JP3741198B2 - Basic structure and construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a foundation structure of a concrete-based compression material such as an RC pile or an SRC pile and a construction method thereof.
[0002]
[Prior art]
The pile foundation is mainly intended to support the vertical load of the superstructure, and it goes without saying that the compressive strength characteristics are important, but in the event of an earthquake, a large shear force is applied to the pile head due to the horizontal force from the superstructure. Depending on the ratio of the height to the horizontal width in the vibration direction, rocking vibration will occur in the upper structure and the end side will float up depending on the ratio of the height to the horizontal width in the vibration direction. A large pulling force may act.
[0003]
In such a case, an excessive pulling force acts on the pile, a crack occurs in the foundation slab to which the pile or the pile is bonded, a tensile failure occurs, or due to a decrease in bending strength or shear strength under the pulling force action, Bending failure and shear failure occur, and as a result, the function of supporting the original vertical load of the pile is lost.
[0004]
In view of these circumstances, the present applicant shall allow the vertical relative displacement between the main bar protruding from the pile head and the foundation slab to prevent destruction of the pile and foundation slab due to rocking vibration of the superstructure. Have been considering.
[0005]
[Problems to be solved by the invention]
According to such a joining format, unlike the case of rigid joining, it becomes possible to prevent the pulling force from acting on the pile or slab.
[0006]
However, when an extremely large earthquake is encountered, the main bar of the pile head may come out of the foundation slab completely due to the rocking vibration of the upper structure, and the structure may fall over. There was a problem that the anchor length of the main muscle had to be secured sufficiently.
[0007]
The present invention has been made in consideration of the above-described circumstances, and provides a foundation structure capable of preventing a structure from overturning while preventing a pile or a slab from being destroyed due to a pulling force, and a construction method thereof. With the goal.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the foundation structure according to the present invention is as described in claim 1, wherein a foundation member made of a foundation slab or a footing is joined to a head of a compression material made of a pile, and the compression material and the In the foundation structure in which at least one of the foundation members is formed of concrete, the reinforcing material protruding from the head of the compression material is placed in a state in which a predetermined damping member is disposed around the reinforcement material. It is embedded in a base member and configured to attenuate the vertical relative displacement between the reinforcing member and the base member with the damping member, and a top space surrounding the vicinity of the top portion of the reinforcing member is provided in the base member. A predetermined stopper is attached in the vicinity of the top of the reinforcing material so that a predetermined gap is formed between the top surface and a contact surface formed below the top space.
Moreover, the foundation structure which concerns on this invention is as described in Claim 2, and while the foundation member which consists of underground slabs is joined to the head of the compression material which consists of a pillar of an underground floor, among the said compression material and the said foundation member In the foundation structure in which at least one of them is formed of concrete, the reinforcing material protruding from the head of the compression material is placed in the foundation member in a state where a predetermined damping member is disposed around the reinforcing material. A vertical space between the reinforcing member and the foundation member is embedded so as to be attenuated by the damping member, and a top space surrounding the vicinity of the top portion of the reinforcing material is provided in the foundation member. A predetermined stopper is attached in the vicinity of the top of the reinforcing material so that a predetermined gap is formed between the contact surface formed below.
[0009]
In addition, the construction method of the foundation structure according to the present invention is a foundation structure in which a foundation member made of concrete or a foundation slab formed of concrete is joined to the head of a compression material made of pile as described in claim 3. In this construction method, a predetermined damping member is disposed around the reinforcing material protruding from the head of the compression material, and a predetermined stopper is attached in the vicinity of the top of the reinforcing material so as to surround the stopper and A hollow frame member is attached near the top of the reinforcing material so that a predetermined gap is formed below, and concrete is placed around the damping member and the hollow frame member in such a state, and the foundation member is To form.
Moreover, the construction method of the foundation structure according to the present invention is the foundation in which the foundation member made of the underground slab formed of concrete is joined to the head of the compression material made of the pillar of the underground floor as described in claim 4. In the construction method of the structure, a predetermined damping member is disposed around the reinforcing member protruding from the head of the compression member, and a predetermined stopper is attached in the vicinity of the top of the reinforcing member so as to surround the stopper. A hollow frame member is attached in the vicinity of the top of the reinforcing material so that a predetermined gap is formed below, and in this state, concrete is placed around the damping member and the hollow frame member, and the foundation member Is formed.
[0010]
Moreover, the construction method of the foundation structure according to the present invention is to fill the hollow mold member with a shrinkable concrete inflow preventing material and then place the concrete.
