JP2001020558A - Base isolation structure of building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation structure of a building capable of increasing the durability of a rubber composite base isolation element and providing a high base isolation capability. SOLUTION: A rubber composite base isolation element 3 is provided between a foundation beam or a foundation bottom plate of a building and the upper edge of a concrete pile 2 provided in the ground under the foundation beam or foundation bottom plate or the upper edge of a base rock, the foundation beam or foundation bottom plate is placed in contact partly with the underground or the ground, and crushed stone or soil and sand are filled between the foundation 1 and the upper edge of the concrete pile 2 or the upper edge of the base rock. When a plurality of high-strength rigid short rods are fixed vertically on the lower surface of the foundation beam or foundation bottom plate near an area occupied by the rubber composite base isolation element 3, the lateral vibration of the foundation 1 and further the building caused at the earthquake can be attenuated by the slidable contact of the foundation or building with the crushed stone or soil and sand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure for a building, and more particularly to a rubber composite seismic isolation element having improved durability.
The present invention relates to a base seismic isolation structure of a building that provides high seismic isolation performance.

[0002]

2. Description of the Related Art In recent years,
In order not to increase the damage caused by the earthquake, seismic measures are taken for buildings. As a major measure against seismic resistance, a method is adopted in which rigidity is high in the vertical direction and rigidity is low in the horizontal direction, and a damper that damps vibration by supporting it with a long-period spring is used. In particular, a seismic isolation element is provided between the building and the ground to generate the relative displacement of the ground and the building's sway at the spring part and to reduce the resonance of the ground and the building's sway during an earthquake. Therefore, seismic isolation structures have been implemented in which the natural period of buildings is extended and the energy of earthquakes is absorbed by deformation of seismic isolation elements. Examples of the seismic isolation structure include a structure in which a rubber composite seismic isolation element is interposed and fixed between a foundation and a building. The rubber composite seismic isolation element is configured by alternately overlapping and joining rubber plates and iron plates. However, the seismic isolation structure in which the rubber composite seismic isolation element is interposed and fixed between the foundation and the building is a structure that supports the vertical load of the building. The burden of the load is large, and the seismic isolation function is reduced. Therefore, the adoption of a seismic isolation structure using a rubber composite seismic isolation element is limited to an area where a building is not extremely heavy. However, in the seismic isolation structure, since the seismic isolation element supports the vertical load of the whole building, there is a problem in the pressure resistance and durability of the rubber plate.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to improve the pressure resistance and durability of a seismic isolation element and to provide a base seismic isolation structure for a building having a high seismic isolation effect. Is provided. That is, the present invention provides: (1) A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a rock under the ground. The foundation beam or foundation bottom plate is partially placed underground or in contact with the ground,
A foundation seismic isolation structure for a building characterized by being filled with crushed stone or earth and sand between the foundation and an upper edge of a concrete pile or an upper edge of a bedrock. (2) A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided below the foundation beam. Or a part of the base plate is placed underground or in contact with the ground,
Crushed stone or earth and sand is filled between the foundation and the upper edge of the concrete pile or the upper edge of the bedrock, and a high-strength rigid short rod is provided at the upper end of the concrete pile near the rubber composite seismic isolation element occupying portion. The base seismic isolation structure of a building, characterized by being fixed upright. (3) A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder, and the foundation beam is provided. Or a part of the base plate is placed underground or in contact with the ground,
Crushed stones or earth and sand are filled between the foundation and the upper edge of the concrete pile or the upper edge of the bedrock, and a high strength is provided on the lower surface of the foundation beam or the foundation bottom plate in the vicinity of the rubber composite seismic isolation element occupying portion. A base seismic isolation structure for a building characterized by a rigid short rod being fixed vertically. (4) A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. Or a part of the base plate is placed underground or in contact with the ground,
Crushed stone or earth and sand is filled between the foundation and the upper edge of the concrete pile or the upper edge of the bedrock, and a high-strength rigid short rod is provided at the upper end of the concrete pile near the rubber composite seismic isolation element occupying portion. And a high-strength rigid short rod is vertically fixed to a lower surface of a foundation beam or a base plate in the vicinity of the rubber composite seismic isolation element occupying portion. . (5) A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. Or a part of the base plate is placed underground or in contact with the ground,
In addition, an earth retaining steel pipe surrounding the rubber composite seismic isolation element is fixed to an upper edge of the concrete pile or an upper edge of the bedrock in a non-contact state with an upper edge of the seismic isolation element, and A foundation seismic isolation structure for a building, characterized in that crushed stone or earth and sand is filled outside a retaining steel pipe between the foundation and an upper edge of a concrete pile or a bedrock. It is.

