JPS61172927A - Method of building underground structure - Google Patents

Abstract

PURPOSE:To decrease the excessive wall thickness of a lining wall, by a method wherein the lining wall is built to a sheathing wall, built in a manner to surround an underground tank, with a specified gap therebetween, and a pressurized air is fed in the gap. CONSTITUTION:A sheathing wall 12 is built under a ground surface 10 in a manner to surround the surrounding of an underground tank by an underground continuous wall construction method. The inside surrounded with the sheathing wall 12 is excavated, and a lining wall 14 is built between the corresponding sheathing walls 12 with a gap part 16 therebetween. Pressurized fluid is fed in the gap part 16 from a pressurizing device 20, e.g., compressor, through a piping 18, the sheathing wall 12 is pressed against the ground 10 side to correct deformation. A solidifying agent is poured in the gap part 16 between the lining wall 14 and the sheathing wall 12 to integrally form the lining wall 14 and the sheathing wall 12. This enables prevention of excessive planing of the lining wall.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to underground structures such as underground tanks for storing petroleum, LNG, LPG, etc. underground, particularly concrete underground structures constructed using earth retaining walls. Concerning methods of constructing things.

(Prior Art and Problems) As is well known, when constructing an underground structure such as an underground tank, an earth retaining wall is formed to surround the underground tank to be constructed.

This type of earth retaining wall is usually a temporary wall that is removed after the underground tank body is formed, but attempts have also been made to use it as a part of the main body wall.

Here, when using an earth retaining wall as the main body wall, there were the following problems.

In other words, when excavating the inside of the constructed retaining wall to form the main body, struts are installed at appropriate locations.
Because the earth retaining wall is subjected to surrounding earth water pressure, most of the walls are deformed to varying degrees, and there are reliability problems in using them as they are as the main wall.

On the other hand, in the design of the inner wall of the main body, due to the above-mentioned problems, it is assumed that all applied loads such as surrounding earth water pressure act on it.

For this reason, there was a tendency for excessive design, such as increased wall thickness, and there was also an economical problem.

The present invention has been made in view of the conventional problems as described above, and its purpose is to make it possible to effectively use the earth retaining wall, which was conventionally constructed as a temporary wall, as the main body wall, and to The purpose of this invention is to provide a method for constructing an underground structure that enables appropriate wall design.

(Means for Solving the Problems) In order to achieve the above object, the present invention forms an earth retaining wall around an underground structure to be constructed, and then the inner side of the earth retaining wall is In an underground structure construction method that forms an inner wall of an underground structure, the inner wall is formed by defining a gap between it and the earth retaining wall, and pressure is introduced into this gap. Features.

(Operation of the invention) When pressure is applied to the gap defined between the earth retaining wall and the inner wall, the earth retaining wall is pushed back toward the ground, the stress during construction is alleviated, and deformation is eliminated.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the method for constructing an underground structure according to the present invention.

The construction method shown in the figure is applied when constructing an underground tank. First, the underground tank to be constructed is surrounded by a continuous underground wall construction method under the ground surface 10. Then, the earth retaining wall 12 is formed.

Next, the inside surrounded by the earth retaining wall 12 is excavated by appropriately installing struts, etc., and the inner wall 14 is formed inside thereof by the reverse winding method.

Here, in the construction method of the present invention, the inner wall 14 is provided so that a gap 16 is defined between the inner surface of the retaining wall 12 and the outer surface of the inner wall 14.

As shown in FIG. 1, the void 16 may be continuous so as to surround the outer surface of the inner wall 14, or may be separated by partially connecting the inner wall 14 and the retaining wall 12. It is also possible to define a plurality of images in the same state.

After constructing a bottom plate section at the bottom of the inner wall 14, a piping 18 and a pressurizing device 2 such as a compressor are inserted into the void section 16.
Set 0.

Note that before starting the pressurizing device 20, the upper end opening of the cavity 16 is closed by inserting a filler such as rubber, for example.

Thereafter, the pressurizing device 20 is driven to send compressed air to introduce pressure A into the cavity 16. This pressure should be of a magnitude commensurate with the loads applied to the earth retaining wall 12, such as the surrounding area and water pressure.

As shown in FIG. 2, the pressure A introduced into the cavity 16 acts on both the earth retaining wall 12 and the inner wall 14.
2 is pushed back toward the ground 10 side, the stress during construction is alleviated, and the deformation is corrected.On the other hand, the inner wall 14 is pushed inward by the pressure A, but this working pressure is as described above. This is the same as the acting load of the earth retaining wall 12.

Therefore, the inner winding wall 14 is in the same state as if the load applied during construction of the earth retaining wall 12 is directly acting on it, and there is no problem.

When the deformation of the earth retaining wall 12 is corrected by the action of the pressure A, a solidifying material such as mortar is injected into the cavity 16 to integrate the earth retaining wall 12 and the inner wall 14, and the construction is completed. do.

In this case, since the void 16 gradually becomes smaller due to the injection of the solidifying material and the internal pressure increases, the void 16
It is desirable to install a pressure gauge inside and adjust the pressure of the pressurizing device 20 so that the pressure A inside the cavity 16 can be maintained at all times.

Now, in the construction method of the underground structure configured as described above, the earth retaining wall 12 is straightened and integrated with the inner wall 14 by the pressure A introduced into the cavity 16. 12 can be effectively used with high reliability as the main body wall of an underground structure.

As a result, the inner winding wall 14 does not need to be over-designed as in the conventional case, and an appropriate design can be performed.

Note that the pressure A introduced into the cavity 16 is applied not only to feed compressed air as in the above-described embodiment, but also to, for example, apply pressure A to the cavity 16 in order to integrate the earth retaining wall 12 and the inner wall 14. Pressure may be applied to the solidifying material such as mortar that is filled and injected into the container, and the solidifying material may be passed through the assimilating material.

Further, the underground structure may be not only an underground tank but also other structures.

(Effects of the Invention) As described above in detail in the examples, according to the construction method of an underground structure according to the present invention, the earth retaining wall, which was conventionally considered for temporary construction, can be effectively used as a part of the main body wall. As a result, excellent effects such as making it possible to keep the wall pressure of the inner winding wall appropriate can be obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the construction method according to the present invention, and FIG. 2 is an enlarged view of the main part of FIG. 1. 10...Ground 12...Earth retaining wall 14...
・Inner wall 16...Gap part A...Pressure

Claims (3)

[Claims] (1) An underground structure construction method in which an earth retaining wall is formed to surround the underground structure to be constructed, and then an inner wall of the underground structure is formed inside the earth retaining wall. A construction method for an underground structure, characterized in that the inner wall is formed by defining a gap between it and the earth retaining wall, and pressure is introduced into the gap. (2) The method for constructing an underground structure according to claim 1, wherein the pressure is introduced using pressurized air. (3) The underground structure according to claim 1, wherein the pressure is introduced through a solidifying material that is filled into the void and integrates the earth retaining wall and the inner wall. construction method.