JP6501558B2 - Seismic isolation repair method - Google Patents

Description

  The present invention relates to, for example, a seismic isolation repair method for seismic isolation of an existing building.

2. Description of the Related Art There has been known a base isolation repair work to isolate existing buildings under the foundation.
In this foundation isolation repair work, a portion under the foundation of the existing building is excavated, a support is erected on the excavated portion, and a reaction force is applied to the bottom of the excavated portion to temporarily support the foundation. After that, attach a seismic isolation device such as laminated rubber immediately below the foundation, and then remove the jack. Thus, the building load temporarily supported by the jack is received by the seismic isolation device installed under the existing foundation. In this way, the base isolation system supports the foundation to isolate the existing building.

  However, in such a method, since the installation time differs depending on the seismic isolation device, the amount of shrinkage of the laminated rubber varies, and there is a possibility that the existing building sinks unevenly.

In order to solve this problem, it has been proposed to load the laminated rubber forcibly in advance in the direction of compression (hereinafter referred to as preload) and install the laminated rubber in this state.
In this way, since the compressive force acts on the laminated rubber in advance by the preload, it is possible to suppress the variation in the amount of contraction of the laminated rubber and to prevent the unequal settlement of the existing building.

For example, in Patent Document 1, a hydraulic jack is installed between upper and lower flange plates of laminated rubber, and the upper and lower flange plates are brought close to each other by this hydraulic jack to introduce a preload into the laminated rubber.
Further, in Patent Document 2, a wedge device is disposed in a cross shape between the upper flange plate of the laminated rubber and the frame of the existing building. Each wedge device receives a reaction force from a fixed wedge plate and a movable wedge plate disposed in close contact with each other in the upper and lower direction and a reaction force washer locked to the fixed wedge plate to move the movable wedge plate to the fixed wedge And a jack for moving the plate horizontally relative to the plate. According to this wedge device, the movable side wedge plate is moved relative to the fixed side wedge plate by the jack to introduce the preload into the laminated rubber.

Japanese Patent Application Laid-Open No. 10-280705 Patent No. 5437113 gazette

However, in the method of Patent Document 1, it is necessary to maintain the preload for a predetermined period after installing the seismic isolation device, but in the hydraulic jack, due to the structure, the oil inside the jack is maintained at high pressure for a long time Hard to hold. In addition, when receiving the building load from the hydraulic jack to the seismic isolation system, the laminated rubber is elastically deformed and the building sinks, so the hydraulic jack may not be removed for unloading.
Further, in the method of Patent Document 2, since four jacks are required, the cost is high. Further, in each wedge device, since the reaction force of the jack is fixed to the fixed wedge plate via the reaction force washer, the reaction force washer may be deformed by applying an excessive force to the reaction force washer, and the reaction force may not be obtained. .

  An object of the present invention is to provide a seismic isolation repair method capable of securely introducing a preload and easily holding the preload for a further long period of time, or reliably unloading the preload.

  The seismic isolation repair method according to claim 1 is a seismic isolation repair method for installing a seismic isolation device in a housing, wherein a temporary support member (for example, temporary support pillar 50 described later) is disposed around the housing. A step of temporarily supporting the housing by the temporary support member (for example, step S1 described later), cutting at least a part of the housing and removing the upper housing (for example, an upper housing described below) 10B) A process (for example, step S2 described later) for providing a space between the lower housing (for example, the lower housing 10A described later) and the lower housing of the housing, and the seismic isolation device is disposed on the lower housing Between upper and lower guides (for example, lower guides described below) which are provided between the upper housing and the seismic isolation device and the distance becomes narrower toward the central portion (for example, lower guides described later) 61 and upper guide 6 And a pair of wedge members (for example, tapered plates 63A and 63B described later) disposed between the pair of guides, and the pair of guides are engaged with each other to horizontally penetrate the pair of wedge members. A support member (for example, a support member 60 described later) including a connection member (for example, a PC steel rod 64 described later) extending in a direction, and a pair of sandwiching members between the wedge members and at both ends of the connection member A jack (for example, a hydraulic jack 65 described later) is installed, and a reaction force is applied to the connection member by the pair of jacks to push the pair of wedge members toward the central portion, thereby providing a shaft to the seismic isolation device. Fixing the position of the wedge member by introducing a force and receiving a load supported by the temporary support member into the support member (for example, steps S5 to S7 described later) A step of maintaining the introduced axial force (for example, step S8 described later) and a step of placing concrete between the upper housing and the upper surface of the seismic isolation device (for example, step S9, S10 described later) And.

