JPH11222840A - Improvement method of contaminated soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improvement method of contaminated soil preventing leaching of the sewage of harmful contaminated soil and being used for bringing the harmful contaminated soil to a harmless state. SOLUTION: A rectangular hole is excavated in a ground, and prismatic piles 3 formed by filling prismatic bag bodies 1 made of a geotextile with zeolite 2 are disposed closely in upright mutually along the sidewall of the hole up to a ground from a specified depth in a hole button, thus forming a diaphragm wall. Zeolite 5 is laid on the hole bottom surrounded by the diaphragm wall in a specified thickness, and harmful contaminated soil is buried onto zeolite 5 on the hole bottom surrounded by the diaphragm wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving contaminated soil containing harmful substances contaminated with chemical substances and the like.

[0002]

2. Description of the Related Art Conventionally, a method of improving contaminated soil contaminated with a chemical substance of this kind is to excavate a rectangular hole in the ground, and erected a steel pile or a resistance pile closely along the side wall of the hole. A hard wall construction method that forms an underground wall and burys contaminated soil in the recess of the hole surrounded by the underground wall, excavates a rectangular hole in the ground, Laying a synthetic resin sheet,
There is a sheet construction method in which contaminated soil is arranged on a sheet.

[0003]

The above-mentioned conventional methods for improving contaminated soil all involve storage of contaminated soil.
The improvement of contaminated soil only by natural drying by solar heat is only performed.However, there is a problem that harmful sewage leaks from the joint part of the pile of the underground continuous wall in the hard wall construction method, which is a disadvantage in maintaining water tightness. was there. Also, in the sheet method, leakage of harmful sewage occurs due to deterioration and breakage of the sheet, etc.Either method is not always perfect, harmful sewage leaches from the side wall and bottom wall of the hole, and the harmful sewage causes environmental damage. Has become a social problem.

[0004] It is an object of the present invention to provide an improved method of contaminated soil that prevents leaching of harmful contaminated soil and makes the harmful contaminated soil harmless.

[0005]

The method of improving contaminated soil according to the present invention is formed by excavating a rectangular hole in the ground and filling a zeolite in a geotextile prismatic bag along the side wall of the hole. Square pillars are erected closely from a predetermined depth in the hole bottom to the ground to form an underground continuous wall, and zeolite is laid to a predetermined thickness at the bottom of the hole surrounded by the underground continuous wall. Hazardous contaminated soil is buried on the zeolite at the bottom of the hole surrounded by underground walls.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 is a plan view of a land on which a method for improving contaminated soil according to the present invention has been implemented. This method employs a geotextile-made rectangular column-shaped bag 1 having water permeability, corrosion resistance and toughness.
Is filled with zeolite powder 2 having an adsorption action, an ion exchange action and a catalytic action to form a large number of square pillar piles 3, and the side walls are inclined or vertical in a predetermined ground by an excavator or the like. Excavating a hole in the shape, excavating the hole, making the square pillar piles 3 adhere to each other along the side wall of the hole, and erection, and constructing four-sided underground connecting walls 4, 4 surrounding the entire site of the hole, Each of the quadrangular pillar piles 3 forming the underground connecting walls 4 and 4 has its lower end buried to a depth at which it can stand on its own from the earth pressure at the bottom of the hole, and its upper end protrudes to the ground. 1 to 3 show a vertical pile wall method in which the side wall of the hole is vertical, and FIG. 4 shows a slant pile wall method in which the side wall of the hole is inclined.

[0008] Zeolite powder 5 is laid to a predetermined thickness at the bottom of the hole surrounded by the underground connecting walls 4 and 4, and the thickness of the zeolite powder 5 at the bottom of the hole is determined by the area of the hole in the site and the pollution status. I do. Contaminated soil containing harmful substances is buried in the concave portion of the hole formed by the zeolite powder 5 at the bottom of the hole and the underground connecting walls 4 and 4 installed on the side wall of the hole.

Further, the method of the present invention can be applied to land having soil containing toxic substances contaminated with chemical substances, such as a former site of a hospital or a printing plant. Harmless soil can be buried in the recess of the hole surrounded by the wall and the bottom of the zeolite hole.

According to the method of the present invention, zeolite is interposed between harmful contaminated soil and harmless soil, and the harmful contaminated soil is made harmless by ion exchange, adsorption and catalysis of the zeolite.

[0011]

According to the present invention having the above-described structure, the underground continuous wall composed of a prismatic pillar made of zeolite-filled geotextile can be semi-permanently formed without corrosion even if groundwater penetrates, and the contaminated soil can be formed. By absorbing sewage generated by harmful pollutants and ion-exchanging with harmless water outside the underground wall or inside the groundwater wall, harmful polluted soil can be detoxified,
It can be used as a newly constructed waste treatment plant that has been used to improve the environment and take measures to block harmful sewage, and can be used to reclaim toxic contaminated soil that has been left unusable.

[Brief description of the drawings]

FIG. 1 is a plan view of a first construction example of a method for improving contaminated soil according to the present invention.

FIG. 2 is a cross-sectional view taken along line AA of FIG.

FIG. 3 is an enlarged plan view showing a cross section of a corner of FIG. 1;

FIG. 4 is a sectional view of a second construction example of the method for improving contaminated soil according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Square pillar-shaped bag 2 Zeolite powder 3 Square pillar pile 4 Underground continuous wall 5 Zeolite powder at bottom of hole

Claims (1)

[Claims] 1. A rectangular pillar formed by excavating a rectangular hole in the ground and filling a zeolite into a geotextile-shaped prismatic bag along the side wall of the hole from a predetermined depth in the bottom of the hole. Up to each other to form an underground continuous wall, lay zeolite with a predetermined thickness on the bottom of the hole surrounded by the underground continuous wall, and place the zeolite at the bottom of the hole surrounded by the underground continuous wall A method for improving contaminated soil, characterized by burying toxic contaminated soil on top.