[0004]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of the present invention will be described with reference to the drawings. 1 to 5 are enlarged cross-sectional views of an example of the base seismic isolation structure of the building of the present invention, and FIGS. 6, 7, and 8 are overall cross sections of an example of the base seismic isolation structure of the building of the present invention. FIG. In the figure, 1 is a foundation, 2 is a concrete pile, 3 is a rubber composite seismic isolation element, 4 is an iron plate, 5
Is a gravel or crushed stone for damping runout, and 6 is a pillar. 7 is a building, and 8 and 8 'are high-strength rigid short rods. 9 is a rubber cap, and 10 is a retaining steel pipe. As shown in FIG. 1, a base seismic isolation structure for a building according to the present invention includes a foundation 1 for a building and a concrete pile 2 cast into the ground below the foundation.
A rubber composite seismic isolation element 3 is installed between the foundation 1 and the upper edge of the concrete pile 2 in the gap 11 between the foundation 1 and the concrete pile 2.
Gravel or crushed stone 5 for vibration damping is filled.

[0005] In general, a foundation, which is a structural portion provided for transmitting loads from pillars, walls, foundations, and the like of a building to the ground or earthwork, is roughly classified into foundation beams and foundation bottom plates. The foundation beam is a horizontal member connecting the foundations of the building and bears the bending moment of the column base and the shearing force due to it. By increasing the rigidity of this beam, the uneven settlement of the foundation is prevented and the entire building is The rigidity is increased. The foundation bottom plate is a slab at the bottom of the foundation, and has a structure in which a foundation reaction force is applied upward. The foundation work for the foundation includes three types of a direct foundation method, a pile foundation method, and a caisson method described below. The direct foundation method, in which the entire load of the building is directly transmitted to the supporting ground by the foundation beam and the base plate, the piles reach the solid supporting ground at the tip of the pile, and the supporting pile, which transmits the entire load of the building to the supporting ground through the pile, and the deep viscosity Pile foundation method consisting of friction piles that are fixed in a high-grade ground layer and support the full load of the building by the adhesive force and frictional force of the viscous ground layer acting on the pile,
A caisson method in which a caisson is constructed by excavating the lower part of a building made in advance on the ground or under the ground and submerging it to the ground at a predetermined depth using its own weight or loading load.
In particular, examples of the foundation employed in the direct foundation method include an independent foundation, a composite foundation, a cloth foundation, and a solid foundation. Here, the solid foundation is a foundation configured to receive the whole or most of the building with one foundation, and is provided on one surface without gaps. Usually, the column base is composed of a connecting beam continuously and vertically and horizontally and a foundation slab surrounded by the column base, and there is a case where the bottom of the column is received by a flat foundation slab or a curved plate. The solid foundation is used, for example, when the building is heavy or the ground strength is low. In the base seismic isolation structure according to the present invention, a rubber composite seismic isolation element is interposed between a foundation beam or a base plate and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. It is a structure, and the foundation beam or base plate is the foundation that supports the building, and if it is the foundation that supports the building such as solid foundation, this foundation seismic isolation structure can be applied regardless of its shape .
In addition, the foundation beam or foundation bottom plate is placed underground in FIG. 1, but may be placed in contact with the ground.

[0006] In general, concrete piles to be poured into the ground, such as centrifugal reinforced concrete piles (RC piles) and pretensioned prestressed concrete piles in which prestresses are introduced in the pile axis direction to prevent cracks and breakage, are introduced. Pre-tension type centrifugal high-strength prestressed concrete piles (PHC piles), which can be used to increase the scale of buildings and lengths in soft ground, and can be used to increase the load per bearing. In addition, concrete piles with outer shell steel pipes (SC piles) that combine the compressive properties of concrete and the tensile properties and toughness of steel pipe piles that can be applied to soft ground or ground where liquefaction is expected can be cited. The concrete pile 2 according to the present invention is installed so as to support the vertical load of the upper building and prevents sinking due to the vertical load, so that the load condition, the ground condition and the construction condition of the construction site are considered. After that, it is desirable that the optimum concrete pile 2 is selected. In addition to concrete piles, rocks and the like can also be used as long as they have strength enough to support the vertical load of the upper building.