[0011]
In the foundation structure and its construction method according to the present invention, the reinforcing material protruding from the head of the compression material is embedded in the foundation member in a state where a predetermined damping member is arranged around the reinforcing material. When the rocking vibration is generated in the upper structure, the reinforcing material protruding from the compression material is pulled out from the inside of the base member, and a damping force is generated by the damping member along with the removal.
[0012]
That is, by allowing the vertical relative displacement between the reinforcing material and the base member, the generation of tensile stress in the compression material and the base member is prevented in advance, and the damping member is provided along with the occurrence of the vertical relative displacement described above. Since the damping force is generated, the rocking vibration of the superstructure is quickly converged.
[0013]
On the other hand, a top space surrounding the vicinity of the top of the reinforcing material is provided in the base member, and a predetermined gap is formed in the vicinity of the top of the reinforcing material so as to form a predetermined gap with the contact surface formed below the top space. Therefore, the vertical relative displacement between the reinforcing member and the base member is limited, so that the upper structure can be prevented from overturning.
[0014]
That is, when the vertical relative displacement is within the gap between the stopper and the abutting surface formed below the top space, in other words, in the case of a small and medium earthquake, the upper structure is compressed with the compression material and The rocking vibration is suppressed by the damping action caused by the vertical relative displacement between the reinforcement and the foundation member without generating a tensile stress on the foundation member, but in the case of a large earthquake, the stopper attached to the reinforcement is Since the vertical relative displacement is constrained by hitting the contact surface formed below the top space in the foundation member, there is no possibility that the reinforcing material will come out of the foundation member, thus preventing the upper structure from being overturned.
[0015]
In the present invention, the compressed material means a pile or a pillar of an underground floor. Moreover, a foundation member means a foundation slab, an underground slab, or a footing. Reinforcing materials include steel bars as well as reinforcing bars.
[0016]
The configuration of the damping member is arbitrary, and any of a friction damping type, a viscous damping type, and a hysteresis damping type may be used.
[0017]
When a friction damping type damping member is used, the gap between the reinforcing material and the base member is filled with a granular or powdery substance, which is used as a damping member, and frictional heat generated by mutual contact of these granular or powdery substances is used. Or friction heat generated by sliding between the friction surface of the damping member and the contact surface of the reinforcing member or the base member can be used. It is conceivable to use a sintered alloy pad obtained by sintering a material, for example, metal powder.
[0018]
When a viscous damping type damping member is used, viscous resistance can be used by filling a gap between the reinforcing member and the base member with a viscoelastic material as a damping member.
[0019]
When a hysteresis damping type damping member is used, the kinetic energy related to the reinforcing member extraction operation is absorbed by the hysteresis attenuation of the attenuation member itself, and the extraction operation can be quickly attenuated. For example, it is conceivable to use a high-damping rubber or a highly-damping resin after being injected and solidified in the gap between the reinforcing material and the base member.
[0020]
When providing a gap between the stopper and the abutment surface, it is necessary to ensure that the rocking vibrations of the structure can be sufficiently absorbed during a small and medium earthquake and that the structure can be prevented from falling by restraining the lift during a large earthquake. What is necessary is just to set a magnitude | size.
[0021]
The configuration of the stopper is arbitrary. For example, a configuration in which the stopper is configured to be screwed into the reinforcing material, or a configuration in which the stopper is configured to be welded to the reinforcing material is conceivable.
[0022]
The hollow frame member attached to the vicinity of the top of the reinforcing material before placing the concrete of the foundation member has the strength to withstand the pressure of the concrete at the time of placing and in the internal space that becomes the top space after placing the concrete. As long as it can maintain high water tightness so that concrete does not flow into it, its structure and mounting method are arbitrary, but after filling the hollow form member with shrinkable concrete inflow prevention material, the concrete is If the casting is performed, it is possible to prevent the inflow of the concrete into the hollow mold member during the concrete casting without providing the hollow mold member with high water tightness. In addition, since the concrete inflow prevention material is freely contractible, the vertical movement of the stopper in the top space during an earthquake, that is, the vertical relative displacement between the reinforcing material and the foundation member is not hindered.
[0023]
The concrete inflow prevention material can be configured in any way as long as it prevents the inflow of concrete into the hollow frame member and allows the stopper to move up and down in the top space after the concrete is placed. For example, it is conceivable to use a low-rigidity material such as rubber or a cushion material.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a basic structure and a construction method thereof according to the present invention will be described with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.
