JPH0826543B2 - Interlocking pipe structure for underground wall construction method - Google Patents

Description

The present invention relates to an interlocking pipe structure used in an underground continuous wall construction method.

(Prior art) Conventionally, underground continuous wall construction method has been performed when piled up underground, and is suitable for constructing a new structure close to an existing structure, especially in urban areas. Widely used as a construction method.

Hereinafter, a method for constructing a continuous underground wall using a conventional interlocking pipe will be described with reference to FIGS.

In FIGS. 5 (A) to (D), 1,1 'are excavation trenches,
2 is a bucket for excavating this excavation groove 1, 1 ′, for example, a clamshell bucket or the like, 3 is a ground collapse prevention that is circulated and injected into the excavation groove 1, 1 ′ excavated by the bucket 2, for example It is a stable solution such as bentonite solution.

Further, 4 is inserted along the side wall of the excavation groove 1, 1'after completion of excavation. Hollow interlocking pipes 5, whose both ends 4a, 4b are open, are rebars inserted into the excavation grooves 1, 1'after inserting the interlocking pipes 4.

Further, 6 is concrete that is placed in the excavation grooves 1 and 1'after inserting the rebar 5, 7 is a tremie pipe for pouring and filling the concrete 6 into the excavation grooves 1 and 1 ',
Reference numeral 8 is a continuous underground wall formed by the solidified concrete 6 placed in the excavation trenches 1 and 1 '.

Normally, in the above-mentioned underground continuous wall construction method, before the foundation work of a newly constructed structure is performed, excavation grooves 1 and 1'are excavated so as to substantially surround the foundation work surface. A)
As shown in FIG. 3, the bucket 2 excavates a digging groove 1, 1 ′ of, for example, about 600 to 1200 mm × 3000 mm to a desired depth per process.

At this time, at the same time as the excavation by the bucket 2, as shown in FIG. 5 (A), a stabilizing solution 3 such as bentonite solution for preventing ground collapse is injected into the excavation groove 1.
The stabilizing solution 3 is circulated by a circulation pump (not shown) or the like so that the specific gravity of the stabilizing solution 3 does not decrease due to the mixing of groundwater flowing into the excavation groove 1, and the stabilizing solution 3 sucked from the excavation groove 1 is adjusted to a constant concentration. And is supplied again into the trench 1.

Then, when excavated to a desired depth, interlocking pipes 4 are inserted into the excavation groove 1 along both side walls of the excavation groove 1 as shown in FIG. 5 is inserted.

The interlocking pipe 4 is provided in the bucket 2 when excavating the next excavation groove 1 ′ at a position adjacent to the excavation groove 1 after the concrete 6 described later is poured into the excavation groove 1 and solidified. This is for facilitating the excavation work, and also for forming the meshing portion of the concrete 6 that is respectively placed in the excavation groove 1 and the next excavation groove.

Since both ends of the interlocking pipe 4 are open, the stabilizing liquid 3 filled in the excavation groove 1 when it is inserted into the excavation groove 1 is as shown in FIG. 5 (B).
It will flow into the internal hollow portion from the opening on the lower end 4b side.

When the rebar 5 is inserted, a tremie pipe 7 is inserted into the excavation groove 1 as shown in FIG. 5 (C), and concrete 6 is poured into the excavation groove 1 through the tremie pipe 7 and poured. Since the specific gravity of the stabilizing solution 3 is sufficiently lower than the specific gravity of the concrete 6, the concrete 6 is filled from the bottom of the excavation trench 1.

The filled concrete 6 is usually solidified after several hours to form a continuous underground wall 8 in the excavation trench 1, and the first step is completed. Then, of the above two interlocking pipes 4, the interlocking pipe 4 on the side for excavating the next excavation groove 1'is extracted,
As shown in FIG. 3D, the next excavation groove 1'is excavated by the bucket 2, and thereafter the same work as described above is performed.

