JP3427370B2 - Crushed stone input promotion device and jointing method of joint of underground continuous 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 method for joining a joint portion between elements of an underground continuous wall (hereinafter referred to as "communicating wall"), and a joint with a trailing element at the time of driving concrete into a preceding element. TECHNICAL FIELD The present invention relates to a crushed stone feeding promoting device used for joining a joint in which crushed stone bears a lateral pressure of concrete by throwing crushed stone into a liquid in a section, and a jointing method for a joint portion of an underground continuous wall.

[0002]

2. Description of the Related Art As shown in FIG. 1, when a large-depth connecting wall is constructed, a jointed steel plate joint system is often used as a method for constructing a free joint between elements of the connecting wall. .

The jointed steel plate joint system is a system in which the jointed steel plate 10 bears the lateral pressure of the concrete 2 when the preceding element 1 is poured into the concrete 2. However, since only the joining steel plate 10 is installed, the joining steel plate 10 is deformed or the strength is insufficient. Therefore, for the purpose of reinforcing the joining steel plate 10, the joining portion 5 on the outside of the joining steel plate 10 is supplementarily supported. A support system using the crushed stones 4 for introducing the crushed stones 4 is used.

In the case of the support system using the crushed stone 4, the crushed stone 4 is attached to the joint portion 5 of the preceding element 1 in order to prevent the joining steel plate 10 from being deformed by the lateral pressure of the concrete 2.
In order to make the amount of crushed stones to be injected into the preceding element 1 larger than the amount of concrete 2 to be injected, the head surface of the crushed stones 4 is provided with a head difference of several meters compared with the surface of concrete 2 to be injected.

At this time, in order to prevent the collapse of the groove wall and stabilize the ground, a stabilizing liquid, which is the liquid 3, is injected into the excavation hole including the joint portion 5. However, since the stabilizing liquid has a large specific gravity, the crushed stone 4 does not drop vertically downward in the stabilizing liquid (particularly, in the liquid 3 having a large specific gravity and large viscosity, the crushed stone 4 drops while touching left and right). The crushed stone 4 enters the side of the preceding element 1 through the gap between the joining steel plate 10 and the side wall of the connecting wall, and there is a problem that the effective cross section of the preceding element 1 decreases or the reinforcing bar cage 13 of the preceding element 1 is exposed. It was

Therefore, conventionally, a side steel plate 12, which is a thin iron plate, is attached from the vicinity of the joint portion 5 of the preceding element 1 to the side surface of the portion into which the crushed stones 4 are put, and then the construction is carried out in a state in which the gap portion is blocked. Was common.

[0007]

However, the above-mentioned side steel plate 1
In the case of attaching 2 for construction, there was a problem that the cost of the side steel plate 12 was high.

When the rebar cage 13 is inserted into the excavation hole,
There is a problem that the side steel plate 12 comes into contact with the ground, and due to the friction, the side steel plate 12 is turned up and the subsequent construction is affected.

Therefore, in order to solve the above-mentioned problem, in the present invention, a method for joining a joint portion between elements of a connecting wall that bears the lateral pressure of concrete injected into a preceding element by crushed stone is used without using a side steel plate. It is an object of the present invention to provide a crushed stone charging promoting device used for realizing the above and a joining method for a joint portion of a connecting wall.

[0010]

In order to achieve the above object, the present invention is a "system in which the lateral pressure at the time of driving concrete of the preceding element is borne by a supporting member, and the supporting member is in liquid in a joint portion. In the method of joining the joint portion of the underground continuous wall of the method of supporting by crushed stones, the crushed stones promoting device used to throw the crushed stones into the liquid, the crushed stones are settled stably In order to achieve this, the crushed stone introduction promoting device is provided with a liquid circulating means for producing a downward water flow in the liquid. ]
Is provided.

Further, in the present invention, specifically, "the liquid circulating means is provided with a suction means for sucking the liquid, a discharging means for discharging the liquid, and a pipe opening at one end thereof is attached to the suction means. A suction pipe having the other end of the pipe port arranged in the liquid, and one end of the suction pipe attached to the discharging means, and the other end pipe port being disposed on or in the liquid surface of the liquid The crushed stone introduction promoting device, characterized in that it comprises a pipe. ] Is provided.

Further, the present invention relates to "a method in which the lateral pressure at the time of driving concrete into the preceding element is borne by a supporting member, and the supporting member is supported by crushed stones poured into the liquid in the joint. In the method for joining the joint portion of the continuous wall, using the crushed stone feeding promoting device, a downward water flow is generated in the liquid, and the step of feeding the crushed stone into the liquid is included. Joining method for joints of continuous walls. ] Is provided.

