JPS583092B2 - Concrete - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a construction method for cast-in-place concrete piles, and its purpose is to provide a construction method that can easily construct a complete concrete pile body without being affected by groundwater. Generally, cast-in-place concrete piles are constructed by drilling holes to a specified depth and filling them with concrete, but often the concrete leaks into groundwater.
There was a problem with the strength of the pile body.

Conventionally, a hollow waterproof body that can be easily deformed into a cylindrical shape is built into the casing, the casing is driven into the ground for an appropriate length, the waterproof body is filled with concrete, and the casing is finally removed. A method of constructing piles is known.

However, in this construction method, the casing is driven into the ground, which is not easy to do, and it is also difficult to pull out the casing after filling with concrete, which poses problems in terms of workability, especially when constructing large-diameter piles. There is.

This invention has been proposed to address the above-mentioned conventional problems.

The present invention will now be explained with reference to the drawings. A reinforcing bar dragon 1 has an annular shoe 2 attached to its tip, and spacing rings 3 are arranged around the shoe at predetermined intervals. are vertically connected, and are connected and held to the reinforcing bar dragon 1 by a small piece 5.

A bag body 6 made of relatively coarse water-permeable cloth is attached to the outer periphery of the spacing ring 3 so as to wrap around the reinforcing bar dragon 1.

This reinforcing bar dragon 1 is then inserted together with the bag body 6 into a pit 7 excavated to a predetermined depth, but the pit 7 often has a cavity 8 created by the collapse of the pit wall.

As a result, there is a high risk that concrete will not be injected into the eight voids and the voids 8 will be left as they are when concrete is poured, which poses a load-bearing problem.
A worker gets down inside the hole and directly checks the gap position, or inserts a detection rod with a horizontal bar at the tip into the hole 7 to check the gap position, and then inserts the reinforcing bar dragon 1 and the bag body 6 into the hole 7. At the time of insertion, the injection pipe 9 is simultaneously inserted from above into the space formed by the reinforcing bar dragon 1 and the bag body 6, and arranged so that its opening (lower end of the pipe) is located near the void 8.

Next, water such as groundwater that has permeated into the bag body 6 is pumped up, concrete is poured into the bag body 6, and mortar is spouted from the injection pipe 9 at the same time to inflate the bag body 6 in that area and fill the void. 8 is filled with concrete and mortar to fill the void 8.

This invention has the above-mentioned configuration, and when pouring concrete into the bag, mortar is jetted out from the injection pipe at the same time, so that the bag is especially inflated in that part,
By eliminating the voids created in the pit wall by pouring concrete and mortar, problems with the strength of piles are resolved, and since the bag body is made of water-permeable fabric, the poured concrete does not flow out and is slightly reduced. The moisture permeates to the outside, causing the bag to adhere tightly to the pit wall, and construction can be carried out while preventing the pit wall from collapsing.

In addition, water such as underground water permeates into the bag, but slime does not enter the bag, so by pumping up water, concrete can be placed in a completely dry state without being affected by slime. Underwater concrete placement is also possible without pumping water.

When pumping up water, the bag body is subjected to earth pressure from the mine wall, but since it is reinforced by spacing rings, frames, or reinforcing bars, it can withstand earth pressure sufficiently.

[Brief explanation of the drawing]

The drawings show an example of this, and Fig. 1 is a longitudinal cross-sectional view;
FIG. 2 is a cross-sectional view. 1... Rebar Dragon, 2... Shoe, 3...
... Spacing ring, 4 ... Steel material, 5 ...
...Small piece, 6...Bag body, 7...Anti, 8
...Void, 9...Injection pipe.

Claims (1)

[Claims] 1 A reinforcing bar with a ring-shaped shoe attached to its tip, spacing rings attached at predetermined intervals around the circumference, and a bag body made of water-permeable cloth covering the periphery, and a space between this reinforcing bar dragon and the bag body. In this process, an injection pipe set to open near the void in the mine wall is inserted into the excavation shaft, concrete is filled into the bag, and mortar, etc. is injected through the injection pipe to fill the void in the mine wall. A concrete pile construction method characterized by filling the concrete pile with mortar etc.