JPH108470A - Earth retaining wall construction method for dry area - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an earth retaining wall construction method, by which the construction cost and the term at works can be reduced. SOLUTION: A box-like earth retaining wall 1 having a rectangular section is formed by combination of a steel-made wedge-like member 1a having a triangular section, which is formed in such a manner that the outer surface is vertical and the inner surface is inclined downward and outward, a concrete wall member 1b which is connected vertically to the upper side of the wedge-like member 1a, and plural stages of plate-like members vertically connected to the upper side of the concrete wall member 1b. The thus formed wall 1 is disposed along the boundary of an installation section of a dry area 2. Subsequently, in order that the wall 1 is sequentially sunk in a body by its dead load, drilling is performed in a section vertically downward along the inner surface of the wall 1 while being left undone in such a manner that stepped parts 2a having a trapezoidal section surrounded with the inner downward inclined surface and the upper horizontal surface are formed in two opposite lower corners of the dry area 2, and after that, the wall 1 is left buried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for constructing a retaining wall for a dry area. More specifically, the present invention relates to a method for constructing a retaining wall for keeping soil on a wall of a shallow dry area having a rectangular cross section from falling.

[0002]

2. Description of the Related Art Conventionally, for example, when an underground tank 10 of a gas station as shown in FIG. Reference numeral 20 denotes a fueling device, 30 denotes an office building, and 40 denotes a fire wall. In FIG. 4, first, a plurality of sheet piles 11 (8 m in length) are driven along a boundary line of a section (12 m × 8 m) in which the underground tank 10 is buried as a retaining wall for a dry area. . Thereafter, a portion surrounded by the sheet pile 11 is excavated to form a dry area 12 (3.5 m in depth).

After the formation of the dry area 12, a plate-like reinforced concrete foundation 13 for supporting the underground tank 10 is cast on substantially the entire bottom surface thereof, and at least two recesses having recesses for mounting the underground tank 10 thereon are provided. Pillow 14 is placed. The underground tank 10 is placed horizontally on the pillow 14, and a plurality of columns 60 are erected. Underground tank 1
A band for fixing is applied to 0 (not shown). Further, after the sheet pile 11 is pulled out, the soil is filled in the dry area 12, and the soil is covered, a reinforced concrete lid 70 covering the dry area 12 is placed on the upper surface of the support column 60, and the work is completed when paved. I do.

[0004]

However, in the above-mentioned conventional earth retaining wall construction work, the construction period is as long as about one month, and the sheet pile 11 having a length of twice or more the depth of the dry area 12 is required. There is a drawback that the cost is high due to the high cost and the cost. The driven sheet pile 11 is pulled out after the completion of the construction.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a method for constructing a retaining wall for a dry area which reduces the construction cost and shortens the construction period. To provide.

[0006]

In order to achieve the above object, a method of constructing a retaining wall for retaining soil on a wall of a dry area having a shallow rectangular cross section so that the soil does not fall, the outer surface is vertical,
A steel wedge-shaped body (1a) having a triangular cross section whose inner surface is inclined downward and outward, and having a thickness substantially equal to the thickness of the wedge-shaped body (1a) connected vertically above the wedge-shaped body (1a). Concrete wall (1b), and a box-shaped retaining wall (1) having a rectangular cross section formed by combining the concrete wall (1b) with a plurality of plate-like members (1p) vertically connected to each other. Are placed along the boundary of the installation section of the dry area (2), and then, at the two opposite lower corners of the dry area (2), Excavating vertically inside the section along the inner surface of the retaining wall (1), while digging remains so as to form a trapezoidal step (2a) surrounded by an inwardly inclined surface and a horizontal surface, and thereafter Consists of leaving the retaining wall (1) buried. (Claim 1).

Further, in the retaining wall (1) according to the first aspect, at least most of the plate-like member (1p) is made of glass fiber reinforced cement (claim 2).

Further, a reinforced concrete foundation (3) having a ship bottom shape in section is cast on the bottom surface of the dry area (2) according to claim 1 or 2, and an underground tank is placed on the foundation (3). (5) is installed (claim 3).

The symbols in parentheses described in the means for solving the above-mentioned problems correspond to the symbols described in the drawings and the embodiments of the invention described later.

