JP2014114581A - Aseismic base isolation bearing mechanism and aseismic base isolation building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aseismic base isolation bearing mechanism enabling an aseismic base isolation device to be exchanged without imparting damage to a surrounding structure.SOLUTION: An aseismic base isolation bearing mechanism includes: a support part 10 formed integrally with a substructure and having a top face as a support face; vertical load receiving means 14 mounted on the support face; an aseismic base isolation device mounting table 18 mounted on the vertical load receiving means; and an aseismic base isolation device 26 mounted on the aseismic base isolation device mounting table. The vertical load receiving means includes a plurality of vertical load receivers 16 of equal height detachably held at least between the support face and the aseismic base isolation device mounting table. The vertical load receivers have jack insertion margins A mutually, and are arranged such that the load of the aseismic base isolation device can be supported only by the plurality of vertical load receivers. Horizontal load receiving means R is formed by projecting a shear key K from one surface part and a shear key reception part M from the other surface part, respectively, among parts corresponding to the support face and the underside of the aseismic base isolation device mounting table.

Description

  The present invention relates to a seismic isolation bearing mechanism and a seismic isolation building, and more particularly, to a seismic isolation support mechanism and a seismic isolation building that facilitate replacement of a seismic isolation device.

  The seismic isolation device is an important member that largely controls the seismic performance of the seismic isolation building, and should be able to be removed and replaced immediately in the event of a failure. Also, when investigating changes in performance over time for the purpose of periodic inspection and maintenance, it is desirable to remove the actual seismic isolation device actually used and conduct a test survey.

  However, exchanging seismic isolation devices that support the vertical load of a building is not easy. Even if only one seismic isolation device is replaced, the vertical load acting on the seismic isolation device is temporarily released, and a vertical clearance is secured directly above or below the seismic isolation device for replacement work. , Jack up part or all of the building.

  There is a high risk that a partial jack-up of the building will damage the upper frame, including the beams on the upper floor, by forcibly deforming it. For example, as shown in FIG. 11, considering that the upper frame is jacked up via a temporary support installed near the seismic isolation device, first, for the replacement of the seismic isolation device compression width e + the seismic isolation device due to the vertical load. Since the jack must be jacked up to a length corresponding to the clearance a, the upper casing is forced to be deformed. On the other hand, full jackup is unrealistic because it requires a large amount of hydraulic jacks and considerable work time and is therefore very costly. For these reasons, the seismic isolation bearing replacement work has hardly been carried out at present, except for a few cases conducted for research purposes.

Therefore, the following method has been proposed in order to eliminate the need for jacking up a part of or the entire building.
(1) After the vertical load supported by the laminated rubber of the seismic isolation structure is temporarily received by a jack, the laminated rubber is cooled and contracted to secure a vertical clearance for replacement work, and the laminated rubber is cooled and contracted at another place What to exchange (Patent Document 1).
(2) A structure in which a compression bolt protrudes from one of the upper and lower flanges of the laminated rubber for seismic isolation and a nut lock with a compression nut protrudes in the opposite direction from the other, and tightening the compression nut to the compression bolt A method of compressing and exchanging laminated rubber (Patent Document 2).
(3) Between the lower structure and the upper structure, the seismic isolation device and the vertical load receiving device are vertically stacked and joined to each other and to each structure, and the vertical load receiving device has a concave upper surface. A method of exchanging a seismic isolation device, comprising a concave member inclined to a concave part and a convex member fitted in the concave part, and allowing the concave part material to be divided into two parts in a horizontal direction by a dividing line passing through the concave part. (Patent Document 3).

JP 9-221921 A JP2011-132769A JP 2005-30107 A

  In the method of Patent Document 1, there are problems such as unclear performance due to cooling the laminated rubber to minus several tens of degrees Celsius, and difficulty in applying to the laminated rubber containing lead.

  In the method of Patent Document 2, since the compression stiffness of a general seismic isolation bearing device is as high as that of reinforced concrete, in order to cause compression deformation sufficient to ensure the vertical clearance required for replacement work, a compression bolt and It is necessary to introduce an axial force of several hundred to several thousand tons into the compression nut. Therefore, it is difficult to realize.

  In the method of Patent Document 3, in order to apply a vertical load of several hundreds to thousands of tons to the seismic isolation device to be inserted at the time of replacement and contract in the height direction, the concave member must be folded from the side like a wedge. It is difficult to implement.

