JP2002309593A - Method of base-isolating existing building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of base-isolating an existing building at low cost and in a short period of construction work by simplified processes. SOLUTION: The lower portion of a foundation 3 of an existing building 1 is dug so that an existing pile 4 is exposed and a new foundation 10 is placed at the bottom of the dug part in such a manner as to wrap the existing pile 4. The foundation 3 is supported by support 12 on the new foundation 10 and the existing pile 4 is cut. A mat slab 13 (base-isolated foundation) is placed to continue with both an additional pile 11 newly provided adjacent the existing pile 4 and the new foundation 10, and a base isolation device 15 is installed between the mat slab 13 and the foundation 3 to support the foundation 3. Thereafter, the support 12 is removed and the existing building 1, together with a bearing part 17 serving as a component member above the base isolation device 15, is moved to the upper portion of the additional pile 11 along a slide plate 16 which is a component member below the base isolation device 15 fixed on the mat slab 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation method using an existing building as a seismic isolation building, and more particularly to a seismic isolation method capable of pulling an existing building into a seismic isolation system in a simple process.

[0002]

2. Description of the Related Art Conventionally, when an existing building is seismically isolated, a clearance between the existing building and a boundary of an adjacent land or an adjacent building is required to be larger than a maximum horizontal displacement expected at the time of a large earthquake. In the case of seismic isolation, if the clearance cannot be obtained, it is necessary to move the existing building away from the border of the adjacent land or the adjacent building. In this case, as the first step, while excavating around the building, excavating under the foundation and placing a mat at the bottom of the excavation, temporarily supporting the building with temporary support materials on the mat, and installing additional piles at the destination I do. As a second step, the mat is extended to the pile, the foundation is supported on the mat, the existing pile is cut, and a support material such as sandals is stacked on rolling materials such as rollers to support the building.

Further, as a third step, the temporary support material is removed, and the building is moved on the rolling material using a jack. As a fourth step, the building is temporarily supported by the temporary support material again at the destination, the support material such as sandals is removed, and the rolling material is removed. The fifth step is to build a seismic isolation base on the mat and install a seismic isolation device on the seismic isolation foundation to support the building. As the sixth step, the temporary support materials are removed, and the building is isolated from seismic isolation. In this way, each step of the so-called Hikiya construction method needed to be relocated to support the existing pile position, although it moved slightly back and forth, and moved to the position of the additional pile and supported again. .

[0004]

By the way, the seismic isolation method for an existing building having the above-mentioned structure requires a large load because the building load is supported before and after the pulling bar even when the building is moved in the horizontal direction by several tens cm to 1 m. Need to set up support and change support. For this reason, there has been a problem that the process is complicated, the cost is increased, and the construction period is prolonged. In addition, since the process is complicated, there is a possibility that the safety of the operation is reduced.

The present invention has been made in view of such a problem, and an object of the present invention is to complete a pulling bar without changing the support, simplify the process, and reduce the cost. To provide a short-period seismic isolation method. Another object of the present invention is to provide a seismic isolation method that increases the safety of a building during construction.

[0006]

In order to achieve the above object,
According to the seismic isolation method of an existing building according to the present invention, in the seismic isolation method of renovating the existing building by interposing a seismic isolation device below the foundation of the existing building, the seismic isolation method using the interposed seismic isolation device is used. It is characterized by moving the building in the horizontal direction. In the above-described seismic isolation method, the seismic isolation device is composed of a portion fixed to the upper existing building side and a portion fixed to the lower foundation side, and it is preferable that both portions can be separated or relatively moved.

The seismic isolation method for an existing building according to the present invention excavates a lower part of the foundation of the existing building so that the existing pile is exposed, and casts a new foundation at the bottom of the excavation with the existing pile wrapped. Then, the existing pile is cut by supporting the foundation with the support material on the new foundation, and the seismic isolation base is placed continuously above the newly installed additional pile and the new foundation adjacent to the existing pile, A seismic isolation device is installed between the foundation and the foundation to support the foundation, the support material is removed, and the seismic isolation device and the existing building are increased along the seismic isolation foundation and moved to the top of the pile. I do.

