JPH0673748A - Cut-off method of underground type storage tank structure - Google Patents

Abstract

PURPOSE:To conduct a cut-off between a clearance section in the periphery of a sidewall and a crushed stone layer in the lower section of a bottom block more effectively without requiring large numbers of execution labor hours and materials in an underground type storage tank structure. CONSTITUTION:A longitudinal ditch is excavated by using a chain cutter 10 along the predetermined position of the construction of a sidewall 1 in the lowermost section of the ground E. When mortar for a cut-off is placed under the state, in which a welding wire-gauze 14 for reinforcing a crack is installed into the excavated ditch 12, a longitudinal cut-off wall 16 is completed. Cut-off concrete 5 is placed at a position corresponding to the bottom of a gutter 4 as a clearance section as cut-off construction, the sidewall 1 is built continued to the upper section of the cut-off wall 16, and a crushed stone layer 2 is spread all over the inside of the side wall 1 and a bottom block 3 is constructed, thus completing the cut-off construction of an underground type storage tank structure having structure, in which the longitudinal cut-off wall 16 is unified into the lower ground E of the sidewall 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of stopping water in an underground storage tank structure for preventing groundwater around the side wall from rushing into a crushed stone layer below the bottom slab.

[0002]

2. Description of the Related Art FIG. 2 shows the structure of a conventional underground storage tank structure, in which a crushed stone layer 2 is laid on the inner side of a ground E on the bottom of a side wall 1 constructed by a reverse winding or forward winding method. , A bottom slab 3 formed on the top of the crushed stone layer 2 in a state where the periphery is integrated with the side wall, and a clearance portion formed on the outer periphery of the side wall 1 and filled with a water-permeable material such as crushed stone or sand. And a roof (not shown) arranged above the side wall 1.

Groundwater supplied from the surrounding ground E is stored in the gutter 4, and the bottom of the groundwater reaches the bottom of the side wall 1. At this portion, a water-stopping concrete 5 is used as a water stop. By placing the above, it is possible to prevent the groundwater from running into the crushed stone layer 2 side.

[0004]

That is, according to the underground storage tank structure having such a structure, the ground water stored inside the gutter 4 is provided on the bottom slab 3 so that the water pressure is not applied. It is possible to prevent the intrusion into the crushed stone layer 2 due to the head difference from the crushed stone layer 2 below the bottom slab 3 and easily manage the circulation of groundwater in the underground storage tank structure. Then, in preparation for the case where the amount of water trying to enter the crushed stone layer 2 increases due to an increase in the water head difference or the like, the groundwater crushed stone layer 2 can be more effectively moved to more easily manage the circulation of groundwater. It is desired to develop a water blocking method that can prevent the intrusion of water.

Therefore, the present invention has been made in view of the above situation, and it is an economical and easy-to-construct underground storage tank that can more effectively prevent intrusion of groundwater into the crushed stone layer. It is an object to provide a method of stopping water for a structure.

[0006]

In order to achieve the above object, the present invention provides a side wall constructed inside the ground, a crushed stone layer arranged inside the bottom of the side wall, and an upper portion of the crushed stone layer. In an underground storage tank structure having a bottom slab having a peripheral edge integrated with a side wall, and a gutter provided around the side wall as a clearance portion filled with a material such as crushed stone or sand,
The ground at the lower part of the side wall is excavated in a vertically long shape by a fine groove excavator such as a chain cutter, and a solidifying material such as mortar for water stoppage or water stoppage concrete is placed inside the excavation groove to continuously connect to the lower part of the side wall. It forms a water blocking wall.

[0007]

With the above construction, since the excavation groove at the bottom of the side wall is excavated by the excavator dedicated to the fine groove, the excavation groove has a narrow groove width without disturbing the peripheral edge of the ground and a deep excavation depth. Therefore, it is possible to more effectively prevent the intrusion of groundwater into the crushed stone layer by forming a water stop wall without increasing the amount of material and easily increasing the permeation path of groundwater. .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. 1 (a) to 1 (c) show the construction procedure of the water stopping method of the present invention. It should be noted that the same parts as those of the conventional art will be described with the same reference numerals. First, in FIG. 3A, a vertically long excavation groove 12 is excavated along a planned construction site of the side wall 1 at the bottom of the ground E using a fine groove excavator, for example, a chain cutter 10.

This chain cutter 10 is well known, and is drawn in a simplified state. However, a large number of cutters planted along the chain at the end of the arm cut the ground while rotating endlessly, It excavates the ground with a groove width that corresponds to the cutter width in sequence, and can excavate accurately with a width that corresponds to the cutter width without disturbing the ground at the periphery of the excavation groove 12 compared to backhoes and other excavators. In the example, the excavation depth is approximately 1.5 m and the groove width is approximately 1 in one excavation operation.
A vertically long excavation groove 12 of about 5 cm is formed along the lower portion of the side wall 1.

Next, as shown in FIG. 1B, if a mortar for stopping water is placed in a state where a welded wire net 14 for cracking is installed in the excavation groove 12, a vertically long water stopping wall 1 is formed.
6 is completed.

After that, water-stopping concrete 5 is placed as a water-stopping work at a position corresponding to the bottom of the gutter 4, and a side wall 1 is continuously constructed on the upper side of the water-stopping wall. Spread layer 2 over. After laying the crushed stone layer 2 and constructing the bottom slab 3, as shown in FIG. 1 (c), the water stop work of the underground storage tank structure in which the vertically long water stop wall 16 is integrated with the lower part of the side wall 1 Is completed. Since this water stop wall 16 is vertically long, it has a sufficient length of groundwater permeation path, and thereby an excellent water stop effect can be obtained.

[0012]

As described above in detail with reference to the embodiments, in the water stopping method for the underground storage tank structure according to the present invention, the infiltration path length is increased to more effectively infiltrate groundwater into the crushed stone layer. In addition to preventing this, a solid material such as water-stopping mortar is placed in a vertically elongated excavation groove formed without disturbing the ground by a fine groove excavator, which saves a lot of construction time and materials to be used. It can be constructed economically without any need.

[Brief description of drawings]

1A to 1C are partial cross-sectional views showing a construction procedure of a water stopping method of the present invention.

FIG. 2 is an explanatory cross-sectional view showing the overall structure of a conventional underground storage tank structure.

[Explanation of symbols]

 1 Sidewall 2 Crushed stone layer 3 Bottom plate 4 Gutter 10 Fine groove excavator (chain cutter) 12 Excavation groove 16 Water stop wall

Claims (1)

[Claims] 1. A side wall constructed inside the ground, a crushed stone layer arranged inside a bottom portion of the side wall, a bottom slab above the crushed stone layer and having a peripheral edge integrated with the side wall, and around the side wall. In an underground storage tank structure provided with a gutter as a clearance portion provided, the ground at the lower part of the side wall is vertically elongated by a fine groove excavator, and mortar for water stop, concrete for water stop, etc. inside the groove. 2. A method of stopping water for an underground storage tank structure, which comprises forming a continuous water stop wall below the side wall by pouring the solidified material.