JP2018003441A - Base-isolated structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base-isolated structure that has higher base isolation performance and that can cope with a greater seismic ground motion.SOLUTION: A base-isolated layer 2 of a building 1 is provided with a dynamic mass 5 of an inertia mass device serving as a mode control mechanism, and the mass of the dynamic mass 5 is adjusted so that a high-order participation function can be small on the basis of a mode control theory.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a seismic isolation structure.

  The seismic isolation structure is a system that achieves both the reduction of ground motion input by increasing the natural period and the efficient absorption of seismic energy by concentrating deformation in the seismic isolation layer. From the viewpoint of increasing needs and BCP (Business Continuity Plan), there are an increasing number of cases in which a seismic isolation structure is provided even in a super high-rise building (see, for example, Patent Document 1).

JP 2014-137109 A

  On the other hand, especially when a high-rise building with a large aspect ratio is seismically isolated, the influence of higher-order modes is significant, and the response in the upper structure (upper floors, upper floors) is amplified even in a base-isolated structure. In addition, the response acceleration and the interlayer deformation angle increase.

  And since the influence of the higher mode is increased and the seismic isolation effect is reduced in this way, the cross section of the superstructure cannot be narrowed down even if the base isolation is performed, and the number of frames cannot be reduced. Moreover, since the acceleration increases as it is closer to the uppermost layer, there is also a problem in terms of comfort and security.

  Furthermore, it has been proposed and put into practical use that a dynamic mass (also called an inertial mass device or inertial connection element) is added to the seismic isolation layer for the purpose of response reduction. On the other hand, there is a problem that response acceleration increases at the time of simple input.

  In view of the above circumstances, an object of the present invention is to provide a seismic isolation structure that has a higher performance seismic isolation performance and can cope with larger seismic motion.

  In order to achieve the above object, the present invention provides the following means.

  The seismic isolation structure of the present invention is configured by providing a dynamic mass of an inertial mass device as a mode control mechanism in a seismic isolation layer of a building, and the dynamic mass has a higher-order stimulus function based on a mode control theory. The mass is adjusted to be small.

  In the seismic isolation structure of the present invention, it is desirable that an overload prevention mechanism is provided in series with the dynamic mass.

  Furthermore, in the seismic isolation structure of the present invention, it is more preferable that a spring / damping parallel element is provided in series with the dynamic mass.

  Further, in the seismic isolation structure of the present invention, the seismic isolation layer includes the dynamic mass provided with an overload prevention mechanism, a seismic isolation device made of natural rubber-based laminated rubber, and a wind lock mechanism. It is further desirable that

  Furthermore, in the base isolation structure of the present invention, the base isolation layer includes one of the base isolation layers, or a plurality of base isolation layers including a base isolation layer and an intermediate isolation layer, and the base isolation layer and / or Alternatively, it is desirable that the dynamic mass is provided in the intermediate seismic isolation layer.

  In the seismic isolation structure of the present invention, by adopting the mode control seismic isolation structure, it is possible to suppress higher-order modes and prevent the seismic isolation effect from diminishing even if the building is made higher.

  In addition, by adopting the mode control seismic isolation structure, the response near the top floor can be greatly reduced than usual. Thereby, the high added value of a building can be achieved.

  Furthermore, by adopting the mode control seismic isolation structure, it is possible to reduce the response interlayer deformation angle and the layer shear force, and it is possible to reduce the number of chassis and the cost of the chassis.

  Moreover, even if it is an existing seismic isolation building, this invention can be implement | achieved by the retrofitting of a damper, and it becomes possible to aim at the improvement of seismic performance easily and reliably.

  Therefore, according to the seismic isolation structure of the present invention, by adopting a mode control seismic isolation structure, it is possible to improve the response performance of the super high-rise seismic isolation, to improve the habitability on the upper floors, and to greatly reduce the number of frames Is possible.