(Problems to be Solved by the Invention) However, since both ends 4a and 4b of the interlocking pipe 4 having the above-described conventional structure are open, as the concrete 6 is cast into the excavation groove 1, As shown in FIG. 5C, the concrete 6 having a high specific gravity pushes up the already-stabilized liquid 3 into the hollow portion from the opening of the lower end 4b of the interlocking pipe 4 and pushes it.

Therefore, when one step is completed and the interlocking pipe 4 is pulled out, the concrete 6 that has flowed in from the opening on the lower end 4b side solidifies, and before the next step is used, the lower end 4b side The concrete 6 that has flowed into the hollow portion near the opening and solidified has to be removed, which causes a problem of lowering work efficiency.

The present invention has been made to solve the above problems, and the purpose thereof is to pressurize the internal space thereof to prevent the inflow of concrete into the excavation groove during concrete pouring. It is to provide an interlocking pipe structure that can be prevented.

Further, the purpose of the present invention is to respond to the inflow pressure of concrete that changes in response to the injection amount into the excavation trench,
An object of the present invention is to provide an interlocking pipe structure capable of adjusting the amount of pressure applied to its internal space.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention is used in an underground continuous wall construction method, and is a hollow with both ends opened to be vertically inserted into an excavation trench filled with a stabilizing solution. In the interlocking pipe structure, the closing lid for closing the opening on the upper end side of the interlocking pipe, and between the closing lid and the stabilizing liquid flowing into the hollow portion from the lower end side of the interlocking pipe. A pressurizing means for pressurizing the space formed, the pressurizing means, based on the detection result of the liquid level sensor for detecting the liquid level of the stabilizing liquid flowing into the hollow portion, the amount of pressurization. Can be changed.

(Operation) According to the present invention, the pressurizing means pressurizes the space formed between the closing lid in the interlocking pipe and the liquid surface of the stabilizing liquid, and applies the stabilizing liquid to the opening side of the interlocking pipe. Since it presses against the end, it is possible to prevent the concrete from flowing into the interlocking pipe from the opening side end.

Further, according to the present invention, when the inflow pressure of the concrete that is about to flow into the hollow portion of the interlocking pipe from the end portion on the opening side of the interlocking pipe changes, the stable liquid in the hollow portion that changes correspondingly changes The liquid level is detected by the liquid level sensor, and the pressurizing means changes the amount of pressurization of the space formed between the closing lid in the hollow part of the interlocking pipe and the liquid level of the stable liquid based on the detection result. Will be done.

Therefore, even if the inflow pressure of the concrete that flows into the hollow portion of the interlocking pipe fluctuates,
By adjusting the amount of pressurization of the space by the pressurizing means, it is possible to prevent the concrete from flowing into the hollow portion of the interlocking pipe.

(Example) Hereinafter, the Example of this invention is described based on drawing.

In the drawings of the present embodiment, the same elements as those shown in FIGS. 5A to 5D referred to in the above description of the prior art are designated by the same reference numerals, and the description thereof will be omitted. .

First, the first embodiment of the present invention will be described with reference to FIGS.
A description will be given with reference to FIGS.

FIG. 1 is a partially cut side view showing an interlocking pipe structure according to a first embodiment of the present invention, and FIGS. 2A to 2C show a method of constructing a continuous underground wall using the interlocking pipe. It is an explanatory view explaining.

In FIG. 1, reference numeral 14 is a hollow interlocking pipe which is inserted along the side walls of the excavation grooves 1 and 1'after completion of excavation and has both ends 14a and 14b opened, and the opening on the upper end 14a side is A closing lid 14c that closes this opening is detachably provided.

This closing lid 14c is provided with a through hole 14d, and an air compressor 14f as a pressurizing means is connected to the through hole 14d via an air feeding pipe 14e. The hollow space inside the locking pipe 14 can be pressurized.

Next, construction of the continuous underground wall 8 using the interlocking pipe 14 having the above structure will be described with reference to FIGS. 2 (A) to 2 (C).