A first object of the present invention is to propose a seismic isolation bearing mechanism or a seismic isolation building that enables a seismic isolation device to be replaced without damaging surrounding structures.
The second object of the present invention is to provide a seismic isolation bearing mechanism that allows the seismic isolation device to be replaced without requiring substantially lifting all or part of the superstructure as in the prior art. Propose a seismic isolation building.
The third object of the present invention is to propose a seismic isolation bearing mechanism or a seismic isolation building that enables the seismic isolation device to be removed and returned from the space between the lower structure and the upper structure any number of times. is there.

The first means is a seismic isolation bearing mechanism provided between the lower structure and the upper structure,
A support part formed integrally with the lower structure and having the upper surface as a support surface;
Vertical load receiving means placed on the support surface;
A base isolation device mounting table mounted on the vertical load receiving means;
A seismic isolation device for supporting the lower surface of the superstructure, which is placed on the base for mounting the seismic isolation device;
Comprising
The vertical load receiving means includes a plurality of vertical load receivers that are detachably sandwiched between at least the support surface and the base isolation device mounting base, and these vertical load receivers are arranged between adjacent vertical load receivers. In order to support the load of the seismic isolation device only by the plurality of vertical load receivers,
Out of the parts corresponding to the support surface and the lower surface of the seismic isolation device mounting base, the shear key is provided from one surface portion, and the shear key receiving portion that surrounds the periphery of the shear key from the other surface portion is slidable in the vertical direction. By projecting, it forms a horizontal load receiving means,
The height of each vertical load receiver is set so that a space for securing a lowering allowance of the seismic isolation device mounting table is formed between the support portion and the seismic isolation device mounting table,
The seismic isolation device can be replaced between the base isolation device mounting table and the upper structure by lowering the base isolation device mounting table in a state where the plurality of vertical load receivers are detached.

  As shown in FIG. 1, this means proposes a seismic isolation bearing mechanism in which a vertical load receiving means 14 and a horizontal load receiving means R are provided between a support portion 10 and a base isolation device mounting table 18. The horizontal load receiving means R is configured to allow the seismic isolation device mounting table 18 to move up and down with the shear key K and the shear key receiving portion M (see FIG. 5). Thereby, the seismic isolation device 26 can be replaced without damaging the upper structure 4 by lowering the seismic isolation device mounting table 18.

The second means has the first means, and the horizontal load receiving means is formed at the center of the back surface of the seismic isolation device mounting table 18 and the support surface portion facing the back surface,
In addition, a plurality of vertical load receivers are arranged around the horizontal load receiving means at a certain interval as the jack insertion allowance.

  In this means, as shown by a dotted line in FIG. 4, for example, the horizontal load receiving means R is provided on the center side of the seismic isolation device mounting table 18, and the vertical load receiver 16 is arranged around the horizontal load receiving means R. Thereby, a horizontal load and a vertical load can be received with good balance.

The third means is a seismic isolation building,
A substructure,
The superstructure,
The first means provided with the lower structure and the upper mechanism and the seismic isolation bearing mechanism described in the second means,
A space for installing a temporary support is provided at least between the upper surface portion of the lower structure and the lower surface portion of the upper structure near each seismic isolation support mechanism.

  This means provides a seismic isolation building having the seismic isolation support mechanism 8 including the above-described seismic isolation device mounting table 18. In the vicinity of the seismic isolation support mechanism 8, a space S for provisional support installation is provided. As a result, the vertical load originally supported by the seismic isolation support mechanism can be temporarily supported by the temporary support C, so that the work related to the replacement of the seismic isolation support mechanism 8 is not hindered and the seismic isolation device can be easily provided. Can be removed and attached. In addition, you may provide an auxiliary reinforcing bar etc. in advance in the site | part which a temporary support | pillar contact | abuts.

According to the invention relating to the first means and the third means, since the shear key and the shear key receiving portion that allow the base isolation device to move up and down are provided between the base isolation device mounting base and the support portion, The apparatus can be easily replaced, and damage to the superstructure can be reduced or eliminated.
According to the second aspect of the invention, the horizontal load receiving means is formed at the center of each of the back surface of the seismic isolation device mounting table and the support surface portion facing the back surface, and the jack insertion allowance is formed around this. Since a plurality of vertical load receivers are arranged at a certain interval, the seismic isolation device mounting table can be stably supported.

