JPH06128934A - Subsoil improvement method - Google Patents

Abstract

PURPOSE:To make it possible to construct a uniform and stabilized column body by incorporating a net body over the peripheral surface of a columnar subsoil improvement body to mix and stir excavated soil and cement hardener to fill. CONSTITUTION:A long and slender bore 6 is excavated in an execution place B by an auger screw 2, and a cylindrical expansion net body 1 is inserted there- into. After the completion of insertion, a reinforcing bar 3 is pulled out upward from the net body 1, so that the net body 1 is spread to a wall surface of the bore 6 and is in a fitting and inserting state. Excavated soil 5 and cement hardener S are mixed and stirred in the bore 6 by the auger screw 2, and it is pulled out while reversely rotating it, so that the excavated soil 5 is compacted by rolling it. According to the constitution, a columnar subsoil improvement body A having a solidified body 7 in the middle side and the net body 1 over the peripheral surface can be formed.

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 columnar ground improvement body formed to improve the ground in order to prevent uneven settlement of small-scale buildings such as houses.

[0002]

2. Description of the Related Art Conventionally, in the case of building a small-scale building such as a house, when the ground at the construction site is soft, the ground is improved by a columnar ground improvement body, and the building is constructed on it. It prevents uneven settlement of the building,
There are two types of ground improvement methods, a dry type and a milk type. The dry type, the soil and the cement-based solidifying material are mixed and stirred to form a pillar of soil that is a ground improvement body,
The pillar is configured to be built in the soft ground, and the milk type is a mixture of soil, water and cement-based solidifying material, and stirred to form a pillar of soil that is a ground improvement body. However, the column body is constructed in the soft ground. And, of the two types of methods, the dry type is the one that requires a simple and small-scale construction machine and device. Therefore, for a small-scale building, the dry type is simple and easy to construct. Many have been adopted.

[0003]

However, in the above-mentioned prior art, the dry type is constructed so that the cement-based solidifying material mixed in the soil reacts with the water contained in the soil and is solidified with the soil. Therefore, as a method of supplying the amount of water for the reaction, there is an uncertain aspect that it is not uniformly supplied due to variations in the water content in the soil, etc. There is a problem that it is not possible to prevent uneven settlement of a building that occurs due to variation, a columnar body having a strength equal to or lower than a setting value that has no resistance to horizontal force is formed, and cracks due to shearing force occur in the columnar body. It occurs. In addition, there is a construction method in which H steel is inserted into the column in order to supplement the strength of the column, but this is not desirable because it increases the work process and cost.
Therefore, the present invention has uniform and stable strength, and
It is an object of the present invention to provide a method for constructing a pillar body which is a ground improvement body that can be easily constructed and does not increase the cost.

[0004]

[Means for Solving the Problems] As a means for solving the above problems, the present invention comprises soil and a cement-based solidifying material for improving the ground to prevent the differential settlement of a small-scale building. In the method of constructing a columnar ground improvement body, the construction is carried out so that a net body is built in the entire outer periphery of the columnar ground improvement body.

[0005]

Next, the operation will be described. The ground improvement method for constructing a small-scale building such as a house at the construction site B of the soft ground is as follows. First, at the construction site B, the auger screw 2 which is an excavator is used. A vertical drilling hole 6 is excavated by using the resin, and a tubular mesh body 1 made of resin is inserted into the drilling hole 6, and the drilling soil 5 and the cement-based solidifying material S are inserted into the drilling hole 6 in which the mesh body 1 is inserted. Throw in,
The excavated soil 5 and the cement-based solidifying material S are mixed and stirred in the drill hole 6 by the auger screw 2, and then the auger screw 2 is reversely rotated to be pulled up and compacted,
The excavated soil 5 in which the cement-based solidifying material S is mixed and stirred is compacted, and the inner side is a solidified body 7 of the excavated soil 5 and the cement-based solidified material S, and the entire outer periphery is a net force against the horizontal force. And the columnar ground improvement body A which does not cause cracks due to shearing force is formed, and the columnar ground improvement body A improves the ground in a columnar shape.