[0025]
FIG. 1A is an overall cross-sectional view showing a foundation structure according to the present embodiment, and FIG. 1B is a detailed cross-sectional view in the vicinity of a pile head. As shown in FIG. 1 (a), the foundation structure according to the present embodiment has a high-damping rubber 6 as a damping member around a reinforcing bar 5 as a reinforcing material protruding from the head of the RC pile 1 as a compression material. The RC base slab 2 is embedded in the RC base slab 2 as a base member, and the RC base slab has a fixing sleeve 3 embedded in the RC base slab as shown in FIG. The high-damping rubber 6 disposed on the base slab 2 is embedded in the base slab 2 so as to be inserted into the fixing sleeve 3.
[0026]
As shown in FIG. 1 (c), the fixing sleeve 3 is formed in a substantially hollow cylindrical shape and is provided with irregularities 7 on the outer peripheral surface thereof so as to ensure adhesion strength with the RC foundation slab 2. is there. The fixing sleeve 3 can be formed of, for example, fiber reinforced plastic.
[0027]
The high damping rubber 6 is configured by filling a gap between the reinforcing bar 5 and the fixing sleeve 3, and when a vertical relative displacement occurs between the reinforcing bar 5 and the RC foundation slab 2, the displacement acts as a forced deformation. And history attenuation is demonstrated.
[0028]
On the other hand, a top space 9 is formed in the RC foundation slab 2 so as to surround the vicinity of the top of the reinforcing bar 5 as can be clearly seen in FIG. 1 (b), and a contact formed below the top space. A stopper 10 is attached near the top of the reinforcing bar 5 so that a gap d is formed between the surface 8 and the surface 8. The stopper 10 may be fixed by welding or the like after a ring-shaped steel plate is fitted into the reinforcing bar 5, for example.
[0029]
When the gap d is provided between the stopper 10 and the contact surface 8, the rocking vibration of the upper structure (not shown) can be sufficiently absorbed during a small and medium earthquake, and the upper structure can be lifted by rocking vibration during a large earthquake. The size thereof is appropriately set so that it can be restrained and its fall can be prevented.
[0030]
The top space 9 is formed as an internal space of the hollow frame member 4 attached so as to surround the vicinity of the top of the reinforcing bar 5, and the contact surface 8 is formed as a bottom surface of the hollow frame material.
[0031]
In order to construct the foundation structure according to the present embodiment, the RC pile 1 is first placed on-site or after the ready-made one is driven, and then, as shown in FIG. The fixing sleeve 3 is fitted into the reinforcing bar 5 protruding in the direction, and the high damping rubber 6 is injected into the gap between the fixing sleeve and the reinforcing bar 5 as shown by the arrow in FIG.
[0032]
At this time, it is preferable to align the center of the fixing sleeve 3 with the center of the reinforcing bar 5 so that the clearance between the fixing sleeve 3 and the reinforcing bar 5 has substantially the same dimension on the entire circumference.
[0033]
Next, as shown in FIG. 2 (b), a stopper 10 is attached in the vicinity of the top of the reinforcing bar 5, and then the reinforcing bar 5 is formed so as to surround the stopper and to form a predetermined gap d below the stopper. A hollow frame member 4 is attached in the vicinity of the top of the.
[0034]
At this time, the hollow frame member 4 has a strength capable of withstanding the pressure of the concrete at the time of placing, and has high water tightness so that the concrete does not flow into the internal space that becomes the top space 9 after the concrete is placed. Install so that it can be held.
[0035]
When the installation of the hollow mold member 4 is completed, after the RC foundation slab 2 is completed, the concrete is cast to form the RC foundation slab 2, and the fixing sleeve 3 and the hollow mold member 10 are attached. Embedded in the slab. In addition, the edge is cut off between the top end of RC pile 1 and the bottom face of RC foundation slab 2 so that a tensile force may not be transmitted.
[0036]
3 and 4 are views showing the operation of the foundation structure and its construction method according to this embodiment. In the foundation structure and its construction method according to the present embodiment, the reinforcing bar 5 protruding from the head of the RC pile 1 is inserted into the fixing sleeve 3 together with the high damping rubber 6 disposed around the reinforcing bar. Since it is embedded in the RC foundation slab 2, as shown in FIG. 3, when rocking vibration due to an earthquake occurs in the upper structure 11, the reinforcing bar 5 protruding from the RC pile 1 comes out of the RC foundation slab 2. At the same time, a damping force is generated by the high damping rubber 6 along with the withdrawal.
[0037]
That is, by allowing the vertical relative displacement between the reinforcing bar 5 and the RC foundation slab 2, generation of tensile stress in the RC pile 1 and the RC foundation slab 2 is prevented, and the occurrence of the vertical relative displacement described above is prevented. Accordingly, since a damping force is generated from the high damping rubber 6, the rocking vibration of the upper structure 11 is quickly converged.
