JPH09125451A - Excavation and agitation of ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate preparation works at every element in the excavating and agitating works of the ground. SOLUTION: When an excavation shaft 10 and agitation shafts 12, 14 are inserted to penetrate the ground to a specified depth, the pushing work by a vertically moving mechanism is brought to a stop and the agitation shafts 12, 14 are rotated and a hardening agent is injected from respective jet holes 12c, 14c of the agitation shafts 12, 14. In this operation, existing soil is agitated by the agitation blades 12b, 14b of respective agitation shafts 12, 14 and the injected agent is mixed with the soil. A driving mechanism 22 is driven after agitating and mixing the soil and the agent to transfer a traveling base 18 along a guide rail 30 and parallelly shift the excavation shaft 10 and the agitation shafts 12, 14. A pair of excavation shafts 10 are reversely rotated against each other by a rotary drive so as to transfer the excavated soil to the first agitation shaft 12 side by the screw blade 10b. When the above works advance in some extent and a mixture zone of the excavated soil and the hardening material is formed at the rear side of the second agitation 14, a core material like a wide-flange shape steel is buried in the mixture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground excavation and agitation device, and more particularly to a device suitable for constructing a retaining wall in a narrow place where the head is severely restricted.

[0002]

2. Description of the Related Art A soil cement continuous wall construction method (SMW construction method) using a multi-screw kneading auger machine is known as a construction method of an earth retaining wall constructed in the ground when constructing an underground structure. A multi-screw kneading auger used for this type of construction method is generally equipped with three stirring shafts arranged in a row, and a drill bit is provided at the tip of each stirring shaft. A spiral stirring blade is provided on the outer circumference of each stirring shaft.

The stirring blades provided on the stirring shafts are arranged such that the rotation ranges of the stirring blades that are horizontally adjacent to each other in plan view partially overlap each other and are spaced vertically. It is located in a position where interference can be avoided. Further, each stirring shaft is provided with a hardening material injection hole penetrating in the axial direction and opening at the tip of the drill bit. When constructing a continuous wall, by rotating each agitation shaft, it is penetrated while excavating the ground with a drilling bit. Each stirring shaft is divided into a plurality of units, and when one stirring shaft is penetrated to a predetermined depth, it is penetrated to a predetermined depth by successively adding another stirring shaft.

In the penetration process, the ground soil is drilled in-situ by the drill bit, and at the same time, the cement milk or the hardening material mixed with bendnite is ejected from the injection hole, and the hardening material and the in-situ sand are mixed. And are mixed and stirred to form a soil cement wall having a length in which three stirring shafts are connected in a row as one element. Then, when the stirring shaft reaches the planned depth of construction of the soil cement wall, the stirring shaft is pulled up to be separated into each unit and dismantled, so that the stirring shaft is overlapped with the end of the element being formed, and the steps described above are sequentially repeated. By doing so, a continuous wall in which elements are laterally connected is constructed.

However, in such a soil cement continuous wall construction method, especially in a narrow place where the head is severely restricted,
For example, there was a technical problem described below when constructing under an overhead line, under a guard, underground, or under a viaduct.

[0006]

That is, in the above-mentioned soil cement continuous wall construction method, since the setup of the stirring shaft is changed for each element, the work period becomes long and the work becomes complicated. Further, especially in a place where the head limitation is severe, it is very difficult to assemble and disassemble the stirring shaft.

The present invention has been made in view of such conventional problems, and an object of the present invention is to excavate the ground, which does not require setup change for each element,
It is to provide a stirring device.

[0008]

In order to achieve the above object, the present invention has a drill bit at the tip, stirring blades are provided on the outer periphery, and the stirring blades are arranged in rows to stir the ground. While a plurality of agitation shafts for injecting a ground hardening material such as cement milk, a rotation drive unit provided on the upper end side of the agitation shaft, a traveling platform that supports the rotation drive unit in a vertically movable manner, and the rotation drive A ground excavation and agitation device comprising an elevating mechanism for vertically moving a section and a drive mechanism for moving the traveling platform along a rail, which is provided at a front end side in the forming direction of the underground continuous wall. Then, a pair of excavating shafts having a drill bit at the tip and screw blades at the outer periphery are arranged opposite to each other on the front side so as to sandwich the shaft center of the stirring shaft, and the screw is driven by the rotary drive unit. Feather said excavated earth and sand The pair of excavation shafts are rotated in reverse to each other so as to be transferred to the stirring shaft side, and the stirring shaft and the excavation shaft are moved horizontally by the drive mechanism without being pulled up after penetrating to a predetermined depth in the ground. I chose An injection hole for the ground hardening material may be provided in the stirring shaft in the vicinity of the drill bit and the stirring blade. According to the ground excavation and agitation device having the above configuration,
Since the agitation shaft and the excavation shaft are horizontally moved without being pulled up after penetrating to a predetermined depth in the ground, it is not necessary to assemble and disassemble the agitation shaft and the excavation shaft for each element.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 3
FIG. 1 shows an embodiment of a ground excavation and agitation device according to the present invention. The device shown in the figure includes a pair of excavation shafts 10 and two first and second agitation shafts arranged in rows. 12, 14
Rotation drive unit 16, traveling platform 18, and lifting mechanism 20
And a drive mechanism 24.

