JP4545563B2 - Seismic isolation structure of building - Google Patents

Description

  The present invention relates to a seismic isolation structure for a building composed of a plurality of types of seismic isolation members.

The shaking period T of the base-isolated building is obtained by T = 2π√ (m / K) (seconds) where m is the mass of the building and K is the rigidity of the base-isolated layer with respect to the horizontal force. As a seismic isolation member that constitutes the seismic isolation layer, a seismic isolation rubber device that has the function of stably supporting the vertical load of the building and the function of giving horizontal restoring force to the building (a large number of alternating rubber and steel plates) In the case of a base-isolated building having only a laminated structure device), the rigidity K of the base-isolated layer with respect to the force in the horizontal direction is increased, and the swing period T cannot be increased. Then, in order to lower the rigidity K of the base isolation layer, a base isolation building is known in which the base isolation layer is configured using a base isolation rubber device and a sliding bearing device as base isolation members (for example, Patent Document 1). etc).
JP 11-293951 A

  In the case of the conventional example in which the seismic isolation layer is constructed using a seismic isolation rubber device and a sliding bearing device, the yield strength of the seismic isolation layer is calculated as the weight of the building to suppress deformation of the seismic isolation layer during strong winds and earthquakes. It is set to about 3 to 5%. However, when the seismic isolation layer set in this way is applied to a so-called slender building with an aspect ratio (tower ratio) of 5 or more, the force in the direction of rotating the building is easily applied to the seismic isolation layer, and the seismic isolation layer Tensile force easily acts on the rubber of the seismic isolation rubber device. Since the rubber of the seismic isolation rubber device is weak against the tensile force, if a large tensile force acts on the rubber of the seismic isolation rubber device, a cavity is generated in the rubber, and if the rubber is further deformed, the rubber breaks. There was a problem.

The seismic isolation structure of the building according to the present invention was measured by a seismic isolation layer composed of a seismic isolation rubber device, an elastic sliding bearing device, and a fluid damper device, an anemometer, an accelerometer, and an anemometer. A control device that controls the fluid damper device by inputting the wind direction information, the wind speed information, and the magnitude information of the earthquake measured by the accelerometer, and as a fluid damper device, is rotatable in the horizontal direction. In addition, only those installed on the building foundation and seismic isolation pit foundation so as to generate a damping force against the force in the direction along the short side of the building having a rectangular cross section are provided. From the accelerometer regardless of whether strong wind information indicating that a wind of a speed equal to or greater than a predetermined value in the direction along the short side of the building is blowing is entered or whether strong wind information is entered. If you entered earthquake information, If the system damper device is unlocked, strong wind information is input from the anemometer and earthquake information is not input from the accelerometer, the fluid damper device is locked, and in the unlocked state, the seismic isolation layer The fluid damper device is operated with the characteristic that the damping force gradually increases as the response speed increases, and in the locked state, the damping force is larger than the unlocked state in the vicinity of 0 of the response speed of the seismic isolation layer. It is characterized by operating the fluid damper device with such a characteristic that the damping force gradually increases in proportion to the increase in the response speed of the seismic isolation layer after the occurrence .