In the above-described seismic isolation method for an existing building, the seismic isolation device is composed of a lower sliding plate portion and an upper bearing portion, and the sliding plate portion is installed along the upper surface of the base. Is preferably moved on the sliding plate portion. In addition, additional piles newly constructed adjacent to the existing piles may be newly constructed after excavating the lower part of the foundation, newly constructed after placing the new foundation, or newly constructed after cutting the existing pile. Any time, as long as it is newly constructed before the foundation is cast.

According to the seismic isolation method for an existing building of the present invention thus constructed, the existing building can be moved in the horizontal direction by using a seismic isolation device interposed under the foundation of the existing building, thereby simplifying the process. it can. The part fixed to the upper existing building, which is the upper component of the seismic isolation device, can be moved from the portion fixed to the lower foundation side, which is the lower component of the seismic isolation device, When moving a building by the Hikiya method,
It is not necessary to support the foundation with the support material many times, the process can be simplified, the work can be completed in a short period of time, and the cost can be reduced. Further, the safety of work can be improved by simplifying the process.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the seismic isolation method for an existing building according to the present invention will be described below in detail with reference to the drawings. The drawings show the steps of the seismic isolation method of the existing building according to the present embodiment, FIG. 1 is a cross-sectional view of a main part of the existing building, FIG. 2 is a cross-sectional view of a state where the foundation is excavated, and FIG. Sectional view of a state in which a new foundation is cast, a foundation is supported, and an additional pile is newly constructed, (b)
FIG. 4A is a cross-sectional view taken along the line AA of FIG. 4A, FIG. 4A is a cross-sectional view of a state where the existing pile is cut, FIG. 4B is a cross-sectional view taken along the line BB of FIG.
FIG. 5A is a cross-sectional view of a state where a mat slab is cast.
6B is a cross-sectional view taken along line CC of FIG. 7A, FIG. 6A is a cross-sectional view showing a state where the seismic isolation device is installed, FIG. 6B is a cross-sectional view taken along line DD of FIG. (a) is a sectional view of a state in which the seismic isolation device has been moved, and (b) is a sectional view taken along line EE of (a).

In FIG. 1, an existing building 1 has a foundation and
An independent foundation 3 is provided at a position corresponding to the pillar 2 of the building, and the independent foundation 3 is supported by a lower pile 4. The pile 4 is an existing pile, and its lower end is not shown, but reaches the ground having a sufficiently large ground strength, and in this example, nine concrete pile piles are used as described later. The independent foundations 3 are connected by an underground beam 5, and a slab floor 6 is formed above the underground beam 5. In this example, the upper surface of the slab floor 6 matches the GL surface of the ground. A method of installing a seismic isolation device below the foundation of the existing building 1 having such a configuration and moving the existing building horizontally by using the seismic isolation device will be described in detail below. .

As shown in FIG. 2, as a first step,
While excavating around the building, the lower part of the foundation 3 of the existing building 1 is excavated so that the existing pile 4 is exposed. This excavation depth is excavated from the lower surface of the foundation 3 to the UL surface corresponding to the sum of the thickness of the mat slab described later and the height of the seismic isolation device. Although not shown, a cut beam, a retaining wall, a retaining wall, or the like is formed on a vertical plane connecting the GL plane and the UL plane as necessary. Then, after dumping concrete (not shown) at the bottom of the excavation, a new foundation 10 having a thickness of about 1 m is laid down from the UL surface as shown in FIG. Then, the existing pile 4 and the new foundation 10 are connected. That is, for example, a plurality of stud bolts (not shown) are planted in a portion of the existing pile 4 where the new foundation 10 is to be cast, and the new foundation 10 is cast with reinforced concrete so as to embed the stud bolts. The pile 4 and the new foundation 10 are brought into close contact with each other. In this example, the existing pile 4
Nine are arranged vertically and horizontally, and the new foundation 10 is formed in a square shape so as to surround the nine existing piles 4.

