Self-adaptive seismic isolation system

Abstract

This system provides a self-adaptive seismic isolation system that maintains the function of the structure by reducing the acceleration transmitted upward during small to medium-sized earthquakes, and protects the system by suppressing the displacement of the seismic isolation layer during large earthquakes. [Solution] The present invention provides a passive self-adaptive seismic isolation system provided between a structural foundation 3 and a superstructure 2, comprising a first support unit 10 and a second sliding support unit between the structural foundation 3 and the superstructure, wherein the second sliding support unit is configured to provide a damping force and / or restoring force different from that of the first support unit in the horizontal direction, and an elastic part 23 capable of providing rigidity in the direction perpendicular to the horizontal direction of the second sliding support unit is assembled vertically.

Description

[Technical Field]

[0001] The present invention relates to a seismic isolation system, and more particularly to a passive, self-adaptive seismic isolation system having variable mechanical properties. [Background technology]

[0002] Currently, the means of preventing buildings from being damaged by earthquakes is the seismic isolation system designed based on seismic isolation technology. Seismic isolation technology refers to, for example, the installation of special seismic isolation bearings between the superstructure and the foundation of a building, which mitigates the transmission of seismic motion to the structure. This reduces the seismic force acting on the superstructure and improves its seismic resistance. Commonly seen seismic isolation bearings are broadly classified into sliding bearings and elastomeric bearings based on the difference in their principles.

[0003] A typical example of the aforementioned sliding bearing is the "friction pendulum system (FPS)." An FPS typically consists of a three-dimensional spherical plate with a fixed radius of curvature R and a slider. During an earthquake, the slider reciprocates on the curved surface of the spherical plate, and when it moves away from the center of the spherical plate, the weight of the superstructure generates a restoring force that tries to return the bearing to the center point (lowest point) of the curved surface, reducing the residual displacement of the seismic isolation bearing after the earthquake. If the effect of friction is not considered, the motion of the slider of the sliding bearing reciprocating on the spherical plate is the same as that of a simple pendulum, so its seismic isolation frequency depends only on the radius of curvature R of the curved surface. Therefore, the seismic isolation frequency of a seismic isolation system can be determined by selecting the radius of curvature of the curved surface.

[0004] However, because the radius of curvature of the sliding surface of the aforementioned sliding bearing is fixed, it has a specific seismic isolation frequency, and as a result, when the excitation frequency of the ground surface is close to the seismic isolation frequency, resonance phenomena are extremely likely to occur. The seismic damping effect of the seismic isolation device using the aforementioned sliding bearing is only exerted when the excitation frequency of the ground surface exceeds the seismic isolation frequency, and is not sufficiently exerted against low-frequency ground motion. In other words, in the seismic isolation device using the aforementioned sliding bearing, the seismic damping effect is determined not only by the frequency composition of the seismic waves, but also by the possibility of low-frequency resonance phenomena occurring.

[0005] Conventional seismic isolation systems have difficulty achieving optimal seismic isolation (damping) effects for different seismic intensities. In particular, during earthquakes near faults, phenomena similar to resonance occur, causing the system's displacement to exceed the predetermined allowable limit, raising concerns about the safety of the structure. [Overview of the project] [Problems that the invention aims to solve]

[0006] To solve the above problems, the present invention provides a self-adaptive seismic isolation system that has "variable" mechanical properties and can exhibit different seismic isolation performance under different seismic conditions. Specifically, it reduces the acceleration transmitted upward during small to medium-sized earthquakes to maintain the function of the structure, and suppresses the displacement of the seismic isolation layer during large earthquakes to protect the system. [Means for solving the problem]

[0007] The self-adaptive seismic isolation system of the present invention is provided between a structural foundation and a superstructure, and includes a first support unit and a second sliding support unit between the structural foundation and the superstructure, wherein the second sliding support unit is configured to provide a damping force and / or restoring force different from that of the first support unit in the horizontal direction, and an elastic part capable of providing rigidity in the direction perpendicular to the horizontal direction of the second sliding support unit is assembled vertically.

[0008] In the self - adaptive seismic isolation system of the present invention, the first support unit may be a sliding support unit or an elastic support unit configured to provide a damping force and / or a restoring force in the horizontal direction, and preferably it is a sliding support unit.

[0009] Preferably, the self - adaptive seismic isolation system of the present invention further includes a third sliding support unit configured to provide a damping force and / or a restoring force different from that of the first support unit and the second sliding support unit in the horizontal direction.

[0010] Preferably, in the self - adaptive seismic isolation system of the present invention, the first support unit has a slider and a sliding surface that is flat or curved.

[0011] Preferably, in the self - adaptive seismic isolation system of the present invention, the second sliding support unit or the third sliding support unit has a slider, a sliding surface that is flat or curved, and an elastic part that can provide rigidity in the vertical direction perpendicular to the horizontal direction of the sliding support unit is vertically assembled.

[0012] Preferably, in the self - adaptive seismic isolation system of the present invention, the sliding surface of the curved surface is a composite spherical sliding panel composed of a plurality of curved surfaces.