According to the present invention, the seismic isolation layer is formed by the seismic isolation rubber device, the elastic sliding bearing device, and the fluid damper device, so that the rigidity of the seismic isolation layer with respect to the force in the horizontal direction can be reduced, and the vibration period of the seismic isolation building Since the yield strength of the seismic isolation layer can be reduced, the seismic isolation effect of the seismic isolation layer can be enhanced and the rubber of the seismic isolation rubber device can be prevented from breaking. Furthermore, since the horizontal displacement of the seismic isolation layer can be suppressed by the damping function of the fluid damper device, the durability of the seismic isolation layer can be increased and the rubber breakage preventing effect of the seismic isolation rubber device can be further improved. . In addition, the yield strength of the seismic isolation layer is lowered as described above so that the seismic isolation layer is easily deformed during strong winds and earthquakes, and the control device sets the fluid damper device to the locked state and the unlocked state. And the fluid damper device is operated. Therefore, when the control device sets the fluid damper device to the unlocked state and operates the fluid damper device, the seismic isolation layer can be displaced and the seismic isolation effect can be exhibited during an earthquake, Since the damping function of the fluid damper device can be set to attenuate the vibration of the building, it is possible to increase the durability of the seismic isolation layer and to realize a seismic isolation building with good habitability. In addition, when the control system sets the fluid damper device to the locked state and operates the fluid damper device, the yield strength of the seismic isolation layer is increased by the damping force of the fluid damper device. The building can be prevented from shaking, and a seismically isolated building with good habitability in strong winds can be realized, and the durability of the seismic isolation layer can be improved. In addition, as a fluid damper device, the foundation of the building and the base of the seismic isolation pit are designed so as to generate a damping force with respect to the force in the direction along the short side of the building having a rectangular cross section so as to be rotatable in the horizontal direction. If the control device does not input strong wind information indicating that the wind is blowing at a speed of a predetermined value or more in the direction along the short side of the building from the anemometer, Regardless of whether strong wind information is input from the anemometer or not, if the earthquake information from the accelerometer is input, the fluid damper device is unlocked, so the seismic isolation layer is It is set in a state where it can be easily displaced in the horizontal direction and can exhibit a seismic isolation effect, it can prevent the rubber of the seismic isolation rubber device from being broken, and the vibration of the building can be attenuated by the damping function of the fluid damper device. Therefore, the durability of the seismic isolation layer can be increased, and a seismic isolation building with good habitability can be realized. That is, in the case of an earthquake with a predetermined seismic intensity or more, the seismic isolation layer can be quickly activated, and the seismic isolation effect in the event of an earthquake can be improved. That is, when earthquake information is input during strong winds, the fluid damper device can be unlocked, and when there is an earthquake of a predetermined seismic intensity or higher during strong winds, the seismic isolation layer can be quickly activated. Therefore, the seismic isolation effect in the event of an earthquake can be improved, the rubber of the seismic isolation rubber device can be prevented from breaking, and the vibration of the building can be attenuated by the damping function of the fluid damper device. In addition, if the control device inputs strong wind information from the anemometer and does not input earthquake information from the accelerometer, the fluid damper device is locked, so that the building can be prevented from shaking during strong winds. A seismically isolated building with good habitability in strong winds can be realized, and the durability of the seismic isolation layer can be improved. Furthermore, by providing only a fluid damper device that generates a damping force against the force in the direction along the short side of the building having a rectangular cross section, it is possible to apply a damping force in a direction that tends to sway due to an earthquake or strong wind. In addition, it is possible to provide a seismic isolation structure with good habitability and to reduce the number of installed fluid damper devices, which is economically advantageous.

  1 to 7 show the seismic isolation structure of the base isolation building of this embodiment, FIG. 1 shows an outline of the base isolation structure, FIG. 2 shows the base isolation rubber device, FIG. 3 shows the elastic sliding bearing device, 4 shows the oil damper device, FIG. 5 shows the arrangement of the seismic isolation rubber device, the elastic sliding bearing device and the oil damper device as the seismic isolation members arranged under the building, and FIG. 6 shows the seismic isolation structure. FIG. 7 shows the characteristics of the oil damper device in the unlocked state and in the locked state.

  As shown in FIG. 1, the base-isolated building of this embodiment includes a base-isolated layer 90 including a base-isolated rubber device 2, an elastic sliding support device 3, and an oil damper device 4 as a base-isolating member, under the building 1. An anemometer 5 provided on the top of the building 1, an accelerometer 7 provided on the seismic isolation pit foundation 6 of the building 1, and the wind direction measured by the anemometer 5 A control device 8 that controls the oil damper device 4 by inputting information, wind speed information, and information on the magnitude of the earthquake measured by the accelerometer 7 is provided. The control device 8 is provided in the building 1.

