JP2891167B2 - Pile head reinforcement structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile head reinforcing structure for reinforcing a pile head inserted under a footing.

[0002]

2. Description of the Related Art In the Hyogoken-Nanbu Earthquake, as well as damage to the superstructure, much damage occurred to the foundation structure. As the damage to the foundation structure, the damage that the pile head deviated from the footing was conspicuous.

[0003] In the conventional pile head joining method, as shown in FIG.
The pile head 1 a of the pile 1 is connected to the footing reinforcing bar 3 in the footing 2.
Often, only a little could be put into the muscleless zone at the bottom of the. In this joining method, although the pile head reinforcing bar 1b protrudes upward from the pile head 1a, when an excessive horizontal force acts on the pile 1, the concrete in the unreinforced zone is damaged,
The pile 1 and the footing 2 are displaced from each other, and the strength of the pile body is not exhibited.

Therefore, in order to prevent this, as shown in FIG. 5A, the pile head 1a is inserted deeply into the lower part of the footing 2, and the periphery of the pile head 1a is reinforced by the pile head reinforcing bar 4. Can be considered. However, the problem here is the method of arranging the pile head reinforcement 4. That is, as shown in FIG. 5B, the vertical streak 4a and the horizontal streak 4
b, arranging the diagonal streaks 4c requires cutting, arranging, and tying the reinforcing bars, and takes much time for on-site work.
There are problems such as individual differences in the arrangement of reinforcing bars, and the reinforcing effect may be different.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to save time and effort in the field work of reinforcing a pile head, and to provide a reliable reinforcing effect without any individual difference. An object of the present invention is to provide a pile head reinforcement structure capable of obtaining a stable structure.

[0006]

A first pile head reinforcing structure according to the present invention is a pile head reinforcing structure for reinforcing a pile head inserted into a lower portion of a footing, wherein a peripheral strut having a shape surrounding the pile head is provided. (Circular ring or square if necessary), stirrup that connects the surrounding muscles, and footing integral reinforcing bar that projects upwards And the pile head reinforcement unit is installed at the pile head.

A second pile head reinforcing structure according to the present invention is a pile head reinforcing structure for reinforcing a pile head inserted into a lower portion of a footing, wherein a footing integrated reinforcing bar is formed from a concrete body surrounding the pile head. A pile head reinforcement unit made of precast concrete protruding upward is manufactured in advance, and the pile head reinforcement unit made of precast concrete is installed at a pile head portion.

In the above construction, a prefabricated pile head reinforcing bar unit is installed around the pile head, and the footing reinforcing bar is assembled using the pile head reinforcing bar unit as a spacer, and the upper and lower portions of the footing are assembled. Pour concrete into the pile head, or place a precast concrete pile head reinforcement unit around the pile head, assemble the footing reinforcement on the precast concrete pile head reinforcement unit, and put concrete on top of the footing. Cast in. By prefabricating, the labor of cutting, processing, and assembling the conventional reinforcing bar can be omitted, and the reinforcing effect does not vary among individuals.

In addition, the prefabricated unit can be used as a spacer, and assembling of the footing reinforcing bar is facilitated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows an example in which a pile head reinforcing bar unit in which steel bars are assembled at a factory is used, and FIG. 2 is a modification of FIG. FIG. 3 shows an example in which a precast concrete pile head reinforcing unit is used.

FIG. 1 shows a footing 2 in a two-pile type.
Is the same rectangular shape from top to bottom. The pile head 1a is inserted deeply into the lower part of the footing 2 similarly to the conventional example of FIG. 5, and a pile head reinforcing bar disposed around the pile head 1a is vertically arranged around the pile head 1a. A plurality of ring streaks 11 arranged concentrically in a step, and a mouth streak 12 arranged in two upper and lower stages outside the ring streaks 11
And a stirrup 13 connecting the upper and lower ring streaks 11 and the mouth streaks 12, and a footing integrated bar 14 protruding into the upper portion of the footing 2, and assembling and manufacturing them at a factory to form a pile head reinforcing bar. Unit 10.

The ring streaks 11 and the mouth streaks 12 are formed in a circular or square shape by welding. A large number of stirrups 13 are radially arranged at intervals in the circumferential direction of the ring streaks 11 in plan view, and connect the plurality of ring streaks 11 or connect the ring streaks 11 and the mouth streaks 12. I do. The ring muscle 11 and the mouth muscle 12 and the stirrup 13 are fixed by welding or binding.

The footing integral reinforcing bar 14 has a vertically elongated U-shape, and the lower portion thereof has a ring bar 11 or a ring bar 1 having two upper and lower stages.
It is formed so as to protrude upward with a sufficient length so as to surround the one and the mouth streaks 12, and a plurality of the streaks are arranged at intervals in the circumferential direction of the ring streaks 11. Also in this case, the ring muscle 11 and the mouth muscle 12 and the footing integral muscle 14 are fixed by welding or binding. Note that a spacer 15 is provided below the pile head reinforcing bar unit 10 to form a gap with the installation surface. By assembling the spacer 15 in advance, the workability can be further improved.

