JPH0418088B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Technical Field] The present invention provides a method for, for example, when constructing a foundation for a bridge pier.
This invention relates to a method for constructing and reusing a water stop wall of a caisson, which is constructed at the top of a caisson when a concrete caisson is sunk while being excavated and structures such as bridge piers are constructed inside the caisson.

[Prior art]

Traditionally, the construction method for constructing bridge piers was to sink concrete caissons while excavating them.
A known construction method involves constructing a cutoff wall around the top of the caisson, constructing the piers in a dry state within the wall, and then removing the upper cutoff wall from the water bottom.

The cut-off wall must be removed after the bridge piers are constructed, and gunpowder holes and cracks are formed in advance during construction so that gunpowder can be attached and partially blasted during the dismantling work of the cut-off wall. Tokukai Akira
There are many known examples, such as No. 61-233129, which relates to temporary water-stop walls for caissons, but in this case, explosives are used, which is dangerous, and requires complicated work to cut the reinforcing bars underwater after dismantling. There was a problem.

On the other hand, in order to avoid such dangerous and complicated work, there are examples in which multiple ring-shaped water-stop walls that can be disassembled into rings are stacked on top of the top of the poured caisson. In this case, it was necessary to secure a manufacturing yard to manufacture the ring-shaped water-stopping wall, which caused the problem of being uneconomical.

[Purpose of the invention]

The present invention was made in order to solve the above-mentioned conventional problems, and can be easily removed by lifting without using dangerous explosives during dismantling, and the water-stopping effect of the removed water-stopping wall is impaired. The purpose is to provide a method that can be easily reused without any problems.

[Structure of the invention]

In order to achieve the above object, the method for constructing and reusing a caisson water-stop wall of the present invention is to apply edge cutting materials such as asphalt roofing to the horizontal separation surface of the top of the caisson, which has been cast by excavation and subsidence. Then, a plurality of ring-shaped water-stop walls are constructed by sequentially placing concrete in the circumferential direction through water-stop materials such as PVC sheets, and after constructing the piers within the caissons, the above-mentioned Each water-stopping wall is lifted up and removed one by one, and each removed water-stopping wall is sequentially stacked and re-stacked on the top of another caisson with water-stopping packing such as a ring-shaped rubber gasket for water-stopping. It is characterized by its use.

According to the above method, when dismantling the ring-shaped cutoff wall built on the top of the caisson, the removal work can be done easily and safely by lifting it with a crane, etc., without using explosives, etc. When reusing the removed water-stopping wall in another caisson, the water-stopping packing such as a ring-shaped rubber gasket must sufficiently maintain the water-stopping effect in the circumferential direction due to the weight of each waterstop wall. Furthermore, these water-stop walls can be reused any number of times.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged side sectional view of the main part of a caisson water-stop wall constructed by the method of the present invention, and FIG. An enlarged side sectional view of the main parts of the water stop wall when it is reused.
Figure 3 is an overall side sectional view of the upper part of the caisson in Figure 1;
FIG. 4 is a plan view of FIG. 3.

First, in FIG. 3, the caisson 2 is made to sink by pouring concrete and excavating it to a predetermined depth while constructing it.

A plurality of ring-shaped water-stop walls 1 are constructed by pouring concrete around the top slab of the caisson 2 cast as described above, and independent reinforcing bars 6 are placed inside each water-stop wall 1. In addition, as shown in Fig. 1, each horizontal edge cutting surface is covered with an alfalut edge cutting material 7 such as asphalt roofing, and the circumferential direction of each edge cutting part is covered with a water-stopping material such as a PVC sheet. 8 are provided respectively.

In this way, a predetermined water stop wall 1 is installed on the top of the caisson 2.
Once the bridge pier 10 is constructed, the pier 10 shown by the broken line in FIGS. 3 and 4 is constructed in the dry state.
0, the ring-shaped water stop wall 1 is removed by lifting it from the top to the bottom using a crane ship or the like.

At that time, the sheet of water stop material 8 provided in a circumferential shape is appropriately cut and separated into upper and lower parts.

Next, when reusing the water stop wall 1 removed as described above on the top of the caisson installed separately, ring-shaped rubber gaskets 11 for water stop are placed and stacked one after another as shown in Fig. 2. The water stop wall 1 can be constructed and the bridge pier 10 can be constructed therein as explained above.

In this way, when the water stop wall 1 is reused, the asphalt edge cutting material 7 and the water stop material 8 that were originally constructed are not necessary, and the ring-shaped rubber gasket 11 is simply pressed by the water stop wall 1's own weight. A complete water-stopping effect can be obtained.

The above-mentioned water-stopping wall 1 can be reused repeatedly as long as there is no damage, and the shape of this water-stopping wall 1 is not limited to the above embodiments, but may be circular or square. etc. Anything is fine.

〔Effect of the invention〕

As explained above, if the method of the present invention is adopted, it will no longer be necessary to use explosives or the like or the complicated cutting of reinforcing bars when dismantling water-stop walls.
The removal work is complete and easy, and the removed water stop wall can be easily and reused any number of times.Furthermore, the water stop wall is constructed at the site where the water stop wall was constructed. Since there is no need for a yard for constructing a water wall, this method has the effect of reducing the cost of constructing a water stop wall.

[Brief explanation of drawings]

Fig. 1 is an enlarged side sectional view of the main part of a caisson water-stop wall constructed by the method of the present invention, and Fig.
FIG. 3 is an enlarged side sectional view of the main part of the water stop wall when reused; FIG. 3 is a side sectional view of the entire upper part of the caisson shown in FIG. 1; FIG. 4 is a plan view of FIG. 3. DESCRIPTION OF SYMBOLS 1... Water-stopping wall, 2... Caisson, 7... Asphalt edge cutting material, 8... Water-stopping material, 10... Bridge pier, 11... Ring-shaped rubber gasket.

Claims (1)

[Claims] 1. Concrete is poured on the top of the poured caisson through edge cutting materials such as asphalt and water-stopping materials, and multiple ring-shaped waterstop walls are built one after another, and bridge piers, etc. are placed inside the caissons. After constructing the structure, each of the above-mentioned water-stopping walls was lifted up and removed one by one, and a water-stopping ring-shaped rubber gasket, etc. for water-stopping was installed on the top of another caisson that had been installed on the removed water-stopping walls. A method for constructing and reusing caisson water-stop walls that are sequentially stacked and reused through packing.