  As shown in FIG. 2, the seismic isolation rubber device 2 includes, for example, a laminated body 11 in which a large number of rubbers 9 and steel plates 10 are alternately laminated and connected to each other by bonding, and an upper surface of the laminated body 11 is not illustrated. An upper flange 12 attached with a fixing material such as a bolt, and a lower flange 13 attached to the lower surface of the laminated body 11 with a fixing material such as a bolt not shown in the figure on the lower surface of the laminated body 11. The rubber 9 is made of natural rubber. An upper base 15 capable of connecting the upper flange 12 is attached to the lower surface of the base isolation upper base portion 14 formed on the lower surface 1 a of the building 1, and the base isolation lower base portion 16 formed on the base isolation pit foundation 6. A lower base 17 capable of connecting the lower flange 13 is attached to the upper surface of the base plate. The upper base 15 and the lower base 17 are formed by providing a plurality of cap nut portions 18 and stud bolts 19 each having a female thread inside a metal bag body on a metal flat plate. The attachment of the upper base 15 to the lower surface of the seismic isolation upper foundation 14 is as follows. First, a predetermined number of cap nut portions 18 are attached to the flat plate by a joining means such as welding in accordance with the position of the bolt through hole (not shown) formed on the flat plate, and the flat plate is securely connected to the concrete. A necessary number of stud bolts 19 are attached to form the upper base 15. The upper base 15 is installed at a predetermined position in the mold form outside the figure, and the reinforced concrete part of the seismic isolated upper base part 14 is cast and filled in the mold form, thereby the seismic isolated upper part formed by the reinforced concrete part. An upper base 15 is attached to the lower surface of the base portion 14. The upper base 15 and the upper flange 12 are joined by a bolt 21 that is fastened to the female screw of the cap nut portion 18 through the bolt through hole formed in the upper flange 12. The method of attaching the lower base 17 to the upper surface of the base isolation base 16 is the same, and the lower base 17 and the lower flange 13 attached to the upper surface of the base isolation lower base 16 are connected by bolts 21.

  As shown in FIG. 3, the elastic sliding support device 3 includes a lower member 32 attached to the upper surface of the base isolation base 31 provided at a position different from the base isolation base 16 and the base isolation. It is formed by an upper member 34 attached to the lower surface of the seismic isolation upper base portion 33 provided at a position different from the upper base portion 14. The lower member 32 includes a lower flange 36 coupled to the lower base 35 having the same configuration as the lower base 17 attached to the upper surface of the base isolation base 31 with bolts 21, and an upper surface of the lower flange 36. It is formed by a base material 37 attached by an external fixing means and a base plate 38 attached to the upper surface of the base material 37 by an external fixing means. The upper member 34 includes an upper flange 40 coupled to an upper base 39 attached to the lower surface of the seismic isolation upper base portion 33 by bolts 21 and an elastic base attached to the lower surface of the upper flange 40 by fixing means (not shown). It is formed by a material 41 and a sliding plate 42 attached to the lower surface of the elastic base material 41 by fixing means (not shown). The elastic base material 41 is formed of an elastic material such as rubber. The sliding plate 42 and the base plate 38 are made of a material having a small coefficient of friction so that the lower surface of the sliding plate 42 and the upper surface of the base plate 38 are in contact with each other and the sliding plate 42 slides on the upper surface of the base plate 38. . By setting the coefficient of friction between the sliding plate 42 and the base plate 38 to, for example, μ = 0.1 or less, the yield strength of the seismic isolation layer 90 can be reduced and the seismic isolation effect by the seismic isolation layer 90 can be increased. it can.

  As shown in FIG. 4, the oil damper device 4 as a fluid damper device includes a rod 45 having a piston 44 at one end, a cylinder 46, and a control mechanism 47. A piston 44 provided at one end of the rod 45 is enclosed in the cylinder 46 so as to be movable between one end surface and the other end surface of the cylinder 46, and two oil chambers, that is, a first oil chamber are contained in the cylinder 46. 48 and the second oil chamber 49 are partitioned. The rod 45 extends to the outside through a rod through hole 50 formed on one end surface of the cylinder 46. Between the outer periphery of the piston 44 and the inner wall of the cylinder 46 and between the outer periphery of the rod 45 and the rod through hole 50 are formed in an oil-tight manner by rubber packing or the like not shown. The other end of the rod 45 is connected to a shaft support member 75 of the attachment member 51 so as to be rotatable in the horizontal direction, and the attachment member 51 is fixed to the seismic isolation pit foundation 6 by a fixture 52 such as an anchor bolt. The other end surface of the cylinder 46 is provided with a support rod 53 that is coaxially attached to the rod 46, and the other end of the support rod 53 is connected to a shaft support member 75 of the attachment member 54 so as to be rotatable in the horizontal direction. The member 54 is fixed to the lower surface 1a of the foundation of the building 1 with a fixture 52 such as an anchor bolt.

