JP2004257120A - Connection structure used for foundation of building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively and sufficiently decrease a response of the building at the time of an earthquake by an easily installed, compact connection structure when the building restores its original posture after a superstructure part of the foundation of the building from a substructure part of the foundation of the building is made to float by an action of an overturning moment due to an earthquake. <P>SOLUTION: The connection structure connecting a pile head of a pile 12 in a pile foundation to a footing 14 is equipped with an outside steel pipe 22 extended in the vertical direction fixed to the pile 12 and an inside steel pipe 24 extending the inside of the outside steel pipe 22 fixed to the footing 14 in the vertical direction, and a gap between the inside of the outside steel pipe 22 and the outside of the inside steel pipe 24 is filled with a damper body 28. An upward projected section of the outside steel pipe 22 is stored in an outside steel pipe storing recess section formed in the footing 14. The footing 14 is made to float from the pipe head of the pile 12 by the overturning moment due to the earthquake, and when it restores its original posture, shear deformations of damper bodies 26 demonstrate a damping function, and the response of the building is thereby decreased in the case of earthquake. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a connection structure used for a foundation of a building.
[0002]
[Prior art]
When a horizontal acceleration is applied to the foundation of a building during an earthquake, a overturning moment acts on the building, and one side of the building attempts to float. This tendency appears more strongly as the aspect ratio (ratio of height to width) of the building increases. For example, in a building using a pile foundation, a tensile load acts on the pile on the rising side of the building, and a compressive load on the pile increases on the opposite side. In order for the members connecting the pile head and the building body to withstand these loads, it is necessary to increase the cross-sectional area of the members, which results in increased material and construction costs. I was
[0003]
Therefore, the pile head is separated from the upper structure such as the footing supported by the pile head so that the upper structure can be lifted off the pile head when a large overturning moment acts due to an earthquake. A basic structure has been proposed. As a structure for cutting off a pile head and an upper structure portion, for example, there are structures disclosed in Patent Documents 1 and 2 and the like.
[0004]
[Patent Document 1]
JP-A-10-331173 [Patent Document 2]
JP 2000-240315 A
According to the structures disclosed in these patent documents, the raised upper structure portion collides with the pile head when repositioning, so that a cushioning material is provided to reduce the impact force. However, the cushioning material used in those structures does not provide sufficient cushioning performance, and when the superstructure part actually rises and relocates, an excessive impact force acts on the foundation of the building. was there.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a foundation for a building having a lower structure fixed to the ground and an upper structure supported on the lower structure. In the connection structure used, the upper structure part rises from the lower structure part under the action of the overturning moment due to the earthquake and provides sufficient cushioning performance to effectively reduce the seismic response of the building when repositioning, In addition, the object is to make it possible by a connection structure having a compact structure that is easy to construct.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a connection structure used for a foundation of a building according to the present invention is a foundation for a building having a lower structure portion fixed to the ground and an upper structure portion supported on the lower structure portion. A connection structure for connecting the lower structure portion and the upper structure portion, wherein the outer structure is fixed to a first structure portion that is one of the lower structure portion and the upper structure portion and extends vertically. A steel pipe, an inner steel pipe fixed to a second structural part, which is the other of the lower structural part and the upper structural part, and extending vertically inside the outer steel pipe; an inner surface of the outer steel pipe; A damper body which is filled between the outer surface and the outer surface and performs a damping function by shearing deformation, wherein the outer steel pipe is housed in a vertically extending outer steel pipe housing recess formed in the second structural portion. Have been Relative to the second structural portion, it is not substantially displaced in a horizontal direction, and is displaceable in a vertical direction, whereby the upper structural portion is moved relative to the lower structural portion. Is relatively not substantially displaced in the horizontal direction, but is displaceable in the vertical direction.If an overturning moment of a predetermined magnitude or more due to an earthquake acts on the building, the upper structural part is By rising from the lower structure portion, the building can be lifted from the ground, and when the upper structure portion rises from the lower structure portion and is relocated, the damper body is sheared and deformed, thereby causing the building to undergo an earthquake. It is characterized in that response is reduced.