The rubber composite seismic isolation element 3 is a composite laminate in which a plurality of hard plates and soft plates are alternately laminated and joined between upper and lower face plates, and the hard plate is made of metal. Plates, ceramic plates, and soft plates are made of thermoplastic rubber, vulcanized rubber, etc., and have load carrying capacity, large deformation performance, and restoring force performance to return to the original position at the end of an earthquake. Things. In particular, seismic isolation elements include natural rubber-based laminated rubber that uses natural rubber with little change in physical properties due to temperature changes, high-damping laminated rubber that uses rubber specially formulated for rubber materials, and laminated rubber with lead plugs. Rara. Each natural rubber-based laminated rubber has excellent tensile strength, elongation, and creep resistance, and its load deformation characteristics are almost independent of fluctuations in axial force and displacement history. The high-damping type laminated rubber has the characteristic that the viscosity of the rubber material is increased and the energy is absorbed by itself by using a specially formulated rubber for the rubber material. Yes, it is a space-saving type because of the integrated damper function. In addition, lead rubber with a lead plug presses lead into a cylindrical hollow hole provided at the center of a natural rubber-based laminated rubber, and during shear deformation of the laminated rubber, energy is generated by plastic deformation of the internal lead plug. It has a characteristic of built-in damper that absorbs. In the basic seismic isolation structure of the building of the present invention, the rubber composite seismic isolation element 3 used may be any of these seismic isolation elements, and may be appropriately adjusted according to the weight and shape of the building and location conditions. Selected ones can be used.

FIGS. 2 and 3 are enlarged sectional views of an example of a base seismic isolation structure of a building according to the present invention. In FIG. In FIG. 3, a plurality of high-strength rigid short rods 8 are fixed on the lower surface of the foundation beam or the base plate (foundation 1) near the occupied portion of the rubber composite seismic isolation element 3. A rod 8 'is fixed vertically. In FIG. 4, a plurality of high-strength rigid short rods 8 are erected and fixed on the upper end of the concrete pile 2 near the occupation area of the rubber composite seismic isolation element 3, and further, near the occupation area of the rubber composite seismic isolation element 3. A plurality of high-strength rigid short rods 8 'are vertically fixed to the lower surface of the foundation beam or foundation bottom plate (foundation 1). A plurality of high-strength rigid short rods 8, 8 ′ that are erected and fixed on the upper edge of a concrete pile near the occupied portion of the rubber composite seismic isolation element 3, or are vertically fixed to the lower surface of a foundation beam or a bottom plate (foundation 1). Is installed to attenuate the roll during an earthquake. For this reason, the high-strength rigid short rods 8 and 8 'are preferably rods made of cemented carbide or stainless steel having a bending strength enough to resist the roll during an earthquake.

FIG. 5 also shows an example of a base seismic isolation structure for a building according to the present invention. FIG. 5 (a) is an enlarged sectional view and FIG. 5 (b) is a plan view taken along the line AA. In this example, a concrete retaining pile 10 surrounds a rubber composite seismic isolation element 3 on the upper edge of a concrete pile 2 and has an upper edge of a foundation beam or foundation bottom plate (foundation 1).
Is fixed in a non-contact state. The outside of the earth retaining steel pipe 10 is filled with gravel or crushed stone 5. The earth retaining steel pipe 10 is used to prevent the earth and sand or the gravel or crushed stone 5 for damping the lateral vibration to be filled between the lower surface of the foundation beam or the bottom plate (foundation 1) and the concrete pile 2 from covering the rubber composite seismic isolation element 3. It is fixed to the foundation beam or foundation bottom plate (foundation 1) in a non-contact state so that the rubber composite seismic isolation element 3 can fully perform its function. A rubber cap 9 is attached to the upper end edge of the retaining steel pipe 10 in order to prevent the moisture from entering the retaining steel pipe 10 and deteriorating the seismic isolation element 3. The rubber cap 9 has an annular groove 9a into which the upper end edge of the retaining steel pipe 10 is inserted, and has a flexure 9b so as to cope with expansion and contraction caused by shaking of the retaining steel pipe 10 during an earthquake. Is preferred. Incidentally, the retaining steel pipe 10 is used not only as a retaining material for earth and sand, gravel, or crushed stone 5 on its outer side, but also when the rubber composite seismic isolation element 3 is deformed during an earthquake, it comes into contact with the retaining steel pipe 10 to reduce the deformation. It also has the effect of minimizing it. Therefore, it is desirable that the earth retaining steel pipe 10 has a strong structure that can withstand the impact when the rubber composite seismic isolation element 3 is deformed. For example, a steel pipe having a thickness of about 8 mm is used.