  The seismic isolation repair method according to claim 2 is characterized in that the introduced axial force is maintained by locking the rear end of the pair of wedge members to the connection member.

According to the present invention, an axial force is introduced to the seismic isolation device by driving a wedge member between the upper casing and the upper surface of the seismic isolation device and pushing up the gap between the upper casing and the upper surface of the seismic isolation device. . Then, by fixing the position of the wedge member, the introduced axial force is maintained.
Therefore, since it is not necessary to maintain the axial force by the hydraulic jack as in the prior art, the preload can be maintained for a long time.

Also, since the wedge member is moved horizontally by the hydraulic jack to introduce axial force, the hydraulic jack is not configured to be installed between the upper housing and the upper surface of the seismic isolation device as in the prior art, so the hydraulic jack can be easily made It can be removed and the preload introduced can be reliably unloaded.
In addition, since the jacks are disposed at both ends of the connecting member and the jacks are driven by receiving a reaction force on the connecting members, the reaction forces of the jacks are canceled each other, so that the reaction force can be reliably taken, and the preloading can be performed. It can be introduced reliably.

It is sectional drawing of the existing pillar in which the seismic isolation apparatus was installed by the seismic isolation repair method which concerns on one Embodiment of this invention. It is sectional drawing of the seismic isolation apparatus which concerns on the said embodiment. It is a flowchart of the procedure of installing the seismic isolation apparatus which concerns on the said embodiment. It is explanatory drawing (the 1) of the procedure which installs the seismic isolation apparatus which concerns on the said embodiment. It is explanatory drawing (the 2) of the procedure which installs the seismic isolation apparatus which concerns on the said embodiment. It is explanatory drawing (the 3) of the procedure which installs the seismic isolation apparatus which concerns on the said embodiment. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG.

Hereinafter, an embodiment of the present invention will be described based on the drawings.
FIG. 1 is a cross-sectional view of an existing column 10 on which a seismic isolation device 20 is installed by a seismic isolation repair method according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the seismic isolation device 20.
Specifically, by installing the seismic isolation device 20 on the existing pillar 10 as a frame of the existing building 2, the seismic isolation structure 1 is constructed, and seismic isolation of the portion above the first floor level of the existing building 2 Do.

The existing pillar 10 is, for example, a pillar on the first floor below the existing building 2. The column base of the existing column 10 is joined to the first floor 11 in the basement, and the column head of the existing column 10 is joined to the first floor beam 12 and the first floor 13.
The seismic isolation apparatus 20 is installed in the middle height of the existing pillar 10, and the reinforcement frame 14 is constructed on the lower surface of the first floor beam 12.

The seismic isolation structure 1 includes the above-described seismic isolation device 20, a lower seismic isolation foundation 30 constructed including the lower column chassis 10A, and an upper seismic isolation foundation 40 constructed including the upper columnar chassis 10B. .
Lower base plate 31 is driven into the upper surface of lower seismic isolation base 30. On the lower base plate 31, a plurality of female screw parts 32 are arranged in an annular shape.
The upper base plate 41 is driven into the lower surface of the upper seismic isolation base 40. On the upper base plate 41, a plurality of female screw parts 42 are annularly arranged. Further, a support member 60 described later is driven into the upper seismic isolation foundation 40.

The seismic isolation device 20 includes a lower flange 21, a laminated rubber 22 provided on the lower flange 21, and an upper flange 23 provided on the laminated rubber 22.
The lower flange 21 is fixed to the female screw portion 32 of the lower base plate 31 of the lower seismic isolation base 30 with a bolt 24.
The upper flange 23 is fixed to the female screw portion 42 of the upper base plate 41 of the upper seismic isolation base 40 with a bolt 24.