[0008]
According to the connection structure used for the foundation of the building according to the present invention, the damper body filled between the outer steel pipe and the inner steel pipe is deformed by shearing when the upper structure part of the foundation of the building rises and repositions. The earthquake response of the building is reduced. In other words, the amount of lifting is suppressed to a small value, and the seating speed at the time of returning is also reduced. Since the damping effect is obtained by the shearing deformation of the damper body, the damping effect is obtained in the process of lifting and the process of returning, providing sufficient damping performance to effectively reduce the earthquake response of the building can do. The connection structure according to the present invention is a double steel pipe structure having a compact configuration in which an inner steel pipe is disposed inside an outer steel pipe. It is also possible to adopt a construction method in which an outer steel pipe, an inner steel pipe, and a unitized damper body are configured in advance, the unit is arranged at a predetermined position, and a pile or footing is driven. Therefore, construction is easy.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIGS. 1A and 1B are partial cross-sectional elevation views showing a connection structure used for a foundation of a building according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line 2-2 in FIG. FIG. 3 is a sectional plan view similar to FIG. 2 showing a first modification of the embodiment of FIG. 1, and FIG. 4 is a diagram showing a second modification of the embodiment of FIG. 1, FIG. 5 is a partial sectional view similar to FIG. 1 showing a third modification of the embodiment of FIG. 1, and FIG. 6 is a fourth sectional view of the embodiment of FIG. FIG. 7 is a partial sectional view similar to FIG. 1 showing a modification, and FIG. 7 is a partial sectional view similar to FIG. 1 showing a connection structure used for a foundation of a building according to a second embodiment of the present invention. .
[0010]
FIGS. 1A and 1B are elevational sectional views showing a connection structure used for a foundation of a building according to a first embodiment of the present invention. The foundation of the illustrated building is a pile foundation using a reinforced concrete pile 12, a reinforced concrete footing (foundation beam) 14 is supported on the pile head of the pile 12, and a reinforced concrete pile is also provided on the upper surface of the footing 14. Are connected to each other.
The pile head of the pile 12 and the footing 14 are not rigidly connected, but are connected via the connection structure according to the present invention. According to this connection structure, when the overturning moment due to the earthquake acts on the building, if the overturning moment is equal to or larger than a certain magnitude, the pile 12 is mounted on one side of the building according to the direction of the overturning moment. The footing 14 can be lifted from the pile head. FIG. 1A shows a state in which the footing 14 has not risen from the pile head of the pile 12, and FIG. 1B shows a state in which the footing 14 has risen.
Therefore, in the foundation of the building shown in FIG. 1, the pile head of the pile 12 is a substructure part fixed to the ground in the foundation of the building, and the footing 14 is formed by the footing 14 of the building. It is an upper structure part of the foundation supported on the lower structure part.
[0011]
The connecting structure shown in FIG. 1 is fixed to a pile 12 as a lower structural part and extends vertically, and an outer steel pipe 22 fixed to a footing 14 as an upper structural part and extends inside the outer steel pipe 22 in a vertical direction. And an inner steel pipe 24.
Each of the outer steel pipe 22 and the inner steel pipe 24 has a plurality of stud bolts 26 implanted on its outer surface. The outer steel pipe 22 and the inner steel pipe 24 are fixed to the pile 12 or the footing 14 by fixing the stud bolts 26 in the concrete of the pile 12 or the footing 14. However, the method of fixing the outer steel pipe 22 and the inner steel pipe 24 is not limited to this, and the steel pipes 22 and 24 may be fixed using a method such as welding to a reinforcing bar (not shown) of the pile 12 or the footing 14. Good.