In the present invention, the space between the foundation 1 and the upper edge of the concrete pile 2 is filled with earth and sand, gravel or crushed stone 5. By filling earth and sand or gravel or crushed stone 5,
The vertical load of the building can be supported in a cushioned manner by the rubber composite seismic isolation element 3 and the earth, sand, gravel or crushed stone 5, so that the load of the rubber composite seismic isolation element 3 on the vertical load can be reduced. In addition, if the vertical load of the building can be supported in a buffered manner, it is also possible to fill things other than earth and sand, gravel or crushed stone 5. Particularly, gravel can be employed as a material having a high buffering property.

FIG. 6 to FIG. 8 are whole sectional views of an example of a base seismic isolation structure for a building according to the present invention. FIG. 6 is a cross-sectional view of the main part adopting FIG. 1, in which a rubber composite seismic isolation element 3 is interposed between a foundation 1 and an upper edge of a concrete pile 2 provided underground. And the pillars 6 of the building 7 above the foundation 1
Is constructed, and gravel or crushed stone 5 is filled between the foundation 1 and the upper edge of the concrete pile 2. FIG. 7 is an overall cross-sectional view employing FIG. 2 in which the rubber composite seismic isolation element 3 is interposed between the foundation 1 and the upper edge of the concrete pile 2 provided under the ground. The pillar 6 of the building 7 is constructed above the upper edge foundation 1 of the concrete pile 2 and the foundation 1
A high-strength rigid short rod 8 is erected and fixed on the upper end of the concrete pile 2. FIG. 8 is an overall sectional view that employs FIG. 5 of the main part, and a rubber composite seismic isolation element 3 is interposed between the foundation 1 and the upper edge of the concrete pile 2 as in FIGS. 6 and 7. A pillar 6 of a building 7 is constructed above the foundation 1, and an earth retaining steel pipe 10 is arranged on the upper edge of the concrete pile 2 so as to surround the rubber composite seismic isolation element 3, and the upper edge thereof is in non-contact with the foundation 1. And outside the retaining steel pipe 10 between the foundation 1 and the upper edge of the concrete pile 2, gravel or crushed stone 5
Is filled.

Next, a construction procedure for constructing an example of a base seismic isolation structure according to the present invention will be described with reference to FIGS.
First, as shown in FIG. 9A, the ground is cut deeper than the concrete pile driving position, and then the concrete pile 2 is driven. Next, as shown in FIG. 9B, the rubber composite seismic isolation element 3 is fixed to the upper edge of the concrete pile 2 with bolts. At that time, in order to securely fix and fix the rubber composite seismic isolation element 3, the iron sheet 4 is tightly fitted between the upper edge of the concrete pile 2 and the rubber composite seismic isolation element 3 (see FIG. 1). In this structure, a plurality of high-strength rigid short rods 8 may be erected near the rubber composite seismic isolation element 3 at the upper edge of the concrete pile 2 (see FIG. 3). These high-strength rigid short rods 8 can attenuate the roll of the foundation 1 and thus the building 7 during an earthquake. In addition, concrete pile 2
An earth retaining steel pipe 10 may be placed on the upper edge of the rubber composite seismic isolation element 3 so as to surround the same (see FIG. 5). In that case, it is securely welded to the iron sheet 4. Next, after the rubber composite seismic isolation element 3 is fixedly fixed to the concrete pile 2, the crushed stone 5 for damping lateral vibration is filled in the void portion 11 dug in the step (a) as shown in the step (c). , Smooth the top surface. When the earth retaining steel pipe 10 is placed, the outside of the earth retaining steel pipe 10 is filled with earth and sand, gravel, or crushed stone 5 for vibration damping.

Next, as shown in FIG. 10D, the foundation 1 is cast on the sediment, gravel or crushed stone 5 and the rubber composite seismic isolation element 3 which have been smoothed in the step (c). At this time, the foundation 1 is cast so that the weight of the foundation 1 and the weight of the building (7) built thereon can be supported by the crushed stone 5 and the rubber composite seismic isolation element 3. In addition, high strength rigid short rod 8 '
May be erected on the gravel or crushed stone 5 before the foundation 1 is cast (see FIG. 2). Further, when the earth retaining steel pipe 10 was placed around the upper edge of the concrete pile 2 around the rubber composite seismic isolation element 3, the fitting groove 9 a of the rubber cap 9 was attached to the upper end edge of the earth retaining steel pipe 10. Thereafter, concrete is cast on the foundation 1 so as to reliably prevent intrusion of moisture (see FIG. 5). After the above steps, the foundation 1 and the surrounding ground are leveled with earth and sand (step e), and a building 7 is built on the solid foundation 1 cast in step (d).