  According to the installation procedure of the seismic isolation apparatus 20 shown in FIG. 3, in step S1, as shown in FIG. 4, a temporary support pillar 50 as a temporary support member is installed. First, the reinforcing frame 14 is constructed on the lower surface of the first floor beam 12. Next, a temporary support column 50 as a temporary support member is disposed in the vicinity of the existing column 10 where the seismic isolation device 20 is to be installed, and the temporary support column 50 temporarily mounts the first floor beam 12 from the underground first floor 11 Support.

  In step S2, as shown in FIG. 4, the existing column 10 is cut with a wire saw or the like, and the concrete frame in the middle part of the existing column 10 is removed, and the upper existing column 10 and the lower existing column 10 are removed. Provide a space between them. Here, the lower side of the portion where the seismic isolation device 20 of the existing column 10 is to be installed is referred to as a lower column body 10A as a lower housing, and the upper side of the portion where the seismic isolation device is to be installed is an upper column body 10B as an upper housing. .

  In step S3, as shown in FIG. 5, the lower seismic isolation foundation 30 is constructed. Specifically, the lower base plate 31 is mounted on the lower column body 10A, the reinforcement is arranged, the formwork is built, and concrete is cast in the formwork.

  In step S4, as shown in FIG. 5, the seismic isolation device 20 is attached on the lower base plate 31, and the upper base plate 41 is attached on the seismic isolation device 20. Studs 43 are fixed by welding on the upper base plate 41. In this state, a space is formed between the seismic isolation device 20 and the upper pillar body 10B.

In step S5, as shown in FIGS. 6-8, the support member 60 is installed between the upper pillar body 10B and the upper surface of the seismic isolation device 20.
The support member 60 is provided between the upper base plate 41 and the upper pillar body 10B, and the pair of upper and lower guides 61 and 62 whose distance in the vertical direction is narrowed as going to the central portion, and between the pair of guides 61 and 62 The pair of wedge-shaped wedge members, which are disposed horizontally opposite to each other, are engaged with taper plates 63A and 63B and a pair of guides 61 and 62 and extend horizontally through the pair of taper plates 63A and 63B. And a PC steel rod 64.

  The pair of guides 61 and 62 includes a lower guide 61 provided on the upper base plate 41 and an upper guide 62 provided below the upper column housing 10B.

The lower guide 61 includes a concrete body 70 built on the upper base plate 41 and a lower guide plate 71 driven into the upper surface of the concrete body 70.
A pair of side walls 72 is formed at the side edge of the upper surface of the lower guide plate 71, and a central wall 73 connecting the pair of side walls 72 is formed at the central portion of the upper surface. Here, portions on both sides of the upper surface of the lower guide plate 71 across the central wall 73 are referred to as guide surfaces 74A and 74B. The guide surfaces 74A and 74B are inclined surfaces and are higher toward the central wall 73.

The upper guide 62 has the same structure as the lower guide 61, and includes a concrete body 80 constructed under the upper column body 10B and an upper guide plate 81 driven into the lower surface of the concrete body 80.
A pair of side walls 82 is formed at the side edge of the lower surface of the upper guide plate 81, and a central wall 83 connecting the pair of side walls 82 is formed at the center of the upper surface. Here, portions on both sides of the lower surface of the upper guide plate 81 across the central wall 83 are referred to as guide surfaces 84A and 84B. The guide surfaces 84A, 84B are inclined surfaces and become lower toward the central wall 83.

Here, the central wall 83 of the upper guide plate 81 is disposed to face the central wall 73 of the lower guide plate 71, and the guide surfaces 84A and 84B of the upper guide plate 81 are also the guides of the lower guide plate 71. It is arrange | positioned facing surface 74A, 74B.
As a result, the distance between the guide surfaces 74A and 74B and the guide surfaces 84A and 84B becomes narrower toward the central walls 73 and 83 which is the central portion.

