JP2023009726A - Impervious wall construction method - Google Patents

Abstract

To provide an impermeable wall construction method that can prevent water leakage.SOLUTION: The impermeable wall construction method includes the steps of: penetrating a cylindrical tube body 2 in a dam body T (see Fig. 2(a)); throwing bentonite mixed soil 4 into the tube body 2 (see Fig. 2(b)); solidifying the bentonite mixed soil 4 thrown into the tube body 2 using a rod 5 (see Fig. 2(c)); and pulling out the tube body 2 from the dam body T by a predetermined length, and pushing the solidified bentonite mixed soil 4 by using the rod 5, discharging it outside the tube body 2 so as to be widened for performing compaction (see Figs. 2(d) and (e)).SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to an impermeable wall construction method.

Among civil engineering structures, earthen structures (e.g., embankments, embankments, embankments, etc.) constructed using natural materials such as soil and rock materials have the lowest material costs, and have been used in places since ancient times. has been built on.

By the way, such earthen structures are often damaged by natural disasters such as earthquakes and heavy rains. The extent of the damage varies from minor damage such as cracks to severe damage leading to collapse. When an earthen structure collapses, it is necessary to take measures such as removing the part of the earthen structure including the collapsed part and rebuilding it. However, compared to cases leading to collapse, there are many minor cases in which cracks are generated or steps are formed around the cracks. In addition to natural disasters, soil structures may develop cracks or voids due to deterioration over time or ground movement, or may generate voids at boundaries with concrete structures or the like.

Thus, if defects such as cracks and voids in such soil structures are left as they are, water leakage may occur, which may lead to accidents such as collapse. Therefore, early repair is required. Therefore, as a method for repairing cracks and the like generated in soil structures, for example, a repair method as described in Non-Patent Document 1 is known. The repair method described in Non-Patent Document 1, as shown in FIG. It is a grouting method that repairs soil structures by pouring.

Ohno, Fujii, ``Observation of chemical solution injection in an aged reservoir'', Soil and Foundation, Geotechnical Society, 2001.1, vol.49, No.1

However, in the grouting method as described above, when an earthquake occurs, as shown in FIG. There was a problem.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for constructing impervious walls that can prevent water leakage.

The above objects of the present invention are achieved by the following means. In addition, although the inside of parenthesis is attached with the reference code|symbol of embodiment mentioned later, this invention is not limited to this.

According to the first aspect of the invention, a step of penetrating a cylindrical tubular body (2) into a soil structure (for example, a bank body T) (see FIG. 2(a));
A step of charging the bentonite mixed soil (4) into the tubular body (2) (see FIG. 2(b));
a step of solidifying the bentonite mixed soil (4) put into the tubular body (2) using a predetermined rod (rod 5) (see FIG. 2(c));
The tubular body (2) is pulled out by a predetermined length from the soil structure (for example, the embankment body T), and the hardened bentonite mixed soil (4) is pushed in using the predetermined rod (rod 5). It is characterized by comprising a step of discharging the pipe body (2) outside, widening it, and compacting it (see FIGS. 2(d) and (e)).

According to the invention of claim 2, in the impermeable wall construction method of claim 1, the tubular body (2) is formed in a polygonal shape, and the tubular body (2) formed in the polygonal shape ) are arranged side by side in the soil structure (for example, bank body T) by means of concave-convex fitting.

Furthermore, according to the invention of claim 3, in the impermeable wall construction method according to claim 1 or 2, an opening/closing lid (51b) is provided at the tip of the predetermined rod (rod 5),
The opening/closing lid (51b) opens the tip portion (lower portion 51a1 of the mounting portion 51a) of the predetermined rod (rod 5) when the bentonite mixed soil (4) is put into the tubular body (2). And, when hardening the bentonite mixed soil (4) thrown into the tubular body (2), the tip portion (lower portion 51a1 of the mounting portion 51a) of the predetermined rod (rod 5) is closed. and

Furthermore, according to the invention of claim 4, in the impermeable wall construction method according to any one of claims 1 to 3, the tubular body (2) has a flange portion (first flange portion 2e1 , a second flange portion 2f1) is provided,
A hopper (3) is connected to the flange portions (first flange portion 2e1, second flange portion 2f1) when the bentonite mixed soil (4) is put into the tubular body (2). .