  The control mechanism 47 includes an oil path 56 that connects the first oil chamber 48 and the tank 55, an orifice 57 provided in the middle of the oil path 56, and an oil path provided on the tank 55 side of the oil path 56 from the orifice 57. An on-off valve 58, an oil passage 59 connecting the second oil chamber 49 and the tank 55, a check valve 60 provided at a position immediately after the second oil chamber 49 in the oil passage 59, and an orifice 57 in the oil passage 56. An oil passage 61 that extends between the position and the check valve 60 in the oil passage 59 to the tank 55 side, a relief valve 62 provided in the middle of the oil passage 61, and a piston 44 are formed in the first oil chamber 48 and the second oil. An oil path 63 connecting the chamber 49 and a check valve 64 provided in the middle of the oil path 63 are provided.

  FIG. 5 shows the arrangement of the seismic isolation members as viewed from the lower surface 1 a side of the foundation of the building 1. The building 1 is a high-rise building having a rectangular cross section, a short pair of sides facing the rectangle, a long pair of other sides facing the rectangle, and an aspect ratio (tower ratio) of 5 or more. As shown in FIG. 5, each seismic isolation member has a short side 70; 71 that is a pair of sides facing each other along a rectangular shape, and a long side 72 that is another pair of sides that are facing each other. The seismic isolation rubber device 2, the oil damper device 4, the elastic sliding support device 3, the oil damper device 4, and the seismic isolation rubber device 2 are arranged in this order on the other long side 73 side. A plurality of sets of seismic isolation members having such an arrangement are provided in the direction along the long sides 72; That is, the arrangement is such that the shaking in the direction along the short sides 70 and 71 of the building 1 (the direction in which the building easily shakes due to wind or earthquake) is suppressed. Since the oil damper device 4 generates a damping force with respect to the force in the direction along the rod 45, the direction in which the damping force is applied is determined depending on the mounting method. Therefore, the building 1 is shaken by providing only a plurality of oil damper devices 4 attached so as to generate a damping force against the force in the direction along the short side 70; 71 of the building 1 that easily shakes the building 1. Since an oil damper device is not provided for generating a damping force with respect to the force in the direction along the long sides 72 and 73 of the difficult building 1, the damping force can be applied in a direction that is easily shaken by an earthquake or a strong wind. This is economically advantageous because a seismic isolation structure building having good habitability can be obtained and the number of oil damper devices 4 can be reduced.

  The seismic isolation rubber device 2 and the elastic sliding bearing device 3 can be displaced in all directions on the horizontal plane, but the rod 45 of the oil damper device 4 moves only in the direction along the short side 70; 71 of the building 1. . Therefore, in the case where the rods 45; 53 and the attachment members 51; 54 are connected in a fixed state, the rod 45; when the force in the direction along the long sides 72; 73 of the building 1 is applied to the building 1. There is a possibility that the connecting portion between 53 and the mounting member 51; Therefore, as shown in FIG. 4, the other ends of the rod 45 and the support rod 53 are supported by a support shaft 76; 76 of a shaft support member 75; 75 fixed to the mounting member 51; Since the rod 45 and the support rod 53 are connected so as to be movable in the horizontal direction around the support shafts 76 and 76, the connection portion of the oil damper device 4 can be prevented from being broken.

  The overall characteristics of the seismic isolation layer 90 composed of the seismic isolation rubber device 2, the elastic sliding bearing device 3 and the oil damper device 4 according to this embodiment are as shown in FIG. In FIG. 6, the vertical axis represents the horizontal load P (W) applied to the base isolation layer 90, and the horizontal axis represents the horizontal deformation amount δ (cm) of the base isolation layer 90. The characteristics of the oil damper device 4 are as shown in FIG. In FIG. 7, the vertical axis represents the damping force (KN), and the horizontal axis represents the response speed (cm / s) of the seismic isolation layer.

