Design system of base isolation structure, design method, and design program

Abstract

To design a base isolation structure which controls the response of a building in a proper range, irrespective of the level of a great earthquake.SOLUTION: A design system 1 includes an attenuation characteristic storage part 5 for storing information regarding a first attenuation characteristic of a first damper and information regarding a second attenuation characteristic of a second damper. The first attenuation characteristic lowers the attenuation coefficient gradually or step-by-step according to the increase in a response amount, and the second attenuation characteristic increases the attenuation force rapidly in a switching amount which is a predetermined response amount, and the switching amount is substantially a border between the response amount of a level 2 earthquake motion and the response amount of a level 3 earthquake motion. The design system 1 includes a control part 2 which acquires a response when the level 2 earthquake motion is inputted and a response when the level 3 earthquake motion is inputted respectively with respect to an analytic model of a building in which the first damper and the second damper are arranged, and which specifies the number of units of the first damper and the second damper so that the response satisfies the performance index of the building.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a design system, a design method, and a program for a seismic isolation structure.

Background Art

[0002] In seismic isolation buildings including super high-rise buildings, measures against large earthquakes including long-period seismic motion are required. In seismic isolation buildings, as seismic isolation members, seismic isolation bearings such as laminated rubber and dampers for attenuating the sway of the building are often used (see, for example, Patent Document 1). According to the conventional Building Standards Act, a seismic isolation building designed for level 2 seismic motion having the maximum level of strength may have a large response displacement when an earthquake of level 2 or higher (hereinafter referred to as level 3 seismic motion) occurs, and may exceed the design clearance of the seismic isolation layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, when designing a seismic isolation building for level 3 seismic motion, the response acceleration of the superstructure located above the seismic isolation layer becomes larger than before during level 2 seismic motion. For this reason, a larger member cross-section is required for the superstructure. Thus, the response displacement and the response acceleration of the superstructure during the occurrence of a large earthquake including level 2 seismic motion and level 3 seismic motion are in a trade-off relationship. For this reason, there is a demand for a design system for a seismic isolation structure that can realize an appropriate response such that the response displacement during level 3 seismic motion is suppressed and the response acceleration during level 2 seismic motion, which is smaller than that, is reduced by appropriately arranging dampers.

Means for Solving the Problems

[0005] A seismic isolation structure design system for solving the above problems, in a seismic isolation structure design system including a damping characteristic storage unit that stores the damping characteristics of dampers arranged in the seismic isolation layer of a building, and a control unit that performs response analysis, the damping characteristic storage unit stores information on the first damping characteristics of a first damper and information on the second damping characteristics of a second damper, the first damping characteristics cause the damping coefficient to gradually or stepwise decrease as the response amount increases, the second damping characteristics cause the damping force to rapidly increase at a switching amount that is a predetermined response amount as the response amount increases, the switching amount is approximately the boundary between the response amount during level 2 ground motion and the response amount during level 3 ground motion, and the control unit obtains the response when level 2 ground motion is input and the response when level 3 ground motion is input for an analysis model of the building in which the number of the first damper and the second damper is set, and specifies the number of the first damper and the second damper so that the response satisfies the performance index of the building.

Effect of the Invention

[0006] According to the present invention, it is possible to design a seismic isolation structure that controls the response of a building within an appropriate range regardless of the level of a great earthquake.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiment for Carrying Out the Invention

[0008] Hereinafter, an embodiment of a seismic isolation structure design system, design method, and program will be described with reference to FIGS. 1 to 8. FIG. 1 is an example of a building 100 targeted by the seismic isolation structure design system, and schematically shows a cross section of the seismic isolation layer 101 thereof. The seismic isolation layer 101 is provided with seismic isolation bearings (not shown), such as laminated rubber, elastic sliding bearings, or rolling bearings, directly below columns 102 or the like. Further, the seismic isolation layer 101 is provided with a plurality of types of dampers 10, which are seismic isolation members, in the X direction and the Y direction.