It is a front view of the base isolation building part around the base isolation bearing mechanism and base isolation bearing mechanism concerning a 1st embodiment of the present invention. It is II-II direction sectional drawing of the seismic isolation bearing mechanism of FIG. It is a front view of the seismic isolation apparatus mounting base of the seismic isolation support mechanism of FIG. It is sectional drawing of the seismic isolation bearing mechanism shown in the state which mounted | wore the 1st jack with the seismic isolation bearing mechanism of FIG. It is explanatory drawing of the horizontal load receiving means of the seismic isolation bearing mechanism of FIG. 1, The figure (A) shows the longitudinal cross-sectional view of the said horizontal load receiving means, and the figure (B) has shown the exploded sectional view. FIG. 2 is a diagram for explaining the normal operation of the seismic isolation bearing mechanism shown in FIG. 1, in which FIG. (A) is a front view of the seismic isolation bearing mechanism for supporting a vertical load, and FIG. It is the figure seen in. It is explanatory drawing which shows the process of the work which removes a seismic isolation apparatus from the seismic isolation bearing mechanism of FIG. 1, the figure (A) is the figure which looked at the said work from the front, and the figure (B) shows the said work in cross section. It is a figure. It is explanatory drawing which shows the process which attaches a seismic isolation apparatus to the seismic isolation bearing mechanism of FIG. 1, The figure (A) is the figure which looked at the said work from the front, The figure (B) is the figure which looked at the said work in cross section It is. It is a front view which shows one modification of the seismic isolation bearing mechanism of FIG. It is a front view which shows the other modification of the seismic isolation bearing mechanism of FIG. It is explanatory drawing which shows the removal operation | work of the conventional seismic isolation apparatus shown as a comparative example with this invention, The figure (A) is a figure which shows the normal use state by which the seismic isolation apparatus was compressed by the vertical load, B) is a view of the seismic isolation device returned to its natural length by jacking up the side jack, and FIG. C is a gap between the seismic isolation device and the superstructure from the state of FIG. It is a figure of the state further jacked up.

  1 to 10 show a seismic isolation building according to the first embodiment of the present invention. This base isolation building includes a lower structure 2, an upper structure 4, and a base isolation support mechanism 8.

  The lower structure 2 is a conventionally known structure, and is configured as a basis in the illustrated example. The foundation includes a ground 2a, a pile 2c driven into the ground 2a, and a surface layer portion 2b covering the surface of the ground 2a excluding a place where the pile 2c is driven and a place where a support portion 10 described later is installed. This structure can be changed as appropriate. Unlike the example shown, for example, the lower half of a multi-layer building

  In the illustrated example, the upper structure 4 is a building portion supported by a foundation. However, the lower half of this building part is constructed separately as the lower structure and the upper half is constructed as the upper structure, and this structure is used for the intermediate seismic isolation device inserted between the lower structure and the upper structure. You may apply the seismic isolation bearing mechanism of invention. The present invention is particularly expected to be applied to nuclear power generation facilities that are required to strengthen the degree of aging of structure performance and buildings (hospitals, fire stations, police stations, etc.) that serve as disaster prevention bases in the region. The In the illustrated example, the column 5 of the upper structure 4 is located above the pile 2 c and is supported by the seismic isolation support mechanism 8. A first beam 6 </ b> A and a second beam 6 </ b> B that are orthogonal to each other are continuously connected to the column 5.

  In the illustrated example, the intersection 6C of the first beam 6A and the second beam 6B is formed thick in the vertical direction and the horizontal direction. On the lower surface of the intersection 6C, a fixing plate 7 fixed by a fixture 7a embedded in the intersection is provided.

  The seismic isolation support mechanism 8 includes a support portion 10, a vertical load receiving means 14, a seismic isolation device mounting table 18, and a seismic isolation device 26.

  The support portion 10 is formed integrally with the lower structure 2 and has rigidity for supporting the vertical load of the upper structure 4. Note that “integrated with the lower structure” originally includes being formed as a part of the lower structure and connecting the lower structure and a separate member so as to be capable of resisting external force. Shall be. In the former case, a part of the lower structure 2 may be used as the support portion 10.

