JPS63312416A - Construction work of underground wall in underground trench with partly degraded wall - Google Patents

Abstract

PURPOSE:To simplify construction work by eliminating the needs for chipping operation by a method in which in excavating the inside ground, hardened fluid substance containing solidifying agent in the ground is removed with bags. CONSTITUTION:When a reinforcing bar cage 17 with a sheet bag 21 is inserted into an underground wall 11, the bag 21 is set in the face of a degraded portion 13. A self-setting stabilizer liquid 25 is then injected through a pipe 23 into the bag 21 from the ground's surface. When concrete 27 is placed and sufficiently hardened, the inside ground of the underground wall 31 is excavated to remove the stabilizer liquid 25 readily. The hardened fluid substance containing solidifying agent can thus be easily removed with the bag 21 when excavating the inside ground.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of constructing an underground wall in an underground trench where a portion of the wall surface has collapsed.

(Prior Art) Generally, when constructing an underground continuous wall, an underground trench is first excavated in the ground. However, because there are weak spots in the geology of the excavated ground, a portion of the wall of this underground trench often collapses. Conventionally, the following method has been used to construct an underground wall when a part of the wall of an underground trench collapses.

First, as shown in FIG. 2(A), a reinforcing bar cage 2 is inserted into an underground trench 1 excavated and formed in the ground.

At this time, a part of the wall surface of this underground trench 1 collapses, and a large void 3 is formed on the outside of the reinforcing bar cage 2.

Next, as shown in FIG. 2(B), concrete is poured into the underground trench 1. As a result, concrete is simultaneously poured into the void 3, and a protrusion 5 of a predetermined size protruding from the surface of the reinforced concrete underground wall 4 is integrally formed. Therefore, this protruding portion 5 is removed by a cutting operation or the like when cutting the inside of the underground wall 4, and the desired underground wall 4 is constructed.

(Problems to be Solved by the Invention) However, the following problems have occurred in the conventional method of constructing an underground wall in an underground trench having a partially collapsed wall surface.

That is, since concrete is placed throughout the underground trench, including the partially collapsed wall surface, concrete is also placed in the collapsed portion. As a result, a concrete protrusion of a predetermined size protrudes from the surface of the basement wall, and in order to construct the desired basement wall, a large amount of this protruding hard concrete itself must be cut, which requires a great deal of effort. The problem was that it had become a thing. Moreover, the amount of concrete also increases during this pouring process, resulting in the problem of being uneconomical.

In addition, if the collapsed wall is located at the bottom of an underground trench and the volume of the collapsed part is large, there is a problem that the installed reinforcing bar cage itself may move due to the pressure of the concrete when concrete is poured. There were also spots.

Therefore, the main object of the present invention is to provide a method for constructing an underground wall in an underground trench having a partially collapsible wall surface, which eliminates the cutting work and is less labor-intensive.

Another object of the present invention is to provide an economical underground wall construction method that reduces the amount of concrete to be placed.

Furthermore, the present invention provides construction of an underground wall that can reliably construct an underground wall without causing the reinforcing bar cage to move due to the pressure of concrete placement, regardless of the location or size of the collapsing wall surface. One of its purposes is to provide law.

(Means for Solving the Problems) Therefore, the present invention provides a method for inserting a reinforcing bar cage into the underground trench when an underground trench is excavated in the ground and there is a partially collapsed wall in the underground trench. Attach an empty bag in advance to the side of the reinforcing bar cage corresponding to the collapsed area, insert the reinforcing bar cage, and pour a self-hardening stabilizing liquid or a solidifying agent-containing liquid such as poorly mixed mortar from underground into the empty bag. A substance is injected to fill and harden the space between the reinforcing bar cage and the collapsing wall surface with the assimilating agent-containing fluid material, and concrete is poured into the underground trench to form the underground wall integrally with the reinforcing bar cage. By removing the hardened material of the solidifying agent-containing fluid substance in the ground together with the bag when the ground inside the underground wall is cut, the underground trench with partially collapsed wall surface can be removed. This is for constructing walls.

(Example) Hereinafter, an example of the method of constructing an underground wall in an underground trench having a partially collapsible wall surface according to the present invention will be described with reference to the drawings.

FIGS. 1A to 1E are cross-sectional views for explaining a method of constructing an underground wall according to one embodiment.

First, as shown in FIG. 1(A), a guide trench is installed at an excavation position in the ground, and an underground trench 11 having a predetermined width and a predetermined depth is excavated in the ground while being filled with bentonite slurry. In this case, an example is shown in which both sides of the upper part of the wall surface of the underground trench 11 have collapsed due to weak geology, etc., and a void (collapsed part) 13 with a predetermined volume is formed. The shape and dimensions of this collapsed portion 13 are determined by the ultrasonic measuring instrument 15.
Detected and measured by etc.