Next, the effects of the present invention will be described with reference to the drawings. In addition, although the inside of parenthesis is attached with the reference code|symbol of embodiment mentioned later, this invention is not limited to this.

According to the first aspect of the invention, the impermeable wall (1) is constructed by widening and compacting the bentonite mixed soil (4). Thereby, water leakage can be prevented.

According to the second aspect of the invention, a plurality of polygonal tubular bodies (2) are arranged side by side in a soil structure (e.g., embankment body T) by means of concave-convex fitting. Construction of impermeable wall (1) becomes possible.

According to the third aspect of the invention, the opening/closing lid (51b) is provided at the tip (mounting portion) of the predetermined rod (rod 5) when the bentonite mixed soil (4) is put into the tubular body (2). When the lower part 51a1) of 51a is opened and the bentonite mixed soil (4) put into the tubular body (2) is hardened, the tip of a predetermined rod (rod 5) (lower part 51a1 of the mounting part 51a) is closed. Therefore, when the bentonite mixed soil (4) is put into the tubular body (2), it is no longer necessary to pull out a predetermined rod (rod 5) from the tubular body (2), thereby improving workability. will improve.

According to the fourth aspect of the invention, when the bentonite mixed soil (4) is put into the tubular body (2), the hopper (3) is connected to the flange portions (first flange portion 2e1, second flange portion 2f1). Therefore, the bentonite mixed soil (4) can be easily put into the tubular body (2), thereby improving workability.

(a) is an explanatory diagram showing a state in which a crack has occurred in a soil structure made of a bank of a reservoir; It is an explanatory view showing a state where impervious walls according to the embodiment are constructed. (a) to (f) are explanatory diagrams for explaining the steps of constructing the impermeable wall according to the embodiment in the soil structure consisting of the embankment of the reservoir. (a) is a plan view showing a tubular body according to the same embodiment, (b) is a plan view showing a state in which a plurality of tubular bodies according to the same embodiment are connected, and (c) is a side view of (b). be. It is a perspective view which shows the state by which the hopper is connected to the tubular body which concerns on the same embodiment. (a) is a vertical cross-sectional side view showing a state in which the rod according to the same embodiment is inserted into the tubular body and the open/close lid is opened, and (b) is a longitudinal cross-sectional side view showing a state in which the rod according to the same embodiment is inserted into the tubular body. , and a vertical cross-sectional side view showing a state in which the open/close lid is closed. (a) is an explanatory drawing showing a state in which a soil structure made of a bank of a reservoir has been repaired by the grouting method, and (b) is an explanatory drawing showing a state in which a crack has occurred in the soil structure made of a bank of a reservoir. is.

An embodiment of the impermeable wall constructing method according to the present invention will be specifically described below with reference to the drawings. In the following description, when the directions of up, down, left, and right are indicated, they refer to up, down, left, and right when viewed from the front of the drawing.

As shown in FIG. 1(b), the impermeable wall 1 according to the present embodiment is erected in a soil structure composed of a bank body T of a reservoir W, for example. That is, as shown in FIG. 1(a), when a crack K occurs in the soil structure consisting of the bank body T of the reservoir W, as shown in FIG. 1(b), in order to repair the crack K, The impermeable wall 1 is erected in the vertical direction. A method for constructing the impermeable wall 1 will be specifically described below.

<Description of how to construct impermeable walls>
In constructing the impermeable wall 1, first, as shown in FIG. As shown in FIGS. 2(a) and 3(a), this tubular body 2 is formed in a rectangular shape with a space S formed therein. and a cylindrical shape with an open lower surface 2b. Then, as shown in FIG. 3(a), a T-shaped first projection 2c1 protrudes from the right side surface 2c of the tubular body 2 formed in this way, and furthermore, the left side of the tubular body 2 A pair of hook-shaped second protrusions 2d1 that can be fitted to the first protrusions 2c1 are provided on the surface 2d. Further, as shown in FIG. 3(a), a first flange portion 2e1 having a plurality of bolt insertion holes 2e1a extending therethrough protrudes from the upper side surface 2e of the tubular body 2. A second flange portion 2f1 having a plurality of bolt insertion holes 2f1a extending therethrough protrudes from the lower side surface 2f. In addition, as shown in FIG. 3(c), a pair of reinforcing ribs 2g are provided on the lower surfaces of the first flange portion 2e1 and the second flange portion 2f1.

