JPH0643219Y2 - Core body attached to the inner circumference of the head of a concrete pile - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a concrete pile head when the concrete pile is inserted and fixed in a pile insertion hole formed in the ground by the concrete milk injection method. The present invention relates to a core body for forming a hollow portion into which a pile head reinforcing bar can be inserted by mounting it on the inner circumference of a section, injecting concrete milk, and removing it after hardening the concrete milk. .

[Conventional technology]

To form a so-called underground beam that serves as a foundation for a concrete building, a concrete pile (hereinafter simply referred to as "pile") is buried in the ground.

To embed a pile in the ground, there are a driving method and a concrete milk injection method. The former is a method of hammering the pile head with a hammer to drive the pile into the ground. However, in a city where the population is concentrated, large vibration and noise cause pollution and cannot be adopted.

For this reason, in order to form an underground beam as a foundation of a concrete building in a city, as shown in FIG. 13, a pile insertion hole having a size and a depth capable of previously inserting the pile P into the ground. 21 is formed and this pile insertion hole 21
The pile P is inserted into the pile P and the concrete milk C is injected into the pile P by a pump, so that the concrete milk C is permeated into the soil at the outer peripheral portion of the pile P to fix the pile P in the ground. The latter concrete milk injection method is adopted. In this method, since the lower half of the pile head reinforcing bar 22 must be inserted into the head of the pile P to form the underground beam, after the concrete milk C is hardened, the lower part of the pile head reinforcing bar 22 is The part where the half part is inserted (indicated by "L" in Fig. 13) must be removed by using a rock drill.

Then, as shown in FIG. 14, the lower half of the pile head reinforcing bar 22 is inserted into the hollow portion 23 of the head of the pile P formed by scraping off the concrete milk C, and the pile is formed using the formwork. Concrete beams are placed around the head reinforcements 22 to form underground beams 24.

However, the work of scraping off the hardened concrete milk C buried in the head of the pile P by using a drilling machine is extremely heavy work, and at the same time, there is a risk of illness due to strong vibration. , Improvement of the construction method of this part was earnestly desired.

[Problems to be solved by the device]

According to the present invention, when the pile is embedded and fixed in the ground by the concrete milk injection method described above, the work of scraping the concrete milk embedded in the head of the pile is not necessary and the workability is improved. It was done as an issue.

[Means for Solving the Problems]

Means adopted by the present invention to solve the above-mentioned problems are as follows: a fall prevention device is fixed to the upper surface of a cylindrical or polygonal cylindrical core body having an outer diameter corresponding to the inner diameter of a pile, and A disk body having a hole having an inner diameter smaller than the inner diameter of the core body is fixed to the lower surface, and one or more rods are provided on the inner peripheral surface of the core body along the axial direction of the core body. That is, a core body having a fixed structure was used, and the core body was attached to the inner circumference of the head of the pile so that the concrete milk was injected.

[Function of device]

The above core is attached to the inner circumference of the head of the pile, concrete milk is injected, and after the concrete milk is hardened, when a large twisting force is applied to the core, the core body has holes. In the outer peripheral part of the hardened concrete milk that is embedded, the rod that is fixed to the inner peripheral surface of the core body is embedded, and the outer diameter of the hardened concrete milk that is embedded in the hole of the disk body. Is smaller than the outer diameter of the hardened concrete milk embedded in the hole of the core body, so the twisting stress concentrates on the hardened concrete milk embedded in the hole of the disk, Hardened concrete milk is broken off in this part.

Then, when the core body is lifted from the pile as it is, the broken concrete milk is taken out of the pile by being supported by the disk body fixed to the lower surface of the core body. This creates a hollow in the pile head,
The lower half of the pile head reinforcement can be inserted into this hollow portion to install the pile head reinforcement on the head of the pile.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

1 to 5 show a core body A according to the present invention. In this core body A, an inner cylinder 2 is inserted inside an outer cylinder 1 having a different inner diameter, and a disc-shaped collar body 3 is fixed to the upper end surfaces of the outer cylinder 1 and the inner cylinder 2 by welding and closed. At the same time, a disc-shaped closing plate 4 is fixed to the lower end surface by welding and closed. The one in which the outer cylinder 1 and the inner cylinder 2 are integrally fixed is referred to as a core body 5. The collar body 3,
And the central portion of the closing plate 4 has holes 5a in the core body 5, respectively.
A hole having the same diameter as is provided.

A disk body 6 having a hole 6a having an inner diameter smaller than the inner diameter of the hole 5a of the core body 5 is fixed to the lower surface of the closing plate 4 by welding, and the inner peripheral surfaces of the core body 5 face each other. A pair of rods 7 are fixed to the portion along the axial direction of the core body 5, and an upper end portion of the rod 7 projects to the upper surface of the core body 5 and is bent outward to form a collar body. 3, the upper end of the rod 7 serves as a hook 7a for hooking the lifting tool.

Then, as shown in FIG. 6, the core body 5 is inserted into the hole portion 8 of the pile P, the core body A is mounted on the inner circumference of the head of the pile P, and the collar body 3 is attached thereto. Hook on the upper end surface of the pile P.

The pile P used in the concrete milk pouring method has a cylindrical shape. A pile insertion hole 9 having a size and a depth capable of inserting the pile P is vertically formed in the ground in advance, and the pile P having the core A attached to the inner circumference of the head is inserted into the pile. When the concrete milk C is inserted into the hole 9 and then the pump is used to inject the concrete milk C into the hole portion 8 of the pile P, as shown in FIG. Partially penetrates into the soil and hardens. By the hardening of the concrete milk C that has penetrated into the soil, the buried pile P is fixed in the soil.

