JP2001032699A - Water stopping method and water stopping structure at joint of underground concrete structure - Google Patents

Abstract

(57) [Summary] [Problem] It is possible to flexibly respond to the opening amount of the joint,
Further, the present invention also provides a water stopping method and a water stopping structure at a joint of an underground concrete structure capable of stopping water against the water pressure of the ground water. Further, the present invention provides a water stopping method and a water stopping structure at a joint of an underground concrete structure capable of improving the reliability of water stopping. Further, the present invention provides a method and a structure for stopping water at a joint of an underground concrete structure, which facilitates installation work of a waterproof material at the joint. SOLUTION: A piston ring 12 protruding from a wife form 5 allows a tip end surface of one concrete wall W1 to be formed.
A groove 21 is formed along a ridgeline where the inner surface and the tip surface intersect, and a bentonite water-stop material 15 is injected into the groove 21 through a water-stop material supply path P provided in the piston ring 12. To the other concrete wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water stopping method and a water stopping structure for an underground concrete structure in which an underground concrete structure is constructed by connecting one concrete wall to another concrete wall. .

[0002]

2. Description of the Related Art Underground concrete structures include, for example, concrete tunnel inner walls. As a method of constructing a tunnel having this kind of concrete inner wall of a tunnel, a tunnel is excavated by an excavator advancing while excavating the ground, an inner formwork is arranged on the inner surface of the excavated tunnel, And place the wife form between the ground and the ground, fill concrete into the concrete casting space formed between the inner form and the ground from the concrete supply pipe provided in the wife form, A tunnel construction method for constructing a concrete tunnel inner wall is known.

In this tunnel construction method, as shown in a side sectional view of FIG. 6, a shield excavator 1 and a concrete placing device 2 are used. The concrete casting device 2
Behind the shield excavator 1, a skin plate 3 arranged to support the ground E along the inner surface of the tunnel T excavated by the shield excavator 1, and also arranged behind the shield excavator 1, An inner formwork 4 that covers an inner surface of the tunnel T excavated by the shield excavator 1 at a position separated from the inner surface of the tunnel T by a predetermined distance; and a skin plate 3 disposed between the skin plate 3 and the inner formwork 4. Wife form 5 which forms a concrete casting space S between the inner form 4 and the back form of the shield excavator 1, which presses the form 5 backward along the axial direction of the tunnel T. And a concrete supply pipe 7 having one end connected to the concrete supply source D and the other end communicating with the concrete placing space S through the end form 5.

In the above-described configuration, the inner form 4 is a unit that is connected in plural numbers along the circumferential direction of the tunnel T, and is provided on the shield excavator 1 side in accordance with the extension of the tunnel T by the shield excavator 1. They are sequentially added in a ring shape to the ends. The wife formwork 5 has a ring shape continuous in the circumferential direction of the tunnel T. In addition, wife formwork jack 6
And the concrete supply pipe 7 are not shown,
Are provided in the circumferential direction, and are connected to each of the wife forms 5. In addition, as the shield excavator 1, for example, a plurality of cutters 8 are provided on an end face facing the excavation direction, and the cutter 8 is driven to rotate around a center so as to excavate the ground E by the cutter 8. A generally cylindrical excavator body 1b, which is provided with a rotating body 1a, a driving device (not shown) arranged behind the rotating body 1a and rotationally driven about the rotating body 1a, and excavation; It is arranged between the rear part of the machine main body 1b and the inner mold 4 and presses and fixes the inner mold 4 rearward by stretching against the inner mold 4,
A shield jack 1c that uses the reaction force as the driving force of the shield excavator 1 is used.

In the tunnel construction method described above, the excavation of the tunnel T by the shield excavator 1 is stopped at regular intervals and the casting of concrete forming the inner wall of the tunnel T is temporarily stopped for convenience of construction. Let me. In addition, there is a case where the placing of concrete is interrupted during construction due to excavation trouble or the like.
When resuming the casting of the concrete forming the inner wall of the tunnel T, the succeeding concrete wall is to be newly connected to the previously cast concrete wall, and the previously cast concrete wall is to be cast. A seam occurs at the joint between the concrete wall and the subsequent concrete wall. Here, the opening amount of the joint (the size of the gap formed at the joint) is expanded to a predetermined size after the concrete is cast, for example, due to drying and shrinkage of the cast concrete.