(A) is a figure which shows the base isolation structure which concerns on 1st Embodiment of this invention, (b) is a figure which shows a normal base isolation structure. (A) is a figure which shows the stimulation function in a primary mode, a secondary mode, and a tertiary mode by providing the seismic isolation structure which concerns on 1st Embodiment of this invention, (b) is a normal seismic isolation structure It is a figure which shows the irritation | stimulation function in primary mode, secondary mode, and tertiary mode. It is sectional drawing which shows an example of the dynamic mass (inertial mass apparatus) with an overload prevention mechanism. It is a figure which shows the model of the dynamic mass (inertial mass apparatus) with an overload prevention mechanism. It is a figure which shows the analysis model of the building provided with the seismic isolation structure which concerns on 1st Embodiment of this invention. It is a figure which shows an analysis result, and is a figure which shows an acceleration response spectrum. It is a figure which shows an analysis result, and is a figure which shows a displacement response spectrum. It is a figure which shows an analysis result, and is a figure which shows the stimulation function of the superstructure of a building. It is a figure which shows the waveform of the input ground motion used for the analysis. It is a figure which shows the pseudo speed response spectrum of the input ground motion used for the analysis. It is a figure which shows the change of the stimulation function by the mode control of the system containing a base isolation layer. It is a figure which shows the acceleration response magnification in the 25th floor. It is a figure which shows the maximum response value in input seismic motion: El Centro NS (Lv2). It is a figure which shows the maximum response value in input seismic motion: K-NET Yokohama NS (2 times). It is a figure which shows the building provided with the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the building provided with the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the stimulation function in the primary mode, secondary mode, tertiary mode, and quaternary mode by providing the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the change of the frequency response magnification by providing the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the analysis result at the time of providing a dynamic mass in a base seismic isolation layer, and the absolute acceleration at the time of inputting each input ground motion to S structure building provided with the seismic isolation structure which concerns on 2nd Embodiment of this invention It is a figure which shows an interlayer deformation angle and a layer displacement. It is a figure which shows an analysis result at the time of providing a dynamic mass in a base seismic isolation layer, and an absolute acceleration at the time of inputting each input ground motion to RC structure building provided with a base isolation structure concerning a 2nd embodiment of the present invention, It is a figure which shows an interlayer deformation angle and a layer displacement. It is a figure which shows the analysis result at the time of providing a dynamic mass in the middle seismic isolation layer, and is a figure which shows the absolute acceleration at the time of inputting each input ground motion, an interlayer deformation angle, and a layer shear force coefficient. It is a figure which shows the example of a change of the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the absolute acceleration at the time of providing the seismic isolation structure of FIG. 22, an interlayer deformation angle, and a layer displacement.

  The seismic isolation structure according to the first embodiment of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1A, the seismic isolation structure A of the present embodiment is provided in a building 1 having a large aspect ratio, such as a high-rise building, for example. Moreover, the building 1 of this embodiment is provided with a base seismic isolation layer 2 in the lower part, and the base isolation layer 2 constitutes the base isolation structure A.

  The base isolation layer 2 of the base isolation structure A is provided with an optional base isolation support (base isolation device) 3 and damping device 4. For example, seismic isolation bearings may be laminated rubber, sliding bearings, linear sliders or a combination of several, and damping devices may be oil dampers, lead dampers (including LRBs contained in laminated rubber), steel dampers, friction dampers. One or more of these are used together. Further, as the seismic isolation device, a device having a damping element (a function of the damping device) such as a laminated rubber with a lead plug or a high damping laminated rubber may be used, and the damping device may be omitted. Furthermore, for example, a wind lock mechanism (wind lock mechanism) that makes it possible to adjust or change the function / performance according to the magnitude of the wind load, such as locking or releasing the damper with a solenoid valve based on the anemometer signal It is preferable to use a damper with an attachment.

  Unlike the conventional base isolation structure B shown in FIG. 1B, the base isolation structure A of the present embodiment is a dynamic mass (inertial mass device, inertia connection element, etc.) serving as a mode control mechanism in the base isolation layer 2. 5 is added.

  In the seismic isolation structure A of the present embodiment, as a more effective configuration (configuration of the seismic isolation layer 2), natural rubber-based laminated rubber (seismic isolation device 3), wind lock mechanism, oil damper (attenuation device 4) ), A configuration including a dynamic mass (inertial mass device 5).