After the concrete milk C is hardened, when a large twisting force T is applied to the core body A, the inner periphery of the core body 5 is attached to the outer periphery of the concrete milk Cb embedded in the hole 5a of the core body 5. The outer diameter of the concrete milk Ca embedded in the hole 6a of the disk body 6 is the same as that of the core body 5 while the two rods 7 fixed to the surface are embedded (see FIG. 10). Since it is smaller than the outer diameter of the concrete milk Cb embedded in the portion 5a (see FIG. 11), the torsion stress concentrates on the concrete milk Ca embedded in the hole 6a of the disk body 6, and in this portion Concrete milk Cb is broken off.

Since the inner diameter of the hole 6a of the disc body 6 is smaller than the inner diameter of the hole 5a of the core body 5, if the core body A is lifted as it is, it is broken off as shown in FIG. The concrete milk Cb is supported by the disk body 6 fixed to the lower end surface of the core body A and taken out of the pile P. As a result, the hollow portion 11 is formed at the head of the pile P.

The pile head reinforcing bar 12 (see Fig. 9) used for the pile P buried in the ground by the concrete milk injection method is different from the pile head reinforcing bar used for the pile buried by the driving method. Since it is not necessary to prevent the poured concrete from spilling downwards, no concrete receiving cap is attached to its lower end. That is, the pile head reinforcing bar 12 has a hoop bar 12b spirally welded to the outer periphery of a plurality of vertical bars 12a arranged along the circumferential direction, and a stopper bar 12c at the center of the vertical bar 12a. Is of a horizontally welded structure.

Then, as shown in FIG. 9, the lower half portion of the pile head reinforcing bar 12 is inserted into the hollow portion 11 formed in the head of the pile P, and the stopper bar 12c is attached to the upper end surface of the pile P. When brought into contact with each other, the pile head reinforcing bar 12 is installed on the head of the pile P. In this state, concrete is placed around the pile head reinforcing bar 12 using a form to form an underground beam 13.

Therefore, unlike the conventional method, it is not necessary to scrape off the hardened concrete in which the pile heads are buried by using a rock drill or the like.

Further, the core body 5 of the above-mentioned embodiment has a cylindrical shape, but as shown in FIG. 12, a tapered core whose outer diameter at the lower end is slightly smaller than that at the upper end. Using the body 5 ', the core A'can be easily taken out from the pile P. Further, the shape of the core body is not necessarily limited to the cylindrical shape, and may be a polygonal cylindrical shape.

Further, in the above embodiment, the collar body 3 is provided on the upper end of the core body 5 as a fall prevention tool for preventing the core body 5 from falling.
The drop-prevention tool is not limited to the collar body, but may be, for example, two rod bodies fixed along the radial direction of the core body.

[Effect of device]

When the core body according to the present invention is used, after the concrete milk injected into the pile is hardened, a large torsional force is applied to the core body so that the concrete milk can be applied to a portion of the hardened concrete milk having the smallest outer diameter. The milk can be broken off and the broken concrete milk can be taken out of the pile by lifting the core from the pile.

For this reason, the pile head reinforcement can be installed on the pile head without scraping off the concrete milk embedded in the pile head, which is a heavy work in the past. It is possible to relieve the operator from the work of shaving concrete milk using the accompanying rock drilling machine, and it is possible to significantly improve the construction method for burying piles.

[Brief description of drawings]

1 to 12 are views for explaining the present invention, and FIGS. 1 and 2 are perspective views of a core A according to the present invention as seen from different directions. 3 is a longitudinal sectional view of the same, FIG. 4 is a bottom view of the same, FIG. 5 is a central transverse sectional view of the same, and FIG. 6 is a pile in which the core A is attached to the inner circumference of the head. Fig. 7 is a cross-sectional view of P, Fig. 7 is a cross-sectional view of the pile P buried in the ground, and Fig. 8 (a) is a state in which the broken concrete milk Cb is lifted by the core A. In the figure, (b), the disk body 6 in which the broken concrete milk Cb is fixed to the lower end surface of the core body A is shown.
9 is an enlarged partial cross-sectional view showing a state in which the pile P is reinforced by the pile head reinforcement 12, and FIG. 10 is a hole portion of the core body 5. 5a is a cross-sectional view of concrete milk Cb embedded in 5a, FIG. 11 is a vertical cross-sectional view of concrete milk embedded in core body 5 and pile P, and FIG. 12 is another embodiment of the present invention. It is sectional drawing of the state which mounted the core body A'of an example to the head inner circumference of the pile P. 13 and 14 are views for explaining the conventional technique. FIG. 13 is a sectional view of the pile P buried in the ground, and FIG. 14 is buried in the head. Pile head reinforcement bar 22
It is sectional drawing of the pile P in the state which inserted the lower half part. The description of the reference numerals of the main parts constituting the present invention is as follows. A, A ': Core body, C: Concrete milk P: Concrete pile 3: Collar body (fall prevention tool), 5,5': Core body 6: Disc body, 7: Rod body 11: Pile head Hollow part 12 formed on: Pile head reinforcement

Claims (1)

[Scope of utility model registration request] 1. When the concrete pile is inserted and fixed in a pile insertion hole preformed in the ground by the concrete milk injection method, the concrete pile is mounted on the inner circumference of the head of the concrete pile, and the inner circumference of the pile head is attached. A core body for forming a hollow portion into which a pile head reinforcement can be inserted, and a fall prevention tool on the upper surface of a cylindrical or polygonal core body having an outer diameter corresponding to the inner diameter of the concrete pile. Is fixed to the lower surface of the core body, and a disc body having a hole portion having an inner diameter smaller than the inner diameter of the core body is fixed to the lower surface of the core body, and one or more rod bodies are formed on the inner peripheral surface of the core body. A core body attached to the inner circumference of the head of a concrete pile, which is fixed along the axial direction of the core body.