JPH05306516A - Composite structure of soil cement continuous wall and core part - Google Patents

Abstract

PURPOSE:To effectively utilize a soil cement continuous wall as an underground continuous wall by a method in which core parts such as H-steel tube left in the soil cement continuous wall, concrete parts, and others are used as stress parts for bending stress and axial forces as structural parts. CONSTITUTION:A core part 2 such as steel or concrete part is buried in a continuous wall 1 made of a soil cement composed of excavated soil and cement milk, where the lower end of the core part 2 reaches the lower hard bearing layer. Or, a bearing mechanism using the surrounding frictional force is formed, or a composite structure consisting of the soil cement continuous wall 1 and the core part 2, using a combination of both effects, is formed. The continuous wall 1 can thus be partly utilized as a real underground structure, the construction period can be greatly shortened, and the liquefaction of the ground by earthquake can also be greatly prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite structure of a soil cement continuous wall and a core material.

[0002]

2. Description of the Related Art Conventionally, a construction method called a soil cement continuous wall construction method has been implemented and achieved great results. This construction method is a construction method of a wall body that was created on site by mixing a slurry suitable for the purpose, such as cement milk or asphalt emulsion, with the earth and sand at the current position. When drilling the soil with a machine, discharge a mixed liquid suitable for the purpose, such as cement milk, special asphalt emulsion, bentonite liquid, from the tip, and mix it with the excavated earth and sand. This is a method of forming a continuous wall body by performing hole-blending and kneading, creating a soil cement wall that is created on-site, and wrapping the walls of each element.

The soil cement continuous wall is not only used as an impermeable soil retaining wall, but also as various impermeable underground walls, ground improvement, etc.
There are versatile uses, the wall thickness is usually 550 mm to 1000 mm, and the wall depth is currently up to 60 m.

However, in the conventional soil cement continuous wall structure, the H-shaped steel as a core material is no longer needed once the temporary construction work is completed and the main construction is started, so it is necessary to pull it out and reuse it. As a matter of course, in reality, the extraction work is difficult and the economic effect is diminished, so it is often left as it is.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a soil cement continuous wall construction method, in which bending stress, which is a core material such as an H steel steel pipe, a box steel pipe sheet pile, or a concrete material remaining in a continuous wall as a structural material, By using it as a stress material corresponding to axial force, it waits for the soil retention and water-blocking functions of the soil cement continuous wall, and instead of the conventional temporary wall, it has a composite structure that can be used effectively as an underground continuous wall. The purpose is to provide.

[0006]

According to the present invention, a core material such as a steel material or a concrete material is embedded in a continuous wall formed by soil cement prepared by kneading excavated soil and cement milk and the lower end of the core material is extended. To reach the hard support layer below, or whether it has a support mechanism mainly composed of frictional force of the periphery,
Alternatively, the object described above is achieved by a composite structure of a continuous wall of soil cement and a core material, which is designed to combine the effects of both.

[0007]

1 is an embodiment showing a cross section of a continuous wall portion of a composite structure of the present invention, in which H-shaped steel is provided as a core material 2 in every other drill hole in the continuous wall 1. Is. FIG. 2 is a sectional view of the second embodiment of the present invention, in which steel pipes or concrete columns are provided as core materials 2 in the continuous wall 1 at every other excavation hole. FIG. 3 is also a sectional view of the third embodiment, in which box steel sheet piles are continuously provided as core materials 2 in the continuous wall 1.

FIG. 4 is a partially cutaway perspective view showing an embodiment of the composite structure of the present invention, in which 1 is a continuous wall made of soil cement and 2 is a core material. 3 is a hardening material for reinforcement near the head of the core material 2, and 4 is a connecting piece with the upper structure. The left side of the drawing shows the stratum for reference, where A is the permeable layer,
B is an impermeable layer, and C is a support layer. Continuous wall 1 is permeable layer A
The core material 2 is further extended to the following, and the lower end of the core material 2 reaches the support layer C and is supported. Although not shown, a frictional force increasing device such as a protrusion or a recess is provided on the outer periphery of the portion of the core 2 that is inside the continuous wall 1, and a portion to which negative friction is applied is also not shown. The outer peripheral surface is provided with a coating for reducing frictional force. As a general rule, the lower end of the core material 2 reaches the support layer C, but depending on the condition of the formation,
In some cases, only the frictional force of the upper soil layer is reached and the support layer is not reached. As for the method of increasing the vertical supporting force of the core material 2, a bottom expanding pile is used or soil cement is replaced with a high-quality hardening material (for example, concrete). Further, in the closed pile, there is also a method in which a movable shoe is provided at the tip of the pile so that the support layer is hit and penetrated. Furthermore, there is also a method of increasing the bearing capacity by expanding the pile tip part from the pile main part in a taper shape, and there is also a method of increasing the strength of soil cement.

[0009]

As described above, the effects produced by the composite structure of the present invention are as follows. (1) Conventionally, a full-scale underground structure was built inside the continuous soil cement temporary wall, whereas in the present invention, a part of the continuous soil cement wall is used as a full-scale underground structure. The construction period can be greatly shortened. (2) Effective use of materials is possible, and economic benefits are increased due to design advantages such as expansion of usable land area. (3) The effect of preventing liquefaction of the ground due to an earthquake increases.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment.

FIG. 2 is a sectional view showing another embodiment.

FIG. 3 is a sectional view showing still another embodiment.

FIG. 4 is a partially cutaway perspective view showing an embodiment.

[Explanation of symbols]

 1 continuous wall 2 core material 3 stiffening material for reinforcement 4 connecting piece with superstructure A water-permeable layer B water-impermeable layer C support layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Kakegai 4-18-5 Mukaidai-cho, Tanashi City, Tokyo (72) Inventor Yoshikiyo Fukushima 4-27-14 Komazawa, Setagaya-ku, Tokyo (72) Inventor Kiyoshi Imaizumi 3-12-45-401 Suga, Tama-ku, Kawasaki City, Kanagawa Prefecture

Claims (5)

[Claims] 1. A core material such as a steel material or a concrete material is embedded in a continuous wall formed of soil cement prepared by kneading excavated soil and cement milk, and the whole or part of the core material is extended downward to extend downward. A composite structure of a continuous wall of soil cement and a core material, which has a support mechanism mainly reaching the hard support layer of the core material or peripheral frictional force of all or part of the core material. 2. The composite of soil cement continuous wall and core material according to claim 1, wherein the portion of the core material that receives negative friction has a smooth outer peripheral surface or is provided with a coating for reducing frictional force. Construction. 3. The continuous soil cement wall and the core material according to claim 1, wherein a frictional force increasing device such as a protrusion or a depression is provided on an outer peripheral surface of a portion of the core material inside the continuous soil cement wall. Composite structure with. 4. The soil cement continuous wall and the core material according to claim 1, wherein the soil cement forming the vicinity of the head portion of the core material of the continuous wall is replaced with a hardened material having high strength such as concrete. Composite structure. 5. A movable shoe is provided at the lower end of the core member to increase the tip supporting force so that the support layer is impacted or penetrated, the pile tip is expanded, or soil cement around the bottom core member is hardened with a hardener, for example. The composite structure of a continuous soil cement wall and a core material according to claim 1, wherein the composite structure is replaced with concrete.