JPH0562170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a pile cap treatment method for cast-in-place concrete piles.

[Conventional technology]

Conventionally, in order to treat pile head excess concrete, the hardened excess concrete is broken down using a breaker, or high-pressure water is sprayed and agitated to reduce the strength of the concrete, and then the concrete is removed manually.

This work is very inefficient as it involves working through a reinforcing bar cage that protrudes from the excess area, and it is also accompanied by noise and dust, which has a large impact on the surrounding area, and is also unfavorable in terms of the hygiene of the workers.

Therefore, it has been proposed to set a cloth bucket or bag filled with granular materials such as sand inside the reinforcing bar cage from the top end, and then remove this bucket when the concrete hardens to form a hole in the center of the pile cap. .

[Problem to be solved by the invention]

However, with the above-mentioned filling buckets, etc., a reinforcing bar cage is set in a pile hole and then suspended from the reinforcing bar cage, and since this occupies the inside of the pile head, only a small gap can be secured around it, and concrete cannot be It becomes difficult to pour.

The purpose of the present invention is to eliminate the disadvantages of the conventional example,
When creating a void in the pile head concrete, this void can be secured after setting the concrete pouring pipe, etc., so it does not interfere with the pouring work, and by providing such a void, the concrete An object of the present invention is to provide a pile cap processing method that can rationalize pile cap processing by reducing the amount of excess fill.

[Means to solve the problem]

In order to achieve the above object, the present invention connects a water injection pipe to the lower part of a flexible water-sealed bag that is divided into upper and lower parts by partitions having water passage holes, and places the water-sealed bag in a contracted state inside the head of a reinforcing steel cage. Then, the water injection pipe is set up so that it protrudes upward, and before or after pouring concrete, water is poured into the water-sealed bag from below to inflate it, and after the concrete has hardened, the water-sealed bag is removed from any damage. The idea is to water it down and then destroy the concrete around it.

[Effect]

According to the present invention, the swollen water-sealing bag creates a void in the concrete of the pile head, which significantly reduces the work required to remove excess concrete.

In addition, the water-sealed bag inflates evenly from the bottom due to water pressure from the water injection pipe connected to the bottom. Furthermore, this water-sealed bag is divided into upper and lower sections by partitions with water holes, and the upper and lower compartments are communicated by small water holes, so that when the lowermost chamber is completely inflated, the upper chamber Water will penetrate and swell. This design makes it possible to steadily inflate from the bottom without bending or bending under the weight of the poured concrete.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

First, referring to Fig. 1, we will explain the pile head processing device used in the construction method of the present invention. In the figure, 1 is a reinforcing bar cage inserted into a pile hole, and this device can be installed inside the head of this reinforcing bar cage 1. It is composed of a flexible water-seal bag 2 and a water injection pipe 3 connected to the water-seal bag 2.

The material for the water-sealed bag 2 is not particularly limited as long as it has the strength to displace concrete and mud by water-sealing pressure, but a thick vinyl sheet is suitable in terms of ease of manufacture and cost. In addition, the water injection pipe 3 is connected at its lower end to the lower side of the vertically long water-sealed bag 2 and is erected upward, and may be made of metal such as steel or synthetic resin such as hard vinyl chloride. It may be manufactured by

Furthermore, when the planar shape of the water-sealing bag 2 is circular, which is the same shape as the pile hole 4 as shown in FIG. 2 (FIG. 2a),
There are various shapes such as a semi-circle or divided circle made by appropriately dividing such a circle (b and c in the same figure), and a donut shape with a hollow part 2b formed in the center for inserting a concrete pouring pipe (d in the same figure). Various types can be selected depending on the shape and size of the pile.

Further, the height of the water-sealed bag 2 is determined by the size of the pile head, and according to this height, it is fixed to the vertical reinforcing bars of the reinforcing bar cage 1 with a fastening material 5 such as a string or wire provided on the outer peripheral side. Similarly, the water injection pipe 3 is also fixed to the vertical reinforcing bars with wires, binding wires, etc.

On the other hand, a check valve 6 that opens only into the water-sealing bag 2 is provided at the connection port between the water-filling pipe 3 and the water-sealing bag 2 to prevent backflow to the water-filling pipe 3 side.

The water-sealed bag 2 may be a single bag with no internal partitions, but as another embodiment, a horizontal partition 2a may be used.
A check valve 8 that opens only inward is provided in the water passage hole 7 formed in the partition 2a.

Next, the pile cap treatment method of the present invention will be explained.