FIG. 7A shows an example of a method for stopping water at the joint of the inner wall of a tunnel (underground concrete structure).
As shown in the figure, the joint end face (tip face) of one concrete wall W1 (concrete wall to be preceded) and the other concrete wall W2 (consecutive concrete wall)
Between the joint end face of one concrete wall W1 side,
A method of embedding the waterproof plate a so as to straddle the joint H, as shown in FIG.
A method of embedding or affixing the sealing material b so as to be in contact with the other concrete wall W2 on the joint end face 1 as shown in FIG. 7C, where one concrete wall W1 and the other concrete wall W2 7 is provided between the one concrete wall W1 and the other concrete wall W2 on the side in contact with the ground so as to straddle the joint H of FIG.
As shown in (d), there is known a method of filling a joint H between one concrete wall W1 and the other concrete wall W2 with a caulking material d.

Here, in the method of stopping water at the joint shown in FIG. 7B, in the former method of constructing a tunnel, a sealing material b is applied to the surface of the end form 5 on the side of the installation space S with an adhesive or the like. By mounting one concrete wall W1 in this state, a groove 9 for accommodating the sealing material b is formed on the joint end face of the one concrete wall W1. After the installation is completed, the sealing material b is bonded to the groove 9 with an adhesive or is buried, thereby separating the sealing material b from the wife formwork 5, and in this state, the other concrete wall W
2 is cast.

[0008]

FIG. 7 (a)
In the conventional method for stopping water at the joint of the inner wall of the tunnel (underground concrete structure) shown in (d), it is possible to cope only when the opening amount of the joint H is within a small range of about several mm to 5 mm. There was a problem. In addition, there is a problem that as the water pressure of the groundwater becomes higher, the corresponding opening amount becomes smaller. Further, if a waterproof material having a size corresponding to the opening amount of the joint H is not used, a gap is generated between the concrete wall and the waterproof material, so it is necessary to estimate the opening amount in advance. However, there is a problem that it takes time. The spliced end faces of the wife formwork 5, the one concrete wall W1, and the other concrete wall W2 are usually wet with the groundwater that springs out of the ground E, and the concrete walls W1, W
There was a problem that a water-stopping effect could not be sufficiently exhibited due to a gap between the water-stopping material 2 and the water-stopping material.

In the case of using the water stopping method of the joint shown in FIG. 7 (b), it is necessary to adhere the sealing material b to the joining end face of the end formwork 5 or one concrete wall W1 with an adhesive or the like. However, the spliced end face of the wife formwork 5 and one concrete wall W1 is usually wet with groundwater that springs out of the ground E, and this moisture makes it difficult to adhere the sealing material b with the adhesive. However, there is a problem that a gap between the concrete walls W1, W2 and the sealing material b is formed due to the water, and the water stopping effect cannot be sufficiently exhibited.

Further, when the concrete walls W1 and W2 are cast, the sealing material b is pushed by the flow of the concrete and is peeled off from the end form 5 or one of the concrete walls W1 and is displaced from an appropriate position. And seal material b
However, there is a problem that the water stoppage at the joint H may be uncertain.

[0011] In any of the above methods,
In order to arrange the waterproof material at the joint H, the wife form 5 must be completely pulled out from between the skin plate 3 and the inner form 4. A seal for preventing the concrete from leaking out of the concrete casting space S is provided between the mold 4 and the concrete. When performing this pulling-out work, it is necessary to carefully perform this work so as not to damage the seal. There was a problem that the work efficiency was very poor.

The present invention has been made in view of the above circumstances, and can flexibly cope with the opening amount of a joint.
An object of the present invention is to provide a method and a structure for stopping water at a joint of an underground concrete structure capable of stopping water against the water pressure of groundwater. Another object of the present invention is to provide a water stopping method and a water stopping structure at a joint of an underground concrete structure capable of improving the reliability of water stopping. It is another object of the present invention to provide a water stopping method and a water stopping structure at a joint of an underground concrete structure, which can easily perform a work of installing a water stopping material at a joint.

[0013]

As a means for achieving the above object, a method and a structure for stopping water at the joint of an underground concrete structure configured as follows are employed. That is, in the method for stopping water at the joint of an underground concrete structure according to claim 1, the underground concrete structure is constructed by constructing an underground concrete structure by connecting a succeeding concrete wall to a concrete wall to be cast in advance. A method of stopping water at a joint, in which a groove is formed in a front end surface of the concrete wall to be preceded on the side of the subsequent concrete wall, and swells in the groove by reacting with water. A bentonite waterproof material is disposed, and then the subsequent concrete wall is connected.

