JPH11280060A - Work execution method for continuous underground wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of processes for constructing an underground wall by using column rows for reinforcing the ground placed at first as a guide for work execution of the underground wall without using a concrete foundation guide when performing work execution of the underground wall. SOLUTION: Two rows of column rows 10, 11 are placed at an interval smaller than a thickness of an underground wall for the ground 1 in which the underground wall is constructed, cut lines 12, 13 are formed using a cutter for the column rows, and a groove for the underground wall 15 is digged using the cut lines as ruler after crushing and removing the inner part. After the groove for the underground wall is digged, reinforcing bars are inserted therein and concrete is placed to construct the underground wall 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for constructing an underground wall, and more particularly to a method for constructing an underground wall based on a soil cement column or the like used for ground improvement.

[0002]

2. Description of the Related Art When constructing a building or the like, a pile for reinforcing the ground for directly supporting the building is constructed, and in addition, a water stop for partitioning the ground around the structure. An underground wall that exerts its function is being constructed. In addition, when the construction site is constructed on soft ground, it is often the case that a columnar ground improvement body is constructed in rows on both sides of the underground wall to further improve the support strength of the ground. Is being done. When constructing the underground wall,
Construct a deep groove with a predetermined thickness and a length of several meters, or excavate a large number of holes continuously to create a deep groove with a predetermined width. A cage-like reinforcing member combined with a reinforcing bar is inserted into the slab, and concrete is injected into the reinforced concrete underground wall.

Conventionally, when constructing the underground wall, a method as shown in FIGS. 5 and 6 is used. First, the underground wall is made to correspond to the width W of the underground wall 5 on both sides thereof. Basic guides 2 and 3 are being constructed. Then, a large excavator is guided on the foundation guides 2 and 3, and the opposing surfaces of the two foundation guides are used as a ruler. Drilling holes for. Therefore, by using the foundation guide as a guide for the underground wall, when excavating the underground wall, it is possible to easily perform the guidance of the construction apparatus, so that the construction of the underground wall with high accuracy can be performed. It becomes possible.

[0004]

The above-mentioned basic guides 2, 3
In order to support a large excavator, it is necessary to construct it with concrete using a large amount of reinforcing steel. For example, in order to support an excavator weighing about 50 tons on soft ground, the width W2 of the foundation guide is set to 2 m and the height h
2 is also configured to be about 2 m, but the foundation guides 2 and 3 are removed after the underground wall 5 is constructed. Then, after the foundation guide is removed, the ground is improved at a predetermined depth on both sides of the underground wall to use a means for strengthening the support ground of the building.

[0005] However, the foundation guide is a large concrete structure, and since a large amount of reinforcing steel is incorporated in the concrete, the construction cost is high. Need to use a lot of labor and machinery. In addition, disposal of a large amount of concrete waste causes an increase in the amount of construction waste, and therefore, there are many problems in disposal sites. Furthermore, when performing the above, it is necessary to remove a large amount of soil, even after crushing and removing the foundation guide, to move the large amount of soil at the site in order to perform work such as burying the soil on the former site There is also a problem such as there is. In addition to the above problems, when building the underground wall in a shape bent at a right angle or at an arbitrary angle, or when building a curved shape, etc., when assembling the formwork when building the foundation guide with reinforced concrete Also requires a lot of effort.

The present invention solves the above-described problem of the construction of the underground wall as described above, and uses a column row constructed for ground improvement as a ruler for the construction of the underground wall. It is an object of the present invention to provide a method of constructing a continuous underground wall that can reduce the number of steps for constructing the underground wall and reduce the construction cost.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method for constructing a column row for reinforcing the ground along a continuous underground wall. The invention according to claim 1 of the present invention includes a step of constructing a column row on the ground on which the underground wall is constructed, and a step of cutting and forming a cut line corresponding to the width of the underground wall in the column row. Removing the portion corresponding to the underground wall side of the cut line of the column row, excavating a groove for the underground wall using the cut line as a ruler, reinforcing steel and concrete in the excavated groove Then, the underground wall is constructed through the step of casting. The invention according to claim 2 is that the column rows are constructed in two rows, and a cut line corresponding to the width of the underground wall is formed by cutting the two column rows, and the two cut lines are formed. It is characterized by excavating a groove for underground wall as a ruler. The invention of claim 3 is characterized in that a work machine for constructing an underground wall is supported on the column row constructed in two rows, and a trench for the underground wall is excavated.