Although the details of the pair of excavating shafts 10 are not shown in FIG. 3, the pair of excavating shafts 10 are arranged on the back surface side of one of the excavating shafts 10 so that the other excavating shafts having the same structure face each other. It is arranged on the front side of the first stirring shaft 12 so as to be on the front end side in the forming direction of the earth retaining wall to be formed. Further, the pair of excavation shafts 10 are arranged at symmetrical positions with the center lines of the stirring shafts 12 and 14 in the column direction sandwiched therebetween.

Each excavation shaft 10 is divided into a plurality of units, and a drilling bit 10a is provided at the tip. Further, a spiral screw blade 10b is provided on the outer periphery of each excavation shaft 10. The first and second agitation shafts 12 and 14 are divided into a plurality of units similarly to the excavation shaft 10, and have drilling bits 12a and 14 at their tips, respectively.
a is provided.

Further, stirring blades 12b and 14b are fixedly provided on the outer circumferences of the first and second stirring shafts 12 and 14, respectively. Stirring blades 12b fixed to the stirring shafts 12 and 14,
14b has a size such that the respective turning radii overlap each other in the horizontally adjacent portions when seen in a plan view, and are spaced vertically in order to avoid mutual interference. It is arranged intermittently. In addition,
The rotation range of the screw blade 10b provided on the excavation shaft 10 is set to be approximately 1/2 of the rotation range of the stirring blades 12b and 14b (see FIG. 5).

The first and second stirring shafts 12 and 14 are provided with a hardening material supply passage (not shown) penetrating through the inside in the vertical direction, and the center of the lower end of the drilling bits 12a and 14a and each stirring blade 12b. , 14b and the injection holes 12c, 14 of the hardening material
c is provided. From the injection holes 12c and 14c, cement milk or a hardening material in which bentonite is mixed is injected. The pair of excavation shafts 10 and the first and second agitation shafts 12 and 14 are rotatably connected by a connecting plate 24 provided at an appropriate position.

The rotary drive unit 16 drives the excavation shaft 10 and the first and second agitation shafts 12 and 14 for rotation, and has a hydraulic motor and a plurality of gears housed therein.
The excavation shaft 10 and the first and second stirring shafts 12 and 14 are provided on the lower surface side.
Is provided with a connector 16a for removably coupling. The rotation drive unit 16 is supported by a support column 26 that is erected on the traveling platform 18 so as to be swingable, and a guide rod 28 that is provided on the front side of the support column 26 so as to be vertically movable.

The traveling platform 18 has a plurality of wheels 16a, and each wheel 16a is fitted to a guide rail 30 extending along the forming direction of the earth retaining wall to be formed. The elevating mechanism 20 moves the rotation drive unit 16 up and down, and is specifically composed of a hydraulic jack arranged along the column 26. The drive mechanism 22
Rotate the wheels 16a to move the carriage 16 to the guide rail 3
It is moved along 0, and is composed of a hydraulic motor, a speed reducer, and the like.

1 and 2, the portion indicated by the reference numeral 32 is a jack for raising and lowering the column 26, and the portion 34 is
It is a hydraulic unit that supplies hydraulic pressure to the rotary drive unit 16 and the like. 4 to 7 show an example of a construction method for continuously constructing an earth retaining wall using the apparatus having the above configuration. When forming the retaining wall, first, as shown in FIG. 4, the retaining wall is installed on one end side of the retaining wall to be formed by the device. At this time, the pair of excavation shafts 10 are positioned on the front end side in the direction in which the earth retaining wall is formed.

When the installation of the apparatus is completed, the rotation driving unit 16 is pushed down by the lifting mechanism 20 while the rotation driving unit 16 is being pushed down.
The excavating shaft 10 and the stirring shafts 12 and 14 are rotated by.
When the excavation shaft 10 and the stirring shafts 12 and 14 are rotated, these shafts gradually penetrate while excavating the ground with the excavation bits 10a, 12a and 14a. Then, when it penetrates to the length of the unit unit, other units are sequentially added,
This operation is performed to the depth at which the retaining wall is to be constructed.

In this case, there is no special limitation on the rotating direction of the pair of excavating shaft 10 and stirring shafts 12 and 14, and they can be rotated in any direction. Excavation axis 10 and stirring axis 12,
When 14 is penetrated to a predetermined depth, as shown in FIG. 6, the pushing by the elevating mechanism 20 is stopped and the stirring shaft 1
While rotating 2 and 14, the hardening material is injected from the injection holes 12c and 14c of the stirring shafts 12 and 14, respectively.

By this operation, the stirring blades 12b and 14b of the stirring shafts 12 and 14 stir the in-situ ground soil and sand, and at the same time, the hardening material injected from the injection holes 12c and 14c is mixed with the soil. Then, when such stirring and mixing progresses, the driving mechanism 22 is driven to move the traveling platform 18 along the guide rails 30 and horizontally move the excavation shaft 10 and the stirring shafts 12 and 14.

