JP2013112945A - Pin connection structure of foundation pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pin connection structure of a foundation pile which pin-connects a pile head of the foundation pile and a superstructure while enabling easy construction at lower cost.SOLUTION: The surface 1b of the pile head 1a of the foundation pile 1 is formed to have an inclined surface 1e inclining downward from the axis O1 center side to the side surface 1c of the foundation pile 1. The superstructure 2 connected to and constructed on the pile head 1a of the foundation pile 1 is provided with a pile head insertion recess 2a which is recessed from the undersurface to the upper side and in which the pile head 1a of the foundation pile 1 is inserted and arranged. An anchor bolt 3 is disposed on an axis O1 of the foundation pile 1 by connecting one end side and the other end side thereof to the foundation pile 1 and the superstructure 2 respectively in a state where the pile head 1a of the foundation pile 1 is inserted and arranged in the pile head insertion recess 2a of the superstructure 2. An elastically deformable filler 4 is injected into a clearance between the pile head insertion recess 2a and the pile head 1a of the foundation pile 1.

Description

  The present invention relates to a foundation pile pin coupling structure in which a pile head and an upper structure of a foundation pile are pin-coupled to transmit stress between the upper structure and the foundation pile.

  In general, when a building is constructed, a foundation pile such as a cast-in-place pile is made to reach the support ground, and the upper structure is constructed by supporting the foundation pile. In addition, conventionally, the pile head of the foundation pile is rigidly connected to the superstructure. In this case, the earthquake may occur and the pile head may be destroyed when subjected to horizontal force. It was necessary to take measures such as densely arranging the pile head reinforcing bars and ensuring a sufficient anchorage length in the footing.

  On the other hand, by installing a foundation pile pin coupling device (foundation pile pin coupling structure) between the upper structure and the pile head of the foundation pile, the upper structure and the pile head of the foundation pile are pin-coupled so that relative rotation is possible. It has been proposed and put to practical use to reduce the bending moment generated in the head and improve the seismic performance.

  This kind of foundation pile pin coupling device includes a pile head member installed at the pile head of the foundation pile, a structure support member fixed to the upper structure and disposed opposite to the pile head member, and these pile head members and There is what comprises a PC steel bar attached to a structure support member (for example, refer to patent documents 1). In this foundation pile pin coupling device, the pile head member is provided with a ball seat, the structure support member is provided with a curved concave surface, the ball seat and the concave surface are brought into contact, and the pile head member and the structure support member And are relatively slidable. Thereby, when an earthquake occurs, the pile head rotates relative to the upper structure, and the bending moment generated in the pile head can be reduced. That is, it becomes possible to improve the earthquake resistance.

JP 2002-70038 A

  However, in the above-mentioned conventional foundation pile pin coupling device, it is possible to provide excellent seismic performance, but the pile head member and the structure support member are made of ductile cast iron, etc., and have a ball seat or a concave surface. Since it is necessary to form it, it is very expensive, requires a lot of labor for construction, and has not yet spread widely. For this reason, there has been a strong demand for a method capable of pin-connecting the pile head of the foundation pile and the upper structure while enabling easy construction at a lower cost.

  In view of the above circumstances, an object of the present invention is to provide a foundation pile pin coupling structure for pin coupling a pile head and an upper structure of a foundation pile while enabling easy construction at a lower cost.

  In order to achieve the above object, the present invention provides the following means.

  The foundation pile pin coupling structure according to the present invention is formed with an inclined surface in which the surface of the pile head of the foundation pile is inclined downward as it goes from the axial center side to the side surface of the foundation pile, and is coupled to the pile head of the foundation pile. The upper structure constructed in this way is provided with a pile head insertion recess that is recessed upward from the lower surface and into which the pile head of the foundation pile is inserted, and the pile head of the foundation pile is inserted into the pile head of the upper structure. An anchor bolt is disposed on the axis of the foundation pile with one end connected to the foundation pile and the other end connected to the upper structure in a state of being inserted and disposed in the recess, and the pile head insertion recess and The gap between the pile heads of the foundation pile is filled with an elastically deformable filler.

  In the pile pile connection structure of the present invention, the pile head insertion formed in the upper structure is formed with an inclined surface that slopes downward as it goes from the axial center side to the side face of the foundation pile. Since the pile head is inserted and placed in the recess, and the space between the pile head insertion recess and the pile head (pile head) is filled with an elastically deformable filler such as urethane foam, when an earthquake occurs, The pile head can be displaced by rotating relative to the superstructure while deforming the filler. That is, with such a simple configuration, the foundation pile and the upper structure can be pin-coupled to improve the earthquake resistance, and the bending moment generated at the pile head during an earthquake can be reduced.

