Wind-resistant locking mechanism for seismic isolation structures

Abstract

To provide a wind resistance lock mechanism of a base-isolated structure that can be made to exhibit base isolation performance in one of the states in earthquake or windstorm.SOLUTION: A wind resistance lock mechanism of a base-isolated structure comprises a wind velocity sensor 12 and an earthquake sensor 13 provided at a base-isolated structure, a pump 14 that is driven depending on a detection result of the wind velocity sensor and the earthquake sensor, a hydraulic jack device 11 that is coupled with the pump and is provided at a base isolation layer between an upper structure body 2 and a lower structure body 3, and a control part 15 for controlling the pump. The hydraulic jack device has a piston storage part fixed to the lower structure body, a piston moving vertically by hydraulic pressure supplied from the pump, and a pod part arranged above the piston. A restraining member is provided to restrain a horizontal relative displacement between the piston storage part and the pod part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a wind-resistant locking mechanism for a seismic isolation structure. [Background technology]

[0002] The amount of damper to be inserted into the seismic isolation layer of a seismically isolated building is determined by the greater of either the optimum amount for earthquakes or the amount required for wind. In recent years, as buildings have become larger, the amount of damper required for wind has tended to increase, resulting in excessive damping for earthquakes and in cases where optimal seismic isolation performance cannot be achieved. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-263430 Summary of the Invention [Problem to be solved by the invention]

[0004] Known conventional wind-resistant locking mechanisms include passive and electrically controlled types. For example, a passive mechanism is the wind-resistant shear pin mechanism. In this mechanism, a shear pin is rigidly inserted directly between the upper and lower seismic isolation structures. However, in order to ensure seismic isolation during earthquakes and to prevent the shear pin from frequently breaking due to relatively small earthquakes, this configuration requires the shear pin to be removed at all times and manually inserted only when a strong wind is expected. Furthermore, if an earthquake occurs simultaneously with a strong wind, the shear pin will be subjected to excessive shear force and break, requiring its removal and replacement.

[0005] Another example is a system in which shear pins are inserted between the upper and lower structures via elastic beams. The elastic beams act as buffers, preventing the shear pins from frequently breaking off due to relatively small earthquakes, making it possible to leave the shear pins inserted at all times. However, with this configuration, the characteristics of the seismic isolation layer during an earthquake depend on the elastic beams, and the original seismic isolation performance cannot be achieved until the shear pins break off due to excessive shear force.

[0006] A known electrically controlled locking mechanism is one that uses oil dampers. Specifically, this mechanism adds a locking mechanism to a general-purpose oil damper, and uses earthquake and wind sensors to detect earthquakes and wind, locking the oil damper during strong winds other than earthquakes. However, because this mechanism is based on an oil damper, it is only effective in the damper axial direction (one direction), and devices must be inserted in both the X and Y directions. In addition, it is necessary to place the necessary number of oil dampers as a wind-resistant locking mechanism, and because these dampers act as normal oil dampers during an earthquake, in some cases the damper volume may be excessive for an earthquake.

[0007] For these reasons, there is a need for a wind-resistant locking mechanism for seismic isolation structures that can demonstrate their inherent seismic isolation performance in both earthquakes and storms.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a wind-resistant locking mechanism for a seismic isolation structure that can demonstrate seismic isolation performance in both earthquakes and storms. [Means for solving the problem]

[0009] In order to achieve the above object, the wind-resistant locking mechanism for a seismic isolation structure according to the present invention comprises a wind speed sensor and an earthquake sensor provided in the seismic isolation structure, a pump that is driven in response to the detection results of the wind speed sensor and the earthquake sensor, a hydraulic jack device connected to the pump and provided in the seismic isolation layer between the upper structure and the lower structure, and a control unit that controls the pump, wherein the hydraulic jack device has a piston accommodating section fixed to the lower structure, a piston that moves up and down by hydraulic pressure supplied from the pump, and a pod section disposed above the piston, and is provided with a restraining member that restrains horizontal relative displacement between the piston accommodating section and the pod section, and the control unit is characterized in that when the detection result of the wind speed sensor is equal to or greater than a set value, the control unit raises the piston to bring the pod section into contact with the underside of the upper structure, and when the detection result of the earthquake sensor is equal to or greater than the set value or during normal times when the detection results of the wind speed sensor and the earthquake sensor are less than the set values, the control unit lowers the piston to separate the pod section from the underside of the upper structure.