[0013] In the self - adaptive seismic isolation system of the present invention, the superstructure supports an upper building and is supported by a plurality of the first support units and a plurality of the second sliding support units. Preferably, the arrangement position of the first support unit or the second sliding support unit corresponds to the position of the structural column in the building.

[0014] Preferably, in the self - adaptive seismic isolation system of the present invention, the arrangement position of the second sliding support unit corresponds to the position between columns of the structural column in the building.

[0015] The elastic part of the self - adaptive seismic isolation system of the present invention is preferably at least one of a bending beam slab, a spring member, a leaf spring member, a columnar member composed of an elastic polymer material, or a combination thereof.

Advantages of the Invention

[0016] The self - adaptive seismic isolation system of the present invention has mechanical properties such as variable damping, variable stiffness, and variable frequency. Thereby, it can exhibit different seismic isolation performances under different earthquake conditions and achieve excellent seismic isolation effects suitable for various types of earthquakes.

[0017] The present invention consists of multiple groups of sliding members with different mechanical properties. By redistributing the vertical load during an earthquake, the friction damping force, restoring stiffness, and seismic isolation frequency of the entire system can be adjusted, and an optimal seismic isolation effect can be achieved at various earthquake intensities.

Brief Description of the Drawings

[0018] [Figure 1] It is a schematic structural diagram showing the self - adaptive seismic isolation system in an embodiment of the present invention. [Figure 2] It is a schematic structural diagram showing the self - adaptive seismic isolation system in another embodiment of the present invention. [Figure 3] It is a schematic diagram showing the arrangement position of the seismic isolation system of the present invention. [Figure 4] It is a schematic diagram showing the arrangement between columns of the seismic isolation system of the present invention. [Figure 5a] It is a schematic diagram showing a variable - curvature sliding surface in a representative example of a slide spherical panel. [Figure 5b] It is a schematic diagram showing a composite slide spherical panel in a representative example of a slide spherical panel. [Figure 6a] It is a schematic diagram showing a bending - beam - type elastic part in the elastic part of the present invention. [Figure 6b] It is a schematic cross - sectional view showing a spring - type elastic part in the elastic part of the present invention. [Figure 6c] It is a perspective cross - sectional view showing a spring - type elastic part in the elastic part of the present invention. [Figure 6d]This is a schematic diagram showing a polymer material type elastic part in the elastic part of the present invention. [Figure 6e] This is a schematic diagram showing a composite elastic part in the elastic part of the present invention. [Figure 7] This is a comparison diagram of the frequency response curves of the acceleration ratio of Example 1 of the present invention and a comparative example. [Figure 8] This is a comparative diagram of hysteresis loops related to the normalized total horizontal shear force in Example 1 of the present invention and in comparative examples. [Figure 9] This is a comparative diagram of the hysteresis loops related to the normalized total horizontal shear force in Example 2 of the present invention and in the comparative example. [Figure 10] This is a comparative diagram showing the relationship between normalized horizontal restoring force and displacement in Example 1 of the present invention and in comparative examples. [Figure 11] This is a comparative diagram showing the relationship between normalized horizontal restoring force and displacement in Example 2 of the present invention and in comparative examples. [Figure 12] This is a comparative diagram of the hysteresis loops related to the normalized horizontal friction force in Example 1 of the present invention and in comparative examples. [Figure 13] This is a comparative diagram of the hysteresis loops related to the normalized horizontal friction force in Example 2 of the present invention and in a comparative example. [Figure 14] This is a comparative diagram showing the relationship between normalized vertical axial force and displacement in Example 1 of the present invention and in comparative examples. [Figure 15] This is a comparative diagram showing the relationship between normalized vertical axial force and displacement in Example 2 of the present invention and in comparative examples. [Figure 16] This is a schematic diagram showing a self-adaptive seismic isolation system in yet another embodiment of the present invention. [Figure 17] This is a comparative diagram of the hysteresis loops related to the normalized total horizontal shear force in Example 3 of the present invention and in the comparative example. [Figure 18] This is a comparative diagram showing the relationship between normalized horizontal restoring force and displacement in Example 3 of the present invention and in comparative examples. [Figure 19] This is a comparative diagram of the hysteresis loops related to the normalized horizontal friction force in Example 3 of the present invention and in the comparative example. [Figure 20]This is a comparative diagram showing the relationship between normalized vertical axial force and displacement in Example 3 of the present invention and in comparative examples. [Modes for carrying out the invention]

[0019] The following are embodiments of the present invention, but this does not limit the invention to being carried out in the following forms; it is merely to explain the details of the invention and the effects of its implementation. Furthermore, the drawings of the present invention are for illustrative purposes only, and the proportions of the objects shown in the drawings are not necessarily those of the actual objects when carrying out the invention.

[0020] In this specification, unless otherwise specified, "horizontal" refers to a plane perpendicular to the vertical direction of gravity. That is, "horizontal direction" refers to a direction parallel to the ground.

