JP2005113453A - Structure and method for joining steel pipe pile and upper structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure and a method for joining a steel pipe pile and an upper structure, which enable cost reduction and the shortening of a construction period by simply and surely installing a transferred stress reducing device. <P>SOLUTION: In the structure for joining the steel pipe pile and the upper structure, the transferred stress reducing device 4 for reducing the transfer of stress is interposed between the steel pipe pile 1 and the upper structure 3 which is formed above the steel pipe pile 1; a filling concrete part 6 is formed in a pile head part 2 of the steel pipe pile 1; a first anchor material 7, which protrudes upward from inside the filling concrete part 6, is protrusively provided on an upper end surface of the filling concrete part 6; and the device 4 is fixed to the first anchor material 7, and fixed to the upper structure 3 by a second anchor material 15 which is fixed to the device 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a joining structure and a joining method between a steel pipe pile and an upper structure such as a footing supported by the steel pipe pile.

  Conventionally, on the basis of reliably transmitting the load of the upper structure to the foundation pile, for example, a joining structure of a steel pipe pile and the upper structure as shown in FIG. 2 has been adopted. A joining structure 100 shown in FIG. 2 is a structure in which a pile head 101a and an upper structure 102 of a pile 101 are tightly coupled by an intermediate reinforcing reinforcing bar 104 provided inside the pile body 103 in the pile head 101a. As a result, the joint structure 100 can be regarded as a rigid connection or a hinge connection depending on the amount of reinforcing bars.

Moreover, in recent years, the pile head and the foundation are not rigidly coupled, but are substantially in the form of pin coupling, and by allowing their relative rotation, bending stress generated in the pile head and foundation is reduced. A structure has been proposed. This structure consists of a structure in which a transmission stress reducing device for reducing the stress transmitted from the pile head to the upper structure is interposed between the pile head and the upper structure. According to this joint structure, it is possible to respond reasonably even during a large-scale earthquake, and the seismic performance of the building is improved. (For example, refer to Patent Document 1).
JP 2003-27499 A (page 3-4, FIG. 1)

  However, according to the former conventional joint structure described above, since the relative rotation of both the pile and the upper structure is restricted, a large bending stress is generated at the pile head joint during an earthquake or the like. Accordingly, the pile head and the upper structure (footing) are required to be robust because they require not only the shaft strength but also the bending strength, and there is a problem that the structure is naturally massive and complicated.

  Further, according to the latter conventional joint structure described above, in order to install the transmission stress reduction device on the pile head, the cone head is welded to the pile head, and the filled concrete is filled in the cone head. It is necessary to install a transmission stress reduction device on the stuffed concrete. For this reason, there exists a problem that material costs, such as a cone head, are required. Further, the cone head has a problem that it has not been confirmed that it has sufficient strength against the horizontal force at the time of an earthquake.

  In the present invention, the above-described conventional problems are taken into consideration, and the transmission stress reduction device improves the seismic performance of the joint structure between the steel pipe pile and the upper structure, and easily and reliably installs the transmission stress reduction device. Therefore, it aims at providing the joining structure and joining method of the steel pipe pile and upper structure which can aim at cost reduction and shortening of a construction period.

  According to the first aspect of the present invention, there is provided a steel pipe pile and an upper structure in which a transmission stress reducing device for reducing the transmission of stress is interposed between the steel pipe pile and the upper structure formed above the steel pipe pile. In this joint structure, a filled concrete portion is formed in the pile head of the steel pipe pile, and a first anchor material protruding upward from the filled concrete portion protrudes from the upper end surface of the filled concrete portion. The transmission stress reduction device is fixed to the first anchor material and is fixed to the upper structure by a second anchor material attached to the upper side of the transmission stress reduction device. It is said.

  With such a feature, the first anchor material for fixing the transmission stress reduction device to the pile head is protruded from the upper end surface of the filled concrete portion.

  The invention according to claim 2 is that, in the joint structure of the steel pipe pile and the upper structure according to claim 1, the non-slip steel material is welded to the inner peripheral surface of the pile head in a hoop shape or a spiral shape. It is a feature.

  Due to such a feature, the joining force between the filling concrete portion for fixing the first anchor material and the pile head portion is increased.