First, similarly to FIG. 5 (A) referred to in the above-mentioned conventional technique, the excavation groove 1 having a desired depth is excavated by the bucket 2 in the state where the stabilizing liquid 3 is injected, and then the excavation groove is formed. Two interlocking pipes along both inner walls of 1
Insert 14,14 with both ends 14a, 14b open,
Then, as shown in FIG. 2 (A), one of the two interlocking pipes 14 has an opening on the upper end 14a side,
A closing lid 14c for closing this is installed.

Here, like the conventional interlocking pipe, the stabilizing liquid 3 is flowing from the lower end 14b side into the hollow portion inside the interlocking pipe 14 at the time of insertion into the excavation groove 1, and this inflow A space S is formed between the liquid surface of the stabilized liquid 3 and the closing lid 14c.

Next, when the reinforcing bar 5 is inserted into the excavation groove 1, the tremie pipe 7 is further inserted, and the concrete 6 is poured and placed,
Concrete 6 is filled from the bottom in the excavation trench 1 as in the conventional case.

By the way, in this state, the poured and filled concrete 6 flows into the hollow portion inside from the lower end 14b side opening of the interlocking pipe 14 as shown in FIG. 2 (B).

Therefore, compressed air is supplied to the space S inside the interlocking pipe 14 by the compressor 14f connected to the through hole 14d of the closing lid 14c via the air feeding pipe 14e, and the space S is pressurized.

As a result, the stabilizing liquid 3 that has flowed into the interlocking pipe 14 is pushed down toward the lower end 14b of the interlocking pipe 14 as shown in FIG. 2 (C), so that the inflow of concrete 6 from the opening on the lower end 14b side is prevented. Be blocked.

As described above, according to the interlocking pipe 14 of the first embodiment, it is possible to prevent the concrete 6 from flowing into the interlocking pipe 14 when the concrete 6 is placed. The work of removing the concrete 6 adhered and solidified in the interlocking pipe 14 before starting the next step can be omitted.

Next, the second embodiment of the present invention will be described with reference to FIGS.
A description will be given with reference to FIGS.

FIG. 3 is a partially cut side view showing an interlocking pipe structure according to a second embodiment of the present invention, FIG. 4 (A),
(B) is an explanatory view for explaining a state inside the interlocking pipe when the interlocking pipe is used for construction of an underground continuous wall.

In Fig. 3, 14g is an interlocking pipe 14
A liquid level sensor for detecting the liquid level position of the stabilizing liquid 3 flowing into the inside, 14h is, in accordance with the liquid level position of the stabilizing liquid 3 inside the interlocking pipe 14 detected by the liquid level sensor 14g,
The control device controls the amount of pressurization of the air compressor 14f with respect to the space S of the pair of interlocking pipes 14.

Next, with respect to the construction of the continuous underground wall 8 using the interlocking pipe 14 with the above configuration, FIG. 4 (A),
This will be described with reference to (B).

In the construction of the continuous underground wall 8 using the interlocking pipe 14 of the second embodiment, the excavation of the excavation groove 1, the insertion of the interlocking pipe 14, and the closing lid 14c to the opening on the upper end 14a side of the interlocking pipe 14 are performed. Installation and
Up to the insertion of the reinforcing bar 5, the work is performed in the same manner as in the case of the first embodiment.

The interlocking pipe of the stabilizing solution 3 that has flowed into the interlocking pipe 14 at this point
The liquid level position in 14 is detected by the liquid level sensor 14g and notified to the control device 14h. On the other hand, the control device 14h receiving this notification causes the liquid level of the stable liquid 3 in the interlocking pipe 14 at present. The surface position is held as a reference position.

Here, when the concrete 6 is poured into the excavation groove 1 through the tremie pipe 7, the concrete 6 flows in from the opening on the lower end 14b side of the interlocking pipe 14 as shown in FIG. 4 (A). , Interlocking pipe 1
The liquid level position in the interlocking pipe 14 of the stabilizing liquid 3 that has flowed into the inside 4 rises, and the position is constantly detected by the liquid level sensor 14g and notified to the control device 14h.

