JPH108455A - Continuous water cut-off wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten the cut-off performance of a continuous water cut-off wall and facilitate construction therefor. SOLUTION: A steel sheet pile 4 is placed through a gap 5 between rear side flanges 1b, 1b of main piles 1, 1 of an earth retaining wall 3. U-tubes 6 are longitudinally disposed on the right and left inner end parts of the outer surfaces of the rear side flanges 1b, 1b of the main piles 1, 1 and on the outer surfaces of both right and left side parts 4a, 3a of the steel sheet pile 4, respectively. When liquid nitrogen is introduced into the U-tubes 6, the gap 5 is freezed to connect the adjacent main pile 1 and the steel sheet pile 4 to each other through a frozen soil column 11, thereby forming a continuous water cut-off wall along the earth retaining wall 3 in the rear thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous water stop wall, and more particularly to a continuous water stop wall used as an auxiliary water stop wall of a mountain retaining by a parent pile horizontal sheet pile method.

[0002]

2. Description of the Related Art A conventional continuous water stop wall is constructed, for example, by arranging a number of steel sheet piles without gaps and driving them into the ground. Here, joint portions are formed at the left and right end portions of each steel sheet pile, and the joint parts of adjacent steel sheet piles are engaged with each other at the time of driving.

[0003]

The operation of engaging and connecting the joints of adjacent steel sheet piles is complicated.
Further, the water blocking wall constructed in this manner may leak from the joint.

[0004] In order to solve such a water leakage, the present applicant has proposed a means for arranging a freezing tube on the outer surface of the joint to freeze the area around the joint.
-63882). However, even in this case, since the joint portions of the adjacent steel sheet piles still mesh with each other, the complexity of the connecting operation is not solved.

[0005] Therefore, technical problems to be solved arise in order to increase the water stopping performance of the water blocking wall and to facilitate the construction thereof, and an object of the present invention is to solve the problems.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and water-stopping steel materials are intermittently arranged and driven into the ground. The present invention provides a continuous water-stop wall in which a freezing pipe is disposed in the vertical direction and liquid nitrogen is introduced into the freezing pipe to connect adjacent water-stopping steel materials via frozen soil columns.

Further, the present invention provides a continuous water stop wall in which the water-stopping steel material is a parent pile for retaining a mountain, a steel sheet pile, an H-section steel or a combination thereof, and a continuous water stop wall in which the freezing tube is a U-shaped tube. It is.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described in detail with reference to FIG. First, the parent pile horizontal sheet pile method in the mountain retaining which is one application field of the present invention will be described with reference to FIG.

The parent pile horizontal sheet pile method is to excavate the ground after placing the parent piles 1, 1,.
This is a mountain retaining method for forming the mountain retaining wall 3 by inserting horizontal sheet piles 2, 2,. Specifically, the parent piles 1, 1...
The flanges 1a,
1b are arranged side by side so that the tips thereof face each other. And, on the inner surface of the opposed front side flanges 1a, 1a,
2 so that the front left and right ends are locked.
Are sequentially stacked without gaps.

[0010] Such a parent pile horizontal sheet pile method is suitable for small- and medium-scale mountain retaining work in view of economy and ease of construction. However, when the groundwater level is high, groundwater flows out from the junction of the horizontal sheet piles 2, 2,. There is a possibility that. Therefore, it is necessary to implement appropriate drainage treatment, so that it is often not applicable when the groundwater level is high.

[0011] Further, the method is characterized in that after excavation of the ground, the horizontal sheet piles 2, 2
… Is inserted, there is a risk of collapse during excavation on grounds that are not self-supporting, such as loose fine sand layers and silt layers. Thus, if the continuous water blocking wall according to the present invention is attached to the retaining wall 3 by the parent pile horizontal sheet pile method, such a weak point of the retaining wall 3 can be compensated as much as possible.