[0021] The self-adaptive seismic isolation system of this embodiment is provided between the structural foundation and the superstructure, and includes at least two groups of sliding bearing units between the structural foundation and the superstructure, with each group distinguished by differences in the mechanical characteristics acting when sliding horizontally. That is, sliding bearing units of the same group have the same or similar mechanical characteristics. Furthermore, at least one group of sliding bearing units is equipped with an elastic part capable of providing vertical rigidity. The elastic part capable of providing vertical rigidity means that the direction of the elastic force mainly provided by the elastic part is vertical. Forces acting on other directions, such as deformation, are not completely excluded unless they affect the overall operation of the seismic isolation system. Preferably, all but one of the at least two groups of sliding bearing units are provided with an elastic part capable of providing vertical rigidity.

[0022] The seismic isolation system, which consists of at least two groups of sliding bearing units, may consist of a first bearing unit and a second sliding bearing unit. That is, multiple first bearing units may constitute a first group, and one or more second sliding bearing units may constitute a second group. The first group is provided with at least three first bearing units because it is necessary to effectively support a plane between the structural foundation and the superstructure, and based on the fact that a plane is formed from at least three points. The second sliding bearing units of the second group generate mechanical effects such as height differences with respect to the surface of the first bearing units of the first group, but the detailed operating principle will be described later.

[0023] The mechanical properties acting on the sliding bearing unit when it slides horizontally include damping force and / or restoring force, of which the damping force specifically includes descriptions that have an energy absorption effect in mechanics, such as friction force, yield stress, and viscous damping force. The first bearing unit has the ability to provide damping force and / or restoring force in the horizontal direction, and the second sliding bearing unit has the ability to provide a different damping force and / or restoring force in the horizontal direction than the first bearing unit. Furthermore, the second sliding bearing unit has an elastic part assembled vertically that can provide rigidity in the direction perpendicular to the horizontal direction. One embodiment of the self-adaptive seismic isolation system of this embodiment may be configured in such a way that a plurality of first bearing units and a plurality of second sliding bearing units are provided between the structural foundation and the superstructure.

[0024] Furthermore, the mechanical properties acting on the sliding bearing unit when it slides horizontally are not limited to being described using technical terms of mechanics. For example, they may be described using the height function of the sliding surface of the sliding bearing unit. One aspect of the self-adaptive seismic isolation system of this embodiment realizes the inventive effects described later by employing different height functions of sliding surfaces of different groups of sliding bearing units, and surfaces made of materials with different coefficients of friction.

[0025] Due to the different height functions of the sliding surfaces of the different groups of sliding bearing units, when the sliding bearing units of each group move, the elastic part that provides vertical rigidity in the sliding bearing unit (second sliding bearing unit) deforms due to the height difference between the sliding surfaces, and the axial pressure of the sliding bearing unit (second sliding bearing unit) changes.

[0026] Furthermore, the primary function of the first bearing unit, which does not have the aforementioned elastic part, is to provide support force in the vertical direction, while providing damping and restoring forces in the horizontal direction as auxiliary forces. The first bearing unit may be a frictional single pendulum bearing that slides on a curved surface, a flat plate sliding bearing that does not provide a restoring force, or a natural rubber bearing that does not provide a damping force.

[0027] First, the self-adaptive seismic isolation system in the embodiment shown in Figure 1 will be described. In this embodiment, both the first support unit and the second sliding support unit have mechanical properties that provide damping force and restoring force in the horizontal direction. Figure 1 is a schematic diagram of the structure of a self-adaptive seismic isolation system in one embodiment of the present invention. The self-adaptive seismic isolation system 1 is provided between the structural foundation 3 and the superstructure 2 and includes a first support unit 10 consisting of a slider 11 and a spherical plate 12, and a second sliding support unit 20 consisting of a slider 21, a spherical plate 22, and an elastic part 23. The elastic part 23 is assembled perpendicular to the horizontal direction of the second sliding support unit 20 and provides rigidity in the vertical direction. As shown in Figure 1, the sliders 11 and 21 in the first support unit 10 and the second sliding support unit 20 are installed to be interlocked with the superstructure 2. In other words, the first support unit 10 and the second sliding support unit 20 support the building and move in accordance with the shaking of the building during an earthquake, and the sliders 11 and 21 slide on the spherical plates 12 and 22 during an earthquake.

[0028] Furthermore, as shown in Figure 2, the self-adaptive seismic isolation system 1' may also include a third sliding bearing unit 30, which consists of a slider 31, a spherical plate 32, and an elastic part 33. The mechanical properties exhibited by the sliding spherical plate 32 are different from those of the first bearing unit 10 and the second sliding bearing unit 20, and are horizontal damping force and / or restoring force.

[0029] Furthermore, the seismic isolation system may further include a fourth sliding bearing unit or more groups of sliding bearing units. In this case, each group of sliding bearing units exhibits different mechanical characteristics during sliding.