In the method for stopping water at the joint of an underground concrete structure, the bentonite water-stopping material that swells by reacting with water is used as the water-stopping material for stopping the joint at the underground concrete structure. When groundwater enters the joint of the underground concrete structure, the bentonite waterproof material reacts with the groundwater and swells,
By clogging at the joint, the joint is closed. In addition, the bentonite waterproof material is positioned and fixed in the groove formed on the front end surface of the concrete wall to be cast in advance.

According to a second aspect of the present invention, there is provided a method for stopping water at a joint of an underground concrete structure, wherein the bentonite water-stopping material is connected to the groove. It is arranged on the inner bottom surface side of the groove so that a water stop space is formed on the front end surface side, and when the subsequent concrete wall is provided, concrete is filled into the water stop space and poured. Features.

In the method for stopping water at the joint of an underground concrete structure constructed as described above, the front end face of the groove is formed on the bottom bottom side of the groove formed on the front end face of the concrete wall to be cast in advance. The bentonite water-stopping material is arranged so that a water-stopping space is formed on the side, and the concrete that composes the subsequent concrete wall is filled into this water-stopping space, so that the subsequent concrete wall has a groove. A water-stop convex portion that fits in the water-stop space is formed, and a wrap portion having a predetermined length is formed in the groove and the water-stop convex portion. The groundwater that entered the joint from the ground due to the opening of the joint was guided into the waterstop space, and reacted with this groundwater, the bentonite waterstop material swelled and closed the waterstop space. At the same time, the gap formed in the lap portion between the groove and the water blocking convex portion is clogged, thereby closing the joint. Then, the bentonite water-stopping material is disposed on the deep bottom surface side of the groove of the concrete wall to be poured in advance, so that the bentonite water-stopping material is more effectively fixed.

According to a third aspect of the present invention, there is provided a method of stopping water at a joint of an underground concrete structure, wherein the underground concrete structure is constructed by connecting a succeeding concrete wall to a concrete wall to be cast first. The method for stopping water at a joint seam of the above, wherein a projecting portion is provided on a spigot form forming a front end surface of the concrete wall to be preceded on the side of the succeeding concrete wall, whereby the precedently sprinkled is provided. A groove is formed in the front end surface of the concrete wall to be formed, and after the curing of the concrete wall to be poured in advance is completed, the protrusion is pulled out from the groove by a predetermined distance, so that the protrusion is stopped at the front end surface side of the groove. A filling space is formed on the inner bottom surface side of the groove while securing a space enough to form a water space, and in the filling space, reacts with water through a water-stopping material supply path provided in the protrusion. Swell Injecting amorphous bentonite water stopping material, when providing the subsequent concrete wall, characterized in that pouring by filling concrete into the waterproofing space.

In the method of stopping water for an underground concrete structure having such a configuration, a groove is formed on the tip end surface of a concrete wall to be cast in advance by providing a projection on the end form. Then, in a state where the protrusion is pulled out from the groove by a predetermined distance, by injecting an irregular bentonite water-stop material into the groove through a water-stop material supply path provided in the protrusion,
A bentonite water-stopping material is injected into the deep bottom surface of the groove while securing a water-stopping space on the tip end side of the groove. When the concrete forming the subsequent concrete wall is filled in the water stopping space, a water stopping convex portion that fits into the water stopping space of the groove is formed on the subsequent concrete wall, and the groove and the stop are formed. A wrap portion having a predetermined length is formed on the water convex portion.

According to a fourth aspect of the present invention, there is provided a watertight structure for a joint of an underground concrete structure provided at a joint between one concrete wall and the other concrete wall. Water structure,
A groove is formed at the joint end face of the one concrete wall with the other concrete wall, and a water blocking space is formed in the groove, and swells by reacting with water on the inner bottom surface side. A bentonite water-stopping material is provided, and a water-stop projection that fits into the water-stop space of the groove is formed on the joint end face of the other concrete wall.