FIG. 2 shows an embodiment of the present invention in which a steel sheet pile 4 is interposed between adjacent parent piles 1, 1. The steel sheet pile 4 is formed of a vertically long steel plate. The left and right side portions 4a, 4a are bent rearward (downward in the drawing) so as to form an obtuse angle with respect to the central portion 4b. The steel sheet pile 4 is placed on the rear side flange 1b of the parent pile 1, 1 after the parent pile 1, 1 has been set and before excavating the ground in front of the parent pile 1, 1 (above the paper surface). It is driven through gaps 5 and 5 between 1b. It is desirable that the gap 5 be approximately 5 to 20 cm.

U-shaped pipes 6 are respectively provided on the outer left and right inner end portions of the rear side flanges 1b, 1b of the parent piles 1, 1 and the outer right and left side portions 4a, 4a of the steel sheet pile 4 in the longitudinal direction. (In the direction perpendicular to the plane of the paper). Here, the U-shaped pipe 6 has a diameter of about 6 mm to 10 mm, and is fixed to the parent pile 1 and the steel sheet pile 4 in advance before driving the parent pile 1 and the steel sheet pile 4 into the ground. You.

As shown in FIG. 3, a liquid nitrogen tank 8 is connected to one end of the U-shaped tube 6 via an electromagnetic valve 7, and the other end of the U-shaped tube 6 is open to the ground. . Further, a temperature sensor 9 is provided in the vicinity of the location of the U-shaped pipe 6 in the parent pile 1 and the steel sheet pile 4, and an output of the temperature sensor 9 is connected to a controller 10.

When the electromagnetic valve 7 is opened by the controller 10 and liquid nitrogen in the liquid nitrogen tank 8 is introduced into the U-tube 6, the ground around the U-tube 6, that is,
The ground near the gap 5 freezes, and a frozen soil column 11 as shown in FIG. 2 is formed and grows. Then, the parent pile 1 and the steel sheet pile 4 are connected via the frozen soil column 11, and a continuous water blocking wall 12 is formed along the retaining wall 3 at the rear thereof.

Thus, the continuous water blocking wall 12 ensures complete waterproofness of the mountain retaining, so that drainage treatment is not required,
The above-mentioned parent pile horizontal sheet pile method can be applied to the ground with high permeability such as a sand layer. In addition, the continuous water blocking wall 12
The independence of the ground is secured by the
Even if the ground is excavated in front of 1, the ground is not likely to collapse, and the parent pile horizontal sheet pile method can be applied to soft ground without independence. Further, since the stress of earth pressure can be shared by the steel sheet pile 4, the number of cut beams, bulging, etc. can be reduced.

In order to form the frozen soil column 11, -3
A temperature of about 0 ° C. to −50 ° C. is sufficient. On the other hand, since the temperature of liquid nitrogen is −180 ° C., it can be frozen efficiently. Once the frozen soil pillar 11 is formed, even if the controller 10 closes the solenoid valve 7 and cuts off the supply of liquid nitrogen, the frozen soil pillar 11 does not easily melt. Therefore, the controller 10 may be configured so as to open the solenoid valve 7 intermittently while monitoring the output of the temperature sensor 9 thereafter, which is extremely economical.

FIG. 4 shows another embodiment of the present invention. In this embodiment, two H-shaped steel members 13, 13 are used instead of the steel sheet pile 4 shown in FIG. It is interposed between the parent piles 1 and 1. Also in this embodiment, between the adjacent parent pile 1 and the H-shaped steel 13 and between the adjacent H-shaped steel 1 and the H-shaped steel 1.
A gap 5 is provided between 3 and 13. Then, the left and right inner ends of the outer side surfaces of the rear side flanges 1b, 1b of the parent piles 1, 1 and the front side flanges 13 of the H-shaped steels 13, 13
The U-shaped tubes 6 are disposed in the vertical direction on the outer side surfaces.

In this case as well, if liquid nitrogen is introduced into the U-shaped tube 6, the surrounding ground is frozen and the frozen soil column 11 is formed and grows. Then, the adjacent parent pile 1 and the H-shaped steel 13 and the adjacent H-shaped steels 13 and 13 are connected to each other via the frozen soil column 11, and the continuous water blocking wall 12 is provided along the retaining wall 3 at the rear thereof. It is formed.