The control of the oil damper device 4 by the control device 8 will be described.
The control device 8 inputs strong wind information indicating that a wind having a speed equal to or higher than a predetermined value (for example, a wind speed of 40 m / s or more) in a direction along the short side 70; 71 of the building 1 is blowing from the anemometer 5 ( Regardless of whether or not strong wind information is input or not, if earthquake information is input from the accelerometer 7 with an acceleration value of a predetermined value or more (for example, 80 gal or more), the oil damper device 4 A solenoid (not shown) that opens and closes the oil passage opening / closing valve 58 is controlled to maintain the oil passage opening / closing valve 58 in the “open state”, thereby bringing the oil damper device 4 into the unlocked state. As a result, the oil in the first oil chamber 48 flows to the tank 55 through the orifice 57 while operating the damping force. In this case, the oil damper device 4 is a linear type damping performance such as the characteristic A shown by the solid line in FIG. 7A or a bilinear type like the characteristic B shown by the dotted line in FIG. The state where the damping performance is exhibited, that is, the unlocked state is set, and the seismic isolation layer 90 operates with the overall characteristic A indicated by the solid line in FIG. That is, in the unlocked state, the control mechanism 47 is maintained in a state where the fluid damper device 4 is operated with such a characteristic that the damping force gradually increases as the response speed of the seismic isolation layer increases. The oil damper device 4 set in the unlocked state lowers the yield strength of the seismic isolation layer 90. Therefore, the seismic isolation layer 90 is set in a state in which it can easily be displaced in the horizontal direction and can exhibit the seismic isolation effect. In addition, the rubber of the seismic isolation rubber device can be prevented from breaking, and the vibration of the building can be attenuated by the damping function of the fluid damper device 4. Therefore, the durability of the seismic isolation layer can be increased, and a seismic isolation building with good habitability can be realized. In the case of a small earthquake, since the horizontal load P is often smaller than the yield strength θy1 of the base isolation layer 90, the base isolation layer 90 may operate in a range where the horizontal load does not reach the yield strength θy1. In many cases, the damping force of the oil damper device 4 can prevent the seismic isolation layer 90 from being displaced in the direction along the short side of the building 1.

  The control device 8 inputs strong wind information indicating that the wind is blowing at a speed equal to or higher than a predetermined value (for example, wind speed of 40 m / s or more) in the direction along the short side 70; 71 of the building 1 from the anemometer 5. If no earthquake information is input from the accelerometer 7 with an acceleration value equal to or higher than a predetermined value (for example, 80 gal or higher), a non-illustrated solenoid that opens and closes the oil passage opening / closing valve 58 of the oil damper device 4 is controlled. By maintaining the path opening / closing valve 58 in the “closed state”, the oil path 56 connecting the orifice 57 and the tank 55 is shut off, and the oil damper device 4 is locked. In this case, when the rod 45 moves in the direction of the arrow A (see FIG. 4) in the direction along the short side 70; 71 of the building 1 due to wind pressure, the oil from the tank 55 passes through the check valve 60. While being supplied to the second oil chamber 49, the oil in the first oil chamber 48 is relieved to the tank 55 while generating a damping force through the relief valve 62. Also. When the rod 45 moves in the direction of the arrow B (see FIG. 4) along the short side 70; 71 of the building 1 due to wind pressure, the oil in the second oil chamber 49 causes the check valve 64 in the piston 44 to move. And enters the first oil chamber 48 through the first oil chamber 48 and the relief valve 62, and is relieved to the tank 55 while generating a damping force. In this case, as shown in FIG. 7 (b), the oil damper device 4 generates a large damping force (a state in which high yield strength is maintained) near the response speed of the seismic isolation layer, and then the response of the seismic isolation layer. It is set in a state where it operates with a characteristic C in which the damping force gradually increases in proportion to the increase in speed, that is, in the locked state, and the seismic isolation layer 90 operates with the overall characteristic B indicated by the broken line in FIG. That is, in the locked state, the control mechanism 47 gradually increases the damping force in proportion to an increase in the response speed of the seismic isolation layer after generating a larger damping force near the response speed of the seismic isolation layer than in the unlocked state. The fluid damper device 4 is maintained in a state of operating with the characteristic C that rises. The oil damper device 4 set in such a locked state raises the yield strength of the seismic isolation layer 90 to the swing along the short side 70; 71 of the building 1 to θy2 larger than θy1, The displacement of the seismic isolation layer 90 in the direction along the short sides 70; 71 of the building 1 is suppressed. That is, since the yield strength of the seismic isolation layer 90 is increased, the building can be prevented from shaking during strong winds, and a seismically isolated building with good habitability in strong winds can be realized, so that the durability of the seismic isolation layer can be improved. become.