In the water stopping structure of the joint of the underground concrete structure thus constructed, a groove is formed in one of the concrete walls at the joint end face with the other concrete wall, and a deep portion inside the groove is formed. On the bottom side, a bentonite water-stop material is arranged so that a water-stop space is formed at one of the joint end surfaces, and a water-stop protrusion formed on the other concrete wall is fitted into this water-stop space. Therefore, a wrap portion having a predetermined length is formed in the groove and the water blocking protrusion. The groundwater that entered the joint from the ground due to the opening of the joint was guided into the waterstop space, and reacted with this groundwater, the bentonite waterstop material swelled and closed the waterstop space. At the same time, the gap formed in the lap portion between the groove and the water blocking convex portion is clogged, thereby closing the joint. Then, the bentonite water-stopping material is disposed on the inner bottom surface side of the groove of the one concrete wall, so that the bentonite water-stopping material is positioned and fixed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Here, as the underground concrete structure, concrete is cast in place by the concrete casting device 2 on the inner surface of the tunnel T excavated by the excavator 1, as shown in FIG. A description will be given of a case where a method and a structure for applying a water stopping method of a joint of an underground concrete structure of the present invention to a joint of the tunnel inner wall are used for a joint of the tunnel inner wall using a concrete tunnel inner wall constructed by a construction method for constructing a tunnel inner wall of the present invention. I do.

First, a detailed structure and a waterproof material of the concrete placing device 2 used for performing the method of stopping water at the joint of an underground concrete structure according to the present invention will be described.
FIGS. 2A and 2B are side sectional views showing how the inner wall of the tunnel T is constructed. Symbol E is ground mountain, symbol 3 is ground mountain E
, A reference numeral 4 denotes an inner mold, a reference numeral 5 denotes a wife mold, and a reference numeral 6 denotes a wife mold jack. Here, FIG.
FIG. 2B is an enlarged view of the vicinity of the wife formwork 5 in FIG.

The wife form 5 is connected to a concrete supply pipe 7 (FIG. 2).
A concrete delivery path (not shown) for connecting the concrete supplied from the concrete supply pipe 7 into the concrete placement space S by connecting the concrete placement space S to the concrete placement space S is provided. In addition, seals 5a and 5b for preventing leakage of concrete poured into the concrete placing space S are provided at portions of the wife formwork 5 that come into contact with the skin plate 3 and the inner formwork 4, respectively.

Further, on the inner surface of the wife formwork 5, that is, the surface on the side of the concrete placing space S, the front end surface (punching) of the concrete wall W1 formed in the concrete placing space S on the side of the subsequent concrete wall W2. A piston ring accommodating groove 11 formed along a ridgeline where the joint end face intersects the inner surface is provided. In the piston ring accommodating groove 11, a piston ring 12 that is operated to project into the concrete placing space S is provided. Are provided over the entire circumference of the piston ring housing groove 11.

A rod insertion hole 13 is formed in the bottom surface of the piston ring accommodating groove 11 so as to extend outside the end form 5, that is, toward the side opposite to the concrete placing space S. The piston ring 12 is provided in the piston ring receiving groove 11.
Is connected to a piston rod 14 which is inserted into a rod insertion hole 13 provided on the bottom surface of the rod and is driven forward and backward along the rod insertion hole 13 by a driving device (not shown). Then, the piston ring 12 and the piston rod 1
One end of the piston ring 12 is opened on the inner surface side of the end mold 5 of the piston ring 12 so as to penetrate the piston ring 12 and the piston rod 14, and the other end
A water-blocking material supply path P is formed to extend outwardly of the wife formwork 4, that is, on the opposite side of the concrete casting space S. Here, the other end of the water-stopping material supply path P is provided with a water-stopping material supply source (not shown) for supplying an irregular-shaped bentonite water-stopping material 15.
It is connected to the.

In the above configuration, the piston ring 12
Is formed by a driving device (not shown) through the piston rod 14 to form a protruding portion that protrudes toward the concrete placing device 2 of the end form 5.

The bentonite water-stopping material 15 for stopping water at the joint between the concrete wall W1 to be poured in advance and the concrete wall W2 to be succeeded is made of a material which reacts with water and swells. By changing the solvent, properties such as hardness and softness and viscosity can be adjusted, and it can be manufactured in a fixed or irregular shape.
The durability performance is semi-permanent. Here, in the present embodiment, the bentonite water-stopping material 15 has an irregular shape.