Next, as shown in FIG. 1(B), a reinforcing bar cage 17 is inserted and arranged in this underground trench 11. At this time, at a predetermined height position of the reinforcing bar cage 17 corresponding to the collapsed part 13 of the underground trench, plywood boards (separators) 19 of a size corresponding to the size of the collapsed part 13 are attached at positions corresponding to the wall surfaces on both sides. It will be done. Furthermore, an empty sheet bag 21 made of a predetermined material and having a volume corresponding to the volume of the collapsible portion 13 is attached to the outside of the plywood board 19. A vibrator 23 extending to the ground is connected to each sheet bag 21.

The reinforcing bar 1 with the empty sheet bag 21 attached in this way!
i! 17 into the underground trench 11, this sheet bag 2
1 will be installed at a position facing the collapsing section 13. Next, the self-hardening stabilizing liquid 25 is injected from the ground into the sheet bag 21 through the pipe 23.

As a result, as shown in FIG. 1(C), when a predetermined amount of the self-hardening stabilizing liquid 25 is injected from the pipe 23 into the sheet bag 21, the sheet bag 21 is swollen with the self-hardening stabilizing liquid 25. . That is, the inside of the collapsible portion 13 is filled with the self-hardening stabilizing liquid 25. In other words, underground trench 1
The wall where part of 1 collapsed has been repaired.

After this self-hardening stabilizing liquid 25 has sufficiently hardened, as shown in FIG. Underground wall 31 will be constructed. In this case, since the sheet bag 21 is filled with the hardened self-hardening stabilizing liquid and is in close contact with the collapsing part, the concrete will not go around into the collapsing part 13.

Finally, after this poured concrete 27 has sufficiently hardened, the ground inside the underground wall 31 is excavated, and the underground wall 31 is
When the inner wall surface of the underground trench 11 is exposed, the self-hardening stabilizing liquid that has filled the collapsed part 3 inside the underground trench 11 and hardened is trapped in the bag 21 and attached to the underground wall 31 via the separator 19. This can be easily removed since it is only in the . As a result, the underground wall 3 has a smooth wall surface.
1 is constructed.

In the above embodiments of the present invention, a self-hardening stabilizer was used as the substance to be injected and filled into the sheet bag.
According to the method of the present invention, other solidifying agent-containing fluid materials such as poorly mixed mortar can also be used without being limited thereto. Further, in the above embodiment, a separator such as a plywood board was used between the sheet bag and the reinforcing bar, but it is also possible to omit this separator.

(Effects) As described above, according to the method of the present invention, the collapsed part of an underground trench is filled with a fluid substance containing a solidifying agent such as a stabilizing liquid or mortar while being confined in a bag. When cutting the ground inside the underground wall after placing concrete, the hardened material of the solidifying agent-containing fluid material can be removed together with the bag, so the conventional cutting work can be omitted.

In addition, when pouring concrete for underground walls, since concrete does not enter the collapsed parts of underground trenches, it is possible to use an economical construction method for underground walls that requires less concrete than before, and it is also possible to Underground walls can be reliably constructed without the walls moving toward collapsed areas due to the pressure during concrete pouring.

[Brief explanation of the drawing]

FIG. 1(A) to FIG. 1(E) each show various steps of a method according to an embodiment of the present invention, and FIG. 1(A) is a side view showing the state in which an underground trench is excavated in the ground. Cross-sectional view, Figure 1 (B) is a side cross-sectional view showing reinforcing steel inserted into the underground trench, Figure 1 (C) is a sheet bag filled with self-hardening stabilizing liquid inside the collapsed area. Its side sectional view showing the condition,
Figure 1 (D) is a side sectional view showing the state in which concrete has been poured into an underground trench, and Figure 1 (E) is after excavating the ground on one side of the underground wall from the state shown in Figure 1 (D). FIG. 2 (A>) and FIG. 18-2 (B) are side sectional views showing the state at each step of the underground wall construction method according to the prior art. 11...Underground trench, 13...Collapsed part, 21...Empty bag, 25...Fluid material containing solidifying agent, 27...
・Concrete, 31... Basement wall. Patent applicant Obayashi Co., Ltd. Agent
People Patent Attorney - Color Ken Axis
Patent Attorney Masatoshi Matsumoto Figure 1 (A) Figure 1 Figure 2 (A) Figure 2 (B)

Claims (1)

[Claims] When an underground trench is excavated in the ground and there is a partially collapsed wall inside the trench, when inserting a reinforcing bar cage into the underground trench, the side of the reinforcing bar cage corresponding to the collapsed part must be placed in advance. Attach an empty bag and insert the reinforcing bar cage, and inject a fluid substance containing a solidifying agent such as self-hardening stabilizing liquid or poorly mixed mortar from underground into the empty bag to create a space between the reinforcing bar cage and the collapsing wall surface. Filling and hardening with the solidifying agent-containing fluid substance, placing concrete in the underground trench to construct an underground wall integrally with the reinforcing bar cage, and cutting the ground inside the underground wall. A method for constructing an underground wall in an underground trench having a partially collapsed wall surface, characterized in that the hardened material of the solidifying agent-containing fluid substance present in the ground is removed together with the bag.