JPH073780A - Method for treating head of cast-in-place concrete pile - Google Patents

Abstract

PURPOSE:To facilitate a pile-head treatment by which an extra-banking portion is separated from a pile main body by installing a plurality of double pipes on the same horizontal plane at a predetermined depth when inserting reinforcing bars into a drilled pile hole. CONSTITUTION:Double pipes 1 comprise an outer pipe 1A, an inner pipe 1B and an inner-pipe extrusion device 1C, and the device 1C is secured to the outer pipe 1A and the two parallel pipes 1 are connected together by means of a joint pipe 2 via a branch pipe 13, and all of the pipes 1 are so formed to be coplanar. With the pipe 1B enclosed in the pipe 1A, reinforcing bars 3 are bound by a binding wire 11 and the pipes 1 are inserted into a pile hole. A rotor 19 is rotated by turning a handle 14 above the ground to push the pipe 1B outside, and the piles 1 are installed with their end faces pressed against the wall 7 of the hole, and underwater concrete is placed by way of a tremie e pipe to construct a pile main body 6. Then earth around the head of the pile is removed, the pipe 1B is extracted, and a jack for a rock crusher is inserted to exert pressure to crack the concrete vertically so as to remove an extra-banking portion 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile head treating method for separating an extra portion of a cast-in-place concrete pile from a pile body.

[0002]

2. Description of the Related Art In general, when constructing a cast-in-place concrete pile, the concrete of the pile body is generally placed underwater by a tremie pipe. Therefore, the concrete on the pile head, which was placed in the initial stage and has been affected by muddy water for a long time, is considered to be qualitatively weak and is treated as an extra portion. The extra portion is taken off from the pile body. Since this chipping work is performed using a breaker or the like, noise and dust are generated, and the vibration causes physical pain to the worker, and the work is performed in an extremely bad environment. Furthermore, chipping may cause cracks in the pile body.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to remove an extra portion, which is considered to be fragile, from a main body in a work in a good environment without performing a chipping work in such a bad environment. is there.

[0004]

The first invention of the present invention comprises:
(A) When inserting and installing the reinforcing bar in the excavated pile hole,
After installing multiple double pipes on the same horizontal surface at a specified depth, pushing out the inner pipe and pressing the inner pipe end face against the wall of the pile hole, concrete is placed in the pile hole with a tremie pipe and cast in place. Step of constructing the pile, (B) Remove the soil around the pile head of the constructed concrete pile, pull out the inner pipe of the double pipe, insert the jack for the split rock machine into the mark and apply pressure to the jack. A step of splitting an outer pipe of a double pipe and a concrete pile up and down, and a pile head treatment method for a cast-in-place concrete pile, wherein the second invention is (A) inserting and installing a reinforcing bar in an excavated pile hole. In this case, a plurality of double pipes are installed on the same horizontal surface of a predetermined depth, and a plurality of pipes or partition plates are installed vertically in the pile head above the installation horizontal surface of the double pipe, The inner pipe of the double pipe was pushed out and the end face of the inner pipe was pressed against the pile hole wall. , A process of placing concrete with a tremie pipe in the pile hole to construct a cast-in-place concrete pile, (B) removing soil around the pile head of the constructed concrete pile, and pulling out the inner pipe of the double pipe, Inserting a jack for a rock breaking machine into the trace and applying pressure to the jack to split the outer pipe of the double pipe and the concrete pile up and down, (C) Pipe or partition plate vertically embedded in the pile head Use
A pile head treatment method for cast-in-place concrete piles, which comprises a step of vertically dividing pile head concrete.

The first aspect of the present invention is that a plurality of holes are provided on the same horizontal surface below the extra heap portion, and a jack for a rock breaking machine is inserted into the holes and pressure is applied to the jacks to form the holes. This is the point where the extra heap is separated from the pile body at the horizontal plane provided. Therefore, (A) above
It can be said that this step is a preparatory step for forming a plurality of holes on the same horizontal surface below the extra embankment.

An important point of the second invention of the present invention is that the extra portion separated from the pile body according to the first invention is further divided in the vertical direction. In order to be able to divide in the vertical direction, a plurality of pipes or partition plates are previously embedded in concrete in the extra part in the step (A) described above.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

1 to 4 illustrate the first invention,
5 and 6 illustrate the second invention.

FIG. 1 shows a pile head of a small diameter cast-in-place concrete pile constructed in the step (A) of the first invention, in which (a) is a horizontal sectional view and (b) is a vertical sectional view. is there.