At this time, the pair of excavating shafts 10 are mutually driven by the rotary drive unit 16 so that the screw blades 10b transfer the excavated earth and sand to the side of the first stirring shaft 12 as shown by the arrow in FIG. Rotate back to. When the excavating shaft 10 is rotated in this way and the drive mechanism 22 horizontally moves in the direction of forming the earth retaining wall, the earth and sand excavated by the screw blades 10b are smoothly moved, which facilitates horizontal movement. At the same time, the balance of directionality is improved.

When the above-mentioned work progresses to a certain extent and a mixture region of excavated soil and hardened material (a portion shown by hatching in FIGS. 6 and 7) is formed behind the second stirring shaft 14, the hardened material is removed. Before being solidified, a core material 32 such as H-section steel is embedded in this mixture. If you continue such work,
By hardening the hardening material, the soil cement wall is sequentially formed from one end side where the apparatus is installed.

When the excavation shaft 10 reaches the other end of the site where the earth retaining wall is to be formed, the horizontal movement is stopped and the elevating mechanism 20 pulls up the excavation shaft 10 and the stirring shafts 12, 14 to disassemble them. And the construction is completed. By the way, according to the ground excavation and agitation device configured as described above, since the excavation shaft 10 and the agitation shafts 12 and 14 are horizontally moved without being pulled up after penetrating to a predetermined depth in the ground,
Assemble stirring shafts 12 and 14 and excavation shaft 10 for each element,
It eliminates the need for dismantling work and shortens the construction period.

Further, since the excavation shaft 10 and the stirring shafts 12 and 14 can be assembled and disassembled only once, they can be constructed in a narrow space where the head is severely restricted, such as under an overhead line, under a guard, underground, or under a viaduct. It can be done relatively easily without much difficulty. In the process of penetration of the excavation shaft 10 and the stirring shafts 12 and 14 described above, the injection hole 1 of the stirring shafts 12 and 14
Whether or not to inject the hardening material from 2c and 14c can be arbitrarily selected, but if the hardening material is injected while being injected, it is possible to move horizontally immediately after the penetration is completed.

[0024]

As described above in detail in the embodiments,
According to the ground excavation and agitation device of the present invention, when the excavation shaft and the agitation shaft are added and assembled first, it is not necessary to repeat the assembly and disassembly for each element unlike the conventional device of this type. Therefore, while saving labor,
Safety is also improved.

Further, the apparatus of the present invention can be applied to a wide range of soil properties, from soft cohesive soil to sand-gravel layer with a tight dip. Further, by appropriately adding a stirring shaft and an excavation shaft, it is possible to construct a relatively large depth, for example, up to about 50 m. Furthermore, it is very effective when there are restrictions on the empty space at the construction site.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of an apparatus for continuously constructing an earth retaining wall according to the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a front view of essential parts of an excavation shaft and a stirring shaft used in the continuous building device.

FIG. 4 is a side view of an initial stage of a construction process when constructing an earth retaining wall using the device according to the present invention.

FIG. 5 is an explanatory view of an excavation range formed in the initial stage of construction in the device.

FIG. 6 is an explanatory front view of a process performed subsequent to FIG.

FIG. 7 is a front explanatory view of a process performed subsequent to FIG.

[Explanation of symbols]

 10 Excavation Shaft 10a Drilling Bit 10b Screw Blade 12 First Stirring Shaft 12a Drilling Bit 12b Stirring Blade 12c Injection Hole 14 Second Stirring Shaft 14a Drilling Bit 14b Stirring Blade 14c Injection Hole 16 Rotation Drive 18 Travel Platform 20 Lifting Mechanism 22 Drive mechanism 30 Guide rail 36 Core material

Claims (2)

[Claims] 1. A plurality of stirring shafts having a drilling bit at the tip, stirring blades provided on the outer periphery, and arranged in rows, for spraying a ground hardening material such as cement milk while stirring the ground. A rotary drive unit provided on the upper end side of the stirring shaft, a traveling platform that supports the rotational drive unit in a vertically movable manner, an elevating mechanism that vertically moves the rotational drive unit, and a rail for the traveling platform. An excavation and agitation device for the ground having a drive mechanism for moving along, in the front end side in the forming direction of the underground continuous wall, on the front side thereof so as to sandwich the axial center of the agitation shaft, A pair of excavation shafts provided with a drill bit at the tip and screw blades on the outer periphery are arranged to face each other, and the pair of excavation shafts are arranged so as to transfer the excavated soil to the stirring shaft side by the rotation drive unit. The excavation axes of It causes the rotation, excavation of the ground, characterized in that horizontally moves by the drive mechanism without raising the said drilling shaft and the stirring shaft after penetration to a predetermined depth in the ground, stirrer. 2. The ground excavating and stirring apparatus according to claim 1, wherein the stirring shaft is provided with an injection hole for the ground hardening material in the vicinity of the drill bit and the stirring blade.