JP3071308B2 - Permeable continuous underground wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permeable continuous underground wall, and is intended for rectification and control of groundwater flow in an underground dam and a subsurface dam, a river or the like.

[0002]

BACKGROUND OF THE INVENTION Prior to the present invention, Patent Application Publication No.
The underground wall of 128425 is known. According to the invention, in an underground wall constructed to a depth reaching an impermeable layer in the ground to block groundwater, a part or all of the underground wall is made of a permeable material (for example, using asphalt or concrete having a large permeability coefficient). Or composed of a water-permeable filter)
This configuration eliminates the drawbacks of the complete water blocking wall, such as extremely low downstream groundwater levels and difficulty in preventing inflowing pollutants. However, no advantageous construction method of the underground wall is disclosed.

[0003]

The present invention has the same purpose as that of the above-mentioned conventional example, but has an object to provide it easily and inexpensively by applying an SMW method described later.

[0004]

The permeable underground wall of the present invention has the following structure as means for achieving the above object.

(1) A solidified portion, a water-permeable material portion, and a water-impermeable material portion are sequentially provided from below in a muddy water digging portion provided on a part of a continuous soil-cement continuous wall constructed by the SMW method, and each of the layers has an impermeable layer. The permeable layer, the permeable layer, face the impermeable layer, as the permeable material part using coarse sand, small gravel, volcanic debris, artificial aggregate, etc. in the case of soil retention, solidified and stiff porosity. None, and in the case of only groundwater control, used without solidification. Further, as the water-impermeable material part, SM
Use W (cement milk, bentonite liquid, etc.).

(2) Injecting a water-soluble polymer liquid or cement milk containing a foaming agent into part or all of the portion of the soil cement underground continuous wall constructed by the SMW method which faces the permeable layer of the stratum. And made it porous.

[0007]

FIG. 1 is a perspective view showing an example of a permeable continuous underground wall of the present invention, and FIG. 2 is a partial plan view of the same. In the figure, reference numeral 1 denotes a continuous wall of soil cement, and reference numeral 2 denotes a mud digging part provided in a part thereof. The soil-cement continuous wall 1 is formed using an SM described later.
It is built by the W (Soil Mixing Wall) method. The muddy digging section 2 is made by a bucket type or a circulation type excavation method. Reference numeral 2a denotes a solidification part provided at the lowermost part of the muddy digging part 2, which is made by mortar, concrete muddy solidification or the like. 2b is a permeable material portion provided thereon, which is made using coarse sand or volcanic debris, small gravel, artificial aggregate, and the like, and in the case of soil retention, solidifies to an okoshi porous shape,
In case of only groundwater control, use without solidification. 2c
Is an impervious material section provided thereabove, and is made using SMW (cement milk, bentonite liquid, etc.).
A, B, and C denote a water-impermeable layer, a water-permeable layer, and a water-impermeable layer of the stratum from below.
c face each other.

FIG. 3 is a perspective view showing another example of the permeable continuous underground wall of the present invention. In the figure, 1 'is a continuous wall of soil cement constructed by the SMW method, 1'b is a water-permeable portion produced by a method described later, and all others are water-impermeable portions. A, B, and C denote an impermeable layer, a permeable layer, and an impermeable layer of the stratum from below, respectively.

FIG. 4 is a front view and a side view of an excavator used in the SMW method. In the figure, reference numeral 3 denotes an excavator, which is a multi-axis excavator in which a plurality of rotary longitudinal axes 4 are arranged side by side, and a bit 5 is provided at a lower end of each rotary longitudinal axis 4.
Is provided with a stirring means 6 such as a stirring blade or a screw portion. A liquid ejection port is provided so that cement milk or the like can be ejected from the bit 5 or an arbitrary portion of the rotation longitudinal axis 4.

The excavator 3 excavates the ground while ejecting cement milk from the ground surface to the impermeable layer A. The excavated earth and the cement milk are mixed and stirred by the stirring means 6 to mix the excavated earth and the cement milk. 2 is pulled up and cured in a state where
And the impermeable soil cement continuous wall in FIG. In producing the water permeable portion 1'b in FIG. 3, similarly to the case of using the cement milk, a water-soluble polymer liquid such as CMC (carboxymethylcellulose) or a cement milk containing a foaming agent is used for excavation. I just need.

In the present invention, the following method can be performed by applying the permeable continuous underground wall shown in the embodiment.

(1) A part or the whole of the continuous underground wall for the purpose of water stoppage, which is currently used for the earth retaining deadline, is formed as a continuous underground wall which can be permeable or flooded, thereby reducing the water pressure applied to the earth retaining work. Facilitates design of retaining walls and shoring.

(2) The influence on the flow of groundwater by the construction work is reduced.

(3) Groundwater is controlled by installing it in a subsurface dam, river, place where there is a lot of underflow water, or the like.

[0015]

The effects achieved by the present invention are as follows.

(1) The use of the SMW method reduces the cost of structural deadlines.

(2) The influence of nearby water veins and the like due to construction is reduced.

(3) The amount of water on the downstream side is adjusted by controlling the flow of groundwater.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention.

FIG. 2 is a partial plan view showing one embodiment of the present invention.

FIG. 3 is a perspective view showing another example of the embodiment of the present invention.

FIG. 4 is a front view and a side view showing an example of an excavator used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Soil cement continuous wall 2 Mud digging part 2a Solid part 2b Permeable material part 2c Impervious material part 1 'Soil cement continuous wall 1'b Permeable part 3 Excavator 4 Rotational longitudinal axis 5 bit 6 Stirrer A Impervious layer B Permeable Layer C impermeable layer

Claims (2)

(57) [Claims] 1. A solidification part, a water-permeable material part, and an impervious material part are sequentially provided from below in a muddy water digging part provided on a part of a continuous soil cement underground wall constructed by the SMW method, and each of the soil layers is formed with a soil layer. The permeable layer, the permeable layer, and the impervious layer are opposed to each other, and the permeable material portion includes coarse sand, small gravel, lapilli,
In the case of soil retention using artificial aggregates, etc., it is solidified to give a stiff, foamy material. In the case of only groundwater control, it is used without solidification. Further, as the impermeable material portion, SMW (cement) is used. Milk, bentonite liquid, etc.). 2. A water-soluble polymer liquid or a cement milk containing a foaming agent is injected into a part or all of a portion of the soil cement underground continuous wall constructed by the SMW method which faces the permeable layer of the stratum. A continuous permeable underground wall characterized by having a porous portion.