As described above, by using the method of constructing the underground wall, it is necessary to cast a reinforced concrete foundation guide as a ruler member for excavating the underground wall as in the conventional method. Therefore, the steps of the construction work of the underground wall can be simplified. In addition, by using the initially installed column row as a guide for the underground wall, there is no need to build a column row after the underground wall construction, and a heavy work machine can be stabilized at the underground wall construction site. It becomes possible to support in a state. Then, by constructing the column row in parallel with the two rows, by supporting the working machine via the column row, the construction work of the underground wall in a place where the ground is soft can be easily performed. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of constructing a continuous underground wall according to the present invention will be described with reference to the illustrated example. In the present invention, as shown in FIGS. 1 and 2, first, column rows 10 and 11 for soil improvement are installed on the ground 1 on which an underground wall is to be installed. At the time of construction of the column row, a column having a depth h of 5 to 7 m and a diameter D is constructed adjacent to each other using a conventionally known construction method, and is constructed as a general soil cement column. Alternatively, it can be constituted by a concrete column in which a reinforcing member such as a reinforcing bar is embedded. As shown in FIG. 2, the column rows are constructed in two rows at intervals so as to enter inside the width W of the underground wall. 1
It is constructed such that opposing inner surfaces of 0 and 11 are cut.

FIG. 3 shows an example of a soil cement column 1.
The rows 0 and 11 are formed so as to be overlapped in the width direction or very close to each other, and correspond to the underground wall having a thickness of Wa. As shown in FIG. 3, when the column rows are very close to each other or when the columns are partially overlapped with each other, in addition to the case where the thickness of the underground wall is not a large value, the load supporting condition of the underground wall construction ground Is applied when good.

The thickness D of the column row is set according to the strength of the ground supporting the structure. When the strength of the ground support is relatively small, the diameter D is large (thick).
The work is carried out so as to reach a deep position, but when the ground support strength is large, it can be easily dealt with by constructing a thin and short column. In addition, not only when the underground wall to be constructed is straight, but also when the underground wall is constructed in a curved shape, or when the underground wall is constructed to be bent at a right angle, the column row formed in the two rows is It can be constructed corresponding to the thickness W of the underground wall,
The excavation work of the trench for the underground wall can be performed using the column row.

As shown in FIGS. 2 and 3, after constructing two column rows 10 and 11 and then constructing an underground wall using the column rows, first, Cut lines 12 and 13 are formed at a predetermined depth from above using a cutter device. The interval between the two cut lines is formed to have a width corresponding to the thickness W of the underground wall. As shown in FIG. 4, the inside portion of the column cut by the cut lines 12 and 13 is crushed using a crusher to form a cutout portion 14, which serves as a ruler when constructing an underground wall. Form a cut line. Then, the soil between the column rows is removed using a drilling device such as a rock breaker or the like, and the column portion below the cut line is removed using a crusher to form a groove corresponding to the width W of the underground wall. Form. When excavating the trench for the underground wall, the inside of the column can be cut using an auger for excavating the trench. As described above, a groove having a predetermined depth H is excavated in the lower part of the ground reinforced with a width corresponding to the underground wall 15, concrete is poured after inserting a reinforcing bar, and the underground wall is constructed.

The soil cement column is made by mixing cement or cement milk into soil while excavating the soil using, for example, an earth auger, and has a pressure resistance after the column is solidified. The strength has a value of about 10 to 30 Kgf per square cm. Therefore, for the column, using a circular saw diamond cutter or other cutting device from the top,
The work of cutting the cut line can be easily performed. In addition, using a tool such as a hand-held rock drill, the inside column portion defined by the cut line can be crushed to easily form a cutout portion. Further, as shown in FIG. 4, the operation of forming a groove by cutting out the lower part of the cutout portion with the width W can be easily performed by using the rock drill or any other working device.

