JPH11140887A - Method for anchoring foundation pile to foundation and pile anchor therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for anchoring a foundation pile to a foundation more excellent in earthquake resistance than A-type construction method, requiring less amount of excavation than B-type construction method, and to provide a pile anchor for use in the method. SOLUTION: A method for anchoring a foundation pile to a foundation includes digging an excavated recess part 4 around the outer periphery of the head 1a of a foundation pile 1, fitting a pile anchor 5 into the excavated recess part 4, closing the hollow part 2 of the pile head 1a with a closer 3, pouring concrete into a space part (a) that forms between the pile head 1a and the pile anchor 5 during placement of the foundation 10, hardening the concrete, forming an SC structural part 11 around the outer periphery of the pile head 1a using the concrete hardened, burying the top of the pile anchor 5 in the foundation 10, and using the top as part of the foundation 10 of an RC structure. The pile anchor 5 has a reinforcing ring 6 fitted into the excavated recess part 4, reinforcement 7 projecting from the reinforcing ring 6 and anchored within the foundation 10, and an interval holding part 8 holding the interval between the reinforcing ring 6 and the pile head 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for anchoring a pile head of a foundation pile and a pile anchoring body used in the method.

[0002]

2. Description of the Related Art As a construction method of a foundation portion of a structure, a structure supported by a foundation pile is generally employed. As a construction method fixed to the foundation of the foundation pile, the pile head is used as shown in FIG. 1a is exposed by about 10 cm from the base line L2, and the lower half of the braided reinforcing bar E composed of the vertical bar e1 and the band bar e2 is inserted into the hollow portion 2 of the pile head 1a, and this is filled with the concrete C2.
And fixed to the pile head 1a with the exposed portion of the pile head 1a and the reinforcing bar E
A method of fixing the upper half of the base 10 to the foundation 10 (hereinafter referred to as an A-type method) and a method of setting the foundation 10 so that the pile head 1a can be exposed from the base line L2 to an outer diameter of the foundation pile as shown in FIG. There is known a method of deepening the concrete thickness and fixing the pile head 1a to the foundation 10 (hereinafter, referred to as a B-type method).

[0003]

In recent years, the seismic resistance of the building has been particularly required, and the conventional A-type construction method has a problem that the pile head fixing degree is small and the seismic resistance is weak. In addition, the B-type method requires deep excavation of the root cutting surface and thickening of the foundation, which increases the amount of earth retaining work, increases the amount of remaining soil treatment and backfilling, and increases the amount of rainwater when rain continues. In addition to the water refilling work, the pile head projecting more than the bottom of the root cuts, and the workability of compacting the foundation, crushed concrete, formwork, reinforcing bars, etc. also deteriorates. In addition, there is a large problem that a large amount of time and labor is required, such as an increase in the amount of concrete used and the amount of reinforcing bars used for the foundation, and the construction cost is also increased.

As means for solving the problems of the conventional A-type method and B-type method, the applicant has previously filed Japanese Patent Application No. Hei 6-264480.
No. (JP-A-8-105066) was invented (hereinafter referred to as the prior invention). In the prior invention, as shown in FIG. 8, a root cutting recess 4 is dug down around the outer periphery of the pile head 1a of the foundation pile 1 penetrating into the ground B, and a soil fastener G is inserted into the root cutting recess 4, and the root cutting is performed. After retaining the concave portion 4, the lower half of the reinforcing bar E is inserted into the space A formed between the earth retaining member G and the pile head 1a, and concrete is poured into the space A when the foundation 10 is cast. Casting, forming the same RC structure as the foundation pile 1 around the pile head 1a. It is superior in seismic resistance to the A-type method and can reduce the amount of root excavation of the foundation compared to the B-type method. have.

[0005]

Therefore, the invention of claim 1 of the present invention has advanced the research of the invention of the prior application, and has a smaller amount of root cutting, superior seismic resistance, and simplified construction than the invention of the prior application. It is an object of the present invention to provide a foundation pile anchoring method capable of shortening a construction period and reducing construction costs. The second aspect of the present invention aims to provide a pile anchoring body used in the first aspect of the present invention.

[0006]