Hereinafter, a method for constructing a tunnel inner wall to which the method for stopping water at the joint of an underground concrete structure and the structure of the present invention is applied by using the concrete casting device 2 thus configured will be described. First, concrete is filled into the concrete placing space S at a predetermined filling pressure from the concrete supply pipe through the concrete delivery path of the wife formwork 5, and the concrete wall W1 to be poured in advance.
After placing the concrete wall (hereinafter abbreviated as concrete wall W1), the supply of the concrete to the concrete supply pipe is stopped.
And the concrete wall W in the concrete placing space S
3, the piston ring 12 provided on the end form 5 is made to protrude from the surface of the end form 5 on the concrete placing space S side as shown in FIG. A groove 21 is formed in the front end face of W1 on the subsequent concrete wall W2 side.

Here, the projecting operation of the piston ring 12 is performed by advancing the piston rod 14 along the rod insertion hole 13 by using a driving device (not shown).
This is performed by pressing the piston ring 12.

Next, after the curing of the concrete wall W1 is completed, the piston ring 12 provided on the end form 5 is pulled back by a predetermined distance, and a space for forming the water stop space 22 on the tip end side of the groove 21 is formed. A filling space F is formed on the inner bottom surface side of the groove 21 while securing, and in this filling space F, an amorphous bentonite water-stopping material is formed through a water-stopping material supply path P provided in the piston ring 12 and the piston rod 14. 15 (see FIG. 4).

Next, the piston ring 12 is pulled back until the front end surface thereof comes to the same position as the edge of the piston ring receiving groove 11 of the end form 5, and the end surface of the concrete wall W 1 is connected to the end form 5. The wife formwork jack 6 pulls out the wife formwork 5 by a predetermined distance so as to secure a new concrete placing space S therebetween. Then, concrete is supplied into the newly secured concrete placing space S, and the subsequent concrete wall W2 (hereinafter, abbreviated as concrete wall W2) is connected to the front end surface of the concrete wall W1 (see FIG. 5). At this time, the concrete cast in the concrete casting space S is cast so as to be filled also in the water blocking space 22 formed in the groove 21 of the concrete wall W1.

Then, at the joint H between the concrete wall W1 and the concrete wall W2, a water stop structure at the joint of the underground concrete structure shown in the side sectional view of FIG. 1A is constructed. That is, the concrete forming the concrete wall W2 is filled in the water blocking space 22 provided in the concrete wall W1, so that the groove 21 is formed in the concrete wall W2.
Is formed in the water stop space 22 of the water stop space 22.
Then, a wrap portion 24 having a predetermined length is formed in the groove 21 and the water blocking convex portion 23.

In the above-described operation for constructing the inner wall of the tunnel, a groove 21 is formed in the tip end surface of the concrete wall W1 by the piston ring 12 protruding from the end mold 5, and the piston ring 12 and the piston rod are formed in the groove 21. An irregular-shaped bentonite water-stopping material 15 is injected through a water-stopping material supply path P provided at 14. Then, the groove 21 formed in the concrete wall W1 with the bentonite waterproof material 15 is formed.
The positioning and fixing of the irregular bentonite water-stopping material 15 are performed by being disposed in the inside. Furthermore, by disposing the bentonite water-stopping material 15 on the inner bottom surface side of the groove 21 of the concrete wall W1, the amorphous bentonite water-stopping material 15 is fixed more effectively.

In the water stopping structure at the joint of the underground concrete structure thus constructed, the joint H
The groundwater that has entered the joint H from the ground E due to the opening is guided into the water stop space 22, and the bentonite water stop material 15 swells by reacting with the groundwater, and swells. At the same time, the gap formed in the wrap portion 24 between the groove 21 and the water stopping protrusion 23 is clogged, thereby closing the joint H (see FIG. 1B).

As a result, according to the method and structure for stopping water at the joint of an underground concrete structure according to the present invention, the size of the gap formed in the wrap portion 24 between the groove 21 and the water stopping protrusion 23 is substantially constant. Therefore, if the length of the groove 21 and the wrap portion 24 of the water stopping protrusion 23, that is, the length of the water stopping space 22 in which the water stopping protrusion 23 is fitted can be secured to a predetermined extent, the joint H Irrespective of the opening amount, the bentonite waterproof material 15 easily clogs the gap formed in the wrap portion 24.
In addition, since the bentonite water-stopping material 15 reacts with water to expand and close the water-stopping space 22, it is not necessary to predict the opening amount of the joint H in advance, and it is possible to flex according to the opening amount. Can be handled. And for similar reasons,
The water stop at the joint H can be effectively performed against the water pressure of the groundwater.