[0012]
As shown in FIG. 2, the outer steel pipe 22 and the inner steel pipe 24 are both circular steel pipes, and are arranged concentrically with each other to form a double steel pipe structure. A damper 28 is filled between the inner surface of the outer steel tube 22 and the outer surface of the inner steel tube 24. The damper body 28 exerts a damping function by generating heat due to internal friction when deformed, and a viscoelastic material or an elastic material having a large internal friction is used as the damper body 28. .
[0013]
The upper portion of the outer steel pipe 22 extends upward from the upper surface of the pile head of the pile 12, and the upper extension of the outer steel pipe 22 is formed in the footing 14 so as to accommodate a vertically extending outer steel pipe receiving recess. Is housed in The inner surface of the outer steel pipe housing concave portion of the footing 14 is defined by the inner peripheral surface of the elastic sleeve 32.
The elastic sleeve 32 is a thick-walled sleeve made of a rubber material, and is fitted so as to be in close contact with the outer periphery of the outer steel pipe 22. However, a lubricant is applied to the outer peripheral surface of the outer steel pipe 22 and the inner peripheral surface of the elastic sleeve 32 that are in close contact with each other, so that the elastic sleeve 32 can slide with respect to the outer steel pipe 22. It has become. The outer peripheral surface of the elastic sleeve 32 is a ground plane, so that the elastic sleeve 32 is firmly adhered to the concrete of the footing 14.
[0014]
The outer steel pipe housing concave portion of the footing 14 is formed when the concrete of the footing 14 is cast. That is, the driving of the pile 12 in which the outer steel pipe 22 is fixed to the pile head is completed, the inner steel pipe 24 and the damper body 28 are located at predetermined positions, and the elastic sleeve 32 is fitted around the outer steel pipe 22. When the concrete of the footing 14 is cast in a state where the reinforcing bar and the formwork for forming the footing 14 are assembled, the outer steel pipe housing portion is formed in the footing 14.
A bottom plate 34 made of a steel plate is attached to a lower end of the inner steel pipe 24. The function of the bottom plate 34 is that the outer steel pipe 22, the inner steel pipe 24, and the damper body 28 are previously configured as a unit, and the unit is disposed at a predetermined position with respect to the reinforcing bar of the pile 12, When the construction method of casting concrete is adopted, the concrete is prevented from entering the inside of the internal steel pipe 24. The bottom plate 34 also serves as a breakage protection material that prevents the concrete in the inner steel pipe 24 from being crushed by the impact force acting when the footing 14 once rises and then sits (rearranges) on the pile head of the pile 12. It also fulfills the function of
[0015]
The outer steel pipe housing recess of the footing 14 formed as described above extends in the vertical direction, and the outer steel pipe 22 has an elastic body whose outer peripheral surface defines the inner surface of the outer steel pipe housing recess. Since the footing 14 is housed in the outer steel pipe housing recess while being in close contact with the inner peripheral surface of the sleeve 32, as shown in FIG. The displacement of the outer steel pipe 22 relative to the recess is regulated. That is, the outer steel pipe 22 is not substantially displaced in the horizontal direction but is displaceable in the vertical direction relative to the footing 14, whereby the footing 14 is attached to the pile head of the pile 12. On the other hand, it is not substantially displaced in the horizontal direction but relatively displaceable in the vertical direction. Therefore, when a falling moment greater than a predetermined magnitude due to an earthquake acts on the building, the building can be lifted from the ground by lifting the footing 14 from the pile head of the pile 12.
When the footing 14 rises from the pile head of the pile 12 and repositions, the damper body 26 performs a shearing deformation as shown in FIG. 1B to exhibit a damping function. Is reduced. In other words, the amount of lifting is suppressed to a small value, and the seating speed at the time of returning is also reduced. In particular, in the present invention, the buffering action is obtained by the shear deformation of the damper body 26, so that the buffering action is obtained in the process of lifting and the process of returning, and the response of the building during an earthquake is effectively reduced. Can provide sufficient cushioning performance.