[0010] According to this invention, the hydraulic pressure supplied to the hydraulic jack device is controlled by a pump. The control unit controls the hydraulic pressure based on the detection results of the wind speed sensor and earthquake sensor, eliminating the need for manual operation when locking the device against wind. The device can also be effective in all horizontal directions. The restraining member limits the relative horizontal movement distance between the piston housing and the pod, restraining the displacement of the pod relative to the substructure, thereby maintaining the wind-resistant locking mechanism in a functional state. Furthermore, the hysteresis characteristics of the seismic isolation layer can be completely independent between earthquakes and storms, allowing the desired seismic isolation performance to be achieved in both earthquakes and storms.

[0011] In the present invention, a sliding member may be provided between the upper surface of the piston and the lower surface of the pod portion. According to this invention, the horizontal force (shear force) acting on the piston can be controlled, and damage to the piston can be prevented.

[0012] In the present invention, a damping material may be provided on an upper surface of the pod portion, and a damping plate may be provided on a lower surface of the upper structure. According to this invention, the seismic isolation layer can function without any problems even if residual displacement occurs in the seismic isolation layer due to an earthquake or a windstorm, and restoration operations after a major earthquake can be eliminated.

[0013] In the present invention, one pump may be connected to a plurality of hydraulic jack devices. According to this invention, the number of pumps to be installed can be reduced, and the arrangement of seismic isolation layers can be made more efficient.

[0014] In addition, the present invention may be configured such that the restraint member is composed of a downward-facing wall extending downward from the periphery of the pod portion, and when the pod portion is in contact with the underside of the upper structure, the downward-facing wall encloses the piston accommodating portion in a state where it at least partially overlaps with the piston accommodating portion in the vertical direction. According to this invention, simply by providing a descending wall in the pod section as a restraining member, the relative horizontal movement distance between the piston accommodating section and the pod section can be limited, and by restraining the displacement of the pod section relative to the lower structure, the wind-resistant locking mechanism can be kept functional. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a wind-resistant locking mechanism for a seismic isolation structure that can demonstrate seismic isolation performance in both earthquakes and strong winds. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of a seismic isolation structure according to an embodiment of the present invention; [Figure 2] 1 is a schematic structural diagram of a wind-resistant locking mechanism according to an embodiment of the present invention; [Figure 3] FIG. 2 is a front view showing the hydraulic jack device of the present embodiment in a jacked-down state. [Figure 4] FIG. 2 is a front view showing the hydraulic jack device of the present embodiment in a jacked-up state. [Figure 5] 3 is a control flowchart of the hydraulic jack device of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] A wind-resistant locking mechanism for a seismic isolation structure according to an embodiment of the present invention will be described below with reference to FIGS.

[0018] As shown in Figure 1, the seismic isolation structure 1 of this embodiment has a seismic isolation layer 4 provided between an upper structure 2 and a lower structure 3. The seismic isolation layer 4 is provided with a seismic isolation device 5 such as seismic isolation rubber, and a hydraulic jack device 11 of a wind-resistant locking mechanism 10. A wind speed sensor 12 is provided on the roof of the upper structure 2, and an earthquake sensor 13 is provided on the lowest layer of the lower structure 3. Note that the wind speed sensor 12 and earthquake sensor 13 may be attached at locations other than those described above.

[0019] As shown in Figure 2, the wind-resistant locking mechanism 10 includes a hydraulic jack device 11, a wind speed sensor 12, an earthquake sensor 13, a pump 14 that drives the hydraulic jack device 11, a control unit 15 that controls the driving of the pump 14, and a hose 16 that connects the pump 14 and the hydraulic jack device 11.

[0020] As shown in Figures 3 and 4, the hydraulic jack device 11 has a piston accommodating section 21 fixed to the lower structure 3, a piston 22 that moves up and down relative to the piston accommodating section 21 by hydraulic pressure supplied below the piston from the pump 14, and a pod section 23 arranged above the piston 22.