[0009] The damper 10 is connected to a structure composed of columns 102 or beams 103 or the like. Here, each damper 10 is a viscous damping type damper. For example, the damper 10 is a velocity-dependent bilinear type damper, a damper with a velocity-dependent amplification function, and a damper with a variable damping coefficient. For convenience of explanation, hereinafter, the velocity-dependent bilinear type damper will be simply referred to as an "oil damper", and the damper with a velocity-dependent amplification function will be referred to as a "rotary amplification damper". The oil damper and the rotary amplification damper correspond to the first velocity-dependent damper. The damper with a variable damping coefficient corresponds to the second velocity-dependent damper.

[0010] The oil damper, the rotary amplification damper, and the damper with a variable damping coefficient show non-linearity in the relationship between the damping force and the response speed within the range below the maximum response speed. Each damper 10 may show linearity in the relationship between the damping force and the response speed in the low speed range, and may show non-linearity in the relationship between the damping force and the response speed in the high speed range. Note that the response speed corresponds to the response amount.

[0011] Each damper 10 has different damping characteristics. The damping characteristics of the oil damper and the rotary amplification damper are the first damping characteristics, and as the response speed increases, the damping coefficient is gradually decreased step by step or gradually decreased.

[0012] The oil damper may obtain bilinear damping characteristics by opening and closing an adjustment valve or a relief valve provided on the piston. The rotary amplification damper may obtain damping characteristics by converting the axial movement into the movement of a rotating body that rotates while receiving viscous resistance.

[0013] The damping characteristics of the variable damping coefficient damper are the second damping characteristics. When the response speed is less than a predetermined response speed, it shows low damping characteristics with a low damping force. When the response speed is greater than or equal to the predetermined response speed, it shows high damping characteristics with a high damping force. The range of the response speed showing the low damping characteristics overlaps with the range of the response speed during the level 2 earthquake motion. The range of the response speed showing the high damping characteristics overlaps with the range of the response speed during the level 3 earthquake motion. The predetermined response speed indicating the boundary between the low damping characteristics and the high damping characteristics is approximately the boundary between the response speed during the level 2 earthquake motion and the response speed during the level 3 earthquake motion. Or, the predetermined response speed indicating the boundary between the low damping characteristics and the high damping characteristics is included in the response speed range that is the range in which the response speed changes from the level 2 earthquake motion to the level 3 earthquake motion.

[0014] The response speed during the level 2 earthquake motion and the response speed during the level 3 earthquake motion change within the response speed range according to the type of earthquake motion input to the analysis model or the elapsed time from the input time and the like in the time history response analysis described later. The response speed range is obtained by simulation or experiment or the like. The fact that the response speed is approximately the boundary means that the response speed is close to the boundary to such an extent that the switching to the high damping characteristics based on the response speed suppresses the response displacement during the level 3 earthquake motion.

[0015] The damping characteristics of the variable damping coefficient damper are different from those of the oil damper and the rotary amplification damper in that the damping force is smaller than that of the oil damper and the rotary amplification damper in the response speed range when seismic motion corresponding to level 2 is input. The damping characteristics of the variable damping coefficient damper show a rapid increase in the damping force at a predetermined response speed as the response speed increases, thereby increasing the damping coefficient.

[0016] The damping characteristics of the variable damping coefficient damper may maintain the damping coefficient before the increase after rapidly increasing the damping force at a predetermined response speed as the response speed increases, or may decrease the damping coefficient from the damping coefficient before the increase when a predetermined relief load is reached. The rapid increase in the damping force is a transient state from the low damping characteristic to the high damping characteristic, meaning that the damping force increases to an extent that it has a damping coefficient larger than the damping coefficient of the low damping characteristic and the damping coefficient of the high damping characteristic.

[0017] The variable damping coefficient damper may switch between high and low damping characteristics by opening and closing an adjustment valve or a relief valve provided on the piston, or by switching the flow path accompanying the pressure change in the damper. In addition to the function of switching between high and low damping characteristics depending on the speed, the variable damping coefficient damper may further have a function of changing the damping force depending on the displacement so as to switch the flow path as the piston displaces.