Next, an additional pile 11 is newly installed adjacent to the existing pile 4. For example, when the existing building 1 is seismically isolated, the additional pile 11 is newly installed in the retreating direction when retreating from an adjacent land boundary in consideration of the maximum horizontal displacement at the time of the earthquake.
The same pile is used. That is, when the existing pile is a friction pile, it is preferable to newly install a friction pile for the additional pile, and when the existing pile is a site development pile, it is preferable to newly construct a field pile for the additional pile.
In this example, nine additional piles similar to the existing pile 4 are juxtaposed. The newly installed additional pile may be formed of a different pile such as a steel pipe press-fitting pile.

As a second step, as shown in FIG.
A plurality of support members 12 support the foundation 3 from the new foundation 10 and cut the existing pile 4. The support member 12 includes a beam member 12a for supporting the outer and inner ends of the foundation 3 and jacks 12b for supporting both ends of the beam member. The jack 12 is vertically adjusted with respect to the new foundation 10. The plurality of foundations 3 are supported while keeping the horizontal state. The existing pile 4 is cut off by removing the concrete at the top of the new foundation 10,
The upper part is curved by protruding the reinforcing bar by a predetermined length. In addition, it is preferable that the reinforcing bar is exposed by peeling the upper concrete portion of the additional pile 11 and the upper portion is curved.

Then, in this cut portion, as shown in FIG. 5, a mat slab 13 as a seismic isolation base continuous with the additional pile 11 and the new foundation 10 is cast over the new foundation 10. At this time, the reinforcing bar of the existing pile 4 and the additional pile 11
After the reinforcing bars of the mat slab 13 are connected to the reinforcing bars of the mat slab 13, the mat slab 13 is cast. The mat slab 13 is made of reinforced concrete having a thickness of about 1 m, and is formed so that the upper surface is horizontal. In addition, although the example of the mat slab was shown as the seismic isolation foundation, an independent foundation may be continuous.

After the mat slab 13 is solidified, the seismic isolation device 15 is installed between the mat slab 13 and the foundation 3 as shown in FIG. Here, the upper part fixed to the foundation 3 on the existing building side,
The seismic isolation device 15 composed of a portion fixed to the mat slab 13 side, which is a lower foundation, will be described in detail. The seismic isolation device 15 used in the present embodiment is an elastic sliding bearing type seismic isolation device, and includes a sliding plate 16 fixed to the mat slab 13 and a bearing 17 located above the sliding plate 16. The support 17 is supported on the foundation 3 via the base plate 18. The support portion 17 includes a flange portion 17a fixed to the base plate 18 and a height adjusting portion 1 below the flange portion 17a.
7b, and a lower laminated rubber portion 17c.

The sliding plate 16 has a thin plate such as a stainless steel plate fixed on a thick iron plate, for example, and its upper surface is polished to a mirror-finished smooth surface. The slide plate 16 is formed so as to extend horizontally from the position of the existing pile 4 to the position of the additional pile 11, and has a narrow horizontally-long rectangular moving portion 16 a corresponding to the upper part of the existing pile 4, and an upper part of the additional pile. And a corresponding wide square-shaped installation portion 16b. Sliding plate 1
Reference numeral 6 denotes an outer peripheral portion fixed to the mat slab 13 by an anchor bolt or the like, and a central portion thereof is a sliding area where the support portion 17 can slide.

The bearing 17 includes a horizontally deformable laminated rubber portion 17c formed by laminating several layers of a steel plate and a rubber plate, for example, below a height adjusting portion 17b for adjusting the bearing height. The lower surface of the rubber portion 17c is formed of a metal plate that has been subjected to processing such as Teflon (registered trademark) processing. For this reason, the friction coefficient μ between the sliding plate 16 and the lower surface of the laminated rubber portion 17c is set to be 0.1 or less.
The elastic sliding bearing type seismic isolation device 15 does not directly transmit the ground displacement at the time of the earthquake to the building, but attenuates the shaking of the earthquake by elastic deformation and sliding.