[0021] The piston accommodating portion 21 includes a flange-shaped bottom portion 31 fixed to the lower structure 3, a side wall portion 32 extending cylindrically from the bottom portion 31, and an upper end flange portion 33 extending toward the central axis O1 at the upper end of the side wall portion 32. For example, the piston accommodating portion 21 is formed in a cylindrical shape.

[0022] The piston 22 is accommodated in the piston accommodating portion 21. The piston 22 includes a columnar main body 35 and a flange 36 formed at the lower end of the main body 35. For example, the piston 22 is formed in a cylindrical shape. A sliding member 40 is attached to the upper surface 35a of the main body 35. The sliding member 40 is, for example, a friction plate or a stainless steel plate. The piston 22 moves up and down hydraulically. In a jacked-down state, the piston 22 is accommodated in the hollow portion 34 of the piston accommodating portion 21. In a jacked-up state, the main body 35 of the piston 22 protrudes upward from an opening 33a formed inside the upper flange 33 of the piston accommodating portion 21. The piston 22 can rise to a position where the flange 36 abuts against the upper flange 33 of the piston accommodating portion 21.

[0023] The pod section 23 is disposed above the piston 22 and moves in accordance with the up and down movement of the piston 22. When jacked down, the pod section 23 has a cylindrical shape with a bottom that covers the piston accommodating section 21 from above. The pod section 23 includes a plate-shaped main body 41 located above the piston 22 and a falling wall 42 extending downward from the periphery of the main body 41. When jacked up, the falling wall 42 is sized so that at least a portion of its lower part overlaps the piston accommodating section 21 in the height direction. A damping material 43 is attached to the upper surface 41a of the main body 41 of the pod section 23. The damping material 43 is, for example, a friction plate or a stainless steel plate.

[0024] Brake plates 45 are attached to the underside 2a of the upper structure 2. When jacked up, the brake material 43 of the pod section 23 and the brake plates 45 of the upper structure 2 are configured to abut and slide against each other. The brake plates 45 are made of, for example, stainless steel plates.

[0025] A sliding resistance can be exerted when the braking material 43 and the braking plate 45 are in contact with each other. For example, when the vertical force of the hydraulic jack of the hydraulic jack device 11 is 4000 kN and the friction coefficient between the braking material 43 and the braking plate 45 is 0.3, a horizontal resistance capacity of 1200 kN can be exerted per hydraulic jack device. By installing multiple such hydraulic jack devices 11, it becomes possible to cope with the wind load of ultra-high-rise seismic isolation buildings.

[0026] In the wind-resistant locking mechanism 10, one hydraulic jack device 11 is connected to one pump 14. Note that multiple hydraulic jack devices 11 may be connected to one pump 14. When connecting multiple hydraulic jack devices 11, a pump 14 with a discharge volume that can accommodate multiple hydraulic jack devices 11 should be selected. The number and placement of pumps 14 should be determined taking into consideration the plan for the layout of the hydraulic jack devices 11 in the seismic isolation layer 4 so that the hoses 16 have an appropriate length.

[0027] When the wind-resistant locking mechanism 10 functions, it is in the state shown in Figure 4, and the piston 22 of the hydraulic jack device 11 is in the raised position, exerting horizontal frictional resistance. In order to control the horizontal force acting on the piston 22, a sliding member 40 with a small coefficient of friction is disposed between the upper surface 35a of the main body 35 of the piston 22 and the lower surface 41b of the main body 41 of the pod portion 23. In this embodiment, the sliding member 40 is attached to the upper surface 35a of the main body 35 of the piston 22, but it may also be attached to the lower surface 41b of the main body 41 of the pod portion 23.

[0028] When a horizontal force acts on the pod section 23 through the friction surface with the upper structure 2, only the friction resistance of the sliding member 40 is transmitted to the piston 22, and the remaining force is handled by the bearing resistance of the inner circumferential surface 42a of the falling wall 42 of the pod section 23 and the side surface 25 of the piston accommodating section 21, thereby avoiding direct action on the piston 22. For example, in the above case, if a sliding member 40 with a friction coefficient of 0.1 is used, the horizontal force transmitted to the piston 22 is 400 kN, and the remaining 800 (= 1200 - 400) kN of the 1200 kN horizontal force is handled by the bearing resistance. Therefore, excessive horizontal shear force is not generated in the piston 22, and damage to the hydraulic jack device 11 can be prevented.