FIG. 2 also shows a pile head of a large diameter cast-in-place concrete pile constructed in the step (A) of the first invention, in which (a) is a horizontal sectional view and (b) is vertical. FIG. The large-diameter pipe and the small-diameter pipe are different from each other only in the number of double pipes installed on the same horizontal plane.

In this example, four double tubes 1 are used, but one outer tube 1A is shared with two inner tubes 1B. The double pipe 1 is composed of an outer pipe 1A, an inner pipe 1B and an inner pipe pushing device 1C, and the inner pipe pushing device 1C is the outer pipe 1
The outer pipe 1A which is fixed to A and is located above the inner pipe pushing device 1C
A handle insertion hole 12 is bored in this. Two parallel
The double pipes 1 of the book are connected by a connecting pipe 2 via a branch pipe 13, and all the double pipes 1 are formed so as to exist in the same plane (see FIG. 4A). All of the double pipes 1 are bound by the reinforcing wires 3 by the binding wires 11 and inserted into the pile holes so that the inner pipe 1B is accommodated in the outer pipe 1A so as to maintain a horizontal plane. At this time, the rotating body 9 in the inner pipe pushing device 1C is fitted to the handle 14 by its protrusion. (See FIG. 4 (b) and FIG. 3 (a)). After horizontally installing all the double pipes 1 at predetermined positions, when the handle 14 is rotated on the ground, the rotating body 9 rotates and the inner pipe 1B is pushed out to the outside, and its end face is crimped to the hole wall 7. (Fig. 3 (b)
And FIG. 4 (c)). After installing the double pipe 1 in this way, the underwater concrete is poured by the tremie pipe without removing or removing the handle 14. After the concrete hardens, the cast-in-place concrete piles shown in FIGS. 1 and 2 are constructed.

When the soil around the pile head of the constructed concrete pile is removed, the end face of the inner pipe 1B is exposed on the pile surface.
Pull out the inner pipe 1B, and at the trace of it, jack for a rock breaking machine (Fig. 1
4 units in the case of, and 8 units in the case of FIG. 2). When the pressure is applied to all the jacks at the same time, the concrete of the outer pipe 1A and the concrete of the concrete pile is cracked up and down, so the work is completed by removing the concrete above.

The outer pipe 1A used in the present invention needs to be split by the pressure of the jack, but on the other hand, it needs to resist the gravity of the concrete placed on the head of the pile, so it is made of a relatively fragile plastic. Is used. Further, the concrete of the extra reinforcement portion 5 is a portion to be removed eventually, and it is easier to split the concrete due to the jack pressure in the present invention if it is not attached to the reinforcement reinforcement 3, so It is preferable to cover the concrete 4 and the reinforcing bar 3 by covering them with a sleeve 4. This sleeve 4 covers the reinforcing bar 3 within a necessary range, and the end thereof is bonded with an adhesive tape or the like.
You just have to fasten it.

As the inner pipe pushing device 1C, in addition to the above-mentioned rotating body, as shown in FIGS. 3 (c) and 3 (d), a spring is used to bind the spring with a binding wire in a contracted state. Keep a part of the tie line to the ground,
It is possible to employ a method of cutting the binding wire on the ground, a mechanism in which the spring is bound with a water-soluble fibrous binding wire in a contracted state, and the binding wire is broken due to muddy water and the spring extends.

FIG. 5 shows a pile head of a small diameter cast-in-place concrete pile constructed in the step (A) of the second invention, (a) is a horizontal sectional view, and (b) is a vertical sectional view. is there. In this example, four vertical pipes 15 are vertically connected to the outer pipe 1A of the double pipe 1 via a branch pipe in which the number of branches of the branch pipe 13 is increased by 1, and an upper end is covered with a lid 16. . Although not shown in the case of a large-diameter cast-in-place concrete pile, about eight vertical pipes are vertically connected to the outer pipe 1A of the double pipe 1 by branch pipes or connecting hardware. After inserting the jack for a rock breaking machine into the outer tube 1A, applying pressure and breaking it up and down,
When a jack for a rock breaking machine is inserted into the vertical pipe 15 and pressure is applied, the concrete in the extra embankment 5 is divided in the vertical direction and becomes a small block.