[0016]
Reference numerals 36 and 38 shown in FIG. 1 denote a steel plate damage protection material attached to the lower surface of the footing 14 and a steel plate damage protection material attached to the pile head upper surface of the pile 12. When the footing 14, which is the upper structure portion, once floats and then sits on the pile head of the pile 12, which is the lower structure portion (repositions), the breakage protection members 36, 38 collide with each other. This is used to prevent crushing of concrete and concrete of the pile head upper surface portion of the pile 12, and is used when the upper structure portion or the lower structure portion is made of reinforced concrete or steel frame concrete.
[0017]
The present invention can be implemented in various other forms other than the embodiment described above. With reference to FIGS. 3 to 6, several modified examples in which various modifications are made to the embodiment shown in FIGS. 1 and 2 will be described. In describing these modified examples, only the modified portions will be mainly described, and portions having the same configuration as the embodiment shown in FIGS. 1 and 2 will not be described in detail. In FIGS. 3 to 6, the same or corresponding components as those used in the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals.
[0018]
FIG. 3 is a cross-sectional plan view similar to FIG. 2. In the modified example shown in FIG. 3, both the outer steel pipe 22 and the inner steel pipe 24 are square steel pipes. In the modification of FIG. 3, a square steel pipe having a square cross section is used, but a steel pipe having a rectangular, hexagonal, or octagonal cross section may be used.
[0019]
In the modified example shown in FIG. 4, in addition to the connection structure shown in FIG. 1, breathing is accumulated on the lower side of the outer steel pipe 22 and the inner steel pipe 24 when the concrete of the pile 12 which is the lower structural part is poured. This is provided with a conical body 40 for preventing the occurrence of the above. The cone 40 is formed of a material having an appropriate strength. When the outer steel pipe 22, the inner steel pipe 24, and the damper body 28 are configured as a unit, the cone 40 is integrally mounted on the unit. It is convenient to keep it. When the lower structural part is made of reinforced concrete, steel frame concrete, or the like, it is preferable to use such a cone.
[0020]
The modified example shown in FIG. 5 is different from the embodiment shown in FIGS. 1 and 2 in that the cushioning mechanism for cushioning the impact force generated when the raised footing 14 is seated is used instead of the breakage protection members 36 and 38. Equipped. The cushioning mechanism includes a first cushioning material form 42 installed on the ground and a cushioning material 44 filled therein, a second cushioning material form 46 installed inside the footing 14 and a cushioning material filled therein. It comprises a material 48, a third cushioning material form 50 installed inside the pile 12, and a cushioning material 52 filled therein.
As the cushioning members 44, 48, and 52, a rubber body, sand, or the like is used. The cushioning material 44 buffers the impact force acting between the lower surface of the footing 14 and the upper surface of the pile head of the pile 12 and between the lower surface of the footing 14 and the ground surface. The cushioning member 48 cushions an impact force acting between the upper end of the outer steel pipe 22 fixed to the pile 12 and the footing 14. In addition, the cushioning member 52 buffers an impact force acting between the lower end of the inner steel pipe 24 fixed to the footing 14 and the pile 12.
[0021]
The modification shown in FIG. 6 is different from the embodiment shown in FIGS. 1 and 2 in that the connection structure including the outer steel pipe 22, the inner steel pipe 24, and the damper body 28 is turned upside down. The steel pipe 24 is fixed to the footing 14 which is the upper structure part, the inner steel pipe 24 is fixed to the pile 12 which is the lower structure part, and the outer steel pipe housing recess is formed at the pile head of the pile 12.
The modification of FIG. 6 does not differ from the embodiment of FIGS. 1 and 2 in operation and effect. As can be seen from the above, the present invention relates to a lower structural part and an upper part used for a foundation of a building having a lower structural part fixed to the ground and an upper structural part supported on the lower structural part. In a connection structure for connecting the structural parts, the outer steel pipe 22 is fixed to one of the lower structural part and the upper structural part, and the outer steel pipe 24 is fixed to the other of the lower structural part and the upper structural part. What should I do?