  Further, as shown in FIG. 2A, the dynamic mass 5 of the seismic isolation structure A of the present embodiment is based on the mode control theory so that the higher-order (secondary or higher) stimulation coefficient becomes extremely small. It is configured by adjusting the mass (inertial mass) and operating so that higher-order modes are not excited. FIG. 2 (b) shows a stimulation function of the conventional / normal seismic isolation structure B in which the shaking is increased in the higher order mode.

  Thereby, in the building 1 provided with the seismic isolation structure A of the present embodiment, the excitation of the higher mode is suppressed even during an earthquake, the response of the upper structure above the base seismic isolation layer 2 is suppressed, and is larger than the conventional one. It becomes possible to improve.

  Here, an example is given and demonstrated about the dynamic mass 5 of this embodiment.

  As shown in FIG. 3, the dynamic mass 5 of the present embodiment includes, for example, two sets of ball screw mechanisms (first ball screw mechanism 10 and second ball screw mechanism 11) having different ball screw leads in the casing 12. So as to exhibit a displacement expanding function and a speed increasing function for the rotating weight 13 by rotating the rotating weight 13 by the two sets of ball screw mechanisms. It is configured.

  In addition, the dynamic mass 5 is provided with both ends of a connecting tool 14 for connecting to the upper structure and the lower structure of the building with the seismic isolation layer 2 as a boundary.

  The first ball screw mechanism 10 includes a first screw shaft 15 and a first nut 16 screwed to the first screw shaft 15, and the base end of the first screw shaft 15 is connected to the upper structure. A first nut 16 screwed on the first nut 16 is rotatably provided with respect to the casing.

  Similarly, the second ball screw mechanism 11 includes a second screw shaft 17 and a second nut 18 screwed to the second screw shaft 17, and the base end of the second screw shaft 17 is a lower structure. A second nut 18 connected to and screwed thereto is provided to be rotatable with respect to the casing.

  The first nut 16 of the first ball screw mechanism 10 and the second nut 18 of the second ball screw mechanism 11 are disposed opposite to each other at a central portion, and the first nut 16 and the second nut 18 are A cylindrical rotating weight 13 is disposed between them. Further, both ends of the rotary weight 13 are connected to the front end surfaces of the first nut 16 and the second nut 18 so as not to rotate relative to each other.

  Further, in the dynamic mass 5 of the present embodiment, a weight support sleeve 19 is disposed between the first nut 16 and the second nut 18, and the weight support sleeve 19 is connected to the first nut 16 and the second nut 18. It is fixed so that both nuts have the same amount of rotation.

  In the weight support sleeve 19, the tip ends of the first screw shaft 15 and the second screw shaft 17 are connected via the sleeve 20 so as not to be relatively rotatable and to be relatively displaceable in the axial direction. The entire nut 1, the second nut 18, and the weight support sleeve 19 are integrally rotatable while being relatively displaced in the axial direction with respect to the first screw shaft 15 and the second screw shaft 17.

  A rotary weight 13 is mounted on the outside of the weight support sleeve 19 via a bearing, and the rotary weight 13 is supported so as to be rotatable integrally with the weight support sleeve 19 and relatively rotatable.

  Further, in the dynamic mass 5 of the present embodiment, a transmission torque limiting mechanism 21 is interposed between the rotary weight 13 and the weight support sleeve 19.

  The transmission torque limit mechanism 21 transmits torque until the torque transmitted from the weight support sleeve 19 to the rotary weight 13 exceeds a predetermined limit value, and rotates the rotary weight 13 together with the weight support sleeve 19. Further, when the torque exceeds the limit value, the rotary weight 13 is rotated relative to the weight support sleeve 19 (idling) to limit torque transmission.

  Specifically, the annular friction plate 22 is fixed to the front portion of the pressing block disposed opposite to the end surface of the rotating weight 13, and the pressing plate 23 is pressed forward, so that the friction plate 22 becomes the end surface of the rotating weight 13. It is made to press against.

  In the present embodiment, the adjusting block 24 presses the pressing block 23 via the pressing plate 25, and the friction plate 22 is pressed against the rotary weight 13.

  Therefore, by adjusting the screwing amount of the adjusting bolt 24 to the block, the pressing force of the friction plate 22 against the rotating weight 13 (that is, the frictional force between the friction plate 22 and the rotating weight 13) can be adjusted freely and widely. It is possible.

