JP2001248154A - Method of processing pile head, head structure of cast-in- place concrete pile, and form for processing pile head, for use in method of constructing cast-in-place concrete pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of processing a pile head, a head structure of a cast-in-place concrete pile, and a form for processing the pile head, for use in a method of constructing the cast-in-place concrete pile such that the extra fill of the pile head is eliminated to eliminate the need for the work of shaving the extra fill and disposal of debris, to prevent noise and vibration and shorter period of construction work. SOLUTION: In the method of constructing the cast-in-place concrete pile, pile reinforcements are placed 4 into a pile hole dug in the ground, a casing 3 is inserted into the pile hole; concrete C is placed by using concrete placing means such as a tremie pipe; and the casing is drawn out. A pile head ring 6 is installed at the level of the head of the cast-in-place concrete pile and the concrete C is placed. While the concrete C has flowability, the casing is pulled up and the concrete on top of the pile head ring 6 is removed to level the top end face of the pile.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pile head treatment method in a construction method of a cast-in-place concrete pile, a pile head structure of a cast-in-place concrete pile, and a formwork for pile head treatment.

[0002]

2. Description of the Related Art In general, cast-in-place concrete piles are formed with a drill hole by a drilling method such as a Benoto method, a reverse method, or an earth drill method, and a pile reinforcing bar is inserted into the hole, and is inserted into the pile reinforcing bar. Concrete was cast from the bottom to the head through the inserted tremy tube. As a conventional pile head processing method, as shown in FIG.
After the concrete is hardened, the surplus portion P1 is shaved off after the concrete is hardened.
As shown in (B), the pile head level was set, and the discarded concrete S was cast around the pile head.

[0003]

However, in the above-mentioned conventional technique, the work of cutting the excess portion P1 is often performed by a hydraulic breaker or the like. In this case, not only noise and vibration are generated, but also the cutting There are many problems such as the need for discharge treatment due to the occurrence of the problem, and a long construction period.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to eliminate the extra work of the pile head to eliminate the shaving work and the waste disposal work. It is an object of the present invention to provide a pile head treatment method, a pile head structure of a cast-in-place concrete pile, and a formwork for pile head treatment in a construction method of a cast-in-place concrete pile capable of eliminating noise and vibration and shortening the construction period.

[0005]

The pile head treatment method in the construction method of the cast-in-place concrete pile according to the present invention comprises the steps of: embedding a reinforcing rod in a pile hole excavated in the ground; and inserting a casing into the pile hole; In the construction method in which concrete is poured into the pile hole by concrete placing means such as a tremie pipe and the casing is pulled out to construct a cast-in-place concrete pile, a pile head ring is installed at a pile head level position of the cast-in-place concrete pile. Then, concrete is poured at least on the pile head ring, and while the concrete has fluidity, the casing is pulled up, the concrete on the pile head ring is removed, and the pile top end face is leveled. It is characterized by the following. Further, it is also characterized in that the ground around the pile head ring is dug below the pile head level, and the concrete on the pile head ring is discarded into the dug portion and flows out as concrete. Further, a kiln place is formed outside the dug-down portion to store a hole wall protection liquid such as a bentonite liquid flowing out as the casing is pulled up. Furthermore, it is characterized in that the ground around the pile head ring is dug below the pile head level at least before raising the casing. Still further, the pile head ring is installed inside a casing. Further, the pile head ring is attached to the pile reinforcement by an attachment means such as welding. Further, the present invention is characterized in that the pile head ring is provided outside the casing.

[0006] The pile head structure of the cast-in-place concrete pile of the present invention is characterized by having a pile head ring around the pile head.

[0007] The formwork for treating a pile head of a cast-in-place concrete pile according to the present invention is constructed by embedding a pile reinforcing steel into a pile hole excavated in the ground, inserting a casing above the pile hole, and setting a tremee in the pile hole. A cast-in-place concrete pile constructed by driving concrete in by means of concrete placing means such as a pipe and pulling out the casing, comprising a pile head ring installed at a pile head level position. Also,
It is also characterized in that the pile head ring is a discarded formwork.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a hole wall of a pile hole formed by a drilling method such as a Benoto method, a reverse method, or an earth drill method, and the hole wall 1 is protected by a hole wall protection liquid 2 such as bentonite liquid. I have. A casing 3 is inserted into the upper part of the hole wall 1. Reference numeral 4 denotes a pile reinforcing bar, and reference numeral 5 denotes a tremy tube inserted into the pile reinforcing bar 4. 6 is a short cylindrical pile head ring,
It is attached and fixed to the pile reinforcing bar 4 by appropriate means such as welding. L1 is the extra level of concrete C, L
2 is the pile head level. The difference between the extra level L1 and the pile head level L2 is suitably about 500 mm, but is not limited to this.

When concrete is poured from the bottom of the pile hole from the tremy tube 5, the hole wall protection liquid 2
Liquid level rises. The hole wall protection liquid 2 is pumped out by a pump or the like so as not to flow out to the surroundings, and the liquid level is kept constant. At this time, care should be taken not to agitate the concrete and the hole wall protection liquid 2 in the uplifted portion of the concrete near the excess filling level L1 so that impurities such as sludge do not enter.

