JP2991017B2 - How to build a continuous underground wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a continuous underground wall capable of performing surface finishing with high accuracy.

[0002]

2. Description of the Related Art When a continuous underground wall is constructed on a collapsible ground such as a very young ground, a ground with a high groundwater level, and a cobblestone ground, collapse of an inner wall surface becomes a problem.

Therefore, conventionally, prior to the excavation of the ditch, the ground has been improved with a self-hardening stabilizer or the like to prevent collapse of the inner wall surface, and the stability of the inner wall surface has been secured by reducing the groundwater level. .

[0004]

However, in practice, it is not always possible to completely prevent the collapse of the inner wall surface only by adding this kind of auxiliary construction method, and as shown in FIG. When concrete C was cast in the collapsed state and the underground wall was constructed, the collapsed portion A required extra concrete C 'by the amount protruding from the planned wall shown by the imaginary line, and wasted much material. .

[0005] Further, when performing root cutting work after the construction of the continuous underground wall, it is indispensable to cut off a block of concrete C 'protruding from the planned wall surface, and the construction cost, the construction period, and the generation of noise at the time of cutting are required. There were problems such as necessity of measures for neighborhood.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to prevent irregularities of the underground wall surface due to collapse of the inner wall surface and to accurately finish the surface without performing complicated work. It is an object of the present invention to provide a method of constructing a continuous underground wall capable of performing the following.

[0007]

In order to achieve the above object, the present invention provides a step of excavating a ditch while supplying muddy water,
A step of hanging a partition plate along the inner wall surface of the groove,
A step of arranging a border sheet that causes relative sliding between the partition plate and the concrete casting surface side of the partition plate, and placing concrete while replacing the muddy water on the inside partitioned by the partition plate. A step of constructing the underground wall by pulling the partition plate out after the concrete is hardened.

Further, in the present invention, after the excavation work, a cross-section measuring machine is suspended in the groove to specify a position and a range of a collapse site on the inner wall surface, and the partition plate and the partition plate are moved to a position covering the collapse site. An edge sheet may be hung to cover the periphery of the collapse site.

[0009]

According to the above construction, the underground wall is constructed inside the partition wall, so that even if the excavated inner wall is collapsed, the concrete can flow into the collapsed portion by the partition plate. Absent. When the partition plate is pulled out after the concrete is hardened, the partition sheet causes relative sliding between the partition plate and the partition sheet, and the partition plate can be pulled out with small frictional resistance.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1A to 1D show a procedure for constructing a continuous underground wall according to a first embodiment of the present invention. First (a)
A pair of guide trenches 1 arranged on the ground surface
The ground E is excavated while filling the muddy water 2 with the guide as a guide to form a vertical groove 3 having a predetermined depth. In this embodiment, it is assumed that the ground E is a collapsed ground as described above, and that the collapsed portion 3a may be formed immediately below the guide trench 1 in the upper layer of the ground E.

After completion of the excavation work, a pair of partition plates 4 are suspended along the inner wall surfaces on both sides of the groove 3 using a heavy machine such as a crane as shown in FIG. Each partition plate 4 has a width of 1 gut and a vertical length equal to the depth of the groove 3.
It is an iron plate of 6 to 26 mm. Then, on the concrete casting surface side of the partition plate 4, as shown in an enlarged part of the figure,
For example, a polyethylene sheet 5 of about 5 mm thickness is arranged,
By suspending the partition plate 4 with the polyethylene sheet 5 inside and keeping the partition plate 4 in close contact with the inner wall surface by a fixture (not shown), the collapsed portion 3a generated during excavation is closed.

Next, a reinforcing bar (not shown) is connected to both partition plates 4.
Then, concrete C is poured inside through a tremi tube or the like and replaced with muddy water 2 as shown in FIG.

Each partition plate 4 is pressed against the inner wall surface in order from the lower side by the casting pressure of the concrete C. As a result, the concrete C is filled substantially along the cross-sectional shape of the groove 3, and the wall is formed by the two partition plates 4. The thickness is set, and the inflow of the concrete C into the collapse site 3a is also prevented.