Since the bentonite waterproof material 15 swells by reacting with groundwater, even if the concrete wall W1 and the concrete wall W2 are wet, the bentonite waterproof material 15 and the concrete walls W1, W2 are brought into close contact with each other. Therefore, the water stopping effect can be sufficiently exhibited to improve the certainty of the water stopping. Since the bentonite water-stopping material 15 is disposed in the groove 21 formed in the concrete wall W1, the positioning and fixing of the bentonite water-stopping material 15 are performed. There is no need to use it, and the positioning and fixing of the amorphous bentonite waterproof material 15 can be performed easily and at low cost. Furthermore, concrete wall W
At the time of casting, the bentonite waterproof material 15 is pressed against the inner bottom surface side of the groove 21 by the cast concrete, so that the bentonite waterproof material 15 can be fixed more reliably, The effect can be sufficiently exhibited, and the certainty of water stoppage can be improved.

The irregular-shaped bentonite waterproofing material 15
Is injected into the filling space F formed on the inner bottom surface side of the groove 21 through the water-blocking material supply path P provided in the piston ring 12 and the piston rod 14, so that the end mold 5 and the skin plate 3 The bentonite waterproof material 15 can be arranged in the groove 21 without completely pulling out the space between the inner mold 4 and the troublesome work of pulling out the wife form 5. Thereby, the installation work of the bentonite waterproof material 15 in the joint H (groove 21) can be performed reliably and easily. Then, the groove 21 and the groove 2
The work of injecting the bentonite water-stopping material 15 into the inside (installation work) and the work of pouring the concrete wall W2 can be continuously performed. Can be mechanized in a series of tasks to build
Work efficiency can be further improved. The groove 21
The gap formed in the wrap portion 24 between the wrap portion 24 and the water blocking convex portion 23 is substantially constant, and the bentonite water blocking material 15 is
Is easily clogged, the amount of leakage of the bentonite water-stopping material 15 from the groove 21, that is, the amount of loss of the bentonite water-stopping material 15, can be reduced, and the cost of the bentonite water-stopping material 15 can be reduced. Can be reduced.

In the above embodiment, a concrete tunnel constructed by casting concrete in place is used as an underground concrete structure to which the method and structure for stopping water of a joint of an underground concrete structure according to the present invention are applied. Although the example using the inner wall was shown, without being limited to this,
As the underground concrete structure, a concrete tunnel inner wall constructed by connecting and arranging preformed concrete segments along the inner surface of the tunnel may be used. In this case, as a segment, a groove 21 is formed on one end face (splice end face) along a ridge line where the one end face and the inner face intersect, and is adjacent to the other end face (splice end face). And a bentonite water-stopping material 15 in the groove 21 is used.
By connecting these segments with the
As shown in FIG. 1, a waterproof structure at the joint of the underground concrete structure is constructed. In addition, underground concrete structures
It is not limited to the inner wall of the tunnel.

In the above embodiment, the bentonite water-stopping material 15 is of an irregular shape. However, the present invention is not limited to this, and a bentonite water-stopping material having a rectangular cross section may be used. In this case, the bentonite waterproof material 15
Is installed in the joint H (installation in the groove 21) after the curing of the concrete wall W1 is completed, and then the wife form 5 is pulled out from between the skin plate 3 and the inner form 4.

In the above embodiment, when the seam H between the concrete wall W1 and the concrete wall W2 is opened, the water stop protrusion is caused by the load generated by the interference between the groove 21 and the water stop protrusion 23. In order to prevent damage such as cracks at the root of the portion 23, the inside and around the groove 21 are
If necessary, a concrete release material may be applied to reduce such friction.

[0041]

According to the method for stopping water at the joint of an underground concrete structure according to the first aspect, the bentonite water-stopping material is used as the water-stopping material. In addition, the bentonite waterproof material reacts with the groundwater to swell, and clogging at the joint causes the joint to be closed. by this,
Even when the opening amount of the joint is large, the joint can be closed and water can be stopped. In addition, since the bentonite waterproof material reacts with the groundwater and swells, it is not necessary to predict the opening amount at the joint, and it is possible to flexibly cope with the opening amount. In addition, even when the concrete wall is wet with water that springs out of the ground, the bentonite water-stopping material reacts with the groundwater and swells thereby, so that the bentonite water-stopping material and these concrete walls can be effectively separated. The water stop effect can be sufficiently exerted by bringing them into close contact with each other, and the reliability of the water stop can be improved. In addition, since the bentonite waterproof material is disposed in the groove formed in the concrete wall to be cast in advance, there is no need to use special means for fixing the bentonite waterproof material, and the positioning of the bentonite waterproof material is performed. And fixing can be performed easily and at low cost.