  By providing such a transmission torque limiting mechanism 21, when relative displacement occurs at both ends of the dynamic mass 5, both the first nut 16 and the second nut 18 cause the same rotation (the amount of rotation of both nuts is naturally). The weight support sleeve 19 integrated with the first nut 16 and the second nut 18 also rotates by the same amount.

  On the other hand, since the rotary weight 13 is supported by the weight support sleeve 19 via the friction plate 22, the torque transmitted between the rotary weight 13 and the weight support sleeve 19 is set to a constant value, and the peak torque At this point, the friction plate 22 slips with respect to the rotary weight 13, and the rotary weight 13 rotates relative to the weight support sleeve 19 (i.e., idle), thereby exhibiting an overload prevention function against excessive acceleration. The

  Since the peak torque is proportional to the pressing force applied by the compression spring if the friction coefficient of the friction plate 22 is constant, a desired limit value can be freely adjusted by the screwing amount of the adjusting bolt 24.

  The dynamic mass 5 of the present embodiment configured as described above exhibits the following operational effects.

(1) By using two ball screw mechanisms with different leads in combination, the displacement of each ball screw mechanism relative to the relative displacement of both ends of the dynamic mass 5 (the amount of movement of the screw shaft relative to the nut) can be greatly increased. On the other hand, the torque reaction force generated at both ends can be greatly reduced, the burden on the structural housing can be reduced, and an effective inertial mass device including the transmission torque limiting mechanism 21 as an overload prevention mechanism can be realized.

(2) The peak load (the peak torque) of the transmission torque limiting mechanism 21 as an overload prevention mechanism can be easily and widely adjusted by increasing / decreasing the pressing amount with respect to the compression spring that presses the friction plate 22 by the adjusting bolt 24. be able to.

(3) Conventionally, as a component, a bearing, a cylinder, and the like were required in addition to the ball screw mechanism, but these are unnecessary, the number of components is reduced, and the mechanism is greatly simplified. Therefore, a large capacity damper can be manufactured at low cost.

(4) Since it is not necessary to make the actual lead of the ball screw mechanism small, it is not necessary to make the ball bearing too small in diameter, so it is possible to secure an appropriate lead that matches the diameter of the screw shaft, so There is no problem.

(5) This type of inertial mass device does not have static rigidity, does not retain restoring force, and can manually rotate the rotating weight, making it easy to adjust the dimensions during on-site installation work. It is also possible to carry out.

  In the seismic isolation structure A of the present embodiment, as described above, the mode control is performed so that the higher-order stimulation coefficient is 0 (zero) (the mode control is performed so that the higher-order stimulation function is as close to 0 as possible). The dynamic mass 5 is arranged only in the seismic isolation layer 2. Thereby, the response of the upper structure is reduced.

  Further, when a large deformation and excessive acceleration of the seismic isolation layer 2 or the like is input to the dynamic mass 5, there is a possibility that the seismic motion is directly transmitted through the rigid body mode. In this embodiment, as shown in FIG. In this way, a friction element is connected in series with the dynamic mass 5 to provide an overload prevention function, so that the friction element starts to slide against an excessive input, enabling mode control with reduced rigid body mode. To do.

  That is, by connecting an overload prevention mechanism in series to the dynamic mass 5, it is possible to suppress an increase in acceleration due to an excessive input without impairing the mode control effect.

  Furthermore, the structure of the seismic isolation layer 2 is most preferably a combination of a dynamic mass 5 with an overload prevention mechanism, a natural rubber-based laminated rubber 3, an oil damper 4, and a wind lock mechanism, and this structure is more effective. Can exhibit the mode control effect.

  Here, the mode control is to control the stimulation coefficient by manipulating the mass term on the vibration equation with an additional mass such as the dynamic mass 5 as shown in the following equation. In order to apply this to high-rise seismic isolation, in this embodiment, as shown in FIG. 5, a multi-mass point system including the seismic isolation layer 2 is separated from a mass point equivalent to the primary mode of the superstructure and the seismic isolation layer 2. The dynamic mass 5 necessary for mode control is obtained by the equation (1). Note that η represents an input reduction effect.