  In the present embodiment, the support portion 10 is formed in a substantially rectangular shape protruding upward from the lower structure 2, and the shear key K is raised from the center portion of the upper surface of the pedestal portion 10 a, and the upper surface portion excluding the center portion is formed. A support surface 10c for supporting a vertical load receiver 16 described later is used.

  The shear key K has a strength capable of resisting a horizontal load received from the upper structure 4 during an earthquake. In a preferred illustrated example, a cover member 12 having a cap-like portion 12a is formed of a steel material or the like at a substantially central portion of the pedestal portion 10a. Has been established. However, this structure can be changed as appropriate. The cover member 12 is part of a means for receiving a horizontal load.

  The vertical load receiving means 14 has a function of supporting the vertical load from the base isolation device mounting table 18 while maintaining the horizontal state of the base isolation device mounting table, and is configured to be detachable from the support portion 10. Has been. The vertical load receiving means 14 of the present embodiment is composed of a plurality of vertical load receivers 16 that are detachably mounted on the support surface 10c of the support portion 10, but the structure can be changed as appropriate. These vertical load receivers 16 are arranged with a certain gap (jack insertion allowance A) between them so as to surround the convex portion 10b on the support surface 10c, and have the same height. desirable. The vertical load receiver 16 in the illustrated example is configured as a member having a substantially constant height and a constant height. Instead, a so-called giraffe jack (a jack that expands and contracts in the axial direction using the rotation of a screw) is employed. May be. Thus, since the height of the vertical load receiver 16 using the giraffe jack can be adjusted freely, the distance between the positions where the vertical load receiver 16 should be installed (the distance between the upper surface of the support surface 10c and the lower surface of the base plate 19) is set. In addition, the construction error of the interval can be absorbed and workability is improved.

  The base isolation device mounting table 18 has a horizontal base plate 19 for mounting the base isolation device, and is supported by placing the outer periphery of the base plate 19 on the plurality of vertical load receivers 16. Yes. A shear key receiving portion M is provided on the rear surface of the center portion of the base plate 19 so as to surround the shear key K so as to be movable up and down. The shear key K and the shear key receiving portion M constitute a horizontal load receiving means R. The shear key K is formed as a rigid convex portion protruding in the vertical direction in the illustrated example. However, any shear structure can be used as long as the seismic isolation device mounting table 18 can be raised and lowered and can resist horizontal force. It may be a thing. Further, the shear key receiving portion M is formed as a receiving tube portion extending in the vertical direction in the illustrated example, but any structure may be used as long as the shear key K can be prevented from coming out in an arbitrary horizontal direction.

  The height of the vertical load receiver 16 is set so that a gap G for lowering the seismic isolation device mounting table is generated between the tip of the shear key K and the base plate portion inside the shear key receiving portion M. To do.

In a preferred illustrated example, a plurality of reinforcing plates 24 joined to the outer surface of the shear key receiving portion M and the outer peripheral portion of the base plate 19 are provided so as to increase the resistance to horizontal loads. However, the reinforcing plate 24 can be omitted. In the present embodiment, a series of gaps that are partitioned by these reinforcing plate 24, is provided so as to be able to insert the vertical load receiving 16 and first jack J ₁ as shown by the dotted line alternately in FIG. 4 Yes. In the present specification, the jack is preferably a hydraulic jack.

  The seismic isolation device 26 is inserted into the upper surface of the seismic isolation device mounting table 18 and the lower surface of the upper structure 4. The seismic isolation device 26 has a conventionally known configuration, and can be, for example, a laminated rubber seismic isolation device in which steel plates and rubber plates are alternately stacked and bonded. The seismic isolation device 26 includes a lower flange portion 28L and an upper flange portion 28U. The lower flange portion 28L is provided on the base isolation device mounting table 18, and the upper flange portion 28U is provided on the upper structure 4, such as bolts and nuts. The fixture 30 is detachably fixed.

  The seismic isolation device 26 is not limited to the laminated rubber seismic isolation device, and any seismic isolation device may be used as long as it can be compressed and deformed to some extent by a vertical load. A sliding bearing isolation device or a rolling bearing isolation device may be used.

