JP2693027B2 - Pile head treatment method for cast-in-place concrete pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a cast-in-place pile made by inserting a reinforcing bar into a hole provided in the ground and filling with concrete, and floating on a pile head portion of the concrete pile. The present invention relates to a pile head processing method for removing the latance (a part of the concrete having a low strength) that has settled out and settled and the part of the concrete mixed with slime.

(Prior art)

When a stratum that can safely support a structure can be obtained only in a relatively deep place, a pile that reaches the stratum is driven from the ground surface and the pile foundation is used as a structure to transfer the load of the structure to the support layer. Used.

Pile driving methods include a method of driving ready-made piles such as PC piles or steel pipe piles, and a cast-in-place pile construction method of constructing reinforced concrete piles into holes excavated by machines or human power.

This cast-in-place pile construction method is advantageous in transporting materials compared to the ready-made pile construction method, that the support layer can be confirmed during construction, large-diameter and long piles can be constructed, and there is no noise and vibration. It is generally used because it can be installed.

However, in the cast-in-place pile method, after the concrete is cast, the concrete part mixed with the leitance and slime that emerges and precipitates on the surface of the concrete, that is, the pile head part of the concrete pile, is solidified to expose the fresh surface of the concrete. Work (pile head treatment) is required.

This pile head treatment is generally performed by operating a breaker, which is a machine that destroys concrete with compressed air, by a special worker called a "scraper".

However, it is difficult to finish the pile head surface flat in the pile head treatment work by the breaker, and noise and vibration during the work are also a serious pollution problem. In addition, it is difficult to secure a special worker called "smuggler", which may delay the process. Furthermore, after pile driving, it is necessary to excavate the ground up to the planned ground height with an excavating machine, but during this work, the bucket of the excavating machine sometimes touched the reinforcing bars in the concrete piles and deformed the reinforcing bars. .

Furthermore, in the conventional pile head treatment method, since the reinforcing bars are exposed from the pile heads of concrete piles after the pile heads are processed, when building steel frames etc. of the building into the pile heads, the reinforcing bars interfere and work efficiency decreases. Was.

[Problems to be solved by the invention]

In consideration of the above facts, the present invention is a noise-free and vibration-free general worker who can flatly remove the pile head portion, and the excavation work and the work of building the pillars of the building into the pile head after the pile head treatment. Even in this case, the purpose is to resist the pile head processing method that can be processed so that the reinforcing bars do not get in the way.

[Means for solving the problem]

In the pile head treatment method for cast-in-place concrete pile according to claim (1), it is used as a cast-in-place pile for constructing a reinforced concrete pile in a hole excavated in the ground, and an upper end portion of the reinforcing bar inserted in the hole. The first step of fixing the joint means of the reinforcing bar having a hollow portion, and the pile head portion of the reinforced concrete pile together with the joint means embedded in the reinforced concrete pile after the pile head portion of the constructed reinforced concrete pile is exposed. It is characterized by including a second step of cutting with a cutting means and a third step of injecting a fixing material through a cutting opening of the joint means and inserting a reinforcing bar to fix the same.

In the pile head treatment method for cast-in-place concrete piles according to claim (2), the cutting position is displayed in the hollow portion of the joint means.

[Action]

In the pile head treatment method for cast-in-place concrete piles having the above structure, a reinforcing bar is inserted into a hole excavated in the ground, and a reinforcing bar joint means having a hollow portion is fixed to the upper end of the reinforcing bar.
A cap is attached to the upper end of the joint means so that concrete poured into the hole will not penetrate into the hollow portion of the joint means. Then, a cast-in-place pile made of reinforced concrete is constructed by placing concrete into the hole.

After the concrete is hardened, the pile head portion of the reinforced concrete pile, that is, the surplus portion (the portion where extra concrete is placed in consideration of the leitance etc.) is cut together with the joint means. The cutting position is confirmed by the display inside the hollow portion of the joint means. The fixing material is injected into the hollow portion of the joint means from the cut opening of the joint means formed by this cutting, and the reinforcing bar integrated with the upper structure is inserted and fixed.

〔Example〕

(Joint Structure of Pile Head Part) FIG. 1 shows a joint structure of a pile head part of a cast-in-place pile to which the present invention is applied.

The upper end of the reinforcing bar 10 constituting the reinforced concrete pile 8 and the insert reinforcing bar 12 which winds up the pillar of the structure are inserted into the sleeve 16 filled with the grout 14 and are butted against each other and are integrally connected.

The sleeve 16 has a substantially cylindrical shape and has openings 18, 20 at both ends.
It has been. A partition wall 22 is formed in the center of the sleeve 16, and the reinforcing bars 10 and 12 inserted through the openings 18 and 20 are attached to the partition wall 22.
And the required fixing length L between the reinforcing bars 10 and 12 and the sleeve 16 is secured.