That is, according to the present invention, by applying a downward water flow to the liquid by using the liquid circulation means,
When crushed stones are thrown in, the crushed stones fall vertically, so that it is possible to prevent the crushed stones from entering the preceding element side. Further, since the crushed stones fall quickly, it becomes easy to adjust the crushed stone top to the target height (the height preceding the concrete top), and the construction of the connecting wall can be speeded up.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a side view showing an example of use of the crushed stone introduction device according to the present invention, and FIG. 3 is a top view showing an example of use of the crushed stone introduction promoting device according to the present invention.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. In this embodiment, "a lateral pressure when the preceding element 1 is poured into concrete 2 is borne by the joining steel plate 10 as a supporting member, and
Joint part 5 of a continuous underground wall of a system in which the support member is supported by crushed stones 4 that are poured into a stable liquid that is a liquid 3 in the joint part 5.
In the joining method of (1), a crushed stone charging promoting device 6 is used for charging the crushed stone 4 into the liquid 3, and a downward water flow A is applied to the liquid 3 in order to stably settle the crushed stone 4. It is a crushed stone charging promoting device 6 ″ characterized in that it has a liquid circulating means 7 for generating it.

The crushed stone introduction promoting device 6 according to the present invention is characterized in that it has a liquid circulating means 7 for producing a downward water flow A in the stabilizing liquid as the liquid 3 in order to stably settle the crushed stone 4. It is a thing. More specifically, “the liquid circulating means 7 is a suction means 7 for sucking the liquid 3.
a, a discharge means 7b for discharging the liquid 3, a pipe opening 8a at one end is attached to the suction means 7a, and a pipe opening 8b at the other end is a suction pipe 7c arranged in the liquid 3 and The pipe opening 9a is attached to the discharge means 7b, and the pipe opening 9b at the other end is composed of a discharge pipe 7d arranged on the liquid surface 3a of the liquid 3 or in the liquid 3.

Here, each component will be described. The preceding element 1 refers to an element in which the concrete 2 is driven first among the adjacent elements (construction unit of the connecting wall in which the concrete 2 is driven at once). The present invention is used in a jointing method for a joint portion 5 of a connecting wall of a system in which the lateral pressure when concrete 2 is driven into the preceding element 1 is supported by the crushed stone 4, and promotes the introduction of the crushed stone 4. To do. The preceding element 1 is usually a reinforcing bar basket 1 in which reinforcing bars are combined in a grid pattern.
3 is inserted, and the concrete 2 is driven by using the reinforced basket 13 as a core material. When the concrete 2 is poured into the preceding element 1, the joining steel plate 10 is mainly attached to the joint portion 5 which is the side of the preceding element 1 to bear the lateral pressure of the concrete 2. ,
This is effective when using the bonded steel plate 10.

The joining steel plate 10 is attached to the boundary between the preceding element 1 and the joint portion 5 in a direction orthogonal to the side wall surface of the preceding element 1. However, since the bonded steel plate 10 is not strong, if the lateral pressure of the concrete 2 is borne by the bonded steel plate 10 alone, the lateral pressure of the concrete 2 causes deformation and the like in the joint portion 5 direction. Therefore, the crushed stone 4 is put into the joint portion 5 to share and bear the lateral pressure.

Further, in the continuous wall construction method, the concrete 2 is generally poured by pouring it into the preceding element 1 with a tremie pipe. Therefore,
Until the concrete 2 hardens, the concrete 2
The force (lateral pressure) to flow out acts on the joined steel plate 10 attached to the rebar cage 13 to deform it. Therefore, the crushed stone 4 is thrown into the joint portion 5 provided on the side of the joined steel plate 10 prior to the driving of the concrete 2 to try to bear the lateral pressure of the concrete 2.

Further, the liquid 3 is a liquid which prevents collapse of the groove wall and stabilizes the ground when excavating the ground in the connecting wall. Any liquid can be used as the stabilizing liquid. Even a liquid can be applied to the present invention. By filling the excavation groove (the preceding element 1 and the joint portion 5) with this liquid 3, collapse of the groove wall can be prevented. For example, polymer (water-soluble polymer, CM
C), bentonite, additive (dispersant, liquid loss preventer) solution and the like can be applied to the present invention.

The liquid surface 3a is a liquid surface when the liquid 3 is filled in the excavation groove, and a pipe port 9b of a discharge pipe 7d, which will be described later, is arranged vertically downward in the air above the liquid surface. Or, it is arranged at the upper position 3b of the liquid 3 described later. The upper position 3b means an upper position near the liquid surface 3a when the excavation groove is filled with the liquid 3.

