JP3825795B2 - Pile head joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joint structure between a pile head such as a concrete pile and a structure side.
[0002]
[Prior art]
In the conventional pile head joint structure, the joint form between the pile head and the structure side is generally regarded as a rigid joint. However, when a large earthquake is encountered, there is a technical problem that stress concentrates on the pile head joint and bending moment becomes excessive, and there is a risk of destruction from the pile head joint. Therefore, in order to protect the head joint of the pile from damage due to earthquake, a sliding material is interposed at the joint between the pile head and the structure side, or the structure side is supported by the pile head so that it can rotate. As a result, a pile head joining technique based on a soft joint that relaxes the seismic action and protects it from destruction has been disclosed (Japanese Patent Laid-Open Nos. 10-227039 and 8-120687). By the way, in these conventional technologies, since the technical form of placing the structure side with respect to the pile head was adopted, there is a problem in strength that the seismic strength against upward seismic force, that is, pitching is weak. There was a construction problem that it took time to construct the pile head joint.
[0003]
[Problems to be solved by the invention]
The present invention was developed in view of the above-described conventional technical situation, and can further reduce the seismic action, improve the seismic strength against pitching, and workability related to the joining work with the structure side. An object of the present invention is to provide a head joint structure of a pile that can improve the strength.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention of claim 1, a deformable member capable of absorbing seismic energy made of rubber or the like is installed around the upper end surface of the pile and the side surface near the upper end, and the upper surface of the deformable member and The side surface is covered with a cap-shaped rigid member made of a steel plate or the like, and a plurality of bolts that are loosely inserted with a gap into a plurality of insertion holes formed in the rigid member are provided on the upper end surface of the pile through the deformation member. By screwing to the pile end plate and installing a reinforcing bar on the upper surface of the rigid member, the deformation of the deformable member absorbs seismic energy and mitigates the seismic action on the joint between the pile and the structure side adopted the technology means that. In addition, the front and back of installation of the said deformation member and a rigid member, and the screwing of the volt | bolt with respect to a pile head end plate are not ask | required. According to the present invention, the seismic energy can be absorbed not only in the flat plate portion of the deformable member in contact with the upper end surface of the pile but also in the cylindrical portion in contact with the side surface in the vicinity of the upper end of the pile. It becomes possible to improve the earthquake resistance. In addition, since the plurality of bolts are configured to be screwed to the pile head end plate provided on the upper end face of the pile through the rigid member and the deformable member, the rigid member and the deformable member are detached from the pile head. Since this is surely prevented, the seismic strength against pitching can be improved. In the invention of claim 2, the technical means is adopted in which the deformable member is integrally formed in a cap shape and the upper end surface of the pile and the periphery of the side surface near the upper end are covered. According to the present invention, the cap-shaped deformable member is crowned on the pile head, and the cap-shaped rigid member is crowned on the deformable member. It is possible to perform a simple work procedure of crowning the pile head in a state where the rigid members are crowned and superposed sequentially or in advance, and accurate positioning on the structure side is realized, which greatly improves workability. Can be improved.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is applicable as various pile head joint structures. The cross-sectional shape and material of the pile are not questioned. The deformable member can be made of a suitable deformable material such as rubber, which is suitable for mitigating seismic action by absorbing seismic energy by deformation. The flat plate part covering the upper part of the upper end surface of the pile constituting the deformable member and the cylindrical part covering the periphery of the side surface near the upper end of the pile may be made of the same material or different materials. Also good. For example, since the weight of the structure does not always act directly on the cylindrical portion, it may be made of a material softer than the flat plate portion. Furthermore, the flat plate portion and the cylindrical portion constituting the deformable members may be formed separately or may be integrally formed in a cap shape. On the other hand, the said rigid member is formed in cap shape from the steel plate etc. which have the rigidity which does not have trouble in supporting the structure with respect to a pile, and is made to crown on the upper surface and side surface of a deformation | transformation member. The plurality of bolts that pass through the rigid member and the deformable member and are screwed to the pile head end plate provided on the upper end surface of the pile may be headed bolts as in the following embodiments, or both screw bolts may be used. It is also possible to use a form in which the portion corresponding to the head is screwed later. By the way, in the case of the construction form in which both screw bolts are first screwed to the pile head end plate, deformation members and rigid members can be installed using the both assembled screw bolts as a guide, which is effective for improving workability. is there.