[0010] After the concrete has been poured, as shown in Fig. 2, the tremy tube 5 is pulled out, and the hole wall protective liquid 2 is discharged as much as possible, and it is confirmed that the top end surface of the concrete C is at the reserve level L1. I do. After the concrete C is placed, the ground around the pile is immediately excavated as shown in FIG. The excavation level L3 is a position dug about 200 mm below the pile head level L2, for example. At the same time, a kiln place 7 is formed.

After the excavation is completed, if the casing 3 is pulled out while the concrete C still has fluidity, as shown in FIG. 4, the hole wall protection liquid 2 flows out and accumulates in the kiln 7. . Since the pile head ring 6 is disposed at the pile head level L2, the concrete C above the pile head ring 6 flows out to the periphery. The outflowing concrete C is spread and leveled to form a discarded concrete 8.
The leveled top level L4 of the discarded concrete 8 is, for example, about -100 mm from the pile head level L2. Finally, tapping is performed on the end face of the pile to match the pile head ring 6. After the above operation is completed, the concrete C is hardened and a cast-in-place concrete pile is constructed.

In the above-described embodiment, the pile head ring 6 is manufactured as a steel ring, and the pile head ring 6 is welded to the pile reinforcing bar 4 to be attached and arranged. It is not limited to this, for example,
A pile head ring made of PCa (precast concrete) may be fixed to a reinforcing bar with an appropriate mounting jig, or may be formed of a mesh that does not allow concrete to flow out.

In the above embodiment, the periphery of the pile head ring 6 is excavated after the concrete is cast. However, the excavation work may be performed simultaneously with or before the concrete is cast. It is sufficient that the casing 3 is dug up before the casing 3 is pulled out.

Further, in the above embodiment, the pile head ring 6 is arranged inside the casing 3, but the present invention is not limited to this, and excavation around the pile head is completed as shown in FIG. After that, before the casing 3 is pulled out, it may be installed on the outer peripheral side of the casing 3. In this case, it is necessary to stably hold (set) the pile head ring 9 so that the position of the pile head ring 9 does not change with the pulling out operation of the casing 3 or the like.

[0015]

As described above, 1) the noise, vibration and shavings discarding processing required for the conventional pile head shaving processing of the excess portion is unnecessary, and the processing cost can be reduced. 2) The pile head top end surface becomes smooth, and the construction efficiency and stability of the steel anchor base are improved. 3) The pile head treatment period is shortened, and the need for work period adjustment is reduced. 4) It is possible to reduce waste concrete around the pile head. 5) Rebar curing costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a construction explanatory view showing one embodiment of a method for constructing a cast-in-place concrete pile of the present invention.

FIG. 2 is a construction explanatory view following FIG. 1;

FIG. 3 is a construction explanatory view following FIG. 2;

FIG. 4 is a construction explanatory view following FIG. 3;

FIG. 5 is a construction explanatory view showing another embodiment of the method for constructing a cast-in-place concrete pile of the present invention.

FIG. 6 is a construction explanatory view of a conventional method of constructing a cast-in-place concrete pile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Perforated wall 2 Perforated wall protective liquid 3 Casing 4 Pile reinforcement 5 Pleated steel tube 6 Pile head ring 7 Kamaba 8 Discarded concrete 9 Pile head ring L1 Extra fill level L2 Pile head level L3 Drilling level L4 Discard concrete level

Claims (10)

[Claims] The present invention is characterized in that a pile reinforcement is erected in a pile hole excavated in the ground, a casing is inserted into the pile hole, and concrete is driven into the pile hole by concrete casting means such as a tremy tube. In the construction method of pulling out the cast-in-place concrete pile, a pile head ring is installed at the pile head level position of this cast-in-place concrete pile,
Pour concrete at least on the pile head ring,
A pile head in a construction method for constructing a cast-in-place concrete pile, characterized in that the casing is pulled up while the concrete has fluidity, the concrete on the pile head ring is removed, and the pile top end face is leveled. Processing method. 2. The method according to claim 1, wherein the ground around the pile head ring is dug below the pile head level, and the concrete on the pile head ring is discarded into the dug portion to flow out as concrete. Pile head treatment method in construction method of cast-in-place concrete pile. 3. A basin is formed outside the dug-down portion to store a hole wall protection liquid such as a bentonite liquid which flows out as the casing is pulled up. Pile head treatment method in the construction method of cast-in-place concrete pile described in 4. 4. The method of constructing a cast-in-place concrete pile according to claim 1, wherein the ground around the pile head ring is dug down to a pile head level or less before at least raising the casing. Pile head treatment method. 5. The pile head treatment method according to claim 1, wherein the pile head ring is installed inside a casing. 6. The pile head treatment method according to claim 5, wherein the pile head ring is attached to the pile reinforcement by welding means or the like. 7. The pile head treatment method according to claim 1, wherein the pile head ring is installed outside a casing. 8. A pile head structure of a cast-in-place concrete pile having a pile head ring around a pile head. 9. A pile rebar is erected in a pile hole excavated in the ground, a casing is inserted above the pile hole, and concrete is poured into the pile hole by concrete casting means such as a tremy pipe. A cast-in-place concrete pile constructed by pulling out a casing, comprising a pile-head ring installed at a pile-head level position. 10. The pile head treatment form of a cast-in-place concrete pile according to claim 9, wherein the pile head ring is a discarded form.