Thus, the tubular bodies 2 formed in this way, as shown in FIG. A plurality of tubular bodies 2 can be connected to each other by inserting them into the two projections 2d1 and fitting the first projections 2c1 and the second projections 2d1 together. As a result, as shown in FIGS. 3(b) and 3(c), a plurality of tubular bodies 2 (three in the drawing) can be continuously arranged side by side. Thus, by doing so, a plurality of tubular bodies 2 (three in the drawing) can be continuously arranged side by side in the soil structure consisting of the embankment body T, thereby forming a continuous water impermeable wall 1 can be constructed.

By the way, in the present embodiment, an example in which the tubular body 2 is formed in a rectangular shape is shown, but it is not limited to this, and may be formed in any shape such as a circular shape. However, a polygonal shape is preferred. If the circular shape is used, the first projection 2c1 and the second projection 2d1 come into contact with the side surface of the tubular body 2 at a point, which weakens the strength. This is because there is a possibility that they will be damaged when they are fitted. Therefore, it is preferable to form the polygonal shape so that the first protrusion 2c1 and the second protrusion 2d1 can come into surface contact with the side surface of the tubular body 2 .

As shown in FIG. 2(a), when the pipe body 2 as described above is penetrated into the soil structure consisting of the embankment body T, what kind of construction method is used, such as the vibro construction method or the inner moat construction method? can be

Next, as shown in FIG. 2(b), a funnel-shaped hopper 3 having a space S1 formed therein is connected to the upper surface 2a of the tubular body 2. Next, as shown in FIG. Specifically, as shown in FIG. 4, the flange portion 3a provided at the bottom of the hopper 3 and the first flange portion 2e1 (see FIG. 3) and the second flange portion 2f1 of the tubular body 2 are bolted together. Join through B. As a result, the hopper 3 is connected to the upper surface 2a of the tubular body 2, so that the space S1 of the hopper 3 and the space S of the tubular body 2 communicate with each other as shown in FIG. 2(b). Become. The bolt B is inserted into the bolt insertion hole 2e1a of the first flange portion 2e1 (see FIGS. 3A and 3B) and the bolt insertion hole 2f1a of the second flange portion 2f1 (see FIGS. 3A and 3B). ).

Thus, when the hopper 3 is connected to the upper surface 2a of the tubular body 2, bentonite is placed in the communicating space S1 of the hopper 3 and the space S of the tubular body 2, as shown in FIG. 2(b). Mixed soil 4 is put in. This bentonite mixed soil 4 is a material obtained by mixing a certain amount of bentonite with sandy soil that serves as a base material. Bentonite is a natural clay mineral and has the property of swelling when it absorbs water. Therefore, due to this swelling property, it can be expected to exhibit high water impermeability and self-healing property (the property of gradually recovering the water impermeability that has been reduced due to damage or other reasons). Therefore, this bentonite mixed soil 4 can improve the water impermeability of the base material due to the swelling property of bentonite. In addition, since the bentonite used in the bentonite mixed soil 4 is an inorganic soil material, it is non-combustible and does not deteriorate or decompose over a long period of time, and can semi-permanently maintain a waterproof function. Furthermore, even if the water impermeability of the bentonite mixed soil 4 deteriorates due to cracks or the like caused by an earthquake or the like, it can exhibit self-healing properties due to the swelling property of bentonite.

By the way, when such bentonite mixed soil 4 is put into the communicating space S1 of the hopper 3 and the space S of the tubular body 2, as shown in FIG. A rod 5 is inserted into the space S of the tubular body 2 . The rod 5 is composed of a long rod-shaped rod body 50 and a lid body 51 attached and fixed to a lower portion 50 a of the rod body 50 . As shown in FIG. 5, the lid body 51 is composed of a plate-shaped mounting portion 51a and a pair of opening/closing lids 51b that are attached to a lower portion 51a1 of the mounting portion 51a so as to be able to be opened and closed. there is The mounting portion 51a is formed in a plate shape so that the bentonite mixed soil 4 that has been put in can flow down to the lower surface 2b of the tubular body 2. As shown in FIG. A lower portion 50a of 50 is attached and fixed. As shown in FIGS. 2B and 5, a stopper 51a3 having a vertically elongated rectangular shape is provided at the center of the lower portion 51a1 of the mounting portion 51a. Hinge portions 51a4 are provided on both side surfaces of the lower portion 51a1. As shown in FIG. 5, the opening/closing lids 51b are attached to the hinge portions 51a4 so as to be rotatable about the hinge portions 51a4. As shown in FIG. 5, the pair of open/close lids 51b are formed in a rectangular cross-sectional shape, and as shown in FIG. 51a1 is opened. On the other hand, as shown in FIG. 5(b), the pair of open/close lids 51b are designed to close the lower portion 51a1 of the mounting portion 51a by rotating in the direction of the arrow Y2. When the pair of opening/closing lids 51b rotates in the direction of arrow Y2, as shown in FIG. there is As a result, the lower portion 51a1 of the mounting portion 51a can be closed with the pair of open/close lids 51b.