  The invention according to claim 3 is a joint between a steel pipe pile and an upper structure that joins the steel pipe pile and the upper structure formed above the steel pipe pile via a transmission stress reduction device that reduces the transmission of stress. In the method, pre- or after pile driving, the steel plate pile is welded to the inner peripheral surface of the pile head with a hoop or spiral shape, and after the steel pipe pile is placed, A first anchor member protruding upward from the pile head is disposed, an inside concrete portion is formed in the pile head, the transmission stress reduction device is fixed to the first anchor member, and the transmission The superstructure is formed on a stress reducing device.

  With such a feature, the non-slip steel material is attached to the inner peripheral surface of the pile head in advance or after pile driving, and the first anchor material is disposed after the steel pipe pile driving to place the filled concrete part. The first anchor material on which the transmission stress reduction device is installed is fixed in a state of protruding from the pile head.

  According to the joining structure and joining method of the steel pipe pile and the upper structure according to the present invention, the seismic performance can be improved by the transmission stress reducing device, and the lower end portion of the first anchor material is in the filled concrete portion. Since it is fixed, the first anchor material for fixing the transmission stress reduction device can be provided easily and reliably, and cost reduction and construction period reduction can be achieved.

  Moreover, since the non-slip steel material is welded to the inner peripheral surface of the pile head in a hoop shape or a spiral shape, the joining force between the filled concrete portion for fixing the first anchor material and the inner peripheral surface of the pile head Is increased, the slippage of the filled concrete portion is prevented, and the transmission stress reduction device can be reliably arranged at a predetermined position. Further, by welding the non-slip steel material to the inner peripheral surface of the pile head in advance, the work at the site is simplified and the construction period can be shortened.

  Hereinafter, embodiments of a joining structure and joining method of a steel pipe pile and an upper structure according to the present invention will be described with reference to the drawings.

  FIG. 1 is a sectional view of the structure of a pile head joint according to the present invention. In this figure, reference numeral 1 denotes a hollow steel pipe pile driven into the ground G. Between the pile head 2 of this steel pipe pile 1 and the footing 3 which is the base part of the upper structure supported by the steel pipe pile 1, they are substantially pin-coupled while allowing their relative rotation. A transmission stress reducing device 4 is interposed.

  The mounting structure of the transmission stress reducing device 4 will be described. A reinforcing bar 5 is spirally welded to the inner peripheral surface 2a of the pile head 2 of the steel pipe pile 1, and the reinforcing bar 5 is flared on both sides. And firmly joined to the inner peripheral surface 2a. The pile head 2 of the steel pipe pile 1 is filled with concrete, and an inside concrete part 6 supported by the reinforcing bar 5 is formed. A plurality of first anchor members 7 made of reinforcing bars having a male screw thread formed on the upper end portion project from the upper end surface of the filled concrete portion 6. The first anchor member 7 has a lower end fixed in the filled concrete portion 6 and an upper end protruded above the filled concrete portion 6. Above the filling concrete part 6, a transmission stress reduction device 4 is installed via a leveling mortar part 8 made of a non-shrink mortar for level adjustment.

  The transmission stress reducing device 4 includes a ball seat 9 having a sliding surface as a part of a spherical surface, an upper lid 10 that is mounted on the ball seat 9 and supported so as to be swingable in all directions, and a high-strength bolt that connects them. 11, a nut 12 and a spherical washer 13. Thus, since the ball seat 9 and the upper lid 10 can swing in all directions in the connected state, the axial force is transmitted between the pile head 2 and the footing 3 and their relative rotation is performed. Acceptable. A plurality of bolt holes 9b are formed in the outer peripheral flange portion 9a of the ball seat 9 at intervals in the circumferential direction, and the upper end portion of the first anchor member 7 is inserted into these bolt holes 9b. A ball seat fixing nut 14 is screwed onto the upper end of the first anchor member 7 above the bolt hole 9b.

  Further, a plurality of bolt holes 10b are formed in the outer peripheral flange portion 10a of the upper lid 10 at intervals in the circumferential direction, and the lower end portion of the second anchor material 15 is inserted into these bolt holes 10b to fix the upper lid. The nuts 16a and 16b are screwed to the outer peripheral flange portion 10a. The second anchor material 15 is fixed and fixed in the footing 3 to be formed thereafter.

