、下方注入剤吐出口29は、最下位
の撹拌翼よりもさらに下方にあるので、撹拌翼13、…
が下方吐出剤吐出口29を追いかける構成となり、ま
た、上方注入剤吐出口28は、最上位の撹拌翼よりもさ
らに上方にあるので、撹拌翼13、…が上方吐出剤吐出
口28を追いかける構成となり、いずれの場合にも吐出
された注入剤が所定の半径にまで注入されてから撹拌作
用が行われるので、土壌と注入剤との撹拌混合効率が高
く、均一で所定の半径の改良区域が得られる。Moreover, since the lower injection agent discharge port 29 is located further below the lowest stirring blade, the stirring blades 13, ...
Follows the lower discharge agent discharge port 29, and the upper injection agent discharge port 28 is further above the uppermost stirring blade, so that the stirring blades 13, ... Follow the upper discharge agent discharge port 28. In any case, since the discharged injecting agent is injected to a predetermined radius and then the stirring action is performed, the stirring and mixing efficiency of the soil and the injecting agent is high, and a uniform and improved area of a predetermined radius is obtained. can get.
【0032】なお、この発明の軟弱地盤改良装置は、そ
の細部が前記実施例に限定されることなく、種々の変形
例が可能である。一例として、前記上方及び下方の注入
剤吐出口28、29の切り替えは、注入軸11の上下動
によるものだけでなく、従来の二重管中空撹拌軸による
地盤改良剤の注入時における流路切換手段など種々の手
段を採用できる。The soft ground improvement device of the present invention is not limited to the details of the embodiment, and various modifications are possible. As an example, the switching of the upper and lower injection agent outlets 28, 29 is not limited to the vertical movement of the injection shaft 11, but also the flow path switching at the time of injection of the soil improvement agent by the conventional double pipe hollow stirring shaft. Various means such as means can be adopted.
【0033】また、前記施工例では撹拌軸7を上下に2
本連結して地盤改良を行っていたが、撹拌軸7の連結本
数あるいは連結の有無については改良すべき地盤の深さ
に応じて適宜選択されればよいことは勿論である。さら
に、前記施工例では、地盤改良目標深さから上下の注入
剤吐出口28、29間の距離だけ手前に注入剤の吐出を
開始していたが、これより以前で注入剤の吐出を開始し
ても良いことは言うまでもない。Further, in the above-mentioned construction example, the stirring shaft 7 is vertically
Although the ground has been connected to improve the ground, it goes without saying that the number of connected stirring shafts 7 or the presence or absence of connection may be appropriately selected according to the depth of the ground to be improved. Further, in the above-mentioned construction example, the injection of the infusate was started before the ground improvement target depth by the distance between the upper and lower infusate injection ports 28 and 29, but the injection of the infusate is started before this. It goes without saying that it is okay.
【0034】[0034]
【発明の効果】本願発明によれば、撹拌軸にはスクリュ
ー羽根があり、注入軸には撹拌翼があるので、上方注入
剤吐出口から注入剤を吐出させつつ撹拌軸及び注入軸を
回転上昇させる際、撹拌軸のスクリュー羽根により注入
剤の注入量に対応する量の余剰の土壌を地上に排出しつ
つ、注入軸に設けられた撹拌翼で地盤土壌と注入剤とを
撹拌混合することで地盤改良を行うことができ、従来懸
念されていた注入剤の注入に伴う地盤の体積膨張を抑制
することができる。これにより、地盤の盛り上がりや不
要な側圧の発生といった現象を可能な限り抑え、周辺地
盤への影響を十分に緩和することが可能となる。 According to the present invention, since the stirring shaft has the screw blade and the injection shaft has the stirring blade, the stirring shaft and the injection shaft are rotated and raised while discharging the injection agent from the upper injection agent discharge port. When doing so, while discharging the excess soil corresponding to the injection amount of the injecting agent to the ground by the screw blade of the stirring shaft, by stirring and mixing the ground soil and the injecting agent with the stirring blade provided on the injection shaft. The ground can be improved, and the volume expansion of the ground due to the injection of the injection agent, which has been a concern in the past, can be suppressed. As a result, it is possible to suppress phenomena such as swelling of the ground and generation of unnecessary lateral pressure as much as possible, and to sufficiently mitigate the influence on the surrounding ground.