[0030] One embodiment of the sliding bearing unit of this embodiment may consist of a sliding spherical plate, a slider, and a friction material. Since the seismic isolation system of this embodiment can be composed of a combination of multiple different types of sliding bearing units, the multi-seismic isolation performance and system characteristics can be optimized by selecting the type of slider and spherical plate as needed. The slider of this embodiment can be selected according to the performance target. Examples of slider materials include nylon, Teflon®, and ultra-high molecular weight polyethylene. Other specifications of the slider can be selected based on the shape of the contact surface, contact area, thickness, etc. Examples of contact surface shapes include dry friction and lubricated friction. Next, regarding the sliding spherical plate of this embodiment, the type of height geometric function of the sliding surface of the spherical plate may be a constant curvature surface or a variable curvature surface. As shown in Figure 5a, in the schematic diagram relating to the variable curvature sliding surface of the sliding spherical plate, the friction element 40 represents the friction point of the slider, and the friction element 40 (slider) slides on the variable curvature sliding surface 50. The radius of curvature of the variable curvature sliding surface 50 is not fixed and can be changed according to the displacement of the friction element 40. A key feature is that a wider variety of mechanical changes can be achieved through changes in the function related to the spherical plate. Furthermore, although the sliding bearing unit of this embodiment uses a spherical plate with a curved surface, it is also possible to replace one or more groups of curved surfaces with planar sliding surfaces.

[0031] The sliding spherical plates in the sliding bearing unit of this embodiment are classified into single sliding spherical plates or composite sliding spherical plates depending on the number of sliding spherical plates. A composite sliding spherical plate refers to one having two or more sliding spherical plates. See Figure 5b for an example of a composite sliding spherical plate. Compared to a single sliding spherical plate, a composite sliding spherical plate can provide a larger seismic isolation displacement allowance for the same bearing size, and also saves installation space. Furthermore, each spherical plate in a composite sliding spherical plate may be a combination of the various spherical plate forms described above or other well-known spherical plate technologies.

[0032] In this embodiment, the main function of the elastic part capable of providing vertical rigidity is to adjust the axial pressure (normal force) to match the difference in height of the sliding surfaces of different sliding bearing units. The elastic part provides rigidity and movement only in the vertical direction, and movement in other horizontal directions must be restricted. The elastic part has an appropriate allowable stroke and sufficient rigidity as required by the design. Specific examples of the elastic part include, for example, spring members, leaf spring members, deflection beams, deflection plates, columnar members made of elastic polymer material, or combinations thereof. As spring members, further examples include coil springs and disc springs.

[0033] Figure 6a is a schematic diagram showing the deflection beam type elastic section of the sliding bearing unit in the seismic isolation system of this embodiment. The deflection beam type elastic section consists of a deflection member 320 installed on the slider 21, with a rotational bearing 350 installed on top of it. The specific installation method of the deflection beam type elastic section can be determined based on rigidity and displacement. Examples of the deflection member 320 include a deflection beam and a deflection plate. Examples of the rotational bearing 350 include a pin bearing 350 and a roller bearing 351. Figure 6a is a schematic diagram showing that the deflection beam type elastic section is a simple beam type combining a roller bearing 351 and a pin bearing 350. In Figure 6a, an example is shown in which the deflection beam type elastic section consists of a single layer of deflection member 320, but the deflection beam type elastic section may also consist of multiple deflection members 320 stacked on top of each other.

[0034] Figures 6b and 6c are schematic diagrams showing the spring-type elastic part of the sliding bearing unit in the seismic isolation system of this embodiment. The spring-type elastic part consists of a component comprising a spring member 310, a side fixing member 311, and a guide rod 360, which is installed and supported on the slider 21. The side fixing member 311 fixes the spring member 310 to a predetermined position on the surface of the superstructure 2, and the guide rod 360 penetrates the superstructure 2 and the spring member 310 vertically and is adhesively fixed above the slider 21. When the slider 21 moves to a high position and compresses the spring inside the side fixing member 311, the guide rod 360 ensures vertical movement. As a result, the spring-type elastic part provides vertical rigidity.

[0035] Figure 6d is a schematic diagram showing the polymer material type elastic part of the sliding bearing unit in the seismic isolation system of this embodiment. The polymer material type elastic part consists of a movable sleeve 340 having a filling elastic material 330 inside, which is installed on the slider 21. The filling elastic material 330 is made by filling one or more polymer materials or rubber-based elastic materials. Examples of polymer materials used in the polymer material type elastic part include nylon.

[0036] Figure 6e is a schematic diagram showing a composite elastic section of the sliding bearing unit in the seismic isolation system of this embodiment. As described above, a specific example of the elastic section of the present invention may be a combination of different types of elastic sections as described above. The composite elastic section in Figure 6e is a combination of a deflection beam type elastic section and a polymer material type elastic section. In Figure 6e, the composite elastic section is composed of a deflection member 320, a rotation bearing 350, and a filling elastic material 330. In the schematic diagram of Figure 6e, a movable sleeve is not depicted outside the filling elastic material 330, but specific surrounding members can be designed as needed.