[0018] Note that the level 2 seismic motion is the seismic motion with the maximum intensity considered at the location where the building 100 exists from the present to the future. The level 3 seismic motion is an extremely large earthquake motion larger than the level 2 seismic motion.

[0019] <Damping characteristics of the damper> (Variable damping coefficient damper) Next, the damping characteristics of each damper 10 will be described in detail.

[0020] Figure 2 shows an example of the damping characteristic C1 with respect to the response speed of a variable damping coefficient damper that switches the flow path according to the pressure change in the damper and switches the flow path according to the displacement of the piston. The horizontal axis represents the absolute value of the response speed (mm / sec), and the vertical axis represents the absolute value of the damping force (kN). The variable damping coefficient damper exhibits a low damping characteristic C that generates a low damping force when the absolute value of the response speed is low L and exhibits a high damping characteristic C that generates a high damping force when the absolute value of the response speed is high H .

[0021] The variable damping coefficient damper switches the damping characteristic at a constant response speed. When the variable damping coefficient damper is in compression, the response speed at which the damping characteristic is switched is referred to as the characteristic switching speed V1. In the present embodiment, the characteristic switching speed V1 corresponds to the boundary value between the response speed range during a level 2 earthquake motion and the response speed range during a level 3 earthquake motion. That is, the characteristic switching speed V1 is set such that when a level 2 earthquake motion is input to the building 100, the response speed of the variable damping coefficient damper is less than the characteristic switching speed V1, and when a level 3 earthquake motion is input, the response speed is equal to or greater than the characteristic switching speed V1. The characteristic switching speed V1 corresponds to the switching amount.

[0022] The variable damping coefficient damper exhibits a low damping characteristic C when it is in compression and the response speed is less than the characteristic switching speed V1 L . At the characteristic switching speed V1, it transitions from the low damping characteristic C L to the high damping characteristic C H , and when the response speed is equal to or greater than the characteristic switching speed V1, it exhibits the high damping characteristic C H . The damping force of the variable damping coefficient damper increases discontinuously (or discretely) at the characteristic switching speed V1. The high damping characteristic C H sharply increases the damping force at the characteristic switching speed V1. The characteristic curve of the variable damping coefficient damper extends substantially along the vertical axis at the characteristic switching speed V1. The high damping characteristic C H includes a first high damping characteristic C H 1 and a second high damping characteristic C H 2. The damping coefficient of the first high damping characteristic C H 1 is the second high damping characteristic CH is higher than the attenuation coefficient of 2. That is, the attenuation characteristics of the variable attenuation coefficient damper are the low attenuation characteristic C L of the attenuation coefficient, the first high attenuation characteristic C H of the attenuation coefficient of 1, and the second high attenuation characteristic C H of 2, and has three attenuation coefficients.

[0023] When in tension, when the response speed of the variable attenuation coefficient damper is greater than the characteristic switching speed V1, the first high attenuation characteristic C H 1 and the second high attenuation characteristic C H 2 are shown. When the response speed reaches the characteristic switching speed V2, the damping force drops sharply, thereby showing the low attenuation characteristic C L In this case as well, the damping force becomes discontinuous (or discrete) and low at the characteristic switching speed V2. The characteristic switching speed V2 is smaller than the characteristic switching speed V1.

[0024] The table in FIG. 3 shows the attenuation characteristics of the variable attenuation coefficient damper for each response speed and response displacement. The variable attenuation coefficient damper switches the attenuation characteristics at a certain characteristic switching displacement, similar to the response speed. The variable attenuation coefficient damper shows the low attenuation characteristic C L only when the response speed is small with respect to the characteristic switching speeds V1, V2 and the response displacement is small with respect to the characteristic switching displacement. The variable attenuation coefficient damper shows the high attenuation characteristic C H regardless of the response displacement when the response speed is large with respect to the characteristic switching speeds V1, V2. Also, the variable attenuation coefficient damper maintains the high attenuation characteristic regardless of the response speed when the response displacement is high with respect to the characteristic switching displacement.