[0006]

EXAMPLE An example of the present invention will be described with reference to FIG.
2 is a side cross-sectional view showing a construction step of the ground improvement method of the present invention, FIG. 2 is a perspective view showing an excavation state of the drill hole 6 by the auger screw 2, and FIG. 3 is a drill hole 6 of the tubular net body 1. FIG. 4 is a perspective view showing the mesh body 1 and auger screw 2 fitted into the drilled holes 6, and FIG. 5 is a partial perspective view of the columnar ground improvement body A.

Referring to FIG. 1, the construction steps of the ground improvement method of the present invention will be described. The ground improvement method is used for constructing a small-scale building such as a house at a construction site B of soft ground. Yes, first, as shown in FIG.
A vertically long drill hole 6 is drilled by an auger screw 2 which is a drilling device, and a cylindrical net body 1 is inserted into the drill hole 6. The mesh body 1 is made of resin and is formed into a cylindrical shape by rolling it up and inserting and fixing the reinforcing bars 3 into the meshes 3a, 3a, ... As shown in FIG. It is suspended by a crane or the like via the and is inserted into the drilled hole 6 by being suspended.

Then, as shown in FIG. 3, by pulling the reinforcing bar 3 upward from the tubular net body 1 after the insertion is completed, the tubular net body 1 spreads to the wall surface of the drill hole 6, and the drill hole 6 is formed.
It is in a state of being inserted into. In addition, the diameter x of the tubular net body 1 inserted and fixed by the rebar 3 is equal to the drilled hole 6
Is set to be smaller than the diameter y. That is, the net body 1 is rolled into a tubular shape so that the relation of x <y is satisfied, and the net body 1 is inserted and fixed by the reinforcing bar 3. The size of the opening of the drilled hole 6 is about 400 to 600 mm in diameter.

Further, as shown in FIG. 4, the excavated soil 5 and the cement-based solidifying material S excavated at the time of excavating the drill hole 6 are put into the drill hole 6 into which the net body 1 is inserted. Therefore, the excavated soil 5 and the cement-based solidifying material S are mixed and stirred in the drilled hole 6 by the auger screw 2. Then, the auger screw 2 is pulled up while being rotated in the reverse direction so as to be compacted and compact the excavated soil 5 in which the cement-based solidifying material S is mixed and stirred.

By carrying out the construction as described above, as shown in FIG. 5, at the construction site B, a pillar having the solidified body 7 of the excavated soil 5 and the cement-based solidifying material S on the inner side and the net body 1 on the entire outer periphery is formed. The ground improvement body A is formed. Then, the columnar ground improvement body A becomes a columnar body that can exert a tenacity against a lateral (horizontal) force and does not cause a crack due to a shearing force, and the columnar body improves the columnar ground. It is done. In addition, a plurality of columnar ground improvement bodies A are provided at appropriate positions in a construction site for constructing a small-scale building such as a house with soft ground, and support the concrete foundation 10 which is the foundation of the building. It has a structure that prevents uneven settlement of buildings.

[0011]

Since the present invention is constructed as described above,
The following effects are achieved. That is, by forming a columnar ground improvement body consisting of a solid body and a net body of soil and a cement-based solidifying material, a columnar ground improvement body that can bear a horizontal force to the construction site of the soft ground, simply, Moreover, since it can be easily installed and it is not necessary to reinforce the strength with H steel as in the conventional case, the construction machine and device can be simple and simple, and the work process can be reduced to reduce the construction period. It is possible to reduce the construction cost and the construction cost.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a construction process of a ground improvement method of the present invention.

FIG. 2 is a perspective view showing a state in which a boring hole 6 is excavated by an auger screw 2.

FIG. 3 is a perspective view showing a step of inserting the tubular net body 1 into the drilled hole 6.

FIG. 4 is a perspective view showing a net body 1 and an auger screw 2 fitted into a drilled hole 6.

5 is a partial perspective view of a columnar ground improvement body A. FIG.

[Explanation of symbols]

 1 mesh body 2 auger screw 5 excavated soil 6 drilling hole A columnar ground improvement body S cement-based solidifying material

Claims (1)

[Claims] 1. A method for constructing a columnar ground improvement body comprising soil and a cement-based solidifying material for improving the ground to prevent uneven settlement of a small-scale building, wherein a net body is built in on the entire outer periphery of the columnar ground improvement body. A ground improvement method characterized by being constructed as much as possible.