JP3825550B2 - Ground improvement and solidified wall construction equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an apparatus used for ground improvement and solidification wall construction.
[0002]
[Prior art]
In order to improve the ground, a plurality of conventional methods for injecting cement preparations and chemicals into the target location have been proposed, and one such method is a jet-type agitation method. In this jet type stirring method, a stirring shaft having a stirring blade at the lower end and digging vertically downward, a high-pressure spray nozzle provided on the stirring blade so as to be oriented in a horizontal direction or an oblique direction, and a cement liquid in the nozzle Using a ground improvement device equipped with a large-capacity ultra-high pressure pump that supplies solidified materials such as the same, a plurality of cylindrical improvement bodies are constructed to improve the ground. And in this jet type agitation method, even if there is an existing structure in the target site for ground improvement, it is possible to create an improved body that is in close contact with it without damaging the existing structure, Even when the improved bodies are connected in series, it can be constructed with good integrity.
[0003]
[Problems to be solved by the invention]
In the ground improvement device used in the above-described conventional jet type stirring method, it is difficult to ensure the vertical accuracy because it digs vertically downward while rotating the stirring shaft itself. Further, the high-pressure spray nozzles are also provided only in two or three stirring blades, and the rotational speed of the stirring shaft is limited. Therefore, in order to obtain an improved body of a quality of a predetermined level or higher, the ground and the solidified material are used. There was a problem that much time was required for mixing and stirring. Furthermore, when a solidified wall is formed by connecting cylindrical improvement bodies continuously, there is a problem in that the outer shape of the solid wall becomes a waveform, and an extra portion in which design strength cannot be expected is generated.
[0004]
Therefore, the present invention is intended to solve the above problems, and the problem is that the vertical accuracy of the improved body can be easily secured when the ground is improved or the solidified wall is constructed. It is possible to shorten the mixing and agitation time of the solidified material, and further improve the ground and solidify that can reduce the extra part that cannot be expected in design strength when the solidified wall is formed by connecting the improved bodies. The object is to provide a wall construction device.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a cutter drum that rotates around a horizontal axis by a drive motor , a support frame that supports the cutter drum and is raised and lowered in the ground, and an outer periphery of the cutter drum. Ground improvement and solidification wall construction comprising a plurality of excavated teeth, a plurality of nozzles provided on the side surface of the cutter drum , and a solidification material supply means for supplying a slurry-like solidification material to the nozzles at high pressure Providing equipment.
In the apparatus of the present invention, the ground improvement is performed while the earth and sand cutting drum is rotated around the horizontal axis, or the solidified wall is constructed. Therefore, compared with the conventional apparatus that excavates by the rotation of the vertical axis, the vertical deviation is smaller. Decrease and improve vertical accuracy. Further, the projection plane of the earth and sand cutting drum rotating around the horizontal axis becomes rectangular, and it becomes possible to construct a rectangular improvement body and a solidified wall, so that the excess portion where the design strength cannot be expected is reduced.
[0006]
Here, the nozzle is provided on the side surface of the earth and sand cutting drum, and is arranged so as to oppose the ground cutting portion. Further, when a plurality of nozzles are provided, each is arranged on a different circumference of the drum. By arranging a plurality of nozzles in this way and rotating the earth and sand cutting drum while rotating the slurry-like solidified material at a high pressure, the ground can be cut evenly, and this high-pressure solidified material can be used to close existing ground. An improved body having good adhesion to an existing structure can be constructed without damaging the structure, and the solidified material and earth and sand can be mixed efficiently.
[0007]
The slurry-like solidifying material may be any material that can be solidified after being mixed with earth and sand to form an improved body or a solidified wall. For example, cement liquid or cement-based solidifying material is made into a slurry. Liquid can be used.
[0008]
In the conventional injection type agitation method, the amount of discharged mud is generally 100% or more of the improved capacity, whereas in the present invention, the ground is cut by both the solidified material injected at a high pressure and the earth and sand cutting drum. Therefore, less spraying for cutting is required, the amount of waste mud can be greatly reduced compared with the conventional jetting agitation method, and the required spraying pressure of the solidified material is also reduced compared to the conventional system, thus simplifying the equipment. It became possible.