[0025] FIG. 4 shows the attenuation characteristic C2 of the oil damper and the attenuation characteristic C3 (first attenuation characteristic) of the rotation amplification damper. The dashed line shows the attenuation characteristic C1 (second attenuation characteristic) of the variable attenuation coefficient damper.

[0026] When the characteristic switching speed is less than V1, the oil damper and the rotary amplification damper generate a large damping force, while the damping coefficient variable damper suppresses the damping force. When the characteristic switching speed is V1 or more, the damping coefficient variable damper generates a damping force comparable to the damping force generated by the oil damper, the rotary amplification damper, and the damping coefficient variable damper.

[0027] That is, when only the oil damper and the rotary amplification damper are arranged in the seismic isolation layer 101 and the number is set according to the level 3 earthquake motion, there is a possibility of over-damping during the level 2 earthquake motion. Further, when the number of the oil damper and the rotary amplification damper is set according to the level 2 earthquake motion, the response displacement becomes excessive, and when the level 3 earthquake motion occurs, the building 100 may collide with the retaining wall. In this case, it is necessary to increase the member cross-section of the superstructure, resulting in an increase in cost.

[0028] On the other hand, the damping coefficient variable damper generates a damping force smaller than that of the oil damper and the rotary amplification damper during the level 2 earthquake motion. On the other hand, since the damping coefficient variable damper has a more complex configuration than at least the oil damper, if all the dampers 10 are damping coefficient variable dampers, it is inconvenient for the construction conditions including the cost effectiveness. For this reason, in the design system of the seismic isolation structure, in order to suppress the over-damping during the level 2 earthquake motion, in addition to the oil damper and the rotary amplification damper, a damping coefficient variable damper is arranged as the damper 10 arranged in the seismic isolation layer 101, and the number of the dampers 10 is optimized.

[0029] (Design System) FIG. 5 is a hardware configuration of one or a plurality of information processing apparatuses H10 constituting the design system of the seismic isolation structure. The information processing apparatus H10 includes a communication apparatus H12, an input apparatus H14, a display apparatus H15, a storage apparatus H13, and a processor H11. Note that this hardware configuration is an example, and it is also possible to realize it by other hardware or a combination of this hardware and other hardware.

[0030] The communication device H12 is an interface that establishes a communication path with other devices and performs data transmission and reception. For example, the communication device H12 is a network interface or the like that communicates via the Internet or the like, either wired or wirelessly.

[0031] The input device H14 is a device that accepts the input of various information based on the operations of the person in charge. Examples of the input device H14 include a touch panel, a mouse, a keyboard, and the like. The display device H15 is a display or the like that displays various information. The input device H14 and the display device H15 only need to be provided in the information processing device H10 used by the user.

[0032] The storage device H13 (computer-readable medium) stores data and various programs for executing various functions. Examples of the storage device H13 include a ROM, a RAM, a hard disk, and the like. The storage device H13 includes any available recording medium that can be accessed by a general-purpose or dedicated computer. The design program and various data used for the execution of the program are recorded in the storage device H13.

[0033] The processor H11 controls each process using the programs and data stored in the storage device H13. Examples of the processor H11 include a CPU, an MPU, and the like. This processor H11 expands the program into the RAM and executes various processes for each process. The processor H11 is not limited to performing software processing for all processes it executes. For example, the processor H11 may include a dedicated hardware circuit (e.g., an application-specific integrated circuit: ASIC) that performs hardware processing for at least a part of the processes it executes. That is, the processor H11 can be configured by any of the following.

[0034] 〔1〕One or more processors that operate according to a computer program (software) 〔2〕One or more dedicated hardware circuits that execute at least a part of various processes 〔3〕circuits including those combinations (Function of the design system) With reference to FIG. 6, the functions of design system 1 realized by executing the design program stored in storage device H13 of information processing apparatus H10 and the data used by design system 1 will be described.