FIG. 5 shows still another embodiment. In this embodiment, the distance between the parent stakes 1 and 1 is large, and a plurality of stakes 1 and 2 are provided between the rear flanges 1b and 1b. The steel sheet pile 4 and the H-section steel 13 are alternately interposed. Also in this embodiment, between adjacent parent pile 1 and steel sheet pile 4, and between adjacent steel sheet pile 4 and H-shaped steel 13
A gap 5 is provided between them. And the parent pile 1,
1 outer right and left inner ends of the rear side flanges 1b, 1b;
And left and right side portions 4a, 4a outer surfaces of the steel sheet piles 4, 4;
In addition, U-shaped pipes 6 are vertically arranged on the outer surface of the front flange 13a of the H-shaped steel members 13, 13, respectively.

In this case as well, if liquid nitrogen is introduced into the U-shaped tube 6, the surrounding ground is frozen and the frozen soil column 11 is formed and grows. The adjacent parent pile 1 and the steel sheet pile 4 and the adjacent steel sheet pile 4 and the H-shaped steel 13 are connected via the frozen soil column 11, and the continuous water blocking wall 12 is provided along the retaining wall 3 at the rear thereof. Is formed.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0023]

As described above, according to the present invention,
When constructing a continuous water-stop wall, complicated connection work such as engaging the joint portions of adjacent steel sheet piles is not necessary, and a water-stop steel material such as a steel sheet pile or an H-section steel is cast into each unit. The construction is extremely easy.
Further, since it is not necessary to provide a joint portion, the variation of the water-stopping steel material is expanded, and the water-stopping steel material can be formed as it is even with a simple-shaped pile made of, for example, a steel pipe.

Further, since a frozen soil column is formed between adjacent water-stopping steel materials, the water-stopping property is improved as much as possible. Furthermore, since such a water-stopping steel material is made of steel, it has good thermal conductivity.
Accordingly, the water-stopping steel material itself is also lowered in temperature, and the frozen soil column is finally formed on the entire continuous water-stop wall, so that the water-stop performance is further improved.

In the freezing tube, the temperature of the inlet of liquid nitrogen is the lowest, and the temperature rises toward the outlet.
By configuring the freezing tube as a U-shaped tube, the degree of freezing with respect to the depth can be averaged.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of a retaining wall constructed by a parent pile horizontal sheet pile method which is one application field of the present invention.

FIG. 2 is a plan view showing the embodiment of the present invention and explaining the embodiment.

FIG. 3 is an explanatory diagram showing a configuration of liquid nitrogen introduction control.

FIG. 4 is a plan view showing another embodiment of the present invention and explaining the embodiment.

FIG. 5 is a plan view showing another embodiment of the present invention and explaining the embodiment.

[Explanation of symbols]

 Reference Signs List 1 parent pile 4 steel sheet pile 5 gap 6 U-shaped pipe 8 liquid nitrogen tank 11 frozen soil column 12 continuous water stop wall 13 H-section steel

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Retsuri 2-1-1 Honohara, Toyokawa City, Aichi Prefecture Inside Mitoyo Techno Construction Co., Ltd. (72) Inventor Tsutomu Kojima 2-1-1 Honohara Toyokawa City, Aichi Prefecture Mitoyo Techno Construction Inside the corporation

Claims (3)

[Claims] 1. A water-stopping steel material is intermittently arranged and poured into the ground, and a freezing pipe is disposed in a vertical direction on a side portion of the water-stopping steel material, and liquid nitrogen is introduced into the freezing pipe. A continuous water-stop wall wherein adjacent water-stop steel members are connected via frozen soil pillars. 2. The continuous water blocking wall according to claim 1, wherein the water stopping steel material is a parent pile for retaining, a steel sheet pile, an H-shaped steel, or a combination thereof. 3. The continuous water blocking wall according to claim 1, wherein the freezing tube is a U-shaped tube.