[0037] As described above, the seismic isolation system of this embodiment includes at least two groups of sliding bearing units with different mechanical properties acting when sliding in the horizontal direction, and at least one group of sliding bearing units is equipped with an elastic part that can provide vertical rigidity. The seismic isolation system of this embodiment can prevent similar resonance phenomena from occurring due to seismic waves through the mechanism of variable rigidity and variable friction damping, and also has superior energy absorption capabilities. Generally, the frictional force of a member is determined by two elements acting on the friction contact surface: the "normal force" and the "coefficient of friction". However, changing the "coefficient of friction" to realize "passive variable friction" is difficult with current circular sliding surface processing technology, and simulating the mechanical properties of different friction materials to design a seismic isolation system is also extremely complex and difficult to implement. In the seismic isolation system of this embodiment, the load is redistributed during the process of the sliding bearing unit's oscillation displacement, and the "normal force" is changed to realize the characteristics of variable friction and variable rigidity.

[0038] Next, with reference to Figure 1, the operating state of the self-adaptive seismic isolation system of the present invention will be described. The self-adaptive seismic isolation system 1 of this embodiment includes a first support unit 10 and a second sliding support unit 20. The first support unit 10 is composed of a slider 11 and a spherical plate 12, and the second sliding support unit 20 is composed of a slider 21, a spherical plate 22 and an elastic part 23. Assuming that the seismic isolation base of the lowest layer of the superstructure 2 is rigid, the horizontal displacement x of the upper ends of the first support unit 10 and the second sliding support unit 20 b and vertical displacement z b These are all the same. However, even if the displacement of the upper end of the unit is the same, the height function z of the sliding surface of each unit i (x b)(Since (i = 1 or 2) is different, due to the height difference between them, the elastic part 23 of the second sliding support unit 20 is compressed or extended, and the magnitude of the axial pressure (vertical resistance) in the vertical direction of the first support unit 10 and the second sliding support unit 20 changes. Specifically, at the initial position before the earthquake, the compression amount of the elastic part 23 of the second sliding support unit 20 is a predetermined value. After the earthquake, the first support unit 10 and the second sliding support unit 20 slide and swing and displace. At this time, based on the position of the swing displacement, the compression amount of the elastic part 23 changes. When the position reached by the slider 11 of the first support unit 10 on the spherical surface plate 12 due to displacement is higher than the position reached by the slider 21 of the second sliding support unit 20 on the spherical surface plate 22 due to displacement, the elastic part 23 is in an extended state, that is, a state with a small compression amount. On the other hand, when the position reached by the slider 11 of the first support unit 10 on the spherical surface plate 12 due to displacement is lower than the position reached by the slider 21 of the second sliding support unit 20 on the spherical surface plate 22 due to displacement, the elastic part 23 is in a compressed state, that is, a state with a large compression amount. Therefore, during the earthquake, the self - adaptive seismic isolation system 1 continuously changes the compression state of the elastic part 23 along with the displacement, and changes the magnitude of the axial pressure (vertical resistance) in the vertical direction of the first support unit 10 and the second sliding support unit 20. Then, the loads of the first support unit 10 and the second sliding support unit 20 are redistributed, and the frictional damping force and the restoring force of the entire seismic isolation system are changed.)

[0039] [Formula for the total shear force related to the system] Hereinafter, taking the embodiment of the seismic isolation system shown in FIG. 1 as an example, the present invention will be described using the formula for the total shear force related to the system. The formula U(x b ) for the total shear force in the seismic isolation system of this embodiment is shown by Equation (1). [Number] U I (x b ) is the horizontal shear force related to a single sliding support unit, ΔU f (x b ) is the variable frictional force, ΔU r (x b) is a variable restoring force, and is shown by equations (2) to (4), respectively.

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[0040] Equation (2) represents the horizontal shear force related to a single sliding bearing unit and can be considered equivalent to that of a conventional seismic isolation device using a frictional single pendulum bearing (FPS). As can be seen from equation (1), compared to a conventional seismic isolation device (equation (2)), the system of the present embodiment has changes in frictional damping force and restoring force resulting from the combination of elastic part and spherical plate, and the magnitude of these changes can be calculated from equations (3) and (4). From the formulas, it is clear that the mechanical changes in the system are based on changes in axial pressure and differences in the mechanical characteristics between sliding bearing units. From equation (3), the change in frictional force ΔU f (x b It was found that ΔU is related to the difference in height function and friction coefficient between units of different groups, and from equation (4), the change in restoring force ΔU r (x b It can be seen that this relates to the difference in height functions and the difference in the first derivative of the height function between units of different groups. Therefore, in order to realize the variable characteristics in frictional force, not only the change in axial pressure but also the difference in the coefficient of friction is an important key.

[0041] The arrangement of bearing units, such as the first bearing unit or the second sliding bearing unit, between the superstructure 2 and the structural foundation 3 can be appropriately arranged according to the design. For example, bearing units can be placed under structural columns or in column-free locations such as under foundation beams or foundation plates. The number of bearing units to be placed is mainly based on the magnitude of the axial force that the bearing units can withstand. A schematic diagram of the arrangement positions for the seismic isolation system of this embodiment is shown in Figure 3.

