JP3799450B2 - Seismic isolation isolator fastening method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a fastening method for a seismic isolation isolator.
[0002]
[Prior art]
Isolators used in seismic isolation buildings have a structure in which rubber plates and steel plates are alternately bonded (baked) and integrated, with the upper plate on the building side and the lower plate on the foundation side. Bolts are fastened. In the event of a large earthquake, it receives horizontal and vertical loads. The horizontal load is mitigated by the large displacement of the isolator. However, since the load in the vertical direction has a large spring constant due to the structure of the isolator, the impact load is not alleviated and the multilayer rubber may be peeled off.
[0003]
[Problems to be solved by the invention]
Reduces the impact load that may cause peeling of the multilayer rubber due to the vertical load during a large earthquake.
[0004]
[Means for Solving the Problems]
The upper plate (building side) of the isolator is bolted through a buffer seat.
[0005]
The lower plate (foundation side) is a general bolt fastening.
[0006]
[Action]
The impact load that could cause the rubber plate to peel off due to the vertical load during a large earthquake can be mitigated.
[0007]
The structure can sufficiently withstand the tensile load on the lower plate (foundation side) fastening bolt due to the horizontal load.
[0008]
【Example】
In FIG. 1, 1 is an upper plate of the isolator, 2 is a lower plate, and 3 is a multilayer rubber to form the isolator. 4 is a bolt for fastening the upper plate, and 5 is a buffer seat. Reference numeral 6 denotes a bolt for fastening the lower plate. The state in the figure shows a state where the isolator is deformed by a large horizontal movement during a large earthquake.
[0009]
FIG. 2 shows an example in which Japanese Patent No. 2529835 (bolt tightening force detection seat) is used, and FIGS. 3 and 4 are simplified types.
[0010]
In FIG. 2, 1 is an upper plate, 4 is a bolt, 5a and 5d are washers, 5b is a disc spring, and 5c is a ring. There is a gap G between the washer 5a and the ring 5c.
When the bolt 4 is tightened, the disc spring 5b is first compressed and deformed, and then when the gap G becomes zero, the washer 5d is deformed. As a result, a load due to elastic deformation of the disc spring and the washer is applied to the bolt tightening force. If the isolator is fastened with the load when the gap G becomes zero (the ring cannot be rotated by the fingertip), the starting point of the bolt tightening force is clarified, so the load characteristics change during a large earthquake Can be easily grasped.
[0011]
In FIG. 3, 11 is an upper plate, 14 is a bolt, 15a and 15c are washers, and 15b is a disc spring. Since it is a simple structure, detailed description is omitted.
[0012]
In FIG. 4, 21 is an upper plate, 24 is a bolt, 25a is a washer, 25b is a ring, and there is a receiving seat portion 25bb for holding the washer 25a.
When the bolt 24 is tightened, the washer 25a is elastically deformed and a tightening force is applied to the bolt 24.
[0013]
In general, the horizontal movement is said to be about twice the height of the multilayer rubber, and the space between the upper plate 1 and the inclined outer periphery of the multilayer rubber is extremely narrow (see Fig. 1). The buffer seats required for this are required to be as compact as possible.
[0014]
In the case of a seismic isolation building, the shock absorbing effect can be obtained if the stroke of the buffer seat is about 5 mm because of the deformation performance of the frame. Therefore, as a result of examining various buffer seats applicable to this, a buffer seat mainly composed of a disc spring or a flat washer-like plate spring has a larger load capacity per unit volume than a commercially available anti-vibration rubber. Was found to be a suitable buffer seat.
[0015]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0016]
During a large earthquake, the peeling load of the isolator multilayer rubber due to vertical movement is reduced. As a result, it is possible to use strong fastening for horizontal movement, soft fastening via a buffer seat for vertical movement, and rational seismic isolation.
[Brief description of the drawings]
[Fig. 1] Side view of the seismic isolation isolator attached [Fig. 2] Cross section of the buffer seat [Fig. 3] Cross section of the simple buffer seat [Fig. 4] Cross section of another simple buffer seat [Description of symbols]
1 upper plate 5a washer 15a washer 2 lower plate 5b disc spring 15b disc spring 3 multilayer rubber 5c ring 15d washer 4 bolt 5d washer 25a washer 5 buffer washer 25b ring 6 bolt 7 building 8 foundation 11, 21 upper plate 14, 24 bolt

Claims (1)

The upper plate (building side) of the isolator, in which the rubber plate having the upper plate and the lower plate and the steel plate are alternately bonded, is bolted via a buffer seat made of a disc spring or a flat washer-like plate spring , and the lower plate (base side) Is a method of fastening a seismic isolation isolator characterized by a general bolt fastening

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