[0006]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded construction diagram showing a construction procedure in one embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a completed state of construction, and FIG. 3 is a longitudinal sectional view showing a state subjected to an earthquake action. FIG. In the figure, reference numeral 1 denotes a pile, and a pile head end plate 3 in which a plurality of female screws 2 are formed is installed in the peripheral portion of the upper end surface of the pile 1. As shown in the figure, the deformable member 4 according to this embodiment integrally forms a flat plate portion 4a covering the upper portion of the upper end surface of the pile 1 and a cylindrical portion 4b covering the periphery of the side surface near the upper end of the pile. And formed into a cap shape. Insertion holes 6 for a plurality of headed bolts 5 are formed in the flat plate portion 4a, and a flange portion 7 is provided at the lower end portion of the cylindrical portion 4b. Further, the rigid member 8 is formed in a cap shape composed of a flat plate portion 8a and a cylindrical portion 8b so that the deformable member 4 can be crowned, and through holes 9 for a plurality of headed bolts 5 are formed in the flat plate portion 8a. did. The insertion hole 9 formed in the flat plate portion 8a needs to be formed so that it can be loosely inserted with a gap as a loose hole so that it can be relatively moved between the bolt 5 and the rigid member 8 during an earthquake. In the case of the insertion hole 6 formed in the flat plate portion 4a of the deformable member 4, it is not necessary to use a loose hole. Further, a plurality of reinforcing bars 10 for joining to the structure are installed on the upper surface of the flat plate portion 8a of the rigid member 8 by welding.
[0007]
Therefore, as shown in FIG. 1, when a structure is joined to the pile 1 installed at a predetermined position of the ground 11, the pile head protruding upward from the concrete 12 surface placed on the ground 11. The following preparatory work for joining is performed on the portion 13. That is, in this embodiment, first, the cap-shaped deformable member 4 is crowned on the pile head 13, and further, the cap-shaped rigid member 8 is crowned outside the deformable member 4. In this case, it is also possible to crown the pile head 13 after the rigid member 8 is crowned on the deformable member 4 in advance. Thereafter, the plurality of head bolts 5 are inserted into the insertion holes 9 formed in the flat plate portion 8 a of the rigid member 8 and the insertion holes 6 formed in the flat plate portion 4 a of the deformable member 4, and the female screw 2 formed on the pile head end plate 3. Threaded onto. At this time, in this embodiment, a washer 14 with an elastic material is interposed between the headed bolt 5 and the rigid member 8, and the action on the headed bolt 5 due to the rotational moment acting on the pile head joint during an earthquake. It was configured to be able to relax. Further, a protective cap 15 made of a deformable member such as an elastic material is attached above the head of the headed bolt 5 in order to relieve the compressive force from the structure. Further, a deformable member such as an elastic material may be filled or inserted into a gap formed between the insertion hole 9 formed in the flat plate portion 8 a of the rigid member 8 and the headed bolt 5.