  Moreover, compared with the case where a pile head member and structure support members, such as those made from ductile cast iron provided with a ball seat or a concave surface, are used as in the prior art, a low-cost foundation pile pin coupling structure can be realized.

  In addition, when the pile head of the foundation pile and the upper structure are pin-coupled, it is possible to save the design compared to the case of rigid coupling.

It is a figure which shows the foundation pile pin coupling structure which concerns on one Embodiment of this invention. It is the figure which expanded the S section of FIG. It is the X1-X1 arrow view figure of FIG.

  Hereinafter, with reference to FIGS. 1 to 3, a foundation pile pin coupling structure according to an embodiment of the present invention will be described.

  First, as shown in FIG. 1, the foundation pile pin coupling structure A of the present embodiment is a pile head (pile head) 1 a of a foundation pile 1 such as a cast-in-place pile that reaches the support layer and is built in the ground G. And it is the structure for pin-joining the upper structure 2 supported and constructed | assembled by this foundation pile 1. As shown in FIG.

  In this foundation pile pin coupling structure A, as shown in FIGS. 1 to 3, an inclined surface in which the surface 1 b of the pile head 1 a of the foundation pile 1 is inclined downward as it goes from the center O1 center side of the foundation pile 1 to the side surface 1 c. 1d is formed in a substantially trapezoidal cross section (substantially arcuate cross section), and the upper structure 2 constructed by being coupled to the pile head 1a of the foundation pile 1 is recessed upward from the lower surface, and the foundation pile 1 The pile head insertion recess 2a in which the pile head 1a is inserted and arranged is provided. In addition, with the pile head 1a of the foundation pile 1 inserted and arranged in the pile head insertion recess 2a of the upper structure 2, one end side is connected to the foundation pile 1 and the other end side is connected to the upper structure 2 to anchor bolt 3 Is disposed on the axis O1 of the foundation pile 1 (an extension of the axis O1). Furthermore, the gap between the pile head insertion recess 2a and the pile head 1a of the foundation pile 1 is filled with an elastically deformable filler 4.

  And when constructing the foundation pile pin coupling structure A of this embodiment comprised in this way, first, a cast-in-place pile is cut of predetermined length and the surface 1b of the pile head 1a is shaped into a trapezoid. At this time, in this embodiment, the circular horizontal surface 1d is formed at the upper end of the axis O1 center of the foundation pile 1 of the pile head 1a, and the portion from the peripheral edge of the horizontal surface 1d to the side surface 1c of the foundation pile 1 is The inclined surface 1e which inclines below gradually is formed from the peripheral end of the horizontal surface 1d toward the side surface 1c of the foundation pile 1, and the surface 1b of the pile head 1a is shaped into a substantially trapezoidal cross section. Moreover, in this embodiment, the inclined surface 1e is formed in the cross-sectional convex arc shape.

  Next, an anchor bolt insertion hole 1f is drilled in the pile head 1a of the foundation pile 1 from the horizontal plane 1d at the center of the axis O1 and along the axis O1, and one end of the anchor bolt 3 is inserted into the anchor bolt insertion hole 1f. Then, grout and install the anchor bolt 3 on the pile head 1a.

  Next, the circumference of the pile head 1a of the foundation pile 1 is measured, the tubular steel pipe 5 is manufactured, and the height is adjusted with a spacer 8 or the like so as to surround the periphery of the pile head 1a. The steel pipe 5 is provided with an inlet 5a and an outlet 5b, and an inlet pipe 6 and an outlet pipe 7 connected to them.

  Then, a dam plate or the like for damming the filler 4 is installed on the steel pipe 5, and the filler 4 such as urethane foam (elastically deformable) is provided between the upper surface 1 b and the side surface 1 c of the pile 1 and between the pile 1 and the spacer. Placing and injecting filler). The thickness of the filler 4 is determined by considering the size of the gap δ obtained from the relative rotation amount of the foundation pile 1 obtained by design, the amount of settlement of the filler 4 when the upper structure is constructed, and the like. The distance between the inner surface (upper surface and side surface) of the head insertion recess 2a and the top end corner portion 1g of the foundation pile 1 is determined to be a gap δ.