[0042] Furthermore, arranging the aforementioned support units in positions without columns is called "inter-column arrangement." Such inter-column arrangements can be used to reinforce the seismic isolation structure of existing buildings or in seismic isolation systems for new buildings. By incorporating sliding support units with elastic parts into existing seismic isolation systems, the damping and seismic isolation performance of the system under specific seismic forces can be improved. A schematic diagram of the inter-column arrangement related to the seismic isolation system of this embodiment is shown in Figure 4.

[0043] Figure 7 is a comparison of the frequency response curves of the acceleration ratio of Embodiment 1 of the present invention and the comparative example. The comparative example uses the frequency response function of the acceleration ratio related to a well-known seismic isolation system (FPS). The horizontal axis is the excitation frequency of the ground surface, and the vertical axis is the maximum absolute acceleration of the structure, with the unit being the acceleration ratio of the seismic isolation body to the earthquake. The ground surface vibration in the figure is an acceleration seismic wave of white noise, with a frequency of 0 to 2 Hz and a peak amplitude intensity of 0.3 g. As can be seen in Figure 7, a clear resonance peak was observed around the seismic isolation frequency of 0.18 Hz in the seismic isolation system of the comparative example, but no resonance peak was observed in the seismic isolation system of the embodiment of the present invention. Therefore, it can be seen that the seismic isolation system of the embodiment of the present invention not only has a resonance prevention effect but also a remarkable vibration reduction effect.

[0044] The self-adaptive seismic isolation system of the present invention has variable friction damping and variable stiffness characteristics. To demonstrate the variable mechanical characteristics of the present invention, the relationship between force and displacement (energy absorption hysteresis loop) obtained from a reciprocating simulation experiment was compared. The results of data simulations performed using the seismic isolation system of the embodiment shown in Figure 1, described earlier, as Example 1, and a well-known seismic isolation system (FPS) as a comparison example, are shown in Figures 8, 10, 12, and 14.

[0045] Furthermore, in the seismic isolation system shown in Figure 1, a modification is made to the first support unit of the two groups of support units, and this is referred to as Example 2. The first support unit in Example 2 is a support unit that provides only vertical support force, and the horizontal shear force (horizontal damping force and restoring force) it provides is 0. That is, the formula for the total shear force related to the seismic isolation system in Example 2 is obtained by setting the parameters of the first group in the above equation (1) to 0 (i.e., U I (x b ), z1(x b This is the result of changing μ1 to 0. A comparison of the data simulation results performed on the aforementioned well-known seismic isolation system (FPS) as a comparative example with Example 2 is shown in Figures 9, 11, 13, and 15.

[0046] Figure 8 is a comparative diagram of hysteresis loops related to the normalized total horizontal shear force of Example 1 of the present invention and a comparative example, and Figure 9 is a comparative diagram of hysteresis loops related to the normalized total horizontal shear force of Example 2 and a comparative example. The horizontal axis represents displacement, the vertical axis represents the normalized total horizontal shear force, and the unit is the ratio of forces. In Figures 8 and 9, the area enclosed by the hysteresis curves represents the amount of energy absorbed, i.e., the damping capacity. From Figure 8, it can be seen that Example 1 of the present invention can still provide changes in mechanical properties even when the displacement is large, and its total area, i.e., energy absorption capacity, is sufficient to suppress response displacement during a large earthquake.

[0047] Figure 10 is a comparative diagram showing the relationship between normalized horizontal restoring force and displacement for Example 1 of the present invention and a comparative example, and Figure 11 is a comparative diagram showing the relationship between normalized horizontal restoring force and displacement for Example 2 of the present invention and a comparative example. The horizontal axis represents displacement, the vertical axis represents normalized horizontal restoring force, and the unit is the ratio of forces. From Figures 10 and 11, it can be seen that the present invention's embodiment exhibits a much smaller initial restoring force than the comparative example, and therefore can demonstrate a superior seismic isolation effect in small-scale earthquakes. Furthermore, the present invention's embodiment can continuously change the restoring force and possesses the characteristics of variable stiffness.

[0048] Figure 12 is a comparative diagram of hysteresis loops related to normalized horizontal friction force in Example 1 of the present invention and a comparative example, and Figure 13 is a comparative diagram of hysteresis loops related to normalized horizontal friction force in Example 2 of the present invention and a comparative example. The horizontal axis represents displacement, the vertical axis represents normalized horizontal friction force, and the unit is the ratio of forces. From Figures 12 and 13, it can be seen that in the present invention, when the displacement is small, the energy absorption area is also small, but as the displacement increases, the energy absorption area increases rapidly. Furthermore, it can be seen that because the system of the example has a small initial friction force, it is easier to exert a seismic damping effect in small to medium-sized earthquakes, and in large earthquakes, the displacement of the seismic isolation system expands, and the energy absorption area increases accordingly, resulting in a remarkable energy absorption effect.

[0049] Figure 14 is a comparative diagram showing the relationship between normalized vertical axial force and displacement in Example 1 of the present invention and a comparative example, and Figure 15 is a comparative diagram showing the relationship between normalized vertical axial force and displacement in Example 2 of the present invention and a comparative example. The horizontal axis represents displacement, and the vertical axis represents normalized vertical axial force (normal force), with the unit being the ratio of forces. From Figures 14 and 15, the axial force changes of the first bearing unit and the second sliding bearing unit can be confirmed, and it can be seen that the axial force is appropriately transferred in the present invention, but in the comparative example the axial force is always 1 and does not change.