[0029] Next, the control law will be explained using the flowchart in FIG. In step S1, wind speed information is measured from a wind speed sensor 12 attached to the seismic isolation structure 1, and acceleration information is measured from an earthquake sensor (acceleration sensor) 13, and the measurement values ​​are collected in the control unit 15. Basically, the hydraulic jack device 11 of the wind-resistant locking mechanism 10 is jacked down normally and during earthquakes, and is jacked up to enter a wind-resistant lock state when an external wind force acts, such as during a storm. The threshold value for jacking due to earthquakes or external wind forces can be freely set.

[0030] In step S2, the maximum wind speed detected by the wind speed sensor 12 is compared with a preset value (threshold value). If the maximum wind speed is greater than the set value, the process proceeds to step S3, and if it is equal to or less than the set value, the process proceeds to step S6.

[0031] In step S3, since it is determined that the wind blowing against the seismic isolation structure 1 is greater than a set value, the wind-resistant locking mechanism 10 is turned ON. Specifically, a drive signal is sent from the control unit 15 to the pump 14, which drives the pump 14 and applies hydraulic pressure to the hydraulic jack device 11 via the hose 16. When hydraulic pressure is applied, the piston 22 rises due to the hydraulic pressure. The pod section 23 also rises as if pushed by the piston 22, and the braking material 43 attached to the upper surface 41a of the main body 41 of the pod section 23 abuts against the braking plate 45 attached to the lower surface 2a of the upper structure 2. This results in a wind-resistant lock state with frictional resistance at the abutting portion (= friction coefficient × jack load).

[0032] In step S4, in the wind-resistant locked state, the acceleration of earthquake sensor 13 is measured, and the measured value is detected in control unit 15. The acceleration detected from earthquake sensor 13 is compared with a preset value (threshold value). If the detected acceleration is greater than the set value, the process proceeds to step S5, and if it is equal to or less than the set value, the process proceeds to step S7.

[0033] In step S5, it is determined that an earthquake of a magnitude greater than a preset magnitude has occurred in the wind-resistant lock state, and the wind-resistant lock state is quickly switched from ON to OFF. Specifically, the control unit 15 sends a signal to release a valve (not shown) in the pump, and the hydraulic pressure of the jack drops, causing the pod section 23 to separate from the underside 2a of the upper structure 2, and then the piston 22 and pod section 23 descend to return to the jacked-down state. When the hydraulic pressure of the jack drops, the contact surface pressure between the pod section 23 and the upper structure 2 drops, reducing the frictional resistance force at the contact point and releasing the locked state.

[0034] In step S6, the wind-resistant locking mechanism is turned OFF because it is determined that the wind blowing against the seismic isolation structure 1 is below the set value. However, if it is determined in step S2 that the maximum wind speed exceeds the set value, the wind-resistant locking mechanism is kept ON for, for example, one hour after the determination. By configuring it in this way, it is possible to prevent the wind-resistant locking mechanism 10 from frequently cycling ON and OFF.

[0035] In step S7, it is determined that no earthquake greater than the set value has occurred in the wind-resistant lock state, and the wind-resistant lock state is maintained in the ON state. However, if it is determined in step S4 that a large earthquake has occurred, the wind-resistant lock mechanism is maintained in the OFF state for, for example, five minutes after the determination. This configuration prevents the wind-resistant lock mechanism 10 from frequently cycling ON and OFF, ensuring that the seismic isolation function of the seismic isolation layer 4 can function reliably even if aftershocks or other earthquakes occur.

[0036] As described above, a timer may be provided to maintain the jacking behavior that should be performed when a disturbance is detected for a certain period of time from the moment an earthquake or wind force is detected. The one hour in step S6 and the five minutes in step S7 are examples, and the periods can be changed as appropriate.

[0037] Furthermore, to ensure that the jacking-down operation is completed reliably, a timer may be added to keep the valve that releases the hydraulic pressure open for a certain period of time. Alternatively, a vertical limit switch or a vertical displacement meter may be added to the hydraulic jack device 11, and a sensor or the like may be provided to physically detect that the piston 22 has been lowered by more than a certain displacement.