１次以外の刺激関数β_ｎは固有ベクトルの直交性（｛η（ベクトル）｝⊥｛_ｎｒ（ベクトル）｝）により０（ゼロ）となる。

The stimulus function β _n other than the first order becomes 0 (zero) due to the orthogonality of the eigenvector ({η (vector)} ⊥ { _n r (vector)}).

The dynamic mass and response spectrum will be described.
A response spectrum is created for a one-mass vibration system having a dynamic mass. The response value of the acceleration response spectrum including the dynamic mass decreases on the short period side from a certain branch period point, but the ground motion acceleration (1-η) y _max (above) is directly transmitted on the long period side.

  Therefore, we decided to connect a frictional element modeled in a fully bilinear model in order to mitigate the influence, and connect it in series, and change its sliding load to create a response spectrum and verify its effect.

The sliding load is referred to as a relief load _Fr, and the load F borne by the dynamic mass on the long period side is assumed by the equation (2). Further, the load relief rate α _r is defined by using F _r as equation (3). M is the mass of a one-mass system.

For each case where α _r is ∞, 1.00, 0.75, 0.50, 0.25, 0.00, (a) EL Centro NS (Lv2), (b) March 11, 2011 When the ground motion obtained by doubling the daily observed wave K-NET Yokohama NS is obtained under the condition of input reduction fluctuation of η = 0.50, the acceleration response spectrum of FIG. 6 and the displacement response spectrum of FIG. 7 are obtained.

In the results of the acceleration response spectrum of FIG. 6, in both (a) and (b), as α _r is smaller, the response on the long period side becomes smaller, approaching the result without dynamic mass, and the ground acceleration of the rigid body mode. It has been confirmed that the communication will be eased. It was also confirmed that the input reduction effect on the short cycle side does not decrease so much.

On the other hand, in the result of the displacement response spectrum in FIG. 7, it is confirmed that the response tends to be reduced over the entire period band. When α _r = 0.25, both (a) and (b) Existence was recognized.

From these results, there is a load relief rate α _r that can reduce the response on the short cycle side without increasing the response on the long cycle side for acceleration, and even if a dynamic mass necessary for mode control is added, It was confirmed that there is a possibility that a relief load _Fr that does not increase the response acceleration on the long cycle side with the seismic isolation cycle can be set.

  Next, the result of analytically verifying the effect of the mode control seismic isolation structure will be described.

  Table 1 shows the target buildings and analysis specifications used in this study.

  The analysis model is an equivalent shear type multi-mass model and the superstructure is elastic. The structural damping was 1% with respect to the first order.

  FIG. 8 shows the stimulation function of the superstructure. Since the mode control is for a linear model, the base material of the seismic isolation layer is composed only of natural rubber laminated rubber. However, an oil damper was added as a damping element to prevent excessive deformation of the seismic isolation layer. The dynamic mass required for mode control obtained as a two-mass contraction system is about 8000 tons from the equation (1).

The analysis cases were three cases: normal seismic isolation case 1, case 2 with a dynamic mass with friction elements, and case 3 with α _r = ∞, and complex eigenvalue analysis and seismic response analysis were performed. The input ground motion was the same as described above, and the input ground motion shown in FIG. 9 and FIG. 10 was input as the waveform and pseudo speed response spectrum.
In addition, (b) K-NET Yokohama NS has a dominant period in the vicinity of 1 to 2 seconds, and has a feature that it is easy to excite higher-order modes of high-rise seismic isolation.

  FIG. 11 shows the change of the stimulation function by the mode control of the system including the seismic isolation layer. FIG. 12 shows acceleration response magnification on the 25th floor. Further, FIG. 13 shows the maximum response value in the input ground motion: El Centro NS (Lv2), and FIG. 14 shows the maximum response value in the input ground motion: K-NET Yokohama NS (double).

  From these results, it was confirmed that the higher-order mode was suppressed by the mode control in Case 2 in which a dynamic mass with a friction element was added.

Moreover, it was confirmed from the response results that the maximum deformation of the seismic isolation layer of the mode control in the normal seismic isolation case 1 and the case 2 with the addition of the dynamic mass with the friction element is almost the same. Furthermore, in the case of El Centro NS (Lv