  A protective cover 17 that protects the transmission stress reduction device 4 is provided around the transmission stress reduction device 4. The protection cover 17 is formed between the footing 3 and the leveling mortar portion 8 so as to surround the transmission stress reduction device 4. Is intervening. Moreover, the footing 3 is formed on the discarded concrete 18 formed on the ground G, and makes the transfer stress reducing device 4 easy to move between the discarded concrete 18 and the upper end portion of the steel pipe pile 1. A floor sand 19 is formed.

  Next, a method of joining the steel pipe pile 1 and the footing 3 using the above-described transmission stress reducing device 4 will be described.

  First, before placing the steel pipe pile 1, the reinforcing bar material 5 previously formed in a spiral shape on the inner peripheral surface 2a of the pile head 2 is welded and attached. The reinforcing bars 5 are firmly joined by flaring the both sides or the upper side.

  The ground G of the portion where the steel pipe pile 1 is placed is dug up, and the pile head from the upper end surface to about 100 mm is taken out from the ground G. Next, the soil or the like in the pile head 2 is dug to make the inside of the pile head 2 hollow, and the soil attached to the inner peripheral surface 2a and the reinforcing bar 5 is removed. And the 1st anchor material 7 is arrange | positioned in the predetermined position in the pile head 2, and it fixes temporarily so that it may not move. The first anchor member 7 is arranged so that the upper end portion protrudes upward from the upper end surface of the pile head 2.

  Next, concrete is poured into the pile head 2, and the filling concrete portion 6 is formed integrally with the reinforcing bar material 5 and the lower end portion of the first anchor material 7. Fresh concrete is poured from the upper end surface of the pile head 2 to about 50 mm, and the upper end surface of the filling concrete portion 6 is slightly lowered from the upper end surface of the pile head 2.

  Next, after the concrete is solidified, the transmission stress reducing device 4 is disposed above the pile head 2 (filled concrete portion 6). At this time, the upper end portions of the plurality of first anchor members 7 protruding from the upper end surface of the filled concrete portion 6 are respectively inserted into the plurality of bolt holes 9 b formed in the outer peripheral flange portion 9 a of the ball seat 9. Then, the ball seat fixing nut 14 is screwed to the upper end portion of the first anchor material 7 above the bolt hole 9b, and the ball seat fixing nut 14 is tightened to fix the transmission stress reducing device 4.

  Next, the lower end portions of the second anchor members 15 are respectively inserted into the plurality of bolt holes 10b formed in the outer peripheral flange portion 10a of the upper lid 10. The upper lid fixing nut 16a is screwed to the lower end portion of the second anchor member 15 below the bolt hole 10b, and the upper lid fixing nut 16b is screwed to the lower end portion of the second anchor member 15 above the bolt hole 10b. The transmission stress reducing device 4 is fixed by sandwiching the flange portion 10a between the upper lid fixing nuts 16a and 15b.

  Next, on the upper end surface of the filled concrete part 6, a frame (not shown) surrounding the gap between the ball seat 9 and the filled concrete part 6 is provided, and non-shrinking mortar is injected from an injection port provided in the frame, A leveling mortar 8 is formed. The error of the height level of the pile head 2 is adjusted by the thickness of the leveling mortar 8, and the transmission stress reduction device 4 can be fixed at a predetermined position by the first anchor material 7. Can be placed at a height.

  Next, the protective cover 17 is attached around the transmission stress reducing device 4, and the portion directly above the pile is backfilled with the spread sand 19, and then the discarded concrete 18 is formed. Then, after the discarded concrete 18 is solidified, a footing reinforcing bar (not shown) is arranged on the discarded concrete 18 and a mold (not shown) is built, and fresh concrete is placed in the mold to form the footing 3. . In the lower end portion of the footing 3, the upper end portion of the transmission stress reducing device 4 and the upper end portion of the second anchor material 15 are provided integrally with the footing 3.

  According to the joining structure of the steel pipe pile 1 and the footing 3 described above, since the transmission stress reducing device 4 is interposed between the steel pipe pile 1 and the footing 3, the transmission stress reducing device 4 improves the seismic performance. be able to. Further, the transmission stress reducing device 4 is fixed to a first anchor member 7 protruding from the upper end surface of the filled concrete portion 6, and the lower end portion of the first anchor member 7 is formed integrally with the pile head 2. Since the first anchor member 7 for fixing the transmission stress reducing device 4 is simply and reliably provided because it is fixed in the filled concrete portion 6, it is possible to reduce the cost and shorten the work period.