The seismic isolation device 15 is provided with a deformation restraining jig 19 so as not to be deformed when moving in the next step. As shown in FIG. 8, the deformation restraining jig 19 has a shape that covers the outer periphery of the cylindrical laminated rubber portion 17c, and for example, two restraining members 19a obtained by bisecting a cylindrical metal member in the axial direction. , 19b connected by bolts and nuts. The laminated rubber portion 17c can be appropriately used such as one having a lead plug attached at the center to improve the damping performance, one having a rubber plate formed of high damping rubber, or the like.

As shown in FIG. 6, a sliding plate 16 as a component below the seismic isolation device 15 is fixed from the existing pile 4 on the upper surface of the mat slab 13 to the additional pile 11. in this case,
For example, although not shown, an anchor bar is fixed to the upper surface of the mat slab 13, and a reinforcing bar is arranged so as to surround the anchor bolt cap nut planted on the lower surface of the slide plate 16 and the anchor bar. A grout filling method in which a non-shrink mortar is injected between the mortar and the sliding plate 16 is suitable.
In addition, a bearing 17 which is a component member above the seismic isolation device 15.
The base plate 18 is fixed to the lower surface of the base 3 by fixing an anchor bar to the lower surface of the base plate 3 and arranging reinforcing bolts to surround the anchor bolt cap nuts and the anchor bar planted on the upper surface of the base plate 18. Then, non-shrink mortar is injected between the lower surface of the base 3 and the upper surface of the base plate 18. Then, the flange portion 17a of the support portion 17, which is a component member above the seismic isolation device 15, is fixed to the cap nut fixed to the upper surface side of the base plate 18 with a bolt. Thus, the foundation 3 and the existing building 1 above the foundation 3 are supported by the seismic isolation device 15 together with the support members 12.

Next, as a third step, the seismic isolation device 15
Is moved along the mat slab 13 in the upper existing building 1 supported by. Prior to the movement, the support material 12 supporting the foundation 3 is removed. As a result, the foundation 3 is supported only by the seismic isolation device 15, and the existing building 1 together with the foundation 3 is provided.
Are also supported by the seismic isolation device 15. Along the sliding plate 16 of the seismic isolation device 15 installed along the upper surface of the mat slab 13, the upper existing building 1 supported by the seismic isolation device 15 is slid and moved. Since the upper surface of the sliding plate 16 is set to have a small friction coefficient, the existing building 1 supported by the seismic isolation device 15 slides on the sliding plate 16 by pressing the foundation 3 laterally with a jack or the like. can do.

As shown in FIG. 7, the upper existing building 1 supported by the seismic isolation device 15 is moved from the position of the existing pile 4 to the position of the additional pile 11 along the slide plate 16 of the seismic isolation device 15. Accordingly, the movement of the foundation 3 and the existing building 1 on the foundation by the necessary distance in the direction of the additional pile 11 is completed. The sliding bearing type seismic isolation device 15 as in this embodiment is not particularly fixed because it is necessary to move relatively during an earthquake,
It is assumed that the laminated rubber portion 17C is located on the upper portion 6b. Although not shown, when a damping device such as an oil damper is used together, it is necessary to fix the foundation 3 or the foundation beam 5 to the mat slab 13.

When an existing building is seismically isolated, when the above-mentioned elastic sliding bearing type seismic isolation device is used together with a laminated rubber bearing type seismic isolation device (not shown), a laminated rubber type seismic isolation device is used. The upper flange of the device is fixed to the foundation 3, the lower flange is not fixed, and the pulling bar is completed by slipping or rolling means. After the completion, the lower flange of the seismic isolation device is fixed to the mat slab 13. Thus, the laminated rubber seismic isolation device can attenuate the vibration of the earthquake by the laminated rubber between the upper and lower flanges.