The crushed stone 4 is the concrete 2
In order to bear the lateral pressure of the above, it is put into the joint portion 5 described later. Since the crushed stone 4 is introduced prior to the driving of the concrete 2, it is possible to prevent the joined steel plate 10 from being deformed by the lateral pressure of the concrete 2.

Further, the joint portion 5 generally refers to a joint portion between elements of a connecting wall or between rebar cages. In the present invention, it refers to a portion into which the crushed stone 4 is put. here,
Due to the difference in the force that can be transmitted between the elements,
There are three types, free joint, rigid joint, and hinge joint,
The present invention can be applied to any joint. For example,
In the case of a free joint, a joined steel plate joint (preceding element 1
Steel plates are attached to both ends of the rebar cage 13 of
In order to prevent the joining steel plate 10 from being deformed by the lateral pressure of the concrete 2, the crushed stone 4 is put in according to the present invention to perform the construction without using the side steel plate 12. Is possible. Further, in the case of a rigid joint or a hinge joint, since the reinforcing bar protrudes from the preceding element 1 to the side of the joint part 5, in order to protect that part, a tie rod in which a reinforcing bar is attached to a horizontal bar or an anti-steel bar combination is used. Steel plate joined using strength material and joint protection material 1
By supporting No. 0 and introducing the crushed stone 4 according to the present invention, it becomes possible to construct without using the side steel plate 12.

Further, the crushed stone introduction promoting device 6 has a liquid circulating means 7 for generating a vertical circulating flow in the liquid 3, and the crushed stone 4 is provided by giving a downward water flow A to the liquid 3. It is a device that makes it possible to easily put the

Specifically, the liquid circulating means 7 has a suction means 7a for sucking the liquid 3, a discharging means 7b for discharging the liquid 3, and a pipe opening 8a at one end attached to the suction means 7a, A suction pipe 7c having a pipe opening 8b at the other end arranged in the liquid 3 and a pipe mouth 9a at the one end are the discharging means 7b.
And a pipe port 9b at the other end is composed of a discharge pipe 7d arranged on the liquid surface 3a of the liquid 3 or in the liquid 3.

The suction means 7a and the discharge means 7b may be any means capable of sucking and discharging the liquid 3, for example,
Anything like an air lift, suction pump,
It is applicable to this invention.

The suction pipe 7c has a pipe opening 8a at one end connected to the suction means 7a, and a pipe opening 8b at the other end.
Are provided so as to be located at the bottom of the liquid 3.

The discharge pipe 7d has a pipe opening 9a at one end.
Is connected to the discharge means 7d, and the pipe opening 9b at the other end
Are arranged vertically downward on the liquid surface 3a. As a result, the liquid 3 is sucked up by the suction means 7a from the pipe port 8b through the suction pipe 7c, and further discharged by the discharge means 7b.
The structure is such that it passes through the discharge pipe 7d and is discharged from the pipe port 9b. Therefore, a circulation flow can be forcibly generated vertically downward from the pipe opening 9b of the discharge pipe 7d connected to the discharge means 7b to the pipe opening 8b of the suction pipe 7c connected to the suction means 7a. It has become. The liquid circulating means 7 used in the present invention is not limited to the above-mentioned embodiment, and means for rotating a stirring blade for generating the downward water flow A may be used.

A method of joining the joint portion of the connecting wall using the present invention will be described. The basic procedure of the joining method of the joint portion of the connecting wall described in this embodiment is the same as the conventional construction method, except that the side steel plate 12 is not used and that a crushed stone introduction promoting device is installed. Different.

The construction procedure of the present invention will be described. First, the preceding element 1 is excavated. The preceding element 1 is excavated for each gut which is a unit that can be excavated at one time by the continuous wall excavator. First, drill the leading gut,
The uncut portion between the preceding gut is excavated as a trailing gut, and the preceding element 1 having a predetermined length is excavated.
Next, the stabilizing liquid that is the liquid 3 is injected into the entire preceding element 1 (including the joint portion 5). Next, the rebar cage 13 is assembled. At that time, in order to prevent the concrete 2 poured into the preceding element 1 from being mixed with the earth and sand that collapses from the side wall and weakening the strength of the concrete, the campus sheet 11 is attached and the direction perpendicular to the side wall The joint plate 5 is formed by attaching the joining steel plate 10 to the predetermined position. Here, if the conventional procedure,
The side steel plate 12 is provided between the side wall of the campus sheet 11 and the side wall of the campus sheet 11, but this side steel plate 12 is not used in this method. Next, the rebar cage 13 is inserted into the preceding element 1 and submerged. Then, the crushed stone feeding promoting device 6 is installed in the joint portion 5, and the crushed stone 4 is thrown into the joint portion 5 while generating a vertically downward circulating flow in the stabilizing liquid in the joint portion 5. Then, while keeping the top of the concrete 2 on the side of the preceding element 1 lower than the top of the crushed stone 4, the stabilizing liquid in the preceding element 1 is added to the concrete 2
In order to replace the above, concrete 2 is placed on the preceding element 1 by a tremie pipe. At this time, crushed stone 4
By raising the tube mouth 8b to the upper part in accordance with the above-mentioned step, the floating of the crushed stone 4 already charged can be prevented in accordance with the top end of the crushed stone 4. Further, by continuing the procedure, concrete 2 is poured into the entire preceding element 1. Then, after the concrete 2 in the preceding element 1 is hardened, the crushed stone 4 is taken out from the joint portion 5 and the succeeding element is constructed, whereby the work is completed.