Upon receiving this notification, the control device 14h determines that the liquid level position in the interlocking pipe 14 of the stabilizing liquid 3 flowing into the interlocking pipe 14 is the above control device.
The amount of pressurization of the space S by the air compressor 14f is increased so as to return to the initial liquid level position held by 14h.

As a result, the stabilizing liquid 3 that has flowed into the interlocking pipe 14 is pushed down to the lower end 14b side of the interlocking pipe 14 as shown in FIG. 4 (B), so that the concrete 6 flows from the lower end 14b side opening. Is blocked.

By the way, the pressure at which the poured concrete 6 tries to flow against the hydraulic pressure of the stabilizing liquid 3 inside the interlocking pipe 14 increases as the pouring amount of the concrete 6 increases. Therefore, if the pressure applied by the air compressor 14f is constant, eventually,
The concrete 6 resists the hydraulic pressure of the stabilizing liquid 3 inside the interlocking pipe 14 and
It flows in from the opening on the side of the lower end 14b, and is in the same state as in FIG. 4 (A).

In this case, the re-elevation of the liquid surface position of the stabilizing liquid 3 in the interlocking pipe 14 is caused by the liquid level sensor 14g.
Detected by the controller 14 based on this detection result.
As h increases the amount of pressurization of the space S by the air compressor 14f, the liquid level position of the stabilizing liquid 3 in the interlocking pipe 14 is controlled by the control device 14h as shown in FIG. 4 (B). Return to the initial liquid level position that was held.

As described above, according to the interlocking pipe 14 of the second embodiment, the space S in the interlocking pipe 14 is
The pressurizing amount of the air compressor 14f for pressurizing the concrete can be adjusted according to the injection amount of the concrete 6.

(Effect of the Invention) As described above, according to the present invention, the pressurizing means pressurizes the space formed between the closing lid in the interlocking pipe and the liquid surface of the stabilizing liquid, and the stabilizing liquid is interlocked. Since the lower end of the pipe is pressed, it is possible to prevent the concrete from flowing into the interlocking pipe.

Further, according to the present invention, when the inflow pressure of the concrete that is about to flow from the lower end of the interlocking pipe fluctuates, the level of the stable liquid that fluctuates in response to this is detected by the liquid level sensor. Since the pressurizing means changes the pressurizing amount of the space in the interlocking pipe based on the above, even if the inflow pressure of concrete into the interlocking pipe fluctuates, the pressurizing amount of the space by the pressurizing means is changed. The adjustment can prevent the concrete from flowing into the interlocking pipe.

[Brief description of drawings]

FIG. 1 is a partially cut side view showing an interlocking pipe structure according to a first embodiment of the present invention, and FIGS. 2 (A) to 2 (C) are construction methods of a continuous underground wall using the same interlocking pipe. 3 is a partially cut side view showing an interlocking pipe structure according to a second embodiment of the present invention, and FIGS. 4 (A) and 4 (B) respectively show the same interlocking pipe underground. FIGS. 5 (A) to 5 (D) are explanatory views when used to construct a wall, respectively, and are explanatory diagrams illustrating a method of constructing a continuous underground wall using an interlocking pipe having a conventional structure. In the figure, 1, 1'is a digging groove, 3 is a stable liquid, 14 is an interlocking pipe, 14a is an upper end, 14b is a lower end, 14c is a closing lid, 14f is an air compressor (pressurizing means), and 14g is a liquid surface. Sensor, S is space.

Claims (1)

[Claims] 1. A hollow interlocking pipe structure which is used in an underground continuous wall construction method and which is vertically inserted into an excavation groove filled with a stabilizing solution and has both ends opened, A closing lid for closing the opening on the upper end side, and a pressurizing means for pressurizing a space formed between the closing lid and the stabilizing liquid flowing into the hollow portion from the lower end side of the interlocking pipe, The pressurizing means is capable of changing the amount of pressurization based on the detection result of the liquid level sensor that detects the liquid level of the stabilizing liquid flowing into the hollow portion. Interlocking pipe structure in.