[0038] Furthermore, in a seismic isolation structure 1 with a seismic isolation layer on an intermediate floor, such as seismic isolation layer 4, a control rule may be added to prevent elevators passing through the seismic isolation layer 4 from stopping during strong winds, such as those during seasonal winds, by monitoring the displacement of the seismic isolation layer 4, which is the stopping condition, and jacking up the elevator if the displacement exceeds a certain value. The displacement of the seismic isolation layer 4 can be measured using a horizontal limit switch or horizontal displacement meter. However, to ensure that the observed displacement is due to wind forces rather than to minute vibrations such as earthquakes or construction vibrations or residual displacement, it is desirable to combine multiple conditions to activate the wind-resistant lock. For example, the wind-resistant lock may be activated when all of the following conditions are met: a wind speed of 20 m / s or more, an acceleration of 5 gal or less, and a seismic isolation layer displacement of 1 cm or more.

[0039] Furthermore, if the wind force increases further while the seismic isolation layer 4 remains in the wind-resistant locked state, the frictional force of the wind-resistant lock may be exceeded, causing the hydraulic jack unit 11 to slide. In this case, the hydraulic jack unit 11 may continue to slide, allowing it to function as a friction damper. Alternatively, based on the design concept of having the hydraulic jack unit 11 target wind forces within a specific return period range and perform wind-resistant locking to ensure habitability and continue elevator operation, the hydraulic jack unit 11 may be jacked down in response to external forces exceeding that range, thereby releasing the wind-resistant lock. In this case, the displacement of the seismic isolation layer 4 may be measured using a horizontal limit switch or horizontal displacement meter, and the jack may be jacked down when the measured value exceeds a certain threshold.

[0040] According to this embodiment, the base isolation structure 1 is provided with a wind speed sensor 12 and an earthquake sensor 13, a pump 14 that is driven in response to the detection results of the wind speed sensor 12 and the earthquake sensor 13, a hydraulic jack device 11 that is connected to the pump 14 and is provided in the base isolation layer 4 between the upper structure 2 and the lower structure 3, and a control unit 15 that controls the pump 14. The hydraulic jack device 11 includes a piston accommodating section 21 fixed to the lower structure 3, a piston 22 that moves up and down by hydraulic pressure supplied from the pump 14, and a pod section 15 that is disposed above the piston 22. 23, and a falling wall (restraint member) 42 is provided that restrains the horizontal relative displacement between the piston accommodating section 21 and the pod section 23, and the control section 15 is configured to raise the piston 22 to bring the pod section 23 into contact with the underside 2a of the upper structure 2 when the detection result of the wind speed sensor 12 is equal to or greater than the set value, and to lower the piston 22 to separate the pod section 23 from the underside 2a of the upper structure 2 when the detection result of the earthquake sensor 13 is equal to or greater than the set value or during normal times when the detection results of the wind speed sensor 12 and the earthquake sensor 13 are less than the set value.

[0041] With this configuration, the hydraulic pressure supplied to the hydraulic jack device 11 can be controlled by the pump 14 in response to a drive signal from the control unit 15. The control unit 15 can adjust the hydraulic pressure by controlling the drive of the pump 14 based on the detection results of the wind speed sensor 12 and the earthquake sensor 13, eliminating the need for manual operation when wind-resistant locking. Because the piston 22 only moves up and down, it can be effective in all horizontal directions. The wind-resistant lock state can be achieved by raising the piston 22 and abutting the pod section 23 against the upper structure 2. The falling wall (restraint member) 42 limits the horizontal relative movement distance between the piston accommodating section 21 and the pod section 23, thereby restraining the displacement of the pod section 23 relative to the lower structure 3, thereby maintaining the wind-resistant locking mechanism in a functional state. In other words, the hysteresis characteristics of the seismic isolation can be completely independent of those during earthquakes and storms, allowing the desired seismic isolation performance to be achieved in both earthquakes and storms.

[0042] In addition, since a sliding material 40 is provided between the upper surface 22a of the piston 22 and the lower surface 41b of the main body portion 41 of the pod portion 23, the horizontal force (shear force) acting on the piston 22 can be controlled, and damage to the piston can be prevented.

[0043] In addition, a damping material 43 is provided on the upper surface 41a of the main body 41 of the pod section 23, and a damping plate 45 is provided on the lower surface 2a of the upper structure 2, so that the seismic isolation layer can function without any problems even if residual displacement occurs in the seismic isolation layer due to an earthquake or strong wind, and operations such as restoration after a major earthquake can be eliminated.