[0038]
On the other hand, as explained in FIG. 1, a top space 9 that surrounds the vicinity of the top of the reinforcing bar 5 is provided in the RC foundation slab 2, and a predetermined gap d is formed between the contact surface 8 formed below the top space. Since the predetermined stopper 10 is attached in the vicinity of the top of the reinforcing bar 5 so as to be formed, a certain restriction is placed on the vertical relative displacement between the reinforcing bar 5 and the RC foundation slab 2, and the upper structure 11 falls. Is prevented in advance.
[0039]
That is, when the vertical relative displacement is within the gap d between the stopper 10 and the abutting surface 8 formed below the top space 9, in other words, in the case of a small and medium earthquake, the upper structure 11 is In the case of a large earthquake, the RC pile 1 and the RC foundation slab 2 do not generate tensile stress, and the rocking vibration is suppressed by the damping action associated with the vertical relative displacement between the reinforcing bar 5 and the RC foundation slab 2. As shown in FIG. 4, the stopper 10 attached to the reinforcing bar 5 hits the contact surface 8 formed below the top space 9 in the RC foundation slab 2 and the vertical relative displacement is restrained. There is no risk of slipping out of the RC foundation slab 2, and thus the upper structure 11 is prevented from falling.
[0040]
As described above, according to the foundation structure and its construction method according to the present embodiment, the reinforcing bar 5 and the RC foundation slab are within the range of the gap d set while receiving the damping action by the high damping rubber 6 at the time of a small and medium earthquake. As a result, the RC pile 1 and the RC foundation slab 2 are not subject to tensile stress, and the bending failure and shear due to the tensile failure and the decrease in the bending strength and shear strength associated with the pulling force. It becomes possible to prevent destruction in advance.
[0041]
On the other hand, since the vertical relative displacement between the reinforcing bar 5 and the RC foundation slab 2 that exceeds the gap d is constrained during a large earthquake, the RC foundation slab 2 is lifted by the rocking vibration of the upper structure 11 within that range. Thus, the upper structure 11 can be prevented from falling down.
[0042]
In this embodiment, the RC pile is assumed as a premise, and the reinforcing bars protruding from the pile head are inserted into the fixing sleeve 3. However, the compression material is not limited to the RC pile. You may make it cover a fixing material on the protruding steel frame.
[0043]
Moreover, in this embodiment, although the compression material was RC pile 1 and the foundation member was RC foundation slab 2, the foundation structure which concerns on this invention is not limited to this structure, In the case where a compression material is a steel pipe pile, Even if it exists, it is possible to prevent the tensile failure of the RC foundation slab, which is the foundation member, and it is possible to prevent the tensile failure of the RC pile even when the foundation member is made of steel beams. .
[0044]
Further, in the present embodiment, the high damping rubber 6 is used as the damping member, but instead of this, a resin having a high damping property may be injected.
[0045]
Further, in the present embodiment, the high damping rubber 6 is configured to be injected and solidified, but instead, a damping sheet formed of high damping rubber or the like is wound around the reinforcing bar 5 and the fixing sleeve 3 is covered thereon. It may be.
[0046]
In the present embodiment, the hysteresis damping material is used as the damping member, but instead, a viscous damping type or friction damping type damping member may be used. When a friction damping type damping member is used, for example, the damping member can be configured by providing an outer peripheral friction surface formed by adhering metal powder. In such a case, the cylindrical damping member is used as the reinforcing bar 5. The fixing sleeve 3 may be covered over the damping member by being fixed to the reinforcing bar by welding or the like.
[0047]
Further, in the present embodiment, the high damping rubber 6 that is a damping member is filled between the fixing sleeve 3 and the reinforcing bar 5. However, the fixing sleeve 3 is not always necessary, and in some cases, a sheet-like shape is used. High damping rubber may be wound around the reinforcing bar 5 and the RC foundation slab 2 may be constructed in this state.
[0048]
Further, in this embodiment, the hollow frame member 4 has a strength capable of withstanding the pressure of the concrete at the time of placing, and the concrete does not flow into the internal space that becomes the top space 9 after the concrete is placed. Although it was attached with high watertightness, instead of this, as shown in FIG. 5, the shrinkable concrete inflow prevention material 21 was filled in the hollow frame member 4, and then the concrete was placed. You may make it do. According to such a configuration, it is possible to prevent the inflow of concrete into the hollow mold member 4 at the time of placing the concrete without giving the hollow mold member 4 high watertightness. In addition, since the concrete inflow prevention material 21 is contractible, the vertical movement of the stopper 10 in the top space 9 during an earthquake, that is, the vertical relative displacement between the reinforcing bar 5 and the RC foundation slab 2 is not hindered.