The inside of the cylinder on the upper side of the sleeve 16 has a tapered shape in which the diameter increases from the opening 18 toward the center, and the grout 14 is sufficiently spread inside the cylinder. Further, uneven portions 24 are formed near both ends of the inner peripheral surface of the cylinder, and together with the ribs 26 provided on the reinforcing bars 10 and 2, the fixing force between the sleeve 16 and the reinforcing bars 10 and 12 is strengthened. ing.

The length of the sleeve 16 is longer than the required fixing length L by a predetermined amount L1 in consideration of a construction error. Correspondingly, marking 28 such as coloring is applied to the inside of the cylinder of the sleeve 16 so that the portion of the required fixing length L can be confirmed.

(Pile head treatment method) As shown in Fig. 2, while excavating from the site board 30, a steel casing tube 32 is pushed into the ground to prevent the wall surface of the hole during excavation from collapsing. In, rebar
Ten is inserted and concrete is poured.

The reinforcing bar 10 is inserted as a reinforcing bar cage in which the axial reinforcing bars of the concrete pile 8 are arranged at a predetermined interval and are integrally formed. A sleeve 16 is attached to the upper end of the reinforcing bar 10 by filling it with a grout 14. A cap 36 is provided in the opening 34 above the sleeve 16 to prevent concrete from entering the inside of the cylinder of the sleeve 16 during concrete pouring.
Is covered.

Next, when concrete is poured up to the design height of 38,
The casing tube 32 is pulled out upward in the drawing (direction of arrow A), and the concrete pile driving work is completed.

At this time, the length of the reinforcing bar 10 is determined by the design length of the reinforcing bar required after the completion of the concrete pile 8 and the sleeve 16 and the reinforcing bar.
It has been shortened in consideration of the fixing length of 10.

Next, after the concrete is hardened, the ground is dug down to a planned ground height of 40 with an excavating machine such as a backhoe, but since the reinforcing bar 10 has not reached the planned ground height of 40, there is no fear of bending the reinforcing bar at the backhoe.

As shown in FIG. 3, the extra pile portion 44 of the concrete pile protruding from the planned pile height 42 is cut by the wire saw cutting machine 46 together with the sleeve 16 embedded in the concrete pile 8.

Since the cutting position is marked 28 inside the hollow of the sleeve 16, the fixing length of the reinforcing bar 12 with the sleeve 16 can be surely secured.

In addition, since the wire saw cutting machine 46 rotates the wire saw 48 attached with an artificial diamond at high speed to cut concrete, noise and vibration are less and the construction speed is faster compared to the case of scraping concrete with a breaker. , The construction period can be shortened.

Next, as shown in FIG. 4, since the extra portion 44 can be treated as a large lump, it is not necessary to treat the waste material.
The cut surface 50 of the sleeve 16 is filled with grout 14 for fixing the reinforcing bar 12 shown in FIG. For the grout 14, for example, a cement-based non-shrinkable high-strength mortar material is used.

Next, as shown in FIG. 5, the steel frame 54 for the pillar of the structure is built on the upper end surface of the concrete pile 8. At this time, since the reinforcing bar is not exposed from the upper end surface of the concrete pile 8, the work of building the steel frame 54 can be made efficient.

Finally, the rebar 12 is inserted into the opening 50 of the sleeve 16, and the steel frame 54 is wound around the rebar 12.

〔The invention's effect〕

As described above, in the pile head treatment method according to the present invention,
Since the pile head portion is cut by the wire saw cutting machine, even a general worker can remove the pile head portion flatly in a short time without noise and vibration. In addition, the reinforcing bars do not get in the way during excavation work, and since the reinforcing bars are not exposed from the top surface of the concrete pile after the pile head treatment, it is possible to easily assemble the pillars of the building on the pile head, thus improving work efficiency. improves.

[Brief description of the drawings]

FIG. 1 is a sectional view of a joint structure of a pile head portion of a cast-in-place pile to which the present invention is applied, and FIGS. 2 to 5 show a work procedure of a pile-head processing method for a cast-in-place pile according to the present invention. It is a schematic diagram. 10, 12 ... Reinforcing bar, 14 ... Fixing material (grout), 16 ... Joint means (sleeve), 46 ... Cutting means (wire saw cutting machine).

Claims (2)

(57) [Claims] 1. A cast-in-place pile for constructing a reinforced concrete pile into a hole excavated in the ground, for fixing a joint means of a reinforcing bar having a hollow portion to the upper end of the reinforcing bar inserted in the hole. 1 step, a second step of cutting the pile head portion of the reinforced concrete pile by a cutting means together with the joint means embedded in the reinforced concrete pile after the pile head portion of the constructed reinforced concrete pile is exposed, and the joint means The third step of injecting the fixing material from the cutting port of the above and inserting the fixing rod to fix the same, and a method of treating the head of the cast-in-place concrete pile. 2. The pile head treatment method for cast-in-place concrete piles according to claim 1, wherein a cutting position is displayed in the hollow portion of the joint means.