After the concrete C is hardened, the partition plate 4 is pulled up to the above-ground portion using the same crane as shown in FIG. The lifting operation may be performed after the concrete C is completely hardened, or may be gradually lifted while waiting for hardening. At this time, the partition plate 4
Relative slip occurs between the sheet and the polyethylene sheet 5,
Since the frictional resistance is small, it can be pulled out with a relatively small force. The extracted partition plate 4 is diverted for the construction of the next gut.

By repeating the above operation, an underground wall continuous in a direction perpendicular to the paper surface of the figure can be constructed, and concrete does not flow into the collapsed portion by the partition plate 4 at the time of root cutting. Becomes unnecessary.

Further, in this embodiment, the surface finish of the constructed continuous underground wall is smooth from the top to the bottom corresponding to the smoothness of the surface of the polyethylene sheet 5 regardless of the presence or absence of the collapsed portion 3a. There is a beautiful and accurate surface finish.

When the present invention is applied to the construction of an underground wall at a large depth, if the length of the partition plate 4 is formed to a length corresponding to the depth of the groove 3, the pull-out resistance becomes excessive. There is also. Therefore, in the second embodiment of the present invention, after the excavation work, as shown in FIG. 2 (a), for example, a section measuring machine 6 such as an ultrasonic probe is suspended in the groove 3 and the depth of the collapse site 3a is reduced. After the position and the collapse range are recorded on a recorder 7 or the like connected to the measuring device 6 and specified, the partition plate 4 is suspended along the inner wall surface to the depth of the collapse site 3a as shown in FIG. , So as to cover only the periphery of the collapse site 3a. According to this embodiment, even when a deep underground wall is constructed, the pull-out resistance of the partition plate 4 does not become excessive, and the pull-out is easy.

In this embodiment, if the inspection shows that there is no collapsed portion 3a, the operation of suspending the partition plate 4 becomes unnecessary. Further, in this embodiment, the entire wall surface of the underground wall cannot be finished smoothly, but at least a large-scale filing operation is not required for the root cutting operation.

[0019]

As described in detail in the above embodiments, in the method for constructing a continuous underground wall according to the present invention, the underground wall is constructed inside the partition wall and the collapsed portion is formed. Since concrete does not flow, it is possible to save the amount of concrete without placing extra concrete and to eliminate the need for filing work at the time of root cutting, thereby reducing the construction period and construction cost. Thus, problems such as noise generation can be solved.
In addition, since the concrete to be poured is regulated by the partition plate, the wall thickness accuracy can be improved, and the surface of the hardened concrete can be beautiful according to the smoothness of the surface of the partition plate. .

Further, in the method of the present invention, it is only necessary to add the steps of suspending and extracting the partition plate in addition to the operation conventionally performed, and the extraction can be easily performed. There is an advantage that a troublesome auxiliary construction method such as construction of a self-hardening stabilizer is not required.

[Brief description of the drawings]

FIGS. 1A to 1D are cross-sectional explanatory views showing a construction procedure according to a first embodiment of the present invention.

FIGS. 2 (a) and 2 (b) are cross-sectional explanatory views showing a construction procedure according to a second embodiment of the present invention.

FIG. 3 is an explanatory sectional view showing a problem in the conventional underground wall construction method.

[Explanation of symbols]

 2 Muddy water 3 Groove 3a Collapse site 4 Partition plate 5 Polyethylene sheet (non-adhesive surface layer) 6 Cross section measuring machine E Ground C Concrete

Continuation of the front page (56) References JP-A-63-132416 (JP, A) JP-A-50-56011 (JP, A) JP-A-58-173217 (JP, A) (58) Fields studied (Int) .Cl. ⁶ , DB name) E02D 5/18-5/20

Claims (2)

(57) [Claims] A step of excavating a ditch while supplying mud;
A step of hanging a partition plate along the inner wall surface of the groove,
A step of arranging a border sheet that causes relative sliding between the partition plate and the concrete casting surface side of the partition plate, and placing concrete while replacing the muddy water on the inside partitioned by the partition plate. A step of constructing an underground wall, and a step of pulling out the partition plate after the concrete is hardened. 2. After the excavation work, a cross-section measuring machine is suspended in the groove to specify the position and the range of the collapse site on the inner wall surface, and the partition plate and the marginal sheet are moved to a position covering the collapse site. 2. The method according to claim 1, wherein the continuous underground wall is suspended to cover the collapsed portion.