According to the seismic isolation method for an existing building of the present embodiment configured as described above, the foundation 3 is supported by the support material 12 at the position of the existing pile 4, the support material 12 is removed, and the seismic isolation device 15 is provided. Since the support is not required after moving the, there is no need to change the support, and the number of processes can be reduced, so that the construction period can be greatly reduced and low cost can be achieved.
The sliding plate 16 of the seismic isolation device 15 can move in the upper existing building 1 supported by the seismic isolation device 15 by the narrow moving part 16a of a horizontally long rectangular shape, and on a wide square installation part 16b at the moving destination. Because the bearing 17 of the seismic isolation device 15 is located in
It can move equally in the horizontal direction during an earthquake and can adapt to displacements in any direction of the earthquake.

As described above, the sliding plate portion 16 which is a lower component of the seismic isolation device is connected to the horizontally long rectangular moving portion 16a,
When formed from the installation portion 16b in a square shape, the support portion 17 of the seismic isolation device 15, which is a component above the seismic isolation device, can be moved along a narrow moving portion. As a result, it is possible to cope with displacements from any direction of the earthquake, and it is possible to reduce the weight of the sliding plate portion and reduce the material. By attaching the deformation restraining jig 19 to the laminated rubber portion 17c, unnecessary deformation of the laminated rubber portion 17c during movement can be prevented, and the movement can be performed smoothly.

Another embodiment of the present invention will be described in detail with reference to FIG. FIG. 9 is a perspective view of another embodiment of the seismic isolation device. This embodiment is different from the above-described embodiment.
A cross linear guide type seismic isolation device is used. In FIG. 9, the seismic isolation device 20 uses two sets of linear guides 21 and 22 for slidably supporting the blocks 21b and 22b on linear guide rails 21a and 22a. The block body 22b is combined with the block body 22b on the top 21b so that the guide rails are orthogonal to each other with the other linear guide 22 turned upside down. The bearing ball is configured to rotate and move along the guide rail with extremely low resistance in the block.

When this seismic isolation device 20 is installed in a base-isolated building composed of a normal foundation and an upper structure, the lower guide rail 21a is fixed to the foundation side, and the upper guide rail 22a is connected to the upper structure. For example, it is fixed to the base. When a seismic displacement is applied to a base-isolated building in which a seismic isolation device is installed in this way, and the foundation is displaced together with the ground due to the earthquake vibration, this displacement is absorbed by the upper and lower linear guides 21 and 22, and the upper building Without being directly transmitted, the displacement is insulated. Since the guide rails 21a and 22a are orthogonal to each other along the horizontal plane, the guide rails 21a and 22a can be insulated even by earthquake displacement from all directions.

When installing the seismic isolation device 20 in the existing building 1 of the above-described embodiment, the guide rail 22a, which is a component member above the seismic isolation device 20, is fixed to the lower surface of the foundation 3 in the state of FIG. , Guide rail 21a as a lower component
Is fixed to the mat slab 13. Lower guide rail 2
1a corresponds to the moving distance of the seismic isolation device.
If the guide rails are constituted by book guide rails, the upper part from the lower block body 21b can be moved along the guide rails.

Instead of using one long guide rail, another guide rail 23 of about one meter may be connected and connected for a necessary moving distance. In this case, after the movement, the connected moving guide rail 23 may be removed, and only the installation guide rail 21a may be left. As described above, the upper portion from the block body 21b below the seismic isolation device 20 can be moved along the guide rail 21a, which is a component member below the seismic isolation device 20, so that it is similar to the above-described embodiment. In addition, the support process can be greatly simplified, and existing buildings can be seismically isolated at a short construction time and at low cost.