  The pair of taper plates 63A and 63B has a substantially rectangular parallelepiped shape. The lower surface and the upper surface of the pair of tapered plates 63A, 63B are inclined surfaces, and the distance from the lower surface to the upper surface becomes narrower toward the central walls 73, 83.

The PC steel rod 64 is locked to the central walls 73 and 83 of the upper guide plate 81 and the lower guide plate 71 via the pair of bearing plates 90 and nuts 91.
That is, the pair of bearing plates 90 is disposed to sandwich the central walls 73 and 83, and the PC steel rod 64 penetrates the pair of bearing plates 90. An internal thread is formed on the outer peripheral surface of the PC steel rod 64. A nut 91 is screwed to the outside of the pair of bearing plates 90 of the PC steel rod 64, and the PC steel rod 64 is centered by tightening the nut 91. Lock on the walls 73, 83.

Further, the outer end surfaces of the tapered plates 63A, 63B are engaged with the PC steel rod 64 via the pair of bearing plates 92 and nuts 93.
That is, the pair of bearing plates 92 is disposed on the outer end face of the tapered plates 63A and 63B, and the PC steel rod 64 penetrates the tapered plates 63A and 63B and the bearing plate 92. The nut 93 is screwed to the outside of the pair of bearing plates 92 of the PC steel rod 64.

In step S6, as shown in FIGS. 6-8, a pair of hydraulic jacks 65 as axial force introducing means is attached. That is, the hydraulic jack 65 exerts a reaction force on the PC steel rod 64 and pushes the pair of tapered plates 63A, 63B in the direction to approach each other, and sandwiches the tapered plates 63A, 63B of the support member 60 to make the PC steel rod. Located at both ends of 64.
The tip end face of the hydraulic jack 65 abuts on the outer end face of the pair of taper plates 63A, 63B.

The PC steel rod 64 is locked to the base end face of each hydraulic jack 65 via a pair of bearing plates 94 and a nut 95.
That is, the pair of bearing plates 94 is disposed on the outer end face of each hydraulic jack 65, and the PC steel rod 64 penetrates the hydraulic jacks 65 and the bearing plate 94. A nut 95 is screwed on the outside of the pair of bearing plates 94 of the PC steel rod 64, and by tightening the nut 95, the PC steel rod 64 is locked to the outer end surfaces of the taper plates 63A and 63B.

In step S7, as shown in FIGS. 6-8, the hydraulic jack 65 exerts a reaction force on the upper guide plate 81 and the lower guide plate 71 and pushes the pair of taper plates 63A and 63B in the direction in which they approach each other. Then, an axial force is introduced to the seismic isolation device 20 (preload).
That is, since the PC steel rod 64 is locked to the upper guide plate 81 and the lower guide plate 71, and the base end surface of the hydraulic jack 65 is locked to the PC steel rod 64, the hydraulic jack 65 The reaction can be taken on the upper guide plate 81 and the lower guide plate 71.

Then, the outer end surfaces of the pair of taper plates 63A and 63B are pressed by the end surface of the hydraulic jack 65.
Then, the tapered plate 63A slides on the guide surface 74A of the lower guide plate 71 and the guide surface 84A of the upper guide plate 81 to push and expand the distance between the guide surfaces. Further, the tapered plate 63B slides on the guide surface 74B of the lower guide plate 71 and the guide surface 84B of the upper guide plate 81 to push and expand the distance between the guide surfaces.

Thereby, an axial force is introduced between the upper column body 10B and the upper surface of the seismic isolation device 20, and the load of the existing building 2 supported by the temporary support column 50 is received by the support member 60.
At this time, the central walls 73, 83 serve as end stoppers for preventing the taper plates 63A, 63B from passing.

  In step S8, the introduced axial force is maintained. That is, the relative position of the taper plates 63A and 63B with respect to the upper guide plate 81 and the lower guide plate 71 is fixed by tightening the nut 93. Thus, the support member 60 is stretched between the upper column body 10B and the upper base plate 41, that is, the seismic isolation device 20.