According to the present invention, in order to achieve the above-mentioned object, a method of fixing a foundation pile to a foundation pile, the present invention is characterized in that roots are formed only around the outer periphery of the pile head of the foundation pile penetrated into the ground. Dig down the cutting recess, insert the pile anchor into the root cutting recess,
Prevent concrete from falling into the hollow part of the pile head,
At the time of placing the foundation, concrete was poured into the space created between the pile head and the pile anchor, and an SC structure consisting of the pile anchor and concrete was formed around the outside of the pile head, The upper part of the pile anchor is buried in the foundation and forms an integral part with the foundation of the RC structure. The digging of the root-cutting recess here means that after the root-cutting ground operation up to the split-cut stone-paving line, the split-cut-stone-paving line around the outside of the pile head is dug deeper. Means all means for digging to the depth of insertion. Here, the foundation is a general term for the lower structure that transmits the load from the upper structure to the ground, and refers to an independent foundation, a cloth foundation, a composite foundation, a solid foundation, a foundation slab provided between the joints of the solid foundation, and the like. Here, the SC structure refers to a structure in which concrete is filled in a steel pipe, and the RC structure refers to a reinforced concrete structure. Here, the foundation pile is a pile that transmits the load of the structure from the foundation to the ground, but the shape, structure, material, etc. are free, but in consideration of seismic resistance etc., PHC pile (prestressed concrete pile) , PRC piles (prestressed reinforced concrete piles) are desirably used. Here, the PHC pile has high axial strength due to high-strength concrete. The bending strength under the action of the axial force is significantly larger than that of the PC pile according to the amount of prestress. Here, the PRC pile is a pile reinforced with high-strength prestressed concrete by deformed reinforcing bars or the like, and has high bending strength and excellent deformability due to the lateral constraint of the spiral.

In order to achieve the above-mentioned object of the present invention, a pile anchor used in the foundation anchoring method is provided.
Providing a reinforcing ring to be inserted between the root recess and the pile head, protruding reinforcing bars fixed in the foundation from the reinforcing ring, and protruding the spacing holding part from the inner circumference of the reinforcing ring toward the pile head In addition, the reinforcement ring also serves as the retaining of the root cutting recess and the concrete form poured into the foundation, and forms the SC structure around the outside of the pile head by solidifying the concrete. And become part of the foundation of the RC structure.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a method of anchoring a foundation pile according to the present invention will be described with reference to FIGS. A root cutting recess 4 is formed by digging around the outer periphery of the pile head 1a of the foundation pile 1 penetrating into the ground B, and a pile anchoring body 5 is inserted into the root cutting recess 4 to form a hollow portion of the pile head 1a. 2 is plugged with plug 3 and foundation 10
When concrete is poured, concrete is poured into a space a formed between the pile head 1a and the pile anchor 5 to solidify it. The SC structure 11 is also formed around the pile head 1a together with the solidified concrete together with the formwork for pouring, and the upper part of the pile anchor 5 is buried in the foundation 10,
Become part of the foundation 10 of the structure.

[0009] The root cutting recess 4 digs further deeply into the outer periphery of the pile head 1a after the ground work of the splitter stone line L1 and cuts the donut-like root around the outer periphery of the pile head 1a. The concave portion 4 or the inverted truncated cone-shaped root concave portion 4 having a wide mouth upward from the bottom surface is formed. After the pile anchoring body 5 is inserted, the split stone D is placed on the split stone floor L1. D. Concrete C1 is placed on D, and the pile anchoring body 5 is compacted, and a baseline L2 is formed with the discarded concrete C1. The root cutting width h of the root cutting recess 4 is such that the pile anchoring body 5 forms the space part a with the pile head 1a and the SC structure part 11 is formed by concrete poured into the space part a.
It is about 1/2 of the root cutting width H in the prior invention, for example, about the arrangement position of the vertical bar e1 of the braided reinforcing bar E.

The lower part of the pile anchor 5 is inserted into the root cutting recess 4, the inner periphery of the root cutting recess 4 is earthed, and the pile head 1a is fixed.
A space a is formed between the SC structure 11 and the formwork of the SC structure 11 when the foundation 10 is cast. The concrete poured into the space a is solidified to form the SC structure 11 together with the concrete.
Is formed and the upper half is buried in the foundation 10 to form a part of the foundation 10 of the RC structure. Closure body 3 for closing hollow part 2 of foundation pile 1
Can be installed in any order as long as the foundation 10 is not yet placed.

Next, the structure of the pile anchor of the present invention used in the foundation anchoring method of the foundation pile will be described with reference to FIGS. 3 and 4 of the embodiment. The pile anchoring body 5 includes a reinforcing ring 6 inserted between the pile head 1a and the root cutting recess 4, a reinforcing bar 7 projecting upward from the reinforcing ring 6 and fixed in the foundation 10, a reinforcing ring 6 and the pile head. And an interval holding section 8 for maintaining an interval between the sections 1a. The reinforcing ring 6 is formed by cutting a long steel pipe having a diameter slightly smaller than the inner circumference of the root cutting recess 4 or welding a steel plate into a cylindrical shape or a substantially cylindrical shape having a diameter slightly smaller than the inner circumference of the root cutting recess 4. , Root cutting recess 4
To form a space a between the pile head 1a and a mold for pouring concrete. The SC structure 11 is formed by solidifying the concrete. Reinforcing bars 7 have the lower half fixed to the inner peripheral surface of the reinforcing ring 6 at appropriate intervals, and the upper half protrudes above the reinforcing ring 6 to become a part of the foundation 10 of the RC structure. The space holding portions 8 are provided at appropriate intervals on the inner peripheral surface of the reinforcing ring 6, and need to be provided so as not to prevent the concrete from flowing into the space a.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS If the inner peripheral surface of the reinforcing ring 6 is roughened, the adhesion to concrete is improved, and the integration of the SC structure 11 is enhanced. It is also possible to use a round bar as the reinforcing bar 7, but it is preferable to use a different-diameter bar having good adhesion to concrete, and it is also possible to use an adhesive as a fixing means to the reinforcing ring 6. However, fixation by welding is preferred. As long as the space holding portion 8 protrudes from the reinforcing ring 6 toward the pile head 1a, the shape, structure, and the like are free, but the lower end of the reinforcing bar 7 is bent, and the bent portion is connected to the space holding portion 8 Or the space holding portion 8 is formed separately, and the reinforcing ring 6
Welding is also possible.