According to the method for stopping water at the joint of an underground concrete structure according to the second aspect, the size of the gap formed at the lap portion between the groove and the water stopping protrusion is determined by the amount of opening at the joint. Since the length of the wrap portion between the groove and the water stop protrusion, that is, the length in which the water stop protrusion is fitted to the water stop space, can be secured to a predetermined extent because the width is substantially constant, the opening amount of the joint at the joint is determined. Regardless of
The bentonite waterproof material easily clogs the gap formed in the wrap portion. In addition, since the bentonite water-stopping material reacts with water to expand and block the water-stopping space, it is necessary to flexibly respond to the opening amount without predicting the opening amount at the joint. Can be. And for the same reason, it is possible to effectively stop the water pressure of the groundwater and stop the water at the joint. And when pouring the subsequent concrete wall, the bentonite water-stopping material is pressed to the bottom bottom side of the groove by the poured concrete, so that the bentonite water-stopping material is more securely fixed, The certainty of stopping water can be improved. In addition, the gap formed in the wrap portion between the groove and the water blocking protrusion is substantially constant, and the bentonite water blocking material easily clogs the gap formed in the wrap portion. , That is, the amount of loss of the bentonite waterproof material, and the cost of the bentonite waterproof material can be reduced.

According to the third aspect of the present invention, a groove is formed on the tip end surface of the concrete wall to be cast in advance by the projection provided on the end form. With the protruding portion pulled out from the groove by a predetermined distance, an indeterminate bentonite water-stopping material is injected into the groove through a water-stopping material supply passage provided in the protruding portion, thereby securing a water-stopping space on the front end side of the groove. Then, the bentonite waterproof material is injected into the inner bottom surface of the groove. Then, concrete forming the subsequent concrete wall is filled in the water stop space, so that a water stop protrusion fitted to the water stop space is formed on the subsequent concrete wall. Thereby, the work of forming the groove and the work of injecting the bentonite waterproof material into the groove,
Further, the subsequent concrete wall setting work can be continuously performed, and at this time, the wand formwork can be moved by a distance to pull out the protrusion from the groove, so that the troublesome wive formwork is required. The work of installing the bentonite waterproof material at the joint (within the groove) can be easily performed by minimizing the pull-out operation. Further, if the projecting portion is constituted by a device such as a ring-shaped piston that can change the amount of projection from the wife mold, a filling space is formed in the groove without moving the wife mold, and the filling space is formed. Since the bentonite water-stopping material can be injected into the inside, the work of installing the water-stopping material at the joint can be performed reliably and easily. Furthermore, since a series of operations for constructing the inner wall of the tunnel including this installation operation can be mechanized, no labor is required and the operation efficiency can be further improved.

According to the waterproof structure of the underground concrete structure according to the fourth aspect, a groove is formed in one concrete wall, and a bentonite waterproof material is disposed in the groove, and the other concrete wall has a groove. A water-stop projection is formed to fit into the water-stop space of the groove. And the opening amount of the joint is
Since the size of the gap formed in the wrap portion between the groove and the water blocking protrusion is substantially constant, the length of the wrap portion between the groove and the water blocking protrusion, that is, the water blocking protrusion fits into the water blocking space. If the combined length can be secured to a predetermined extent, the bentonite waterproof material easily clogs the gap formed in the wrap portion regardless of the opening amount of the joint. In addition, since the bentonite water-stopping material reacts with water to expand and block the water-stopping space, it is necessary to flexibly respond to the opening amount without predicting the opening amount at the joint. Can be. And for the same reason, it is possible to effectively stop the water pressure of the groundwater and stop the water at the joint. And when pouring the subsequent concrete wall, the bentonite water-stopping material is pressed against the bottom bottom side of the groove by the poured concrete, so that the bentonite water-stopping material is more reliably fixed, The certainty of stopping water can be improved. In addition, the gap formed in the wrap portion between the groove and the water blocking protrusion is substantially constant,
Since the bentonite water-stopping material easily clogs the gap formed in the wrap portion, the amount of bentonite water-stopping material leaking from the groove, that is, the amount of loss of the bentonite water-stopping material, can be reduced, and the bentonite water-stopping material can be reduced. Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a water stopping structure at a joint of an underground concrete structure according to an embodiment of the present invention.