As shown in FIG. 3, a water-sealed bag 2 in a contracted state is attached in advance to the head of a reinforcing bar cage 1 placed on the ground without water. In that case, the tip of the water injection pipe 3 is made to protrude upward more than the tip of the reinforcing bar cage 1,
When reinforcing bar cage 1 is set, make sure that it comes out above the ground. If the pile to be constructed is a reverse pile, stand pipe 1 as shown in Figure 4.
The reinforcing bar cage 1 is set in the pile hole 4 that has been drilled by setting the concrete 10, and the concrete 10 is poured using the tremie pipe 9. When installed, pressurized water is injected into the water seal bag 2 through the water injection pipe 3.

As a result, as shown in FIG. 5, the water-sealed bag 2 is inflated sequentially and evenly from below due to the water pressure.

Furthermore, this water-sealed bag 2 is divided into upper and lower sections by a partition 2a having water holes 7, and a small water hole connects the chamber partitioned at the bottom with the chamber above it. After the lower chamber is completely inflated, water penetrates into the upper chamber and it expands. This design makes it possible to steadily inflate from the bottom without bending or bending under the weight of the concrete.As will be explained later, the laitance floating above the concrete is pushed up,
A high-quality pile that does not contain this can be obtained.

In this way, as shown in FIG.
Completely inflate and wait for concrete 10 to harden. Reference numeral 12 in the figure indicates the backfill soil filling the top of the pile.

Incidentally, it is preferable to interpose a protective tube 14 around the outer periphery of the tremie tube 9 as shown in FIG.

Once the concrete 10 has hardened, the ground surface is excavated to expose the pile head as shown in FIG.
Remove water from the damage and remove small pieces of the outer periphery of the pile using a concrete breaker. In order to break the water-sealed bag 2 and release water in this way, it is sufficient to make a hole in the pile cap with a breaker and then tear the water-sealed bag 2.

In the figure, 15 is a laitance layer.

As described above, when the borehole is filled with circulating water as a reverse pile, the water seal bag 2 can be inflated after the tremie pipe 9 is set and before concrete 10 is poured, as shown in Figure 2. If the water-sealed bag 2 is donut-shaped as shown in d, the tremie tube 9 may be passed through the hollow portion 2d after being inflated.

On the other hand, when the concrete 10 is placed in the pile hole 4 like a Benoto pile and the reinforcing bar cage 1 is inserted after that, the water-sealing bag 2 is inserted after the reinforcing bar cage 1 is set, that is, after the concrete 10 is placed. will inflate.

〔Effect of the invention〕

As described above, the pile cap processing method of the present invention can significantly reduce the amount of excess concrete by providing a void without concrete inside the pile cap excess portion of a cast-in-place concrete pile, and as a result, the amount of excess concrete can be significantly reduced. This will reduce the amount of concrete breaker work that involves crushing concrete, reduce the impact of noise and dust on the surrounding environment, and improve the sanitary environment for workers.

In addition, since there is less work to break into pieces inside the reinforcing bar cage, which is particularly inefficient, the pile head processing cost is reduced and the construction period can be shortened.

In addition, such voids can be created by inflating the water-sealed bag after concrete is poured, so they do not interfere with concrete pouring work and push the laitance upwards, making it highly reliable. The stake is what you get.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing one embodiment of the apparatus used in the pile cap processing method of the present invention, Fig. 2 is an explanatory view showing the planar shape of a water-sealing bag, and Figs. 3 to 7 are the invention of the present invention. A front view showing each step of the construction method, FIG. 8 is a plan view for reverse piles, and FIG. 9 is a plan view for Benoto piles. 1... Rebar cage, 2... Water seal bag, 2a... Partition, 2b... Hollow part, 3... Water injection pipe, 4... Pile hole, 5... Fastening material, 6, 8... Check valve , 7... water hole, 9... tremie pipe, 10... concrete, 11... stand pipe, 12... backfill soil, 13... leveled concrete, 14... protection pipe, 15... laitance layer .

Claims (1)

[Claims] 1. Connect a water injection pipe to the lower part of a flexible water-sealed bag divided into upper and lower parts by a partition having water holes, place the water-sealed bag in a contracted state inside the head of a reinforcing steel cage, and stand up the water injection pipe. The water-sealed bag is set so that it protrudes upwards, and water is poured into the water-sealed bag from below to inflate it before or after concrete is poured, and after the concrete has hardened, the water-sealed bag is broken and water is removed, and the concrete around its outer periphery is removed. A pile head processing method characterized by destruction.