[0050] Next, a self-adaptive seismic isolation system in yet another embodiment of the present invention will be described. Figure 16 is a schematic diagram of the structure of a self-adaptive seismic isolation system in yet another embodiment of the present invention. The seismic isolation system in Figure 16 is the same as the seismic isolation system in Figure 1, except for the first bearing unit 110. The first bearing unit 110 is an elastic bearing unit, and specific examples of elastic bearing units include, for example, lead-plugged rubber bearings (LRB), high-damping rubber bearings, and natural rubber bearings.

[0051] During an earthquake, the first bearing unit 110 deforms horizontally in response to the shaking, in addition to the vibration-absorbing effect of the material itself. Simultaneously, the second sliding bearing unit 20 also slides and begins to oscillate. The elastic part 23 changes the amount of spring compression according to the height of the position where the second sliding bearing unit 20 slides on the spherical plate. This redistributes the load between the first bearing unit 110 and the second sliding bearing unit 20.

[0052] The formula for the total shear force related to the system in the embodiment of the seismic isolation system shown in Figure 16 is U'(x b ) is shown by equation (5).

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[0053] Furthermore, in Example 3, where the first bearing unit is an elastic bearing unit in a seismic isolation system, Figures 17 to 20 show a comparison of the relationship between force and displacement (energy absorption hysteresis loop) obtained from horizontal reciprocating displacement. In Figures 17 to 20, the comparative example is the same well-known seismic isolation system (FPS) as described above, and the restoring stiffness of the first bearing unit 110 in Example 3 is set to be the same as the restoring stiffness provided by the first bearing unit 10 in Example 1. In addition, yield stress is applied as shown in equation (6) above in order to simulate the actual operating state of the elastic bearing unit.

[0054] From the comparative diagrams of hysteresis loops related to normalized total horizontal shear force (Figure 17), the relationship between normalized horizontal restoring force and displacement (Figure 18), the hysteresis loop related to normalized horizontal friction force (Figure 19), and the relationship between normalized vertical axial force and displacement (Figure 20), it can be seen that, compared to the comparative example, Example 3 has superior energy absorption capacity, can continuously change the restoring force and possesses variable stiffness characteristics, has variable friction characteristics where the friction force increases with displacement, and has axial force change characteristics. Also, as can be seen from Figure 17, except that much of the initial shear force is provided by the elastic bearing, the hysteresis of the total shear force is similar to that of Example 1, but the amount of change in the height difference in the entire system is relatively large. From Figure 19, it can be seen that the initial sliding force is provided by the damping force of the elastic bearing, and the energy absorption area consists of a combination of the variable friction force of the sliding bearing unit and the damping force of the elastic bearing. Although the hysteresis loop becomes somewhat asymmetrical due to the addition of damping force, a significant change in energy absorption can still be observed.

[0055] As described above, the self-adaptive seismic isolation system of the present embodiment is superior to conventional seismic isolation systems because it has many excellent characteristics, such as (1) variability of seismic isolation stiffness, (2) variability of energy absorption due to friction, and (3) redistribution of load between sliding bearing units of each group.

[0056] (1) Variableness of seismic isolation stiffness The variable characteristics of seismic isolation stiffness in this invention are mainly due to the presence of multiple groups of sliding bearing units with different surface functions within the system. The restoring force and stiffness provided by each group of sliding bearing units are related to the height function of the surface, and the restoring force and stiffness of the seismic isolation layer in the entire system are related to the difference in height functions and their first derivatives between different groups (see equation (4)). By combining vertical elastic parts, a change in axial force can be introduced, and the force configuration of the stiffness changes as a result of the combined action of the axial force change and the difference in horizontal restoring force in the spherical plate. Furthermore, this change depends on the horizontal displacement of the seismic isolation layer. In addition, the system can also be given the effect of variable stiffness by introducing sliding bearing units with variable characteristics into the system. The characteristic of variable stiffness in this invention is that the restoring force can be continuously changed during the displacement process, as shown in Figure 10.

[0057] (2) Variability of energy absorption due to friction In this invention, due to the variability of energy absorption by friction, friction can be adjusted not simply from a fixed coefficient of friction, but from changes in axial force and differences in the coefficient of friction between sliding parts (see Equation (3)). At the same time, since the frictional force changes with displacement, the required energy absorption capacity can be achieved at a predetermined displacement, and the energy absorption capacity can be significantly improved compared to conventional seismic isolation systems. This difference can be clearly seen from the comparison of hysteresis loops in Figure 12.

[0058] (3) Redistribution of load between sliding bearing units in each group The change in axial force within each group of sliding bearing units, and the redistribution of load axial force between different groups of sliding bearing units, are the most important concepts and features of the seismic isolation system of the present invention. By introducing elastic components, the axial force of the sliding bearing units changes, and the axial force of the members in each group is converted and flows due to the transfer of displacement and axial force, thereby applying the expected load to the sliding bearing units. In addition, the benefits of redistribution include not only the optimization of the performance of individual bearings, but also the improvement of the overall system performance.