[0035] Design system 1 includes control unit 2, damping characteristic storage unit 5, and seismic wave storage unit 6. Control unit 2 has setting unit 3 and response analysis unit 4. Damping characteristic storage unit 5 stores information indicating the damping characteristics of oil dampers, rotational amplification dampers, and damping coefficient variable dampers.

[0036] Seismic wave storage unit 6 stores seismic waves for inputting ground motions to the analysis model of building 100. Seismic wave storage unit 6 stores seismic waves for inputting level 2 ground motions and seismic waves for inputting level 3 ground motions. The seismic waves are notificatory waves, site waves, etc., which are simulated design seismic waves considering the ground and the like.

[0037] Setting unit 3 sets the analysis model of building 100. For example, setting unit 3 uses, as the analysis model, a multi-degree-of-freedom model including mass points corresponding to each floor and damper elements. Also, setting unit 3 sets the performance criteria of building 100. At this time, setting unit 3 may set the performance criteria for each level of ground motion. The performance criteria for level 2 ground motion are, for example, the upper limit value of the inter-story drift angle of the superstructure above the seismic isolation layer 101 of building 100 and the upper limit value of the displacement amount of seismic isolation layer 101. The performance criteria for level 3 ground motion are the upper limit value of the inter-story drift angle of the superstructure, the upper limit value of the displacement amount of seismic isolation layer 101, and the maximum response speed of damper 10. The inter-story drift is the horizontal displacement of each floor with respect to the lower floor when building 100 is deformed horizontally under the action of seismic force, and the inter-story drift angle is the value obtained by dividing the displacement amount by the floor height.

[0038] The response analysis unit 4 obtains the responses when level 2 seismic motion is input and the responses when level 3 seismic motion is input for the analysis model of the building 100 in which each damper 10 is arranged. Further, the response analysis unit 4 optimizes the number of each damper 10 so that the response satisfies the performance index of the building 100. <Operation of this embodiment> With reference to FIGS. 7 and 8, the operation of the seismic isolation structure design system 1 will be described. Note that the order of each step can be changed as long as there is no contradiction.

[0039] (Setting process) FIG. 7 shows a setting process performed before the response analysis. The setting unit 3 performs the setting of the analysis model (step S1). Specifically, the analysis model is set based on the height, number of floors, structural type, etc. of the building 100 input by the user.

[0040] The setting unit 3 performs the setting of the performance index for level 2 (L2) seismic motion and level 3 (L3) seismic motion (step S2). Further, the setting unit 3 performs the setting for wind load (step S3). Specifically, the setting unit 3 determines an appropriate rank from the three ranks regarding the behavior of the seismic isolation layer 101 with respect to the wind load defined in the seismic design guidelines for seismic isolation buildings.

[0041] The setting unit 3 performs the setting of the restoring force characteristics of the seismic isolation layer 101 (step S4). Specifically, the setting of the layer shear force coefficient at the yield point of the seismic isolation layer 101 is performed.

[0042] (Response analysis process) Next, the response analysis process will be described with reference to FIG. 8. The response analysis unit 4 sets the number of dampers 10 for level 2 seismic motion and sets the number of dampers 10 for level 3 seismic motion. First, the response analysis unit 4 sets the number of dampers 10, J and K, for the level 2 ground motion via the setting unit 3 (step S10). Here, the response analysis unit 4 sets the number of oil dampers J and the number of rotation amplification dampers K. At this time, the number of damping coefficient variable type dampers is set to "0".

[0043] The response analysis unit 4 inputs the level 2 ground motion into the analysis model and performs a time history response analysis (step S11). Then, the response analysis unit 4 determines whether the result of the time history response analysis satisfies the performance index (step S12). For example, the response analysis unit 4 determines whether the inter-story drift angle included in the analysis result is less than or equal to the upper limit value of the inter-story drift angle as the performance index. Also, the response analysis unit 4 determines whether the displacement amount included in the analysis result is less than or equal to the upper limit value of the displacement amount as the performance index, etc.