The closing member 3 has a disk shape substantially the same as the inner diameter of the hollow portion 2 and is closed by suspending it from above the pile head 1a with a hanging tool such as a wire, or the balloon-like closing member 3 is hollow. In order to close the hollow part 2 by inflating it in the space 2 or covering it like a lid on the pile head 1a as shown in FIG. Concrete C2 is filled. The closing body 3 does not need to completely cover the hollow portion 2, and may be of such a degree that concrete does not flow into the hollow portion 2.

[0014]

As described above, the method of anchoring a foundation pile according to the present invention is as described above. Since the digging of the root cutting recess is about 1/2 of the prior invention,
As a result, the amount of root cutting is small, and the remaining soil treatment and earth retaining work can be easily and easily performed. In addition, the pile anchoring body inserted into the root cutting recess secures the root cutting recess, forms a space between the pile head and the pile, serves as a formwork when setting the foundation, and the outer periphery of the pile head. In addition, since the SC structure is formed with the solidified concrete, it exhibits greater seismic resistance than the A-type construction method and the prior invention. In addition, by reducing the amount of root cutting and simplifying the earth retaining work, the anchoring work of the foundation becomes smooth, and the labor cost and the construction period can be greatly reduced.

Since the pile anchor of the present invention is as described above, the following effects can be obtained. If the pile anchoring body of the present invention is used for the foundation anchoring method, the reinforcing ring first secures the root cutting recess, forms a space between the pile head and the pile head, and forms a formwork when the foundation is cast. Next, along with the solidified concrete,
An SC structure is formed around the outside of the pile head to strengthen the anchorage between the foundation pile and the foundation. Reinforcing bars are embedded in the foundation and become part of the foundation of the RC structure. In addition, since pile anchors can be mass-produced in factories, there is an advantage that they can be provided at low cost.

[Brief description of the drawings]

1 (A), 1 (B) and 1 (C) are process diagrams showing a method for anchoring a foundation pile according to the present invention.

FIGS. 2A, 2B, and 2C are partially cutaway plan views.

FIG. 3 is a longitudinal sectional view showing a structural example of a pile anchor according to the present invention.

FIG. 4 is a vertical cross-sectional view of a pile fixing member showing an example of forming a spacing member.

5 (A) and 5 (B) are views showing a use state of a pile anchoring body.

FIG. 6 is a cross-sectional view showing a conventional A-type method.

FIG. 7 is a cross-sectional view showing a conventional B-type method.

8 (A) and 8 (B) are cross-sectional views showing the prior invention invention method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foundation pile, 1a pile head 2 Hollow part 3 Closure body 4 Root cutting recess 5 Pile anchoring body 6 Reinforcement ring 7 Reinforcing bar 8 Spacing part 10 Foundation, 11 SC structure part B Ground C1 Discarded concrete, C2 Filling concrete D Split stone E Braided bar, F base bar G Earth fastener A Space from pile head to earth fastener a Space from pile head to pile anchor H, h Root width L1 Split stone floor line, L2 Base line

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[Procedure amendment]

[Submission date] November 21, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

Claims (2)

[Claims] 1. A root cutting recess (4) is dug around the outer periphery of a pile head (1a) of a foundation pile (1) penetrated into the ground (B),
The pile anchoring body (5) is inserted into the root cutting recess (4), and concrete is prevented from dropping into the hollow part (2) of the pile head (1a). The concrete is poured into the space (a) created between the pile head (1a) and the pile anchor (5), and the outer periphery of the pile head (1a) is solidified by the pile anchor (5) and the solidified concrete. In the SC structure part (1
1) A method for anchoring a foundation pile, wherein an upper part of a pile anchor (5) is buried in a foundation (10) and becomes a part of a foundation (10) having an RC structure. 2. A reinforcing ring (6) inserted between the root cutting recess (4) and the pile head (1a), and protrudes upward from the reinforcing ring (6) and is fixed in the foundation (10). A pile anchor used in a foundation anchoring method for a foundation pile, comprising: a reinforcing bar (7); and an interval holding part (8) for maintaining an interval between the reinforcing ring (6) and the pile head (1a). .