According to the present invention, when the concrete 2 is driven into the preceding element 1 by the tremie pipe, the crushed stone 4 is charged into the joint portion 5 by using the crushed stone charging promoting device 6. Since it can be done easily, the efficiency of construction increases.

Further, by sucking the liquid 3 by using the suction means 7a as the liquid circulation means 7, the preceding element 1
Since the liquid 3 on the side is also sucked (the outward water flow B is generated), the campus sheet 11 installed on the side of the preceding element 1 spreads outward, and the campus sheet 11 is also prevented from being caught in the concrete 2. Can be done. As a result, it is possible to reduce the cost of the side steel plate 12, and solve the problem that occurs when using the side steel plate 12 because it comes into contact with the ground and rolls up, affecting later processes. Is possible.

[0033]

As described above, according to the present invention, since the crushed stone falls vertically downward and the crushed stone does not enter the preceding element side, it is not necessary to use the side steel sheet. There is no cost involved.

Further, since it is not necessary to use the side steel plate, there is no problem that the side steel plate comes into contact with the ground and rises up, which affects the subsequent construction.

Further, since a downward water flow can be given to the liquid, the crushed stones drop quickly, so that there is a difference in height between the top of the crushed stones of the crushed stones to be charged in advance and the top of the concrete of the concrete to be charged. Easy to manage.

Further, by sucking the liquid using the liquid suction means, the campus sheet installed on the preceding element is sucked (the liquid on the preceding element side causes an outward water flow), so that the campus sheet is grounded. Since it spreads to the mountain side, it is possible to prevent the campus sheet from being caught in the concrete.

[Brief description of drawings]

FIG. 1 is a top view showing a conventional method of joining a joint portion of an underground underground wall by a method of supporting by crushed stone.

FIG. 2 is a side view showing an example of use of the crushed stone charging promoting device according to the present invention.

FIG. 3 is a top view showing a usage example of the crushed stone charging promoting device according to the present invention.

[Explanation of symbols]

1 preceding element 2 concrete 3 liquid 3a Liquid level 3b upper position 4 crushed stone 5 joint 6 Crushed stone input promotion device 7 Liquid circulation means 7a suction means 7b Ejection means 7c suction tube 7d discharge pipe 8a tube mouth 8b tube mouth 9a tube mouth 9b tube mouth 10 Bonded steel plate 11 Campus sheet 12 side steel plate 13 Rebar cage A downward water flow B Outward water flow

Claims (3)

(57) [Claims] 1. A joint part for a continuous underground wall, which is a system in which a lateral pressure at the time of driving concrete into the preceding element is borne by a support member, and which is supported by crushed stones which are poured into the liquid in the joint part. In the joining method of
A crushed stone charging promoting device used for charging the crushed stone into a liquid, comprising a liquid circulation means for causing a downward water flow in the liquid in order to stably settle the crushed stone. A crushed stone charging promotion device. 2. The liquid circulation means includes suction means for sucking the liquid, discharge means for discharging the liquid, and a pipe opening at one end attached to the suction means, and a pipe opening at the other end in the liquid. And a discharge pipe having a pipe opening at one end attached to the discharging means and a pipe opening at the other end arranged on the liquid surface of the liquid or in the liquid. The crushed stone introduction promoting device according to claim 1. 3. A joint part of an underground continuous wall of a system in which a lateral pressure at the time of driving concrete into the preceding element is borne by a supporting member, and the supporting member is supported by crushed stones poured into the liquid in the joint part. The method of joining according to claim 1, wherein the crushed stone charging promoting device according to claim 1 is used to generate a downward water flow in the liquid, and to charge the crushed stone into the liquid. A method for joining joints of underground underground walls, characterized by including the above.