Thus, the pair of open/close lids 51b configured in this manner are always positioned vertically downward by their own weight, as shown in FIG. 5(a). Therefore, the lower portion 51a1 of the mounting portion 51a is always open. Therefore, as shown in FIG. 2B, even if the rod 5 is inserted into the space S1 of the hopper 3 and the space S of the tubular body 2 that communicate with each other, the lower portion 51a1 of the mounting portion 51a is always open. there is Therefore, the fed bentonite mixed soil 4 can flow down to the lower surface 2 b of the tubular body 2 .

Thus, when the bentonite mixed soil 4 has been introduced into the space S of the tubular body 2 in this way, as shown in FIG. , the rod 5 (see FIG. 2(b)) is moved so that the ends of the pair of open/close lids 51b are located. Then, the rod 5 is moved in the arrow Y3 direction (downward) shown in FIG. For example, the pair of opening/closing lids 51b rotates in the direction of arrow Y2 shown in FIG.

Thus, when the bentonite mixed soil 4 is being charged into the tubular body 2, the lower portion 51a1 of the attachment portion 51a is opened, and when charging of the bentonite mixed soil 4 into the tubular body 2 is completed, the attachment By providing a pair of open/close lids 51b for closing the lower portion 51a1 of the portion 51a, when the bentonite mixed soil 4 is put into the tubular body 2, there is no need to bother to pull out the rod 5 from the tubular body 2. Since the work can be performed in the state of , workability is improved.

By the way, in this embodiment, the hopper 3 is connected to the upper surface 2a of the tubular body 2, and the bentonite mixed soil 4 is put into the tubular body 2. However, the hopper 3 is connected to the upper surface 2a of the tubular body 2. The bentonite mixed soil 4 may be put directly into the tubular body 2 without connecting the . However, when the hopper 3 is connected to the upper surface 2a of the tubular body 2, it becomes easier to charge the bentonite mixed soil 4 into the tubular body 2 and the workability is improved. , hopper 3 is preferably connected.

Next, as shown in FIG. 5(b), after the lower portion 51a1 of the mounting portion 51a is closed by the pair of opening/closing lids 51b, the rod 5 is moved in the direction of arrow Y3 (downward) shown in FIG. 2(c). , the bentonite mixed soil 4 put into the tubular body 2 is hardened by a pair of opening/closing lids 51b.

Next, as shown in FIG. 2(d), a winch (not shown) or the like is used to pull out the tubular body 2 by a predetermined length (for example, 20 cm) from the soil structure consisting of the embankment body T. Then, as shown in FIG. As a result, as shown in FIG. 2(d), the bentonite mixed soil 4 is discharged from the lower surface 2b of the tubular body 2 to the outside of the tubular body 2. As shown in FIG.

Next, as shown in FIG. 2(e), the rod 5 is moved in the arrow Y4 direction (downward) while being vibrated by using a high-frequency vibrating hammer (not shown). As a result, the bentonite mixed soil 4 remaining in the tubular body 2 is pushed by the rod 5, and the bentonite mixed soil 4 in the tubular body 2 is all discharged from the lower surface 2b of the tubular body 2 to the outside of the tubular body 2. The Rukoto. Thus, by doing so, the width H1 (eg, 400 mm) of the bentonite mixed soil 4 shown in FIG. 2(d) is expanded to the width H2 (eg, 500 mm) as shown in FIG. 2(e). The Rukoto. Then, the bentonite mixed soil 4 widened in this manner is compacted by using a vibrating rod 5 .