[0014]

According to the base seismic isolation structure for a building provided in the present invention, the vertical load of the building is dispersed and supported by crushed stone or earth and sand and the rubber elastic seismic isolation element, and the vertical load of the building is It is no longer necessary to support the seismic isolation element only with rubber composite elements, so the load on the seismic isolation element can be reduced, the durability and pressure resistance of the seismic isolation element can be improved, and the size of the seismic isolation element Can also be reduced. In addition, crushed stone or earth and sand is filled around the rubber composite seismic isolation element,
Since it serves as a shock-absorbing material in the event of an earthquake, the rolling of the building can also be reduced. In addition, by standing and anchoring high strength rigid short rods and earth retaining steel pipes, it becomes a basic seismic isolation structure of a building that is strong against lateral shaking and has high seismic isolation performance.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of an example of a base seismic isolation structure of a building according to the present invention.

FIG. 2 is an enlarged sectional view of another example of the base seismic isolation structure of the building of the present invention.

FIG. 3 is an enlarged sectional view of still another example of the base seismic isolation structure of the building of the present invention.

FIG. 4 is an enlarged sectional view of another example of the base seismic isolation structure of the building of the present invention.

FIG. 5 is an enlarged sectional view of still another example of the base seismic isolation structure of the building of the present invention.

FIG. 6 is an overall sectional view of an example of the base seismic isolation structure of the building of the present invention.

FIG. 7 is an overall sectional view of another example of the base seismic isolation structure of the building of the present invention.

FIG. 8 is an overall sectional view of another example of the base seismic isolation structure of the building of the present invention.

FIG. 9 is a construction procedure diagram of a base seismic isolation structure of a building according to the present invention.

FIG. 10 is a construction procedure diagram of a base seismic isolation structure of a building according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 foundation 2 concrete pile 3 rubber composite seismic isolation element 4 iron sheet 5 crushed stone for vibration damping 6 pillar 7 building 8, 8 'high-strength rigid short rod 9 rubber cap 9a annular groove 9b flexure 10 earth retaining steel pipe 11 gap

Claims (5)

[Claims] 1. A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. The foundation beam or base plate shall be partially laid underground or in contact with the ground, and be filled with crushed stone or earth and sand between the foundation and the upper edge of concrete pile or rock. The basic seismic isolation structure of a building. 2. A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. The foundation beam or foundation plate is partly placed underground or in contact with the ground, and the space between these foundations and the upper edge of concrete pile or rock is filled with crushed stone or earth and sand, and A base seismic isolation structure for a building, wherein a high-strength rigid short rod is erected and fixed at the upper end of a concrete pile near the rubber composite seismic isolation element occupying portion. 3. A rubber composite seismic isolation element is interposed between a foundation beam or a bottom plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. The foundation beam or foundation plate is partly placed underground or in contact with the ground, and the space between these foundations and the upper edge of concrete pile or rock is filled with crushed stone or earth and sand, and A basic seismic isolation structure for a building, wherein a high-strength rigid short rod is vertically fixed to a lower surface of a foundation beam or a foundation bottom plate near the rubber composite seismic isolation element occupying portion. 4. A rubber composite seismic isolation element is interposed between a foundation beam or a base plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. The foundation beam or foundation plate is partly placed underground or in contact with the ground, and the space between these foundations and the upper edge of concrete pile or rock is filled with crushed stone or earth and sand, and A high-strength rigid short rod is erected and fixed at the upper end of the concrete pile near the rubber composite seismic isolation element occupation part. Basic seismic isolation structure for buildings, characterized by short rods fixed vertically. 5. A rubber composite seismic isolation element is interposed between a foundation beam or a bottom plate of a building and an upper edge of a concrete pile or an upper edge of a bedrock provided thereunder. A part of the foundation beam or foundation plate is placed underground or in contact with the ground, and an earth retaining steel pipe surrounding the rubber composite seismic isolation element is provided on the upper edge of the concrete pile or the upper edge of the rock. The upper edge is fixed to the foundation beam or foundation plate in a non-contact state, and the outside of the retaining steel pipe between the foundation and the upper edge of the concrete pile or rock is filled with crushed stone or earth and sand. The base seismic isolation structure of a building characterized by the following.