  Next, grout is filled into the steel pipe 5 from the inlet 5a of the steel pipe 5. Grout filling management is performed by confirming the discharge of the grout from the discharge pipe 7.

  Finally, the superstructure 2 is constructed. In the upper structure 2, the upper end side (the other end side) of the anchor bolt 3 is embedded, the anchor bolt 3 is connected to the upper structure 2 and the foundation pile 1, and the pile of the upper structure 2 is placed on the horizontal plane 1 d of the pile head 1 a. The inner surface facing downward of the head insertion recess 2a comes into contact, and the load of the upper structure 2 is transmitted and supported by the foundation pile 1. This completes the construction of the foundation pile pin coupling structure A of the present embodiment.

  And in the foundation pile pin coupling structure A of this embodiment which consists of the said structure, when an earthquake generate | occur | produced, the top end angle of the pile head 1a of the pile head insertion recess 2a of the upper structure 2 and the pile head 1a of the foundation pile 1 The pile head 1a rotates relative to the upper structure 2 by an amount corresponding to the size of the gap δ between the portion 1g. Thereby, the stress which arises in the pile head 1a at the time of an earthquake is reduced, and the improvement of seismic performance is aimed at. In the present embodiment, the size of the gap δ between the inner surface of the pile head insertion recess 2a of the superstructure 2 and the top end corner portion 1g of the pile head 1a of the foundation pile 1 is the level 2 earthquake motion. It is set based on the pile head rotation angle at which the pile head 1a of the foundation pile 1 rotates with respect to the superstructure 2 when it occurs.

  Therefore, in the foundation pile pin connection structure A of this embodiment, the surface 1b of the pile head 1a of the foundation pile 1 is provided with the inclined surface 1e which inclines below as it goes to the side surface 1c of the foundation pile 1 from the axis O1 center side. The pile head 1a is inserted and disposed in the pile head insertion recess 2a formed in the upper structure 2 and elastic deformation such as urethane foam is possible between the pile head insertion recess 2a and the pile head (pile head) 1a. Since it is filled with the filler 4, when an earthquake occurs, the pile head 1 a can be displaced by being relatively rotated with respect to the upper structure 2 while deforming the filler 4. That is, with such a simple configuration, the foundation pile 1 and the upper structure 2 can be pin-coupled to improve the earthquake resistance, and the bending moment generated in the pile head 1a during an earthquake can be reduced.

  In addition, as compared with the case of using a pile head member such as a ductile cast iron having a ball seat or a concave surface and a structure support member as in the past, a low cost foundation pile pin coupling structure A is constructed (realized). Can do.

  Furthermore, since the pile head 1a of the foundation pile 1 and the upper structure 2 are pin-coupled, it is possible to save the design compared to the case of rigid coupling.

  As mentioned above, although one Embodiment of the foundation pile pin coupling structure concerning this invention was described, this invention is not limited to said one Embodiment, In the range which does not deviate from the meaning, it can change suitably. For example, in the present embodiment, the upper structure 2 is finally constructed. However, after the clearance between the inclined surface 1e and the side surface 1c of the pile head 1a and the upper structure 2 is secured by some method, the upper structure 2 is first formed. And the filler 4 may be injected from a previously installed inlet.

DESCRIPTION OF SYMBOLS 1 Foundation pile 1a Pile head 1b Surface 1c Side surface 1d Horizontal surface 1e Inclined surface 1f Anchor bolt insertion hole 1g Top end corner 2 Superstructure 2a Pile head insertion recess 3 Anchor bolt 4 Filler 5 Steel pipe pipe 6 Injection pipe 7 Discharge pipe 8 Spacer A Foundation pile pin connection structure G Ground O1 Axis

Claims (1)

The surface of the pile head of the foundation pile is formed with an inclined surface that is inclined downward as it goes from the axial center side of the foundation pile to the side surface,
In the upper structure constructed by being coupled to the pile head of the foundation pile, a pile head insertion recess in which the pile head of the foundation pile is inserted and arranged is recessed upward from the lower surface,
With the pile head of the foundation pile inserted and placed in the pile head insertion recess of the upper structure, one end side is connected to the foundation pile and the other end side is connected to the upper structure, and anchor bolts are connected to the foundation pile. Arranged on the axis,
A foundation pile pin coupling structure, characterized in that an elastically deformable filler is filled in the gap between the pile head insertion recess and the pile head of the foundation pile.

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