【0035】しかも、撹拌軸等を回転下降させる時には
下方注入剤吐出口から注入剤を吐出し、かつ、撹拌軸等
を回転上昇させる時には上方吐出口から注入剤を吐出で
きるように、上下2つの注入剤吐出口が撹拌翼の高さ位
置よりもさらに上下位となるように設けてあるので、未
改良区域が残らないようにすることができる。Moreover, when the stirring shaft or the like is rotated and lowered, the injection agent is discharged from the lower injection agent discharge port, and when the stirring shaft or the like is rotated and raised, the injection agent can be discharged from the upper discharge port. Since the injection agent discharge port is provided further above and below the height position of the stirring blade, it is possible to prevent the unimproved area from remaining.
【0036】これらの効果に加えて、本願発明では、注
入撹拌に際して注入軸に設けられた撹拌翼が吐出口を追
いかける構成となるから、 注入剤が所定半径範囲に確実に注入されるので、改良
強度(品質)が確実に得られ、要求に応じた地盤強度が
得られる。 注入剤の撹拌に斑がないので、所定半径内では均一な
強度の地盤改良柱が得られる。 という優れた効果が得られる。In addition to these effects, in the present invention, since the stirring blade provided on the injection shaft follows the discharge port during the injection and stirring, the injection agent is surely injected within a predetermined radius range, which is an improvement. The strength (quality) is surely obtained, and the ground strength according to the demand is obtained. Since there is no unevenness in the stirring of the injection material, a ground improvement column having uniform strength can be obtained within a predetermined radius. An excellent effect is obtained.
【図面の簡単な説明】[Brief description of drawings]
【図1】 本願発明に係る軟弱地盤改良装置の一実施例
を示すための全体構成を示す正面図である。FIG. 1 is a front view showing the overall configuration for showing an embodiment of a soft ground improvement device according to the present invention.
【図2】 図1におけるII円内を拡大視して示した正面
図である。FIG. 2 is a front view showing an enlarged view of a circle II in FIG.
【図3】 注入軸のみを取り出して示した正面図であ
る。FIG. 3 is a front view showing only an injection shaft.
【図4】 注入軸が最上端に至った状態の縦断面図であ
る。FIG. 4 is a longitudinal sectional view showing a state where an injection shaft reaches an uppermost end.
【図5】 注入軸が最下端に至った状態の縦断面図であ
る。FIG. 5 is a longitudinal sectional view showing a state where an injection shaft reaches a lowermost end.
【図6】 本発明に係る軟弱地盤改良装置を用いた施工
例としての軟弱地盤改良工法について説明するための工
程図である。FIG. 6 is a process diagram for explaining a soft ground improvement method as a construction example using the soft ground improving device according to the present invention.
【符号の説明】 G 地盤 S 地盤土壌 6 撹拌軸駆動装置 7 撹拌軸 9 スクリュー羽根 11 注入軸 13 撹拌翼 18 供給管 27 切換手段 28、29 注入剤吐出口[Explanation of Codes] G Ground S Ground soil 6 Stirring shaft drive device 7 Stirring shaft 9 Screw blade 11 Injection shaft 13 Stirring blade 18 Supply pipe 27 Switching means 28, 29 Injectant discharge port
───────────────────────────────────────────────────── フロントページの続き (72)発明者 林 富貴男 東京都中央区京橋二丁目16番1号 清水建 設株式会社内 (72)発明者 小田原 卓郎 東京都中央区京橋二丁目16番1号 清水建 設株式会社内 (72)発明者 黒澤 正之 東京都江戸川区船堀5―8―23 黒沢鉄工 株式会社内 (72)発明者 池田 勉 東京都江戸川区船堀5―8―23 黒沢鉄工 株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomio Hayashi 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Takuro Odawara 2-1-1-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Masayuki Kurosawa 5-8-23 Funabori, Edogawa-ku, Tokyo Kurosawa Iron Works Co., Ltd. (72) Inventor Tsutomu Ikeda 5-8-23 Funabori, Edogawa-ku, Tokyo Kurosawa Iron Works Co., Ltd.