[0009]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of the ground improvement and solidified wall construction apparatus of the present invention, FIG. 2 is an enlarged side view showing the periphery of the earth and sand cutting drum in the apparatus of FIG. 1, and FIG. FIG. 4A is a plan view schematically showing a planar arrangement, FIG. 4A is a cross-sectional view schematically shown along the alternate long and short dash line IVa-IVa in FIG. 2, and FIG. 4B is a diagram of FIG. It is sectional drawing shown simply along the dashed-dotted line IVb-IVb. As shown in FIGS. 1 to 3, the ground improvement and solidified wall construction apparatus 10 (hereinafter simply referred to as “ground improvement apparatus 10”) of the present invention is moved around a pair of horizontal rotating shafts 16 and 16 by a hydraulic motor 11. Two rotating left and right cutter drums 12a and 12b, and a tooth holder 14 and a tooth drum 14 ', which are attached to the outer periphery of the cutter drums 12a and 12b and hold a plurality of teeth 13 for excavation, are integrally supported. A support frame 17, a base machine 18 that lifts and lowers the support frame 17, and a power unit that supplies high-pressure hydraulic pressure to a hydraulic motor or the like. Further, a plurality of high-pressure injection nozzles 15 are provided on the side surfaces of the cutter drums 12a and 12b so as to be scattered on the diameter thereof, and each of the high-pressure injection nozzles 15 is connected to a high-pressure pump by a communication pipe (not shown). (Not shown), and this high-pressure pump can pump the cement liquid from a cement liquid supply device, such as a cement liquid stirring tank or a cement tank tank (not shown), to the high-pressure injection nozzle 15. Configure.
[0010]
Here, as shown by the arrow X, the two left and right cutter drums 12a and 12b rotating around the pair of horizontal rotation shafts 16 and 16 rotate in different directions. As a result, the cutter drums 12a and 12b counteract each other and cancel the force to move in the horizontal direction. Further, since the horizontal rotation shafts 16 and 16 of the cutter drums 12a and 12b are horizontal, the vertical digging direction shift is suppressed as compared with a conventional device that digs by rotating the vertical shaft. That is, in the conventional apparatus, since the axis of the rotating shaft and the excavation direction are the same, once an error occurs in the excavation direction, there is a disadvantage that the excavation error increases. 10 can prevent it.
[0011]
Next, the operation of the ground improvement device 10 of the present invention will be described. As shown in FIG. 4 (b), when the improved body 22 is constructed adjacent to the existing structure 20, first, the support frame 17 is hung at a position separated from the existing structure 20 by a predetermined length, and high pressure injection is performed. The cutter drums 12a and 12b are rotated by the hydraulic motor 11 without causing the cement liquid to be ejected from the nozzles 15 for use, and digging vertically downward.
When the cutter drums 12a and 12b reach the ground improvement depth, the cutter drums 12a and 12b are rotated while the support frame 17 is raised, and at the same time, the cement liquid is pumped from the supply device to the high-pressure spray nozzle 15. Spray from the cutter drums 12a and 12b. The cement liquid 21 sprayed at this high pressure excavates the surrounding ground, and the cutting soil and cement liquid 21 are mixed to form an improved body 22 (solidified wall).
[0012]
As a method for forming the improved body (solidified wall), in addition to the method described above, when the cutter drums 12a and 12b are rotated to dig vertically downward, the cement liquid 21 is simultaneously supplied from the supply device to the high-pressure injection nozzle 15. It is also possible to form an improved body (solidified wall) by pumping and spraying from the cutter drums 12a and 12b, and raising the support frame 17 when the planned depth is reached.
[Brief description of the drawings]
FIG. 1 is a schematic view of a ground improvement and solidified wall construction apparatus according to the present invention.
FIG. 2 is an enlarged side view around the earth and sand cutting drum in the apparatus of FIG.
FIG. 3 is a plan view schematically showing the earth and sand cutting drum.
4A is a cross-sectional view taken along one-dot chain line IVa-IVa in FIG. 2, and FIG. 4B is a cross-sectional view taken along one-dot chain line IVb-IVb in FIG.
[Explanation of symbols]
10 Ground improvement device (Ground improvement and solidified wall construction device)
11 Hydraulic motor (drive motor)
12a, 12b Cutter drum (sediment cutting drum)
15 Nozzle 16 Horizontal axis

Claims (2)

A cutter drum that rotates around a horizontal axis by a drive motor, a support frame that supports the cutter drum and is raised and lowered in the ground, a plurality of excavation teeth provided on the outer periphery of the cutter drum, and the cutter drum A ground improvement and solidified wall construction apparatus comprising a plurality of nozzles provided on a side surface of the steel plate and a solidified material supply means for supplying a slurry-like solidified material to the nozzles at a high pressure. The ground improvement and solidified wall construction device according to claim 1, wherein the plurality of nozzles are arranged on different circumferences of drum side surfaces.

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