[0059] The self-adaptive seismic isolation system of the present invention, possessing variable mechanical properties, offers superior advantages over conventional seismic isolation systems due to its passive self-adaptive performance, and can be designed to meet various required performance requirements. The seismic isolation system of the present invention can achieve different seismic isolation performance targets in response to different seismic forces, and the seismic isolation performance targets can be adjusted and set based on the needs of the structure or equipment user and the characteristics of the installation site.

[0060] Through appropriate performance design, the self-adaptive seismic isolation system of the present invention exhibits superior seismic damping effects in small to medium-sized earthquakes, which have a high incidence rate. Furthermore, in large earthquakes, which have a low incidence rate, the displacement of the seismic isolation system can be further reduced, allowing for a smaller size of seismic isolation bearings and resulting in superior cost-effectiveness.

[0061] Because the self-adaptive seismic isolation system of the present invention has a resonance prevention effect, it can avoid situations in which the safety of structures and people is threatened by significant seismic displacement during pulse-type earthquakes near faults or low-frequency earthquakes.

[0062] This invention enhances the flexibility of seismic isolation system design and provides various combinations of sliding bearing units that meet the seismic requirements of various structures or facilities.

[0063] The present invention is not limited to this embodiment, and can be implemented with various modifications within the scope of its spirit. In the above embodiment, the installation of a building on the ground was described as an example, but as a modification of the present invention, it can also be applied to seismic isolation of floor slabs or equipment, and is not limited to application to the ground.

[0064] The above embodiments are merely illustrative of embodiments of the present invention and illustrate its technical features, and do not limit the scope of protection of the present invention. All modifications and equivalent arrangements that can be easily completed by those skilled in the art are also included within the scope claimed by the present invention. The scope of protection of the rights according to the present invention is based on the claims. [Explanation of symbols]

[0065] 1. Self-adaptive seismic isolation system 1' Self-adaptive seismic isolation system 2 Superstructure 3 Structural foundation 10 First support unit 11 Slider 12 Spherical plate 20 Second sliding bearing unit 21 Slider 22 Spherical plate 23 Elastic part 30 Third sliding bearing unit 31 Slider 32 Spherical plate 33 Elastic part 40 Friction child 50 Variable curvature sliding surface 100 Self-adaptive seismic isolation systems 110 First support unit 310 Spring component 311 Side fixing member 320 Flexible member 330 Filling elastic material 340 movable sleeves 350 Rotary bearing 351 Roller bearing 360 Guide Rod

Claims

1. It is provided between the structural foundation and the superstructure, and includes a first support unit and a second sliding support unit between the structural foundation and the superstructure. A self-adaptive seismic isolation system comprising a second sliding bearing unit configured to provide a different damping force and / or restoring force in the horizontal direction than the first bearing unit, and an elastic part vertically assembled to provide rigidity in the direction perpendicular to the horizontal direction of the second sliding bearing unit.

2. The seismic isolation system according to claim 1, wherein the first bearing unit is a sliding bearing unit configured to provide a damping force and / or restoring force in the horizontal direction.

3. The seismic isolation system according to claim 1, wherein the first bearing unit is an elastic bearing unit configured to provide a damping force and / or restoring force in the horizontal direction.

4. The seismic isolation system according to claim 2, wherein the first support unit has a slider and a planar or curved sliding surface.

5. The seismic isolation system according to claim 1, wherein the second sliding bearing unit has a slider and a planar or curved sliding surface.

6. The seismic isolation system according to claim 5, wherein there is a difference in height between the curved sliding surface of the second sliding support unit and the first support unit.

7. The seismic isolation system according to any one of claims 1 to 6, further comprising a third sliding bearing unit configured to provide a damping force and / or restoring force different in the horizontal direction from that of the first bearing unit and the second sliding bearing unit.

8. The seismic isolation system according to claim 7, wherein the third sliding bearing unit has a slider, a planar or curved sliding surface, and an elastic part is assembled vertically to provide rigidity in a direction perpendicular to the horizontal direction of the third sliding bearing unit.

9. The seismic isolation system according to claim 4 or 5, wherein the sliding surface of the curved surface is a composite sliding spherical plate composed of a plurality of curved surfaces.

10. The seismic isolation system according to claim 4 or 5, wherein the sliding surface of the curved surface is a variable curvature sliding surface.

11. The superstructure supports the building above and is supported by a plurality of the first support units and a plurality of the second sliding support units. The seismic isolation system according to claim 1, wherein the position of the first support unit or the second sliding support unit corresponds to the position of the structural columns in the building.

12. The seismic isolation system according to claim 11, wherein the position of the second sliding bearing unit corresponds to the position between structural columns in the building.

13. The seismic isolation system according to claim 1, wherein the elastic part is at least one of a deflection beam plate, a spring member, a leaf spring member, a columnar member made of an elastic polymer material, or a combination thereof.

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