[0008]
When the mounting of the deformable member 4 and the rigid member 8 to the pile head 13 is completed by the above work, as shown in FIG. The work on the structure side of the pile head 13 is finished. Thus, since the concrete 16 on the structure side is joined to the pile 1 with the deformable member 4 interposed as described above, when subjected to an earthquake action, as shown in FIG. Since the deformable member 4 is deformed to absorb the seismic energy, the influence on the structure is mitigated. In that case, not only energy absorption due to deformation of the flat plate portion 4a of the deformable member 4 but also energy absorption due to deformation of the cylindrical portion 4b are added, so that the effect of mitigating seismic action on the structure can be increased. Furthermore, the deformation of the washer 14 with the elastic material and the deformation of the member filled or inserted into the gap between the insertion hole 9 and the headed bolt 5 at the time of an earthquake are also effective in reducing the seismic action on the structure. As described above, the addition of energy absorption due to the deformation of the cylindrical portion 4b of the deformable member 4 reinforces the seismic strength particularly against roll. In addition, the installation of the headed bolt 5 reliably prevents the rigid member 4 and the deformable member 8 from coming off the pile head 13 and improves the seismic strength against pitching. Further, when the deformable member 4 is integrally formed in a cap shape as in this embodiment, the deformable member 4 and the rigid member 8 are covered with the pile head 13 and the headed bolt 5 is inserted. By simply inserting the holes 6 and 9 and screwing into the female screw 2 formed on the pile head end plate 3, preparation work for joining the pile 1 and the structure side is completed, so the workability is greatly improved. Is done. In addition, regarding the installation of the reinforcing bar 10 on the rigid member 8, it is possible to employ an appropriate fixing means such as screw connection instead of the above-described welding.
[0009]
【The invention's effect】
According to the present invention, the following effects can be obtained.
(1) In invention of Claim 1, the deformation | transformation member which can absorb the seismic energy which consists of rubber | gum etc. is installed around the upper part of the upper end surface of a pile, and the side surface of the upper end vicinity, The upper surface and side surface of the deformation member are steel plates etc. Since the technical means of covering with a cap-shaped rigid member made of is used, not only the flat plate portion of the deformable member in contact with the upper end surface of the pile but also the cylindrical portion in contact with the side surface near the upper end of the pile Since it can absorb, more seismic energy can be absorbed, and in particular, the seismic resistance against rolling can be improved.
(2) In addition, since the plurality of headed bolts are configured to be screwed to the pile head end plate provided on the upper end surface of the pile through the rigid member and the deformable member, the rigid member and the deformable member are connected to the pile. Since it is reliably prevented from coming off the head, the seismic strength against pitching can be improved.
(3) In the invention of claim 2, since the deformation member is integrally formed in a cap shape and the technical means of covering the upper part of the upper end surface of the pile and the periphery of the side surface near the upper end is adopted, Since the cap-shaped rigid member is crowned on the deformable member and the cap-shaped deformable member is crowned on the pile head, in the construction, the deformable member and the rigid member are sequentially or in advance. A simple work procedure of crowning the pile head in a state of being crowned and superposed is possible, and since accurate positioning on the structure side is realized, workability can be greatly improved.
[Brief description of the drawings]
FIG. 1 is an exploded view showing a construction procedure in one embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a completed state of construction.
FIG. 3 is a longitudinal sectional view showing a state in which an earthquake action is received.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pile, 2 ... Female screw, 3 ... Pile head end plate, 4 ... Deformation member, 4a ... Flat plate part, 4b ... Cylindrical part, 5 ... Headed bolt, 6 ... Insertion hole, 7 ... Collar part, 8 ... Rigidity Member: 8a ... Flat plate part, 8b ... Cylindrical part, 9 ... Insertion hole, 10 ... Reinforcing bar, 11 ... Ground, 12 ... Concrete, 13 ... Pile head, 14 ... Washer with elastic material, 15 ... Protective cap, 16 ... foundation concrete

Claims (2)

A deformable member made of rubber or the like that can absorb seismic energy is installed around the upper end of the pile and the side surface near the upper end, and the upper and side surfaces of the deformable member are covered with a cap-shaped rigid member made of steel plate or the like. And screwing a plurality of bolts loosely inserted through the plurality of insertion holes formed in the rigid member to a pile head end plate provided on an upper end surface of the pile through the deformation member, and the rigid member The head of the pile that joins the pile and the structure side, which is configured to absorb the seismic energy by the deformation of the deformable member by relaxing the seismic action by installing a reinforcing bar on the upper surface of the pile Joining structure.   The head of a pile according to claim 1, wherein the deformable member is integrally formed in a cap shape so as to cover the upper part of the upper end surface of the pile and the periphery of the side surface near the upper end. Junction structure.

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