That is, the control device 8 inputs information indicating that a wind having a speed equal to or higher than a predetermined value (for example, a wind speed of 40 m / s or more) in a direction along the short side 70; If the earthquake information is input from the accelerometer 7 with an acceleration value equal to or higher than a predetermined value (for example, 80 gal or higher), the oil passage opening / closing valve 58 is kept in the “open state”. On the other hand, the control device 8 displays strong wind information indicating that wind at a speed higher than a predetermined value (for example, wind speed of 40 m / s or more) in the direction along the short side 70; 71 of the building 1 from the anemometer 5 is blowing. In the case of input, when earthquake information is input from the accelerometer 7 with an acceleration value of a predetermined value or more (for example, 80 gal or more), the oil passage opening / closing valve 58 is switched from the “ closed state” to the “open state”. . For this reason, in the case of an earthquake with a predetermined seismic intensity or more, the seismic isolation layer 90 can be quickly activated, and the seismic isolation effect in the event of an earthquake can be improved. The control mechanism 47 may be set in a state where the oil damper device 4 is operated in the locked state and the unlocked state by manually opening and closing the oil passage opening / closing valve 58.

  The seismic isolation structure of the present invention is suitable for a high-rise building such as a so-called slender high-rise building having an aspect ratio (a tower ratio) of 5 or more, but can also be applied to a low-rise building without any trouble. As long as it has the same function as the oil damper device described above, a fluid damper device using a fluid other than oil may be used.

The block diagram which shows a seismic isolation structure (best form). Sectional drawing which shows a seismic isolation rubber apparatus (best form). Sectional drawing which shows an elastic sliding support apparatus (best form). The block diagram which shows an oil damper apparatus (best form). Arrangement drawing (best form) of seismic isolation rubber device, elastic sliding bearing device and oil damper device as seismic isolation member placed under the building. The figure which shows the comprehensive characteristic of the seismic isolation layer which comprises a seismic isolation structure (best form). The figure which shows the characteristic of an oil damper apparatus (best form).

Explanation of symbols

1 building, 2 seismic isolation rubber device, 3 elastic sliding bearing device,
4 Oil damper device (fluid damper device), 47 Control mechanism.

Claims (1)

Measured by the seismic isolation layer composed of seismic isolation rubber device, elastic sliding bearing device and fluid damper device, wind direction anemometer, accelerometer, wind direction information measured by wind direction anemometer , wind speed information and accelerometer And a control device for controlling the fluid damper device by inputting information on the magnitude of the earthquake
As a fluid damper device, it is mounted on the building foundation and seismic isolation pit foundation so as to generate a damping force against the force in the direction along the short side of the building with a rectangular cross section as a fluid damper device. Provided only
The control device determines whether or not strong wind information indicating that wind at a speed equal to or higher than a predetermined value in the direction along the short side of the building is blowing from the anemometer or whether strong wind information is input or not. Regardless, when earthquake information is input from the accelerometer, the fluid damper device is unlocked, strong wind information is input from the anemometer, and earthquake information is not input from the accelerometer. The system damper device is in the locked state, and in the unlocked state, the fluid damper device is operated with the characteristic that the damping force gradually increases as the response speed of the seismic isolation layer increases. It is possible to operate the fluid damper device with the characteristic that the damping force gradually increases in proportion to the increase in the response speed of the seismic isolation layer after generating a damping force larger than that in the unlocked state near the response speed of the layer. Seismic isolation structure of the building and said.

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