[0022]
Although the connection structure of FIGS. 1 to 6 described above is used for the connection between the pile head of the pile 12 and the footing 14, the connection structure according to the present invention is limited to the connection between them. Instead, for example, it may be used between a footing and a column base of a column connected thereon, and such a configuration will be described below with reference to FIG.
FIG. 7 is a schematic view showing an elevation view of a connection structure used for a foundation of a building according to a second embodiment of the present invention. The foundation of the illustrated building is a pile foundation using a reinforced concrete pile 12, a reinforced concrete footing (foundation beam) 14 is connected to the pile head of the pile 12, and a reinforced concrete pile is also provided on the upper surface of the footing 14. Of the column 16 is supported.
The footing 14 and the column base of the column 16 are not rigidly connected, but are connected by the connection structure according to the present invention. According to this connection structure, when the overturning moment due to the earthquake acts on the building, if the overturning moment is equal to or larger than a predetermined magnitude, the pillar 16 is disposed on one side of the building according to the direction of the overturning moment. The pedestal can be lifted from the footing 14.
[0023]
Therefore, in the foundation of the building shown in FIG. 7, the footing 14 is a substructure part fixed to the ground of the foundation of the building, and the column base of the pillar 16 is the foundation of the building. The upper structure portion is supported on the lower structure portion.
The connecting structure shown in FIG. 7 is an outer steel pipe 22 fixed to the footing 14 as the lower structural part and extending in the vertical direction, and an inner steel pipe 22 fixed to the column 16 as the upper structural part and extending in the vertical direction. And an inner steel pipe 24. A damper 28 is filled between the inner surface of the outer steel tube 22 and the outer surface of the inner steel tube 24. The upper portion of the outer steel pipe 22 extends upward from the upper surface of the footing 14, and the upper extension of the outer steel pipe 22 is housed in a vertically extending outer steel pipe housing recess formed in the column 16. Have been. The inner surface of the outer steel pipe accommodating concave portion of the column 16 is defined by the inner peripheral surface of the elastic sleeve 32. The configuration and operation of the outer steel pipe housing concave portion and the elastic sleeve 32 in the connection structure of FIG. 7 are the same as those in the connection structure of FIGS.
The other components used in the connection structure of FIG. 7 are the same as or correspond to the respective components used in the connection structure of FIGS. 1 and 2, and the same or corresponding components include The same reference numerals are given.
[0024]
In the connection structure according to the embodiment shown in FIG. 7, the operation and effect are the same as those of the connection structure according to the embodiment shown in FIGS. 1 and 2, and the footing 14 and the column 16 The only difference is that they were equipped in between. Further, the same modifications as the modifications shown in FIGS. 3 to 6 can be made to the connection structure according to the embodiment shown in FIG. In particular, with regard to the change of equipping the cushioning mechanism shown in FIG. 5, in the connection structure of FIG. 7, a cushioning form is installed on the upper surface of the footing 14 and the cushioning material filled therein is used to form the pillar 16. The impact force acting between the lower surface of the column base and the upper surface of the footing 14 may be buffered.
Further, the connection structure according to the present invention can be applied to other connection points on the foundation of a building.
[0025]
【The invention's effect】
As is clear from the above, according to the present invention, when the upper structural portion of the foundation of the building is lifted and relocated, the damper body filled between the outer steel pipe and the inner steel pipe is sheared and deformed. Seismic response is reduced. In other words, the amount of lifting is suppressed to a small value, and the seating speed at the time of returning is also reduced. Since the damping effect is obtained by the shearing deformation of the damper body, the damping effect is obtained in the process of lifting and the process of returning, providing sufficient damping performance to effectively reduce the earthquake response of the building can do. Further, the connection structure according to the present invention is a double steel pipe structure having a compact configuration in which an inner steel pipe is disposed inside an outer steel pipe. It is also possible to adopt a construction method in which an outer steel pipe, an inner steel pipe, and a unitized damper body are configured in advance, the unit is arranged at a predetermined position, and a pile or footing is driven. Therefore, construction is easy.
