JPH062329A - Shoring and cut-off method by underground continuous wall - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] To provide a retaining method and a waterproofing method for underground structures using continuous underground walls. [Structure] The earth retaining and water stopping method of the underground continuous wall of the present invention is based on the underground continuous wall 1 reaching the impermeable layer 4 in the deep portion.
First, the method of building the underground continuous walls 2 and 3 on the inside or outside to the depth required as resistance to earth pressure and water pressure, and the underground to reach the impermeable layer 4 in the deep part. The continuous wall is first constructed, and then, inside or outside thereof, is integrated with the underground continuous wall at a right angle to the underground continuous wall 2 to a depth required as a resistance force against earth pressure and water pressure. This is a method in which the underground continuous wall 3 is integrated at right angles to construct the underground continuous wall to the same depth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an underground tank for LNG or crude oil, a vertical shaft for shield tunnels, or a mountain retaining by a continuous underground wall in a subterranean structure or a waterproofing method.

[0002]

The underground structure is becoming larger and larger. For example, in the case of an LNG underground tank, the capacity of 60,000 KL 20 years ago was recently constructed to be 200,000 KL. ing. The underground tank for crude oil has a capacity of 350,000 KL. In the case of large underground structures, large earth pressure and water pressure are applied. Therefore, in most cases, the earth retaining and water stopping methods using continuous underground walls are used.

The continuous underground wall is a continuous strip-shaped reinforced concrete wall constructed in the ground to resist earth pressure and water pressure, and to secure water stopping performance by the continuous wall.
In general, the upper part of the underground wall is expected to have resistance to earth pressure and water pressure, whereas the lower part is expected to have only water stoppage.

Due to the excavating machine, the continuous underground wall is generally constructed with a constant wall thickness, but considering the functions of the upper and lower portions of the continuous underground wall, the underground continuous wall is thin. A medium continuous wall is sufficient, and it is uneconomical to make the thick wall thickness necessary for earth pressure and water pressure in the upper part to the same size in the lower part.

In order to solve this problem, an underground continuous wall with a variable cross section has been developed and Japanese Patent Application Laid-Open No. 59-154217 has been filed.

This method is for constructing an underground continuous wall with a variable cross section, which is an integrated structure made of reinforced concrete. To set. This construction method has the following problems.

That is, the skin of the excavated surface is liable to be removed at the portion where the cross section changes, and it is difficult to secure the waterproofness.

Further, since it takes a long time to excavate, it is difficult to secure a stable hole wall.

In addition, after excavating the upper part with an excavating machine having a large wall thickness, the excavating machine is changed to excavate the lower part having a small wall thickness, so that two types of excavating machines are required.

Further, when the reinforcing bars in the lateral direction are wrapped, it is difficult to insert the reinforcing bar cage.

The present invention is a method developed to solve the above problems.

[0012]

According to the earth retaining and water stopping method of the underground continuous wall of the present invention, the underground continuous wall reaching the impermeable layer in the deep portion is first constructed, and the earth pressure is applied to the inside or outside of the underground continuous wall. The method of constructing a continuous underground wall to the depth required for resistance to water pressure and repeating this work until the required wall thickness is secured, and first constructing a continuous underground wall reaching the impermeable layer in the deep part. , Next, inside or outside, it is integrated with the underground continuous wall in the direction perpendicular to it to build the underground continuous wall to the depth required as resistance to earth pressure and water pressure, and in the direction perpendicular to the underground continuous wall. It is a method to build a continuous underground wall to the same depth.

[0013]

[First Embodiment] The first invention is a superposition type underground connection wall,
First, the underground continuous wall 1 reaching the impermeable layer 4 in the deep part is constructed. The underground continuous wall 2 is constructed inside or outside to a depth required as a resistance force against earth pressure and water pressure.
This process is repeated until the required wall thickness is secured. Also, grout between the underground continuous walls 1 and 2 as needed. Further, in order to improve the heat insulating property, the continuous wall 2 may be made of porous concrete such as concrete mixed with pearlite (perlite concrete).

The second aspect of the present invention is a double girder underground continuous wall, and the underground continuous wall 1 reaching the impermeable layer 4 in the deep portion is first constructed. Next, the underground continuous wall 2 is integrated with the underground continuous wall 1 in the direction perpendicular to the inside or outside thereof, and the underground continuous wall 2 is constructed to a depth required as a resistance force against earth pressure and water pressure. Furthermore, the underground continuous wall 2 is integrated with the underground continuous wall 2 at a right angle.
The underground wall 3 is constructed to the same depth as.

After that, when the axial compressive force is predominant, such as a cylindrical mountain clasp, the inside of the girder is excavated and replaced with concrete to a depth required as resistance to earth pressure and water pressure.

If necessary, as in the first aspect of the invention, a material is placed in the area between the continuous walls 1 and 3 divided by 2 for the purpose of the heat insulation.

[0017]

EFFECTS OF THE INVENTION The present invention has the above-described structure. Since the underground wall has the same wall thickness, only one type of excavating machine is required, the machine can be operated efficiently, and the construction cost can be reduced.

Further, since the concrete is sequentially placed from the portion where the excavation is completed, it is easy to ensure the stability of the hole wall.

Since a general-purpose excavating machine can be used, it is easy to procure the machine and the cost is low.

Further, the same waterproofness as the conventional continuous underground wall is secured.

Further, depending on the scale of the Yamadome required,
Increase the number of double girders in the double girder type underground continuous wall by increasing the number of underground continuous walls in the pile type continuous continuous wall to the depth required as resistance to earth pressure and water pressure. Can be handled more easily.

[Brief description of drawings]

FIG. 1A is a cross-sectional view of the first embodiment of the invention, and FIG.
FIG. 4 is a partial vertical sectional view.

2A and 2B are a horizontal sectional view and a partial vertical sectional view, respectively, of an embodiment (a) of the second invention.

[Explanation of symbols]

 1,2,3 ... Continuous underground wall, 4 ... Impermeable layer.

Claims (2)

[Claims] 1. An underground continuous wall that reaches an impermeable layer in a deep portion is first constructed, and then an underground continuous wall is constructed inside or outside the soil to a depth required for resistance to earth pressure. A mountain retaining and water stopping method using a continuous underground wall, which is repeated until the required wall thickness is secured. 2. The underground continuous wall reaching the impermeable layer in the deep portion is first constructed, and then, inside or outside thereof, integrated with the underground continuous wall in a direction perpendicular to the earth continuous wall, and resistance to earth pressure and water pressure. The underground continuous wall is built up to the required depth, and the underground continuous wall is integrated at right angles to the same depth to build the underground continuous wall to the same depth. Construction method.