  A space around the seismic isolation support mechanism 8 is an open space where workers can enter and exit, and a space S for provisional strut installation is provided between the lower structure 2 and the upper structure 4 in the vicinity of the seismic isolation support mechanism 8. Exists (see FIG. 6).

  In the above configuration, the seismic isolation bearing mechanism 8 supports the vertical load from the upper structure 4 by exhibiting the supporting force indicated by the black arrows in FIG. The shear key K and the shear key receiving portion M of the seismic isolation bearing mechanism 8 exert a horizontal supporting force against the shaking of the earthquake and have a gap G. Relative vertical displacement is possible. Further, the vertical load receiving means 14 exhibits a vertical supporting force facing the upper structure 4. Next, replacement work of the seismic isolation device will be described with reference to FIGS. These FIGS. 7 and 8 exaggerate the movement of the seismic isolation bearing mechanism than it actually is.

First stage of seismic isolation device removal process (see Fig. 7 {A1} and {B1})
In the state of FIG. 6, it is assumed that the seismic isolation device 26 is compressed and deformed by d in response to the vertical compression load W from the upper structure 4. When exchanging the seismic isolation device from this state, first, the first jack J ₁ is prepared, and the temporary support C between the upper surface of the lower structure 2 and the lower surface of the upper structure 4 near the seismic isolation support mechanism 8. and second inserting the jack _{J 2.} Then superstructure 4, the provisional strut C, and Tightened bolts or the like so that it can resist the second tensile force between the jack J ₂ and the lower structure 2.

Second stage of seismic isolation device removal process (see Fig. 7 {A2} and {B2})
The first jack J ₁ is inserted into each jack insertion allowance A of the seismic isolation bearing mechanism 8. The base plate 19 is jacked up by the displacement Δd above the reference horizontal plane H by the first jack J ₁ to compress the seismic isolation device 26 sandwiched between the base plate 19 and the upper structure 4 by Δd. . In this case the first jack J ₁ is a load to push the seismic isolation device 26 with W + [Delta] W, and thus the upward force acts [Delta] W is the upper structure 4. To counteract this, pulling ΔW downwardly upper structure 4 with the second jack J _2. In this state, a gap Δd is formed between the upper surface of each vertical load receiver 16 and the base plate 19, so that these vertical load receivers 16 are taken out between the support portion 10 and the base plate 19. In order to facilitate the take-out operation, a sliding material made of a resin composition containing, for example, a tetrafluoroethylene-based resin as a main component, for example, Teflon (registered trademark), which is well known as a representative, is provided on the upper and lower surfaces of the vertical load receiver 16. If a sheet such as a material having a low friction coefficient and good sliding performance is attached in advance, ΔW and Δd can be set to very small values.
Then replace receiving the weight of the upper structure 4 from the first jack J ₁ to the first jack J _2. That is, the upward load W + ΔW of the first jack J ₁ is gradually reduced to zero, and the downward load ΔW of the second jack J ₂ is gradually increased to the upward load W. This task, isolator 26 can be replaced undergoing weight W of the upper structure 4 which was in charge to the temporary strut C and the second jack J _2.

Third stage of seismic isolation device removal process (see Fig. 7 {A3} and {B3})
Then operating the upper flange portion 28U together with removing the fixture for fixing the upper structure 4 side, each first jack J ₁ so as to jack down to below the reference horizontal surface H of the base plate 19 of the isolator 26 To do. Then, since the seismic isolation device 26 is lowered together with the base plate 19, a gap is generated between the seismic isolation device 26 and the lower surface of the upper structure 4. Next, the fixing tool for fixing the lower flange portion 28L of the seismic isolation device 26 to the seismic isolation device mounting base 18 is removed, and the seismic isolation device 26 may be removed as indicated by a white arrow. A forklift or the like may be used to remove the seismic isolation device 26.