Thus, by repeating the work shown in FIGS. 2(b) to 2(e), the impermeable wall 1 can be constructed in the soil structure consisting of the embankment body T as shown in FIG. 2(f). Become. Needless to say, after the water impermeable wall 1 is constructed, the tubular body 2 and the rod 5 are pulled out in the arrow Y5 direction (upward) as shown in FIG. 2(f).

Therefore, if the impermeable wall 1 is constructed by expanding and compacting the bentonite mixed soil 4 in the soil structure by the method shown in the embodiment described above, the earth structure will not be damaged by an earthquake or the like. Even if cracks or the like occur, the water impermeable wall 1 can maintain the water impermeability due to the self-healing property resulting from the swelling property of bentonite.

In addition, when constructing the impermeable wall 1, by expanding and compacting the bentonite mixed soil 4, the quality control standard value D value in impermeable zone embankment described in the land improvement project design guideline "reservoir development" Construction satisfying 95% or more is also possible.

Furthermore, when constructing the impermeable wall 1, by widening and compacting the bentonite mixed soil 4, it is possible to perform construction that satisfies a permeability coefficient of 1.0 × 10 ^-6 cm / sec or less, and impermeable wall. Thinning of the zone is also possible.

Thus, according to this embodiment described above, water leakage can be prevented.

Further, according to the present embodiment, when a water leakage location is specified in a reservoir or the like, the impermeable wall 1 can be pinpointed at that location. Work is not generated, and thus workability is improved.

Furthermore, according to this embodiment, as described above, as shown in FIGS. Therefore, a plurality of tubular bodies 2 (three in the drawing) can be continuously arranged side by side in the soil structure composed of the embankment body T. Thus, by doing so, it is possible to construct a continuous impermeable wall 1 . At this time, since the impermeable wall 1 is constructed by widening and compacting the bentonite mixed soil 4, the degree of compaction and the impermeable performance of the connecting portion between the impermeable walls 1, which are considered to be weak portions, are secured. be able to.

The method of constructing the impermeable wall shown in this embodiment is merely an example, and various modifications and changes are possible within the scope of the present invention described in the scope of claims. For example, in the present embodiment, the rod 5 is vibrated using a high-frequency vibrating hammer, but the rod 5 may be vibrated using a low-frequency vibrating hammer. However, it is preferable to vibrate the rod 5 using a high-frequency vibro-hammer. When compacting the bentonite mixed soil 4, it is better to use a low-frequency vibro-hammer. Because there is Therefore, it is preferable to use a high-frequency vibro-hammer.

In addition, in the present embodiment, the embankment body T of the reservoir W was described as an example of the soil structure, but it is not limited to this, and can be applied to any location such as contaminated water as long as it is a location to prevent water leakage. Applicable.

1 impervious wall 2 tubular body 2c1 first projection 2d1 second projection 2e1 first flange portion (flange portion)
2f1 second flange portion (flange portion)
3 hopper 4 bentonite mixed soil 5 rod (predetermined rod)
51a Mounting portion 51a1 (Mounting portion) lower portion (predetermined rod tip)
51b Open/close lid T Bank body (soil structure)

Claims (4)

a step of penetrating a tubular tubular body into an earthen structure;
A step of introducing bentonite mixed soil into the tubular body;
a step of hardening the bentonite mixed soil put into the tubular body using a predetermined rod;
a step of pulling out the tubular body by a predetermined length from the soil structure, pushing in the hardened bentonite mixed soil using the predetermined rod, discharging it out of the tubular body, widening it, and compacting it; a water impermeable wall construction method comprising: 2. The impermeable wall constructing method according to claim 1, wherein the tubular body is formed in a polygonal shape, and a plurality of polygonal tubular bodies are arranged side by side in the soil structure by means of concave-convex fitting. . An open/close lid is provided at the tip of the predetermined rod,
The opening/closing lid opens the tip of the predetermined rod when the bentonite mixed soil is put into the tubular body, and when the bentonite mixed soil put into the tubular body is hardened, the tip of the predetermined rod is opened. 3. The impermeable wall constructing method according to claim 1 or 2, wherein the part is closed. The tubular body is provided with a flange,
The impermeable wall construction method according to any one of claims 1 to 3, wherein a hopper is connected to the flange portion when the bentonite mixed soil is charged into the tubular body.

Images