[0044] When the response analysis unit 4 determines that the result of the time history response analysis does not satisfy the performance index (step S12: NO), it increases the number of dampers 10 via the setting unit 3 (step S13). For example, the response analysis unit 4 performs at least one of an increase in the number of oil dampers J (J → J + 1) and an increase in the number of rotation amplification dampers K (K → K + 1). At this time, the response analysis unit 4 may alternately perform an increase in the number of oil dampers J (J → J + 1) and an increase in the number of rotation amplification dampers K (K → K + 1) each time step S13 is performed.

[0045] Then, the response analysis unit 4 repeats the time history response analysis (step S11) of inputting the level 2 ground motion and the increase in the number of dampers 10 (step S13) until the performance index of the level 2 ground motion is satisfied.

[0046] When the response analysis unit 4 determines that the performance index of the level 2 ground motion is satisfied (step S12: YES), it sets the number M of variable damping coefficient dampers for the level 3 ground motion (step S14). At this time, the number J of oil dampers and the number K of rotational amplification dampers maintain the numbers set in the response analysis process for the level 2 ground motion. The response analysis unit 4 inputs the level 3 ground motion and performs a time history response analysis (step S15).

[0047] The response analysis unit 4 determines whether the result of the time history response analysis satisfies the performance index (step S16). When the response analysis unit 4 determines that the result of the time history response analysis does not satisfy the performance index (step S16: NO), it increases the number of variable damping coefficient dampers via the setting unit 3 (step S17). Then, the response analysis unit 4 repeats the time history response analysis (step S15) of inputting the level 3 ground motion and increasing the number M of variable damping coefficient dampers (step S17) until the performance index of the level 3 ground motion is satisfied.

[0048] Then, when the response analysis unit 4 determines that the performance index of the level 3 ground motion is satisfied (step S16: YES), it determines whether the story shear force coefficient of the superstructure located above the seismic isolation layer 101 is equal to or less than the target value (step S18). Here, the response analysis unit 4 determines whether excessive damping may occur by performing a time history response analysis with the level 2 ground motion input.

[0049] When the response analysis unit 4 determines that the story shear force coefficient of the superstructure exceeds the target value as a result of the response analysis (step S18: NO), it estimates that overdamping may occur, resets the number J of oil dampers and the number K of rotational amplification dampers (step S19), and returns to step S11. At this time, the response analysis unit 4 sets the number M of dampers with variable damping coefficients to "0" via the setting unit 3. Further, the response analysis unit 4 increases or decreases the number J of oil dampers and the number K of rotational amplification dampers. For example, the response analysis unit 4 may reduce at least one of the number J of oil dampers and the number K of rotational amplification dampers. Further, the response analysis unit 4 may change the ratio of the number J of oil dampers and the number K of rotational amplification dampers.

[0050] When the response analysis unit 4 determines that the story shear force coefficient of the superstructure is equal to or less than the target value (step S18: YES), it determines the number J, K, and M of dampers 10 and ends the process. <Actions and Effects of the Present Embodiment> As described above, according to the above embodiment, the following effects can be obtained.

[0051] (1) According to the above embodiment, the design system 1 optimized the number of oil dampers, rotational amplification dampers, and dampers with variable damping coefficients based on the results of the response analysis in which the level 2 ground motion and the level 3 ground motion were input. Thereby, it is possible to design a seismic isolation structure in which high damping force acts during a level 3 ground motion while suppressing overdamping during a level 2 ground motion.

[0052] (2) According to the above embodiment, after the design system 1 optimized the number of oil dampers and the number of rotational amplification dampers so as to satisfy the performance index of the level 2 ground motion, it optimized the number of dampers with variable damping coefficients so as to satisfy the performance index of the level 3 ground motion. Since the oil damper and the rotational amplification damper have a great influence on the damping of the building 100 during the level 2 ground motion, the design of the seismic isolation structure can be efficiently performed by tentatively optimizing the number of dampers 10 during the level 2 ground motion. <Modification Example> This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non - conflicting range.