As described above, the column rows 10, 11
Then, a groove having a width W is created, and a trench for the underground wall is constructed with the width W while excavating the soil under the groove, thereby constructing a groove reaching the hard support base. When the deep trench for the underground wall is constructed, the construction is performed while injecting muddy water to prevent collapse of the side wall, and the excavation work includes an earth drill device, a clamshell, a bucket device, and the like. Can be used. Then, after excavating the trench for the underground wall, an assembly of reinforcing bars is inserted into the trench, concrete is poured from the bottom of the trench using a pipe lowered to the bottom of the trench, and muddy water is poured. Is constructed from above, and the underground wall 15 is constructed.

As shown above, the column rows 10 and 11 constructed in two rows correspond to the strength of the ground at the construction site of the building, and the thickness of the column row set by the diameter D at which the column is constructed. Is selected. For example, for a ground having a low supporting strength, the diameter D is set to a large value or the amount of the solidifying material is increased, and a small diameter D is selected in a place where the ground strength is relatively large. Is done. Also,
The depth h at which the column rows are cast is, as in the case of determining the diameter of the columns, constructed to an arbitrary depth corresponding to the ground support strength. Therefore, even when a heavy working machine is mounted on the column rows, the two column rows can be sufficiently stably supported, and it is possible to prevent the column rows from sinking or deforming. .

Of course, when excavation work is carried out by placing a heavy working machine on the column row, a thick iron plate is laid on the top of the column row, and the crawler places a large load locally on the column row. Is performed so as not to be given. In other words, distributing the weight of the work equipment to the column rows via the iron plate so that a large load is not locally concentrated on a specific column row can be achieved by using a conventional excavator. It is carried out in the same way as the construction work for the inner wall. In addition, the place where the underground wall is constructed,
If the ground is relatively soft, the work equipment can be supported using the column rows cast before the construction of the underground wall, so a large number of thick iron plates must be laid to support the work equipment. Therefore, the material for that purpose is not wasted.

[0017]

Since the underground wall of the present invention is constructed as described above, as in the case of using the conventional method, a reinforced concrete foundation is used as a ruler member for excavating the underground wall. There is no need to cast a guide, and the construction process of the underground wall can be simplified. In addition, by using the initially installed column row as a guide for the underground wall, there is no need to build a column row after the underground wall construction, and a heavy work machine can be stabilized at the underground wall construction site. It becomes possible to support in a state. Then, by constructing the column rows in parallel with the two rows, by supporting the working machine via the column rows, the construction work of the underground wall in a place where the ground is soft can be easily performed. As well as
Underground walls that are accurately positioned can be constructed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a process of constructing a column row on the ground.

FIG. 2 is a plan view of FIG.

FIG. 3 is an explanatory view of an example in which the work is carried out by approaching column columns.

FIG. 4 is an explanatory diagram of a process of constructing an underground wall using column rows.

FIG. 5 is an explanatory view of a conventional underground wall construction method.

FIG. 6 is an explanatory diagram of a basic guide used in the method of FIG. 5;

[Explanation of symbols]

1 Ground, 2.3 Basic Guide, 5/15
Underground wall, 10.11 column row, 12.13 cut line, 14 cutout.

Claims (3)

[Claims] 1. A step of constructing a column row for a ground on which an underground wall is constructed when constructing a column row for ground reinforcement along a continuous underground wall; A step of cutting and forming a cut line corresponding to the width; a step of removing a portion corresponding to the underground wall side of the cut line of the column row; a groove for the underground wall using the cut line as a ruler And constructing an underground wall through a step of excavating steel and placing a reinforcing bar and concrete in the excavated trench. 2. The method according to claim 1, wherein the column rows are constructed in two rows, and cut lines corresponding to the width of the underground wall are formed by cutting the two column rows, and the two cut lines are used as a ruler. The method for constructing a continuous underground wall according to claim 1, wherein a trench for an underground wall is excavated. 3. An excavation of a trench for an underground wall by supporting a working machine for underground wall construction on the column row constructed in two rows. Construction method of continuous underground wall described in.