In the above embodiment, the additional pile 11
Although the example in which the foundation 3 is supported by the support material 12 and the existing pile 4 is cut after the new construction is shown, this step may be performed before and after, for example, the new foundation 10 is driven in close contact with the existing pile 4. After the installation, the foundation 3 is supported by the support material 12 and then the additional pile 11 is newly installed, and thereafter, the existing pile 4 can be cut or changed.

[0031]

As can be understood from the above description, the seismic isolation method of an existing building according to the present invention can reduce the number of supports by the support materials after the foundation is moved, so that there is no need to change the support and the process is greatly reduced. It is possible to achieve simplification, short construction period, low cost, and seismic isolation of existing buildings with high safety.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an existing building, illustrating an embodiment of a seismic isolation method for an existing building according to the present invention.

FIG. 2 is a cross-sectional view of a state where the lower part of the foundation of the existing building of FIG. 1 is excavated.

FIG. 3 shows the next step of FIG. 2, in which (a) is a sectional view of a state in which a new foundation is cast, the foundation is supported, and an additional pile is newly installed;
(B) is a sectional view taken along line AA of (a).

4A and 4B show the next step of FIG. 3, wherein FIG. 4A is a cross-sectional view of an existing pile cut, and FIG. 4B is a cross-sectional view taken along line BB of FIG.

5A and 5B show the next step of FIG. 4, wherein FIG. 5A is a cross-sectional view in which a mat slab is cast between an existing pile and an additional pile, and a sliding plate is installed, and FIG. CC sectional view.

6A and 6B show the next step of FIG. 5, wherein FIG. 6A is a cross-sectional view in a state where the seismic isolation device is installed, and FIG. 6B is a cross-sectional view taken along line DD of FIG.

7A and 7B show the next step of FIG. 6, wherein FIG. 7A is a cross-sectional view showing a state in which the support material has been removed and the seismic isolation device has been moved, and FIG.
Sectional view taken along the line EE of FIG.

FIG. 8 is a schematic perspective view of the disassembled state showing the seismic isolation device and the deformation restraining jig.

FIG. 9 is a schematic perspective view in which a part of another embodiment of the seismic isolation device is omitted.

[Explanation of symbols]

1 Existing building, 3 Foundation, 4 Existing pile,
10 new foundations, 11 additional piles,
12 support materials, 13 mat slab (base seismic isolation), 15 seismic isolation device, 16 sliding plate (sliding plate part), 1
6a moving part, 16b installation part, 17 support part, 17c laminated rubber part, 18 base plate, 19 deformation restraining jig, 20 seismic isolation device, 2
1,22 linear guide

Continued on the front page F term (reference) 2D046 CA01 DA13 2E176 AA01 AA07 BB28

Claims (4)

[Claims] 1. A seismic isolation method for repairing an existing building by interposing a seismic isolation device below a foundation of an existing building, wherein the existing building is horizontally moved using the interposed seismic isolation device. A seismic isolation method for existing buildings. 2. The seismic isolation device comprises a part fixed to an existing building on the upper side and a part fixed to a foundation on the lower part, and both parts can be separated or relatively moved. The seismic isolation method for existing buildings described in 1. 3. Excavating the lower part of the foundation of the existing building so that the existing pile is exposed, placing a new foundation in a state where the existing pile is wrapped at the bottom of the excavation, and using the support material on the new foundation. Supporting a foundation, cutting the existing pile, placing a seismic isolation foundation continuously above the newly installed extension pile and the new foundation adjacent to the existing pile, and setting the seismic isolation foundation and the foundation together. A seismic isolation device is installed between the two to support the foundation, the support material is removed, and the seismic isolation device and the existing building are moved to the upper part of the additional pile along the seismic isolation foundation. The seismic isolation method for existing buildings. 4. The seismic isolation device comprises a lower sliding plate portion and an upper bearing portion, wherein the sliding plate portion is installed along an upper surface of the seismic isolation base, and the bearing portion is provided with the sliding plate. The seismic isolation method for an existing building according to claim 3, wherein the building is moved on a part.