According to the first aspect of the present invention, the box-shaped retaining wall having a rectangular cross section disposed along the boundary of the installation section of the dry area is integrated, and the inside of the section is vertical along the outer surface thereof. As it is excavated downward, it sinks sequentially under its own weight. At this time, the lower corners of the two opposing surfaces of the dry area are dug out and a trapezoidal step is formed, so that the retaining wall is driven from the outside by the main earth pressure from the outside and the trapezoidal step formed by the trapezoidal step. The passive earth pressure balances the earth, and the earth retaining wall is stably installed at a position where the earth retaining wall becomes independent. Therefore,
The excavation may be shallower than before. For this reason, the long and expensive sheet pile conventionally used is abolished, and the execution of the retaining wall becomes remarkably easy. Therefore,
The construction period is shortened and the construction cost is reduced.

According to the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, most of the retaining wall can be replaced with a lightweight and inexpensive glass fiber reinforced cement. Costs are lower.

Further, according to the third aspect of the present invention,
In addition to the functions and effects of the invention of claim 1 or 2, even if oil should leak from the underground tank, it is retained in the foundation,
The danger of groundwater contamination and ignition is reduced.

[0013]

Embodiments of the present invention will be described with reference to the drawings. The same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. 1 is a perspective view of the whole view of the gas station, FIG. 2 is a sectional view showing an underground tank buried state according to the embodiment of the present invention, and FIG. 3 is an enlarged view showing a retaining wall according to the embodiment of the present invention. It is sectional drawing.

The basic construction of the retaining wall construction method of the present invention for keeping the soil on the wall of the shallow dry area having a rectangular cross section from falling down is as follows. That is, first, the box-shaped retaining wall 1 having a rectangular cross section is arranged along the border of the installation section of the dry area 2. Next, the inside of the section is excavated vertically downward along the outer surface of the retaining wall 1 so that the retaining wall 1 integrally sinks by its own weight. Dry area 2
Are excavated while the lower corners of the two opposing surfaces are left undigged, and a trapezoidal stepped portion 2a on which the retaining wall 1 is supported is formed at the lower corner.

First, the retaining wall 1 is composed of a steel wedge-shaped body 1a having a triangular cross section in which the outer surface is vertical and the inner surface is inclined downward and outward, and the vertical direction of the wedge-shaped body 1a. It is composed of a concrete wall 1b connected upward and a plurality of plate-like members 1p vertically connected to the concrete wall 1b, and these are combined to form a rectangular cross-section box shape.

More specifically, the wedge-shaped body 1a
Is a concrete wall 1b made by bending or welding a steel plate and connected to a wedge-shaped body 1a.
Is a glass fiber reinforced concrete plate (hereinafter referred to as G
Concrete plate is filled in between the RC plates, the height is 1 meter, the thickness is substantially equal to the thickness of the wedge-shaped body 1a, and the foundation bolt AB is embedded in the upper part. The plate-like member 1p is mainly composed of a GRC plate, has a height of 0.7 m, and a length of 2 m, and is provided with upper and lower adjacent angle members and bolts B (or foundation bolts AB). Linked to Note that the plate-like member 1p
From the viewpoint of price and weight, a GRC plate is preferable, but a steel plate may be used.

The method of implementation will be described by taking an underground tank for a gas station as an example.
A box-shaped retaining wall 1 having a rectangular cross section of the same shape and size is arranged along the boundary of (meter × 8 meter). Next, the inside of the section is excavated vertically downward along the inner surface of the retaining wall 1. As the excavation is performed, the retaining wall 1 is integrally settled down by its own weight sequentially (open type submersion method). Therefore, it is not necessary to drive the retaining wall 1. After the excavation depth reaches a predetermined value (for example, 2.4 m), only the central portion is excavated further to a depth of 3.5 m, and the lower corners of two opposing surfaces of the dry area 2 are left undigged, In the lower corner, a step 2 having a trapezoidal cross section surrounded by an inwardly inclined surface and a horizontal surface
a is formed. At this time, the retaining wall 1 is equilibrated by the main driving earth pressure PX from the outside and the passive earth pressure PY from the inside by the formed step portion 2a having a trapezoidal cross section, and is installed at a position where the retaining wall 1 becomes independent. become