In step S9, as shown in FIG. 2, the hydraulic jack 65 is unloaded and removed.
In step S10, as shown in FIG. 2, the upper seismic isolation foundation 40 is constructed. That is, the reinforcement is placed and the formwork is built, and concrete is placed in the formwork.

According to the present embodiment, the following effects can be obtained.
(1) By inserting taper plates 63A and 63B between the upper column body 10B and the upper surface of the seismic isolation device 20, and expanding the distance between the upper column body 10B and the seismic isolation device 20, the seismic isolation device 20 Introduce axial force (preload). Then, by fixing the positions of the taper plates 63A and 63B, the introduced axial force is maintained.
Therefore, since it is not necessary to maintain the axial force by the hydraulic jack as in the prior art, the preload can be maintained for a long time.

Further, since the taper plates 63A and 63B are horizontally moved by the hydraulic jack 65 to introduce axial force, the hydraulic jack is not installed between the upper housing and the upper surface of the seismic isolation apparatus as in the prior art. The jack 65 can be easily removed to reliably unload the introduced preload.
In addition, since the hydraulic jacks 65 are arranged on both ends of the PC steel rod 64 and these hydraulic jacks 65 are driven against the PC steel rod 64 with a reaction force, the reaction forces of the hydraulic jacks 65 cancel each other. Force can be taken reliably and preload can be introduced reliably.

The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like as long as the object of the present invention can be achieved are included in the present invention.
For example, in the present embodiment, the seismic isolation device is provided in the existing column, but the present invention is not limited thereto, a new foundation is constructed immediately below the existing foundation, and the seismic isolation device is provided between the new foundation and the existing foundation. It is also good.

DESCRIPTION OF SYMBOLS 1 ... Seismic isolation structure 2 ... existing building 10 ... existing pillar 10A ... lower column rod body (lower column body) 10B ... upper column rod body (upper column body)
11 ... basement 1 floor 12 ... floor 1 beam 13 ... floor 1 14 ... reinforcement frame 20 ... seismic isolation device 21 ... lower flange 22 ... laminated rubber 23 ... upper flange 24 ... bolt 30 ... lower isolation base 31 ... lower base plate 32 Female thread portion 40 Upper base isolation base 41 Upper base plate 42 Female thread portion 43 Stud 50 Temporary support post (temporary support member) 60 Support member 61 Lower guide 62 Upper guide 63A, 63B Tapered plate (Wedge member) 64 PC steel rod (connected member) 65 Hydraulic jack 70 Concrete body 71 Lower guide plate 72 Side wall 73 Central wall 74A, 74B Guide surface 80 Concrete body 81 Upper guide plate 82 ... side wall 83 ... central wall 84A, 84B ... guide surface 90 ... bearing plate 91 ... nut 92 ... bearing plate 93 ... nut 94 ... bearing Plate 95 ... nut

Claims (2)

It is a seismic isolation repair method of installing a seismic isolation device in a housing, and
Placing a temporary support member around the housing and temporarily supporting the housing with the temporary support member;
Cutting and removing at least a part of the casing, and providing a space between an upper upper casing of the casing and a lower casing below the casing;
Placing a seismic isolation device on the lower housing;
A pair of upper and lower guides which are provided between the upper housing and the seismic isolation device and whose distance is narrowed toward the central portion, a pair of wedge members disposed between the pair of guides, and the pair of And a connecting member which is engaged with the guide and extends horizontally through the pair of wedge members, and a side wall is formed on each side edge of the pair of guides, and each of the pair of guides is formed A central wall is formed at a central portion of the housing, and a support member for locking the connection member is installed on the central wall, and a pair of jacks are installed on both ends of the connection member with the wedge member interposed therebetween. By applying a reaction force to the connecting member by the pair of jacks and pushing the pair of wedge members toward the central portion, an axial force is introduced to the seismic isolation device and supported by the temporary support member Load A step of changing receiving the support member,
Maintaining the introduced axial force by fixing the position of the wedge member;
And D. placing concrete between the upper housing and the upper surface of the seismic isolation device.   The base isolation repair method according to claim 1, wherein the introduced axial force is maintained by locking the outer ends of the pair of wedge members to the connection member.

Images