[0053] (Damper) · In the above - described embodiment, the damper 10 used in the seismic isolation layer 101 is exemplified by an oil damper and a rotational amplification damper, but its type is not limited. As the damper 10 used in the seismic isolation layer 101, a viscous - damping - type damper other than an oil damper and a rotational amplification damper may be used in addition to or instead of an oil damper and a rotational amplification damper. Or, in addition to or instead of an oil damper and a rotational amplification damper, a hysteretic - damping - type damper using plastic deformation energy of metal and Coulomb friction energy, or a combination thereof may be used.

[0054] (Design method) · In the above - described embodiment, after setting the number of oil dampers and rotational amplification dampers so as to satisfy the performance index of level 2 seismic motion, the number of variable - damping - coefficient dampers is set so as to satisfy the performance index of level 3 seismic motion. The order of setting the number of dampers 10 is not limited as long as the performance index for level 2 seismic motion and the performance index for level 3 seismic motion can be finally satisfied. For example, in the process of satisfying the performance index of level 2 seismic motion (steps S10 - S13), the response analysis unit 4 may specify not only the number of oil dampers and rotational amplification dampers but also the number of variable - damping - coefficient dampers. In the process of satisfying the performance index of level 3 seismic motion (steps S14 - S16), the response analysis unit 4 may specify not only the number of variable - damping - coefficient dampers but also the number of oil dampers and rotational amplification dampers. Also, the response analysis unit 4 may verify whether or not the performance index of level 2 seismic motion and the performance index of level 3 seismic motion are satisfied for a plurality of combinations of the number of oil dampers, rotational amplification dampers, and variable - damping - coefficient dampers in any order.

[0055] (Damping characteristics) ·In the above embodiment, the characteristic switching speeds V1 and V2 are set to values near the boundary between the response speed when the level 2 seismic motion is input and the response speed when the level 3 seismic motion is input. The characteristic switching speeds V1 and V2 may be any response speeds at which overdamping is likely to occur in the seismic isolation layer 101 where only the first velocity-dependent damper is arranged. The characteristic switching speeds V1 and V2 do not necessarily have to be the boundary values between the response speed when the level 2 seismic motion is input and the response speed when the level 3 seismic motion is input. ·In the above embodiment, the damper 10 is a velocity-dependent damper, and the switching amount in the response amount is mainly described as the switching speed in the response speed. In the above embodiment, the "response speed" corresponds to the response amount in the claims, and the "switching speed" corresponds to the switching amount in the claims. Instead of or in addition to this, the damper 10 provided in the seismic isolation layer 101 may be a displacement-dependent damper. When the damping coefficient variable damper corresponding to the second damper rapidly changes the damping force at a predetermined response displacement as the response displacement increases, the switching displacement is the response displacement that is approximately the boundary between the response displacement during the level 2 seismic motion and the response displacement during the level 3 seismic motion. Note that the damping coefficient variable damper that rapidly changes the damping force depending on the displacement may switch the high and low damping characteristics by opening and closing an adjustment valve or a relief valve provided in the piston, or by switching the flow path accompanying the displacement of the piston. In the displacement-dependent damper 10, the "response displacement" corresponds to the response amount in the claims, and the "switching displacement" corresponds to the switching amount in the claims.

[0056] Next, the technical idea that can be grasped from the above embodiment and the alternative example is added as follows. [A] The control unit inputs the level 2 seismic motion to the analysis model in which the number of the first damper and the second damper is optimized to obtain a response, and determines whether the response satisfies the performance index for the upper structure of the building. When it is determined that the response does not satisfy the performance index for the upper structure of the building, at least one of the number of the first damper and the second damper is optimized again. The seismic isolation structure design system according to claim 1. [B] a first damper having a first damping characteristic; a second damper having a second damping characteristic, and the first damping characteristic is such that the damping coefficient gradually or stepwise decreases as the response amount increases, the second damping characteristic is such that the damping force rapidly increases at a switching amount which is a predetermined response amount as the response amount increases, and the switching amount is approximately the boundary between the response amounts during level 2 earthquake motion and level 3 earthquake motion, a seismic isolation structure in which, for an analysis model in which the first damper and the second damper are arranged, the responses when a level 2 earthquake motion is input and when a level 3 earthquake motion is input are respectively obtained, and the number of the first damper and the second damper is optimized so that the responses satisfy the performance index of the building.