When the underground tank 5 is buried,
First, along the bottom surface of the dry area 2, a ship bottom-shaped reinforced concrete foundation 3 is cast. In this way, even if petroleum leaks from the underground tank, it is retained in the foundation 3, so that the danger of groundwater contamination and ignition is reduced. Next, at least two pillows 4 having recesses for placing the underground tank 5 are placed thereon. Hereinafter, the underground tank 5 is placed vertically and horizontally on the pillow 4, and a plurality of columns 6 are erected. A fixing band is hung on the underground tank 5 (not shown). Further, after the dry area 2 is filled with soil and covered with soil, a reinforced concrete lid 7 that covers the dry area 2 is finally cast on the upper surface of the column 6 and paved. In addition, unlike the conventional example, the earth retaining wall 1 is not pulled out and is left buried.

If most of the retaining wall 1 is made of lightweight and inexpensive glass fiber reinforced cement, the material cost is lower than that of the steel plate. Also excellent in corrosiveness.

According to the method for constructing a retaining wall for a dry area according to the embodiment of the present invention, an underground tank is required for about 10 days with respect to the construction period (about one month) when the conventional sheet pile 11 is used. 10 burials could be performed.

[0021]

As described above, according to the first aspect of the present invention, the earth retaining wall is settled by its own weight by the latent box method, so that it is easy to bury the earth, and furthermore, the earth is balanced by the active earth pressure and the passive earth pressure. Since the earth retaining wall is to be installed at a position where the earth retaining wall becomes independent, it is not necessary to excavate the earth retaining wall more deeply than necessary. Therefore, the construction of the earth retaining wall becomes remarkably easy. In addition, since it is not necessary to use a long and expensive sheet pile, which has been conventionally used, by driving or pulling the sheet pile, it is possible to shorten the construction period and reduce the construction cost.

According to the invention of claim 2, according to claim 1,
In addition to the effects of the invention, most of the retaining walls are replaced by lightweight and inexpensive glass fiber reinforced cement,
Lower material costs. Also excellent in corrosiveness.

Further, according to the third aspect of the present invention,
In addition to the functions and effects of the invention of claim 1 or 2, even if oil should leak from the underground tank, it is retained in the foundation,
The danger of groundwater contamination and ignition is reduced.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing a gas station.

FIG. 2 is a sectional view showing an underground tank buried state according to the embodiment of the present invention.

FIG. 3 is an enlarged sectional view showing a retaining wall according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing an underground tank buried state according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Retaining wall 1a Wedge-shaped body 1b Concrete wall body 1p Plate-shaped member 2 Dry area 2a Stepped part 3 Foundation 4 Pillow 5 Underground tank 6 Post 7 Lid 10 Underground tank 11 Sheet pile 12 Dry area 13 Foundation 14 Pillow 60 Post 70 Cover AB Foundation bolt B Bolt PX Active earth pressure PY Passive earth pressure

Claims (3)

[Claims] 1. A method for constructing a retaining wall for a dry area for keeping soil on a wall of a shallow dry area having a rectangular cross section from falling down, the method comprising a triangular cross section in which an outer surface is vertical and an inner surface is inclined downward and outward. A steel wedge-shaped body, a concrete wall connected vertically above the wedge-shaped body and having a thickness substantially equal to the thickness of the wedge-shaped body, and a plurality of plate-shaped connected vertically above the concrete wall body After arranging a box-shaped retaining wall with a rectangular cross-section formed by combining the members along the border of the installation area of the dry area, the dry area is designed so that the retaining wall is settled down by its own weight sequentially. Excavating vertically inside the section along the inner surface of the retaining wall, while digging left at the two opposing lower corners so that a step portion with a trapezoidal cross section surrounded by an inwardly inclined surface and a horizontal surface is formed, Then the earth retaining wall Earth retaining wall construction method for dry area, characterized in that to leave the meta. 2. The method according to claim 1, wherein at least a majority of the plate-like members of the retaining wall are made of glass fiber reinforced cement. 3. A dry area for a dry area according to claim 1, wherein a reinforced concrete foundation having a cross section of a ship bottom is cast on a bottom surface of the dry area, and an underground tank is installed on the foundation. Earth retaining wall construction method.