FIG. 2 is a side cross-sectional view showing a state of construction of an inner wall of a tunnel to which a method and a structure for stopping water of a joint of an underground concrete structure according to an embodiment of the present invention are applied.

FIG. 3 is a side sectional view showing a state of an operation of constructing a tunnel inner wall to which a method and a structure for stopping water of a joint of an underground concrete structure according to an embodiment of the present invention are applied.

FIG. 4 is a side sectional view showing an operation of constructing a tunnel inner wall to which a method and a structure for stopping water of a joint of an underground concrete structure according to an embodiment of the present invention are applied.

FIG. 5 is a side sectional view showing a state of an operation of constructing an inner wall of a tunnel to which a method and a structure for stopping water of a joint of an underground concrete structure according to an embodiment of the present invention are applied.

FIG. 6 is a side sectional view showing a schematic configuration of a concrete placing device used in the present invention and a conventional tunnel construction method.

FIG. 7 is a side cross-sectional view showing a water stopping structure at a joint of an underground concrete structure by a conventional method of stopping water at a joint of an underground concrete structure.

[Explanation of symbols]

4 Inner Formwork 5 Wife Formwork 12 Piston Ring (Protrusion) 15 Bentonite Water Stopping Material 21 Groove 22 Water Stopping Space 23 Water Stopping Convex F Filling Space H Joint P Water Stopping Material Supply Path W1 Concrete wall W2 Subsequent concrete wall

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshimitsu Aso 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Tetsuya Aoyama 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Maho Watanabe 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Shinichi Nishimura 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation ( 72) Inventor Kazuo Miyazawa 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Hiromichi Sugiyama 23-5, Tsukudashi-Funamachi, Jobanshita-Funaomachi, Iwaki, Fukushima Prefecture 72) Inventor Yuji Kawaguchi 1-10-5 Iwamotocho, Chiyoda-ku, Tokyo Inside Kunimine Industries Co., Ltd. (72) Inventor Takeshi Nakamura Tokiwa Shimawamachipile, Joban Shimomachi, Iwaki, Fukushima Prefecture Work No. 23 No. 5 Kunimine Industrial Co., Ltd. in the F-term (reference) 2D055 BA01 BB01 DA03 GC09 KB14 KC01 LA02 2E172 AA05 DB13 DD04

Claims (4)

[Claims] 1. A method for stopping water at a joint of an underground concrete structure in which an underground concrete structure is constructed by connecting a succeeding concrete wall to a concrete wall to be poured in advance, and A groove is formed in the front end surface of the concrete wall to be formed on the side of the subsequent concrete wall, and a bentonite waterproof material that reacts with water and swells in response to water is arranged in the groove. A method for stopping water at the joint of an underground concrete structure, characterized by joining. 2. The method according to claim 1, wherein the bentonite water-stopping material is disposed on a bottom surface side of a deep portion of the groove so that a water-stopping space is formed on the front end surface side of the groove. 2. The method for stopping water in a joint of an underground concrete structure according to claim 1, wherein the water is filled into the water stopping space and poured. 3. A method for stopping water at a joint of an underground concrete structure in which an underground concrete structure is constructed by connecting a succeeding concrete wall to a concrete wall to be poured first. Forming a groove on the leading end surface of the concrete wall to be cast in advance by providing a projection on the end form forming the leading end surface of the concrete wall on the subsequent concrete wall side; After curing the concrete wall to be installed, by pulling out the protrusion from the groove a predetermined distance,
A filling space is formed on the bottom surface side of the deep portion of the groove while securing a space enough to form a water stopping space on the front end surface side of the groove, and a water stop provided on the protruding portion in the filling space. Injecting an irregular-shaped bentonite waterproofing material that swells by reacting with water through a material supply path, and when the subsequent concrete wall is provided, concrete is filled into the watertight space and poured. How to stop water at the joint of underground concrete structures. 4. A water stop structure at a joint of an underground concrete structure provided at a joint between one concrete wall and the other concrete wall, wherein the other concrete wall of the one concrete wall is provided. A groove is formed in the end face of the joint, and a water-stop space is formed in the groove, and a bentonite water-stopping material that reacts with water and swells in response to water is disposed on the inner bottom surface side, A water-stop structure for a splice of an underground concrete structure, wherein a water-stop convex portion that fits into the water-stop space of the groove is formed on a joint end surface of the other concrete wall.