[0044] Furthermore, the restraint member is formed of a falling wall 42 extending downward from the periphery of the pod section 23, and is configured to enclose the pod section 23 in a state where the falling wall 42 overlaps at least partially in the height direction with the piston accommodating section 21 when the pod section 23 is in contact with the underside 2a of the upper structure 2. In other words, with the simple configuration of providing the falling wall 42, the relative horizontal movement distance between the piston accommodating section 21 and the pod section 23 can be limited, and the wind-resistant locking mechanism 10 can be kept functional. Furthermore, when a horizontal force acts on the pod section 23 through the friction surface with the upper structure 2, only the friction resistance of the sliding member 40 of the force is transmitted to the piston 22, and the remaining force is handled by the bearing resistance of the inner circumferential surface 42a of the falling wall 42 of the pod section 23 and the side surface 25 of the piston accommodating section 21, thereby avoiding direct action on the piston 22.

[0045] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and can be modified within the scope of the gist of the present invention as defined in the claims.

[0046] In addition, in this embodiment, a sliding member 40 is provided between the upper surface 22a of the piston 22 and the lower surface 41b of the main body portion 41 of the pod portion 23, but the sliding member 40 may not be necessary as long as the desired frictional resistance is ensured.

[0047] In addition, in this embodiment, a braking material 43 is provided on the upper surface 41a of the main body 41 of the pod section 23, and a braking plate 45 is provided on the lower surface 2a of the upper structure 2, but the braking material 43 and braking plate 45 may not be necessary as long as the desired frictional resistance is ensured.

[0048] Furthermore, in this embodiment, the falling wall 42 of the pod section 23 functions as a restraining member, but the restraining member may have a different configuration. [Explanation of symbols]

[0049] 1. Seismic isolation structures 2 Superstructure 2a Bottom side 3 Undercarriage 4. Seismic isolation layer 10 Windproof locking mechanism 11 Hydraulic jack device 12 Wind speed sensor 13 Earthquake Sensor 14 Pump 15 Control Unit 21 Piston housing 22 Piston 22a Top side 23 Pod Section 40 Sliding material 41 Main body 41a Top side 41b Bottom side 42 Falling wall (restraining member) 43 Braking material 45 Brake plate

Claims

1. a wind speed sensor and an earthquake sensor provided in the seismic isolation structure; a pump that is driven in response to the detection results of the wind speed sensor and the earthquake sensor; a hydraulic jack device connected to the pump and installed in the seismic isolation layer between the upper structure and the lower structure; a control unit that controls the pump, The hydraulic jack device is a piston accommodating portion fixed to the lower structure; a piston that moves up and down by hydraulic pressure supplied from the pump; a pod portion disposed above the piston, a restraining member is provided that restrains horizontal relative displacement between the piston accommodating portion and the pod portion, The control unit When the detection result of the wind speed sensor becomes equal to or greater than a set value, the piston is raised to bring the pod part into contact with the lower surface of the upper structure, A wind-resistant locking mechanism for a seismic isolation structure, characterized in that when the detection result of the earthquake sensor exceeds a set value, and when the detection results of the wind speed sensor and the earthquake sensor are below a set value under normal circumstances, the piston is lowered to separate the pod portion from the underside of the upper structure.

2. 2. A wind-resistant locking mechanism for a seismic isolation structure according to claim 1, wherein a sliding member is provided between the upper surface of the piston and the lower surface of the pod portion.

3. 3. A wind-resistant locking mechanism for a seismic isolation structure according to claim 1, wherein a damping material is provided on the upper surface of the pod portion, and a damping plate is provided on the lower surface of the upper structure.

4. 4. A wind-resistant locking mechanism for a seismic isolation structure according to claim 1, wherein one pump is connected to a plurality of hydraulic jack devices.

5. the restraint member is formed of a falling wall extending downward from the peripheral edge of the pod portion, A wind-resistant locking mechanism for a seismic isolation structure as described in any one of claims 1 to 4, wherein the pod section is in contact with the underside of the upper structure and the falling wall is configured to enclose the piston accommodating section in a state where it overlaps at least partially in the height direction.

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