Claims (2)
オーガースクリュー状に形成された撹拌軸と、この撹拌
軸先端に取り付けられて複数段の撹拌翼を有する注入軸
とを備え、かつ、前記注入軸の上下に注入剤吐出口が設
けられた軟弱地盤改良装置で注入剤と地盤土壌とを撹拌
混合させることで地盤改良を行う際に、前記撹拌軸及び
注入軸を回転下降させることでこれらを地盤改良すべき
地盤内に貫入させる工程と、地盤改良目標深さから少な
くとも注入剤吐出口間の距離だけ手前の位置で下方に位
置する注入剤吐出口から注入剤を吐出させつつさらに撹
拌軸及び注入軸を回転下降させる工程と、前記注入軸先
端が地盤改良目標深さまで到達した後に、上方に位置す
る注入剤吐出口から注入剤を吐出させつつ前記撹拌軸及
び注入軸を回転上昇させることで、地盤土壌と注入剤と
を撹拌混合させながら余剰の土壌を排出して地表面まで
地盤改良を行うことを特徴とする軟弱地盤改良工法。1. An injection shaft comprising an agitating shaft formed in an auger screw shape with screw blades attached to an outer periphery thereof, and an injection shaft having a plurality of stages of stirring blades attached to a tip of the agitation shaft. When the soil is improved by agitating and mixing the infusate and the ground soil with the soft soil improvement device having the injectant discharge port above and below, the agitating shaft and the injecting shaft are rotated and lowered to make them ground. Step of injecting into the ground to be improved, and further stirring shaft and injection while injecting the injectant from the injectant discharge port located below at a position at least a distance between the injectant discharge ports from the ground improvement target depth Rotating and lowering the shaft, and after the tip of the pouring shaft reaches the ground improvement target depth, while rotating the stirring shaft and pouring shaft while ejecting the pouring agent from the pouring agent discharge port located above. By doing so, the soil soil and the injecting agent are stirred and mixed while discharging the excess soil to perform the soil improvement to the ground surface.
オーガースクリュー状に形成された中空撹拌軸と、この
撹拌軸先端に所定距離上下動自在に取り付けられ、外周
に複数段の撹拌翼を有する注入軸とを備え、この注入軸
は軸線方向に延びる二重筒に形成されていると共に、そ
の上下にはそれぞれ注入剤吐出口が設けられ、上方に位
置する注入剤吐出口は前記二重筒の外筒内部に連通され
ていると共に、下方に位置する注入剤吐出口は二重筒の
内筒内部に連通され、かつ、この注入軸には、自身の上
方および下方への移動に応じてそれぞれ外筒及び内筒内
部を前記撹拌軸内部へ連通させる切換装置が設けられて
いることを特徴とする軟弱地盤改良装置。2. A hollow stirring shaft formed into an auger screw shape with screw blades attached to the outer periphery, and an injection shaft having a plurality of stages of stirring blades attached to the tip of this stirring shaft so as to be vertically movable for a predetermined distance. The injection shaft is formed in a double cylinder extending in the axial direction, and injection agent discharge ports are provided above and below the injection cylinder, and the injection agent discharge port located above is outside the double cylinder. While being communicated with the inside of the cylinder, the injectant discharge port located below is communicated with the inside of the inner cylinder of the double cylinder, and the injection shaft is externally attached to the injection shaft according to the upward and downward movements of itself. A soft ground improvement device comprising a switching device for communicating the inside of the cylinder and the inside of the cylinder to the inside of the stirring shaft.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP30220096A JPH09273148A (en) | 1996-11-13 | 1996-11-13 | Weak ground improving equipment |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP30220096A JPH09273148A (en) | 1996-11-13 | 1996-11-13 | Weak ground improving equipment |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63184819A Division JPH0639779B2 (en) | 1988-07-25 | 1988-07-25 | Soft ground improvement method and equipment |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15823298A Division JPH10311025A (en) | 1998-06-05 | 1998-06-05 | Improvement method for weak subsoil |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH09273148A true JPH09273148A (en) | 1997-10-21 |
Family
ID=17906152
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP30220096A Pending JPH09273148A (en) | 1996-11-13 | 1996-11-13 | Weak ground improving equipment |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH09273148A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6592300B2 (en) | 2001-07-25 | 2003-07-15 | C. S. Kim And Associates | Pile apparatus and construction process of placing concrete pile in ground |
KR100923437B1 (en) * | 2009-02-25 | 2009-11-02 | 주식회사 정토지오텍 | Agitating apparatus |
-
1996
- 1996-11-13 JP JP30220096A patent/JPH09273148A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6592300B2 (en) | 2001-07-25 | 2003-07-15 | C. S. Kim And Associates | Pile apparatus and construction process of placing concrete pile in ground |
KR100923437B1 (en) * | 2009-02-25 | 2009-11-02 | 주식회사 정토지오텍 | Agitating apparatus |
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