[Brief description of the drawings]
FIGS. 1A and 1B are partial cross-sectional views each showing an elevation view of a connection structure used for a foundation of a building according to a first embodiment of the present invention.
FIG. 2 is a sectional plan view taken along line 2-2 of FIG.
FIG. 3 is a sectional plan view similar to FIG. 2, showing a first modification of the embodiment of FIG. 1;
FIG. 4 is a partial sectional view similar to FIG. 1, showing a second modification of the embodiment in FIG. 1;
FIG. 5 is a partial cross-sectional view similar to FIG. 1, showing a third modification of the embodiment of FIG. 1;
FIG. 6 is a partial sectional view similar to FIG. 1, showing a fourth modification of the embodiment of FIG. 1;
FIG. 7 is a partial cross-sectional view similar to FIG. 1, showing a connection structure used for a foundation of a building according to a second embodiment of the present invention.
[Explanation of symbols]
12 pile 14 footing 16 pillar 22 outer steel pipe 24 inner steel pipe 28 damper body 32 elastic body sleeve 34 bottom plate 36 damage protection material 38 damage protection material 40 cone

Claims (7)

A connection structure for connecting the lower structure portion and the upper structure portion, which is used for a foundation of a building having a lower structure portion fixed to the ground and an upper structure portion supported on the lower structure portion. hand,
An outer steel pipe fixed to a first structural part that is one of the lower structural part and the upper structural part and extending in a vertical direction;
An inner steel pipe fixed to a second structural part that is the other of the lower structural part and the upper structural part and extending vertically inside the outer steel pipe;
A damper body filled between the inner surface of the outer steel pipe and the outer surface of the inner steel pipe and exerting a damping function by being subjected to shear deformation,
The outer steel pipe is received in a vertically extending outer steel pipe receiving recess formed in the second structural portion, and is substantially displaced in a horizontal direction relative to the second structural portion. The upper structure portion is not substantially displaced in the horizontal direction, but is displaced in the vertical direction, relative to the lower structure portion. It is possible, if the overturning moment of a predetermined magnitude or more due to the earthquake acts on the building, the upper structure portion is lifted from the lower structure portion, the building can be lifted from the ground,
When the upper structure portion is lifted from the lower structure portion and repositioned, the damper body is configured to be subjected to shear deformation to reduce an earthquake response of the building.
A connection structure used for the foundation of a building, characterized in that: The connection structure according to claim 1, wherein the outer steel pipe and the inner steel pipe are both circular steel pipes or rectangular steel pipes. The connection structure according to claim 1, wherein the lower structure portion is a pile head of a pile used for a pile foundation, and the upper structure portion is footing. The connection structure according to claim 1, wherein the lower structure portion is a footing, and the upper structure portion is a column base. When the lower structure portion and the upper structure portion are made of reinforced concrete or steel frame concrete, and the upper structure portion raised on the upper surface of the lower structure portion and the lower surface of the upper structure portion is seated on the lower structure portion. The connection structure used for a foundation of a building according to claim 1, further comprising a breakage protection material for preventing crushing of the concrete. The lower structural portion is a reinforced concrete or steel concrete pile or footing, and is used to prevent accumulation of breathing on the lower side of the outer steel pipe and the inner steel pipe when placing the concrete of the lower structural portion. The connection structure used for a foundation of a building according to claim 1, further comprising a cone. The connection structure according to claim 1, further comprising a buffer mechanism for buffering an impact force generated when the raised upper structure portion is seated.

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