JP2000314132A - Pile head treatment method of concrete pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily remove a pile head after concrete is cured in a pile head treatment method wherein an extra fill portion of a pile head of a cast-in-place concrete pile is crushed and lifted to remove it, wherein air and/or liquid is injected under pressure into a separation device set on the boundary surface between the pile head and the extra fill portion thereof to vertically separate the concrete. SOLUTION: A separation device is set beforehand in a reinforcing bar cage A located on the boundary surface between an extra fill portion and a pile head portion of a concrete pile. Just after concrete is placed, air and/or liquid is injected under pressure into the device through a tube C connected thereto expand or elongate the device, thereby providing a separation layer in the concrete, and hence the extra fill portion can be separated without applying any force to the cured concrete. Thus, in the pile head treatment to remove an extra fill portion of the pile, noises and vibration are not generated and moreover a pile removal operation can be easily and economically performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of treating a pile head of a cast-in-place concrete pile (JP-A-61-257532, JP-A-62-117914, JP-A-64-6).
413, JP-A-5-67732, JP-A-5-67732.
Japanese Patent Application Laid-Open No. 207661/1996 and Japanese Patent Application Laid-Open No. Hei 8-60653) discloses an apparatus for easily separating a boundary surface between a pile top and a pile top in order to remove a pile top pile from the pile top. Related to the method of installation.

[0002]

2. Description of the Related Art In the cast-in-place concrete pile method, a reinforced cage assembled on site is inserted into a pile hole and concrete is sequentially driven from the bottom to form a foundation pile. The low-quality layer and the latence layer are formed in the concrete by entraining the muddy soil and muddy water generated at the bottom of the pile and on the way. For this reason, in the current construction method, the safety of the strength of the pile head is expected, and the design pile length is set to 50 to 100 in advance.
It is necessary to cast concrete about an extra centimeter (referred to as a surplus portion).

[0003] The extra pile is removed after the concrete is hardened in order to secure the design pile length and the predetermined strength. However, since this removal operation is performed by a breaker or a call pick hammer, noise, vibration, and construction pollution caused by dust are reduced. The occurrence is inevitable, and the work period tends to be longer.

[0004] For this reason, the excess concrete is suction-removed before hardening, the strength of the concrete after hardening is reduced by using a pile head treating agent, or the concrete is statically crushed by an expanding material. Accordingly, a method of treating a pile head that suppresses noise, vibration, and dust has been proposed (see the above-mentioned publication).

However, in these methods, it is difficult to maintain the level of the top of the pile, or the concrete is apt to deteriorate in strength. Noise and vibration could not be suppressed. In addition, these operations require a great deal of manpower and equipment, and do not satisfy the intended effects and efficiency of the operations.

[Problems to be solved by the invention]

[0006] Recently, with the development of a crusher capable of crushing waste concrete at the site with low noise, it has become possible to crush and recycle the overfilled concrete at the site with a large amount of extra pile concrete. The method of processing is also largely divided.

Accordingly, the present invention relates to a pile head treatment method for removing excess concrete from a pile head while dividing the excess concrete into large portions. It was created to provide a pile head treatment method that can be separated economically.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, a method of separating the excess concrete is to set a separating device in advance at a predetermined position which is to be the top of a pile of a reinforcing bar inserted into a perforated hole, and after the concrete has been poured, From the tube connected from the ground, air and or liquid are injected under pressure into the device to expand or expand horizontally, and the extra head part of the anti-head and the pile top are cut off and separated, and concrete After being cured, it can be lifted and removed without applying new force.

[0009] The device for separating concrete is installed outside the reinforcing bar in the pile hole, and the outside of the reinforcing bar is expanded or stretched by the device, and the device expanded and contracted inside pressurizes air and / or liquid. It expands by pouring and extends to the center of the pile to cover it. In addition, the shape may be a comb-like shape toward the center, or a fan-like shape or a slide-type shape, which can be expanded or expanded by injecting air and / or liquid under pressure to be horizontal, and can be trimmed while covering the whole.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The object of the present invention is to largely remove the conventional method of processing pile heads while generating noise, vibration and dust by human power, with the advent of concrete crushers due to the improvement of technology. The purpose of the present invention is to simply and economically provide a simple and economical method of dividing a surplus portion of concrete to contribute to low noise, no dust, recycling of construction waste material, etc. by crushing with a crusher and treating inside the plant.

The air and / or liquid is connected by a tube to a compressor on the ground, and is injected under pressure into a separation device set at a predetermined position. The number of tubes to be injected under pressure is appropriately determined according to the pile diameter and the like. .

[0012] The separating device is provided with a jet port for jetting air and / or liquid from the tip or the other in order to reduce the resistance of the concrete when expanding or expanding with air and / or liquid injected under pressure.

In addition, the separating device may be provided with a guide so as to be horizontally expanded or expanded by using a spring, a rod-shaped or a string-shaped device.

The liquid to be injected under pressure into the separation device is sprayed into concrete using fresh water, concrete retarder, bentonite or high molecular polymer, aluminum powder suspension, etc. to chemically secure the separation layer. I do.

A method may be used in which a disc-shaped cap is attached to the pile top position as a spacer also as a spacer on the outer periphery of the reinforcing bar cage, and a separating device is placed thereon to inflate or expand the reinforcing bar by pressure injection.

[0017]

As described above, the present invention aims at suppressing the recycling of construction waste materials to the outside and recycling them, and aims to reduce the excess portion of cast-in-place concrete piles on the premise of secondary crushing by crushers. The method can be performed very easily and economically.

[Brief description of the drawings]

FIG. 1 is a perspective view of a separation device in a folded state.

FIG. 2 is a perspective view showing a state where a separation device is expanded and expanded.

FIG. 3 is a perspective view of a disk-shaped cap which also serves as a spacer on the outer periphery of a reinforcing bar.

FIG. 4 is a perspective view of an example of an arrangement of injection ports for injecting air and / or liquid when the separation device is expanded.

[Explanation of symbols]

 A Reinforced basket B Telescopic part of separation device C Pressurized injection tube D Disc-shaped cap E Injection port

Claims (3)

[Claims] 1. A device installed at a boundary between an extra pile head and a pile top of a cast-in-place concrete pile, air and
Alternatively, a pile head treatment method characterized in that concrete is separated into upper and lower parts by injecting a liquid under pressure to expand or expand the device, thereby facilitating removal of a hardened portion after hardening. 2. An apparatus for separating concrete between a pile head extra portion and a pile top is made of a bag or a plate which can be expanded or contracted with canvas, vinyl, plastic, metal, or the like. Fold it in a predetermined position of the reinforcing bar to be inserted into the pile hole and set it in advance.
The air and / or liquid is inflated or expanded to a predetermined length or width by pressure injection. 3. When the pile head extra portion and the pile top are separated, the folded device is provided with an injection port for injecting air and / or liquid in order to easily expand or expand horizontally in the concrete. In some cases, a spring or a rod-shaped rail may be provided.