Installation process of seismic isolation device (see Fig. 8)
The installation process of the seismic isolation device 26 may be performed in the reverse order of the removal process. That is, as shown by an imaginary line in {A4} of FIG. 8, the seismic isolation device 26 is placed on the seismic isolation device mounting table 18, and its lower flange portion 28L is fixed to the seismic isolation device mounting table 18 side. . Then by the first jack J ₁ as {A5} in Figure 8, the isolator mounting table 18 is jacked up, to fix the upper flange portion 28U on the upper structure side. Then replace receiving the weight of the upper structure 4 from the second jack J ₂ in the first jack J _1. That at the same time as gradually downward load [Delta] W the second upward load W of the jack J _2, to gradually upward load W + [Delta] W the first load of the jack J ₁ from zero. Thereafter, the vertical load receiver 16 is inserted between the base plate 19 and the support portion 10 by using the generated gap Δd. Next, the loads of the first jack J ₁ and the second jack J ₂ are both reduced to zero, and the load of the upper structure 4 is returned to the vertical load receiver 16. The first jack _{J 1} further continue the jack down, take out the first jack _{J 1} from between the base plate 19 and the support surface 10c. Thereafter the may be removed to temporary posts C and the second jack J _2.

[Example]
FIG. 9 shows an embodiment in which the cap-shaped portion 12a of the cover member 12 is solid as a modification of the horizontal load receiving means R. The cover member 12 can be integrally formed of steel or the like as a whole.
FIG. 10 shows, as a modification of the horizontal load receiving means R, a state in which the shear key K protrudes from the seismic isolation device mounting table 18 side and the shear key receiving portion M protrudes from the support portion 10 side.

  It should be understood that the above embodiment has been given for the purpose of describing the present invention, and the scope of the present invention is not limited to this embodiment.

DESCRIPTION OF SYMBOLS 2 ... Lower structure 2a ... Ground 2b ... Surface layer part 2c ... Pile 4 ... Upper structure 5 ... Column 6A ... 1st beam 6B ... 2nd beam 6C ... Intersection 7 ... Reinforcement plate 7a ... Mounting tool 8 ... Seismic isolation bearing Mechanism 10 ... Supporting part 10a ... Pedestal part 10c ... Supporting surface 12 ... Cover member 12a ... Cap-like part 12b ... Hook part 12c ... Leg part 14 ... Vertical load receiving means 16 ... Vertical load receiving part
DESCRIPTION OF SYMBOLS 18 ... Base isolation device mounting base 19 ... Base plate 20 ... Shear key receiving part 22 ... Horizontal load receiving means 24 ... Reinforcement plate 26 ... Seismic isolation device 28U ... Upper flange part, 28L ... Lower flange part A ... Jack insertion allowance C ... temporary post G ... gap H ... horizontal reference plane J 1 _... first jack J 2 _... second jack
K ... Shear key M ... Shear key receiving part R ... Horizontal load receiving means

Claims (3)

A seismic isolation mechanism provided between the lower structure and the upper structure,
A support part formed integrally with the lower structure and having the upper surface as a support surface;
Vertical load receiving means placed on the support surface;
A base isolation device mounting table mounted on the vertical load receiving means;
A seismic isolation device for supporting the lower surface of the superstructure, which is placed on the base for mounting the seismic isolation device;
Comprising
The vertical load receiving means includes a plurality of vertical load receivers that are detachably sandwiched between at least the support surface and the base isolation device mounting base, and these vertical load receivers are arranged between adjacent vertical load receivers. In order to support the load of the seismic isolation device only by the plurality of vertical load receivers,
Out of the parts corresponding to the support surface and the lower surface of the seismic isolation device mounting base, the shear key is provided from one surface portion, and the shear key receiving portion that surrounds the periphery of the shear key from the other surface portion is slidable in the vertical direction. By projecting, it forms a horizontal load receiving means,
The height of each vertical load receiver is set so that a space for securing a lowering allowance of the seismic isolation device mounting table is formed between the support portion and the seismic isolation device mounting table,
The seismic isolation device can be replaced between the base isolation device mounting base and the upper structure by lowering the base isolation device mounting base in a state where the plurality of vertical load receivers are separated. , Seismic isolation mechanism. The horizontal load receiving means is formed at the center of the back surface of the base isolation device mounting table and the support surface portion facing the back surface,
2. The seismic isolation bearing mechanism according to claim 1, wherein a plurality of vertical load receivers are arranged around the horizontal load receiving means at a predetermined interval as the jack insertion allowance. A substructure,
The superstructure,
A plurality of seismic isolation bearing mechanisms according to claim 1 or 2 provided with a lower structure and an upper mechanism;
A space for installing a temporary support is provided at least between the upper surface portion of the lower structure and the lower surface portion of the upper structure near each seismic isolation bearing mechanism.
Base-isolated building.