Description of Symbols

[0057] 1... design system, 2... control unit, 3... setting unit, 4... response analysis unit, 5... damping characteristic storage unit, 6... seismic wave storage unit, 10... damper.

Claims

1. In a seismic isolation structure design system comprising a damping characteristic memory unit that stores the damping characteristics of dampers arranged in the seismic isolation layer of a building, and a control unit that performs response analysis, the damping characteristic memory unit stores information on the first damping characteristics of the first damper and information on the second damping characteristics of the second damper, the first damping characteristics are such that as the response amount increases, the damping coefficient gradually or stepwise decreases, the second damping characteristics are such that as the response amount increases, the damping force rapidly increases at a switching amount that is a predetermined response amount, and the switching amount is approximately the boundary between the response amount during level 2 earthquake motion and the response amount during level 3 earthquake motion, the control unit obtains, for an analysis model of the building in which the number of the first damper and the second damper is set, the response when a level 2 earthquake motion is input and the response when a level 3 earthquake motion is input, respectively, and specifies the number of the first damper and the second damper so that the response satisfies the performance index of the building. A seismic isolation structure design system.

2. The control unit inputs the level 2 earthquake motion to the analysis model of the building in which the first damper is arranged to obtain a response, and sets the number of the first damper so that the response satisfies the performance index during the level 2 earthquake motion, further arranges the second damper in the analysis model in which the number of the first damper is set, inputs the level 3 earthquake motion to the analysis model to obtain a response, and sets the number of the second damper so that the response satisfies the performance index during the level 3 earthquake motion. The seismic isolation structure design system according to Claim 1.

3. In a seismic isolation structure design method using a damping characteristic memory unit that stores the damping characteristics of dampers arranged in the seismic isolation layer of a building, and a control unit that performs response analysis, the damping characteristic memory unit stores information on the first damping characteristics of the first damper and information on the second damping characteristics of the second damper, the first damping characteristics are such that as the response amount increases, the damping coefficient gradually or stepwise decreases, the second damping characteristics are such that as the response amount increases, the damping force rapidly increases at a switching amount that is a predetermined response amount, and the switching amount is approximately the boundary between the response amount during level 2 earthquake motion and the response amount during level 3 earthquake motion, the control unit A seismic isolation structure design method, which obtains the responses when level 2 seismic motion and level 3 seismic motion are input respectively for an analysis model of the building with the number of the first dampers and the second dampers set, and specifies the number of the first dampers and the second dampers so that the responses satisfy the performance index of the building.

4. In a program for designing a seismic isolation structure using an attenuation characteristic storage unit that stores the attenuation characteristics of dampers arranged in the seismic isolation layer of a building and a control unit that performs response analysis, the attenuation characteristic storage unit stores information on the first attenuation characteristics of the first damper and information on the second attenuation characteristics of the second damper, the first attenuation characteristics are such that the attenuation coefficient gradually or stepwise decreases as the response amount increases, the second attenuation characteristics are such that the damping force rapidly increases at a switching amount that is a predetermined response amount as the response amount increases, and the switching amount is approximately the boundary between the response amount during level 2 seismic motion and the response amount during level 3 seismic motion, the control unit is made to function as means for obtaining the responses when level 2 seismic motion and level 3 seismic motion are input respectively for an analysis model of the building with the number of the first dampers and the second dampers set, and specifying the number of the first dampers and the second dampers so that the responses satisfy the performance index of the building, in a seismic isolation structure design program.

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