FIG. 2 shows a footing 2 in a two-pile type.
This is a case where the footing upper portion 2a having a rectangular horizontal section and the pile head reinforcing portion 2b having a circular horizontal section are formed. In this case, it is needless to say that the stoma 12 can be omitted. Further, a spacer 16 is provided on the pile head reinforcing bar unit 10 in order to form a gap between the bottom surface of the footing upper portion 2a and the footing reinforcing bar 3. Also in this case, the spacer 16 may be assembled in advance.

The pile head reinforcing bar unit 1 having the above configuration
At 0, construction is performed in the following procedure. (1) After placing the pile, excavate around the pile head, lay crushed stone 17 on the bottom, and place the discarded concrete 18.

(2) The prefabricated pile head reinforcing bar unit 10 is disposed on the discarded concrete 18.

The footing reinforcing bar 3 is assembled by using the pile head reinforcing bar unit 10.

(3) Concrete C on footing 2
, The pile head reinforcement is completed.

Next, in FIG. 3, the pile head reinforcing unit 2b is composed of a precast concrete pile head reinforcing unit 20 having a circular horizontal cross section. Also in this case, the footing integral reinforcing bar 22 is made to protrude upward from the concrete frame 21 with a sufficient length. The internal reinforcement of the concrete body 21 is composed of a ring reinforcement and a stirrup, as in the embodiment of FIG. 2, but may have another configuration. Further, since a gap is formed between the concrete body 21 and the pile head 1a, a toro (softening mortar) 23 is filled therein. In addition, a spacer 24 is interposed between the concrete frame 21 and the footing reinforcement 3, and the footing reinforcement 3
Does not contact the upper surface of the concrete body 21.

In the precast concrete pile head reinforcing unit 20 having the above-described structure, the construction is performed in the following procedure. (1) After placing the pile, excavate around the pile head, lay crushed stone 17 on the bottom, and place the discarded concrete 18.

(2) The pile head reinforcement unit 20 made of precast concrete is disposed on the discarded concrete 18. The toro 23 is packed between the concrete body 21 and the pile head 1a.

(3) The footing reinforcement 3 is assembled on the concrete body 21. At this time, a gap is formed between the concrete frame 21 and the footing reinforcing bar 3 by providing a spacer 24 or the like.

(4) Pile head reinforcement is completed by placing concrete C on the footing 2a.

[0024]

According to the present invention, a pile head reinforcing bar for reinforcing the periphery of a pile head inserted into a lower portion of a footing is constituted by a factory-manufactured pile head reinforcing unit or a precast concrete pile head reinforcing unit. Since it is installed around the pile head, the work of cutting, processing, and assembling the rebar at the site can be omitted, and the construction period and cost can be reduced. Furthermore, there is no individual difference in the reinforcing effect, and a reliable and stable reinforcing effect can be obtained. Further, the unit can be used as a spacer for a footing reinforcing bar, and has an advantage that assembling of the footing reinforcing bar becomes easy.

[Brief description of the drawings]

FIG. 1 is an example of a pile head reinforcing structure for footing by a pile head reinforcing bar unit according to the present invention, wherein (a) is a cross-sectional view cut vertically, (b) is a cross-sectional view cut horizontally, and (c). FIG. 3 is a perspective view of a reinforcing bar of a pile head reinforcing bar unit.

FIG. 2 is an example in which the footing shape is different in the footing reinforcement structure of the footing of FIG. 1, (a) is a cross-sectional view cut vertically, (b) is a cross-sectional view cut vertically at another location,
(C) is a cross-sectional view cut horizontally.

FIG. 3 is an example of a pile head reinforcement structure for footing using a precast concrete pile head reinforcement unit according to the present invention, wherein (a) is a cross-sectional view cut vertically, and (b) is a vertical cut at another location. It is sectional drawing.

FIG. 4 is a vertical cross-sectional view showing a conventional general pile head joint structure.

FIG. 5 shows an example in which the pile head joint structure of FIG. 4 is improved (a).
Is a cross-sectional view cut vertically, and (b) is a cross-sectional view cut horizontally.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pile 1a ... Pile head 2 ... Footing 3 ... Footing reinforcing bar 4 ... Pile head reinforcing bar 10 ... Pile head reinforcing bar unit 11 ... Ring bar 12 ... Mouth bar 13 ... Stirrup 14 ... ... Footing integrated bar 15 ... Spacer 16 ... Spacer 17 ... Crushed stone 18 ... Discarded concrete 20 ... Precast concrete pile head reinforcement unit 21 ... Concrete frame 22 ... Footing integrated bar 23 ... Mortar) 24 spacer

Claims (2)

(57) [Claims] 1. A pile head reinforcement structure for reinforcing a pile head inserted into a lower portion of a footing, comprising: a peripheral muscle having a shape surrounding the pile head; a stirrup connecting the peripheral muscle; A pile head reinforcement structure characterized by forming a pile head reinforcement unit by previously assembling integrally with a footing integral reinforcement to form a pile head reinforcement unit, and installing the pile head reinforcement unit at a pile head part. 2. A pile head reinforcement structure for reinforcing a pile head inserted into a lower portion of a footing, wherein a precast concrete pile head having a footing integral bar projecting upward from a concrete frame surrounding the pile head. A pile head reinforcement structure in which a reinforcement unit is manufactured in advance and the precast concrete pile head reinforcement unit is installed at a pile head portion.