  Further, a reinforcing bar material 5 is spirally welded to the inner peripheral surface 2 a of the pile head 2, and the reinforcing bar material 5 is integrally provided in the inside concrete portion 6. The joining force between the filling concrete portion 6 that fixes the inside of the pile head 2 and the inner peripheral surface 2a of the pile head 2 is increased, the slippage of the filling concrete portion 6 is prevented, and the transmission stress reduction device 4 is securely placed at a predetermined position. Can be placed.

  Moreover, according to the joining method of the steel pipe pile 1 and the footing 3 described above, the reinforcing bar 5 is attached to the inner peripheral surface 2a in advance, and the first anchor material is disposed after the steel pipe pile is placed, and the filled concrete By forming the portion 6, the first anchor material 7 that fixes the transmission stress reduction device 4 is fixed in a state of protruding from the pile head 2. As a result, the work of installing the transmission stress reduction device 4 on site is reduced, and the construction period can be shortened.

  As mentioned above, although embodiment of the joining structure and joining method of the steel pipe pile concerning this invention and an upper structure was described, this invention is not limited to above-described embodiment, The range which does not deviate from the meaning It can be changed as appropriate. For example, in the above-described embodiment, the reinforcing bar 5 is preliminarily welded to the inner peripheral surface 2a before placing the steel pipe pile 1, but in the present invention, concrete is put into the pile head 2 after the pile placing. The reinforcing bar 5 may be welded before placing.

  Further, in the above-described embodiment, the reinforcing bar 5 is formed in a spiral shape, but the present invention is not limited to the spiral shape, and is substantially orthogonal to the load direction (vertical direction) acting on the pile head. The reinforcing bars 5 need only be arranged in the direction. For example, a plurality of reinforcing bars formed in a hoop shape may be arranged at intervals on the inner peripheral surface 2a and welded. Further, instead of the reinforcing bar material 5, a non-slip steel material made of flat steel or the like may be processed into an annular shape and welded to the inner peripheral surface 2a. In the above-described embodiment, the first anchor material 7 is set before the filling concrete portion 6 is placed. However, the present invention uses a chemical anchor or the like for post-working construction to form the first anchor material 7. 7 may be protruded from the upper end surface of the filled concrete portion 6.

It is sectional drawing for demonstrating embodiment of the joining structure of the steel pipe pile and upper structure concerning this invention, and the joining method. It is sectional drawing for demonstrating embodiment of the joining structure and joining method of the conventional steel pipe pile and an upper structure.

Explanation of symbols

1 Steel pipe pile 2 Pile head 2a Inner peripheral surface 3 Footing (superstructure)
4 Transfer stress reduction device 5 Rebar material (Steel prevention steel)
6 Filled concrete part 7 First anchor material 15 Second anchor material

Claims (3)

Between the steel pipe pile and the upper structure formed above the steel pipe pile, a transfer stress reduction device that reduces the transmission of stress is interposed between the steel pipe pile and the upper structure.
A filled concrete portion is formed in the pile head of the steel pipe pile, and a first anchor member protruding upward from the filled concrete portion is provided on the upper end surface of the filled concrete portion, and the transmission A steel pipe pile fixed to the first anchor member and fixed to the upper structure by a second anchor member attached to the upper side of the transmission stress reducing device; Bonding structure with the upper structure. In the joining structure of the steel pipe pile according to claim 1 and the upper structure,
A joining structure between a steel pipe pile and an upper structure, wherein a non-slip steel material is welded to the inner peripheral surface of the pile head in a hoop shape or a spiral shape. In the joining method of the steel pipe pile and the upper structure, which joins the steel pipe pile and the upper structure formed above the steel pipe pile via a transmission stress reduction device that reduces the transmission of stress,
Pre- or after pile driving, a steel plate is welded to the inner peripheral surface of the pile head of the steel pipe pile in a hoop shape or a spiral shape, and the pile head is inserted into the pile head after the steel pipe pile is placed. A first anchor material protruding upward from the inside is disposed, a filled concrete portion is formed in the pile head, the transmission stress reduction device is fixed to the first anchor material, and the transmission stress reduction device A method for joining a steel pipe pile and an upper structure, wherein the upper structure is formed on the upper structure.

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