[0049]
How is the concrete inflow prevention material 21 configured to prevent the inflow of concrete into the hollow frame member 4 and to allow the stopper 10 to move up and down in the top space 9 after the concrete is placed? Is optional, and for example, it is conceivable to use a low-rigidity material such as rubber or cushioning material.
[0050]
【The invention's effect】
As described above, according to the foundation structure and the construction method thereof according to the present invention, the vertical relative displacement between the reinforcing member and the foundation member within the gap set while receiving the damping action by the damping member during a small and medium-sized earthquake. Therefore, no tensile stress is generated in the compressed material or the base member, and it is possible to prevent bending failure and shear failure due to the decrease in bending strength and shear strength due to their tensile failure and pull-out force. It becomes.
[0051]
On the other hand, in the case of a large earthquake, the vertical relative displacement between the reinforcing member and the foundation member exceeding the gap described above is restricted, so that the foundation member is lifted by the rocking vibration of the upper structure within the gap. It is possible to prevent things from falling over.
[0052]
[Brief description of the drawings]
1A and 1B are diagrams showing a basic structure according to the present embodiment, where FIG. 1A is an overall cross-sectional view, FIG. 1B is a detailed cross-sectional view near a pile head, and FIG. Side view.
FIG. 2 is a view showing a state in which a foundation structure according to the present embodiment is constructed.
FIG. 3 is a view showing the operation of the basic structure and the construction method thereof according to the present embodiment.
FIG. 4 is a diagram showing the operation of the basic structure and the construction method thereof according to the present embodiment.
FIG. 5 is a view showing a basic structure according to a modification of the embodiment, and is a detailed view showing a part in cross section.
[Explanation of symbols]
1 RC pile (compressed material)
2 RC foundation slab (foundation member)
4 Hollow frame member 5 Reinforcing bar (reinforcing material)
6 High damping rubber (damping member)
8 Contact surface 9 Top space 10 Stopper 21 Concrete inflow prevention material

Claims (5)

In a foundation structure in which at least one of the compression member and the foundation member is formed of concrete and a foundation member made of a foundation slab or footing is joined to the head of the compression member made of a pile,
A reinforcing member protruding from the head of the compression member is embedded in the foundation member in a state where a predetermined damping member is disposed around the reinforcement member, and a vertical relative displacement between the reinforcement member and the foundation member is caused. The damping member is configured to be attenuated, and a top space that surrounds the vicinity of the top of the reinforcing member is provided in the base member, and a predetermined gap is formed between the contact surface formed below the top space. A basic structure in which a predetermined stopper is attached in the vicinity of the top of the reinforcing material so as to be formed. In the foundation structure in which at least one of the compression material and the foundation member is formed of concrete and a foundation member made of an underground slab is joined to the head of the compression material consisting of a pillar of the underground floor,
A reinforcing member protruding from the head of the compression member is embedded in the foundation member in a state where a predetermined damping member is disposed around the reinforcement member, and a vertical relative displacement between the reinforcement member and the foundation member is caused. The damping member is configured to be attenuated, and a top space that surrounds the vicinity of the top of the reinforcing member is provided in the base member, and a predetermined gap is formed between the contact surface formed below the top space. A basic structure in which a predetermined stopper is attached in the vicinity of the top of the reinforcing material so as to be formed. In the construction method of a foundation structure in which a foundation slab formed of concrete or a foundation member made of footing is joined to the head of a compression material made of a pile,
A predetermined damping member is disposed around the reinforcing material protruding from the head of the compressed material, and a predetermined stopper is attached in the vicinity of the top of the reinforcing material so as to surround the stopper and below the stopper. A hollow frame member is attached in the vicinity of the top of the reinforcing material so that the base member is formed by placing concrete around the damping member and the hollow frame member in this state. How to build a basic structure. In the construction method of the foundation structure in which the foundation member consisting of the underground slab formed of concrete is joined to the head of the compression material consisting of the pillar of the underground floor,
A predetermined damping member is disposed around the reinforcing material protruding from the head of the compressed material, and a predetermined stopper is attached in the vicinity of the top of the reinforcing material so as to surround the stopper and below the stopper. A hollow frame member is attached in the vicinity of the top of the reinforcing material so that the base member is formed by placing concrete around the damping member and the hollow frame member in this state. How to build a basic structure.   The method for constructing a foundation structure according to claim 3 or 4, wherein a shrinkable concrete inflow preventing material is filled in the hollow frame member, and then the concrete is placed.

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