FIG. 6 shows another example of a pile head of a small diameter cast-in-place concrete pile constructed in the step (A) of the second invention. (A) is a horizontal sectional view and (b) is It is a vertical cross-sectional view. In this example, a large number of partition plates 17 are vertically connected to the upper portion of the outer pipe 1A of the double pipe 1 and the connecting pipe 2 with a normal connecting metal piece. The reason why a large number of partition plates 17 are provided at intervals is to prevent the flow of concrete during concrete pouring from being obstructed. Therefore, it is preferable that the intervals be narrow as long as the flow of concrete is not obstructed.
Since the concrete in the extra portion 5 is divided by a large number of partition plates 17, after inserting the jack for a rock breaking machine into the outer pipe 1A and applying pressure to divide it vertically, the concrete in the extra portion 5 is impacted. Then, the concrete is easily divided at the part of the partition plate 17 and becomes a small block. Partition board 1
Since the concrete of the extra portion 5 is for dividing the concrete into a large number of portions, a plastic plate having a weak adhesion to the concrete is preferable, and it is sometimes preferable to perform an adhesion preventing process.

[0017]

The surplus portion can be separated from the pile main body by splitting by jacking force instead of the hanging work.
Furthermore, since the extra portion can be divided into small pieces, it is free from the hanging work in a bad environment. In addition, the pile body does not crack.

[Brief description of drawings]

FIG. 1 shows a pile head of a small diameter cast-in-place concrete pile constructed in the step (A) of the first invention, in which (a) is a horizontal sectional view and (b) is a vertical sectional view.

FIG. 2 shows a pile head of a large-diameter cast-in-place concrete pile constructed in the step (A) of the first invention, (a) is a horizontal sectional view, and (b) is a vertical sectional view. .

FIG. 3 is a horizontal cross-sectional view showing an inner pipe pushing mechanism,
(A) and (b) use a rotating body, (a) shows before rotation, and (b) shows after rotation. (C) and (d) use a spring, (c) shows a contracted state, and (d) shows an extended state.

FIG. 4 shows a connection between a double pipe and a connecting pipe, (a) is a horizontal sectional view, (b) and (c) are A-A arrow views of (a), and (b). Shows before the rotation of the rotating body, and (c) shows after the rotation of the rotating body.

FIG. 5 shows a pile head of a small diameter cast-in-place concrete pile constructed in the step (A) of the second invention, in which (a) is a horizontal sectional view and (b) is a vertical sectional view.

FIG. 6 shows another example of a pile head of a small diameter cast-in-place concrete pile constructed in the step (A) of the second invention, (a) is a horizontal sectional view, and (b) is a vertical sectional view. It is a figure.

[Explanation of symbols] 1 ... Double pipe, 1A ... Outer pipe, 1B ... Inner pipe, 1C ...
Inner pipe pushing device, 2 ... Connection pipe, 3 ... Reinforcing bar, 4
..Sleeve, 5 ... Excessive portion, 6 ... Pile body, 7 ...
Pile hole wall, 8 ... Inner tube lid, 9 ... Rotating body, 10 ... Spring, 11 ... Bundling wire, 12 ... Handle insertion hole, 13 ...
・ Branch pipe, 14 ・ ・ Handle, 15 ・ ・ Vertical pipe, 16 ・
.Vertical pipe lids, 17..partition plates

Claims (2)

[Claims] 1. (A) When inserting and installing a reinforcing bar into an excavated pile hole, a plurality of double pipes are installed on the same horizontal plane of a predetermined depth, and the inner pipe is extruded and the end face of the inner pipe is piled. After press contacting the hole wall, the step of placing concrete with a tremie pipe in the pile hole to construct a cast-in-place concrete pile, (B) Removing the soil around the pile head of the constructed concrete pile, Pile head treatment for cast-in-place concrete piles, which consists of pulling out the inner pipe of the pipe, inserting a jack for a rock breaking machine into the mark and applying pressure to the jack to split the outer pipe of the double pipe and the concrete pile up and down Method 2. (A) When inserting and installing reinforcing bars in an excavated pile hole, a plurality of double pipes are installed on the same horizontal plane of a predetermined depth, and the double pipes are installed above the horizontal plane. Install multiple pipes or partition plates in the vertical direction on the pile head,
A step of constructing a cast-in-place concrete pile by pushing out the inner pipe of the double pipe to press the end face of the inner pipe against the wall of the pile hole, and then placing concrete by a tremie pipe in the pile hole, (B) Remove the soil around the pile head of the concrete pile, pull out the inner pipe of the double pipe, insert a jack for a split rock machine at the mark and apply pressure to the jack to move the outer pipe of the double pipe and the concrete pile up and down. Pile head treatment method for cast-in-place concrete piles, which comprises a step of dividing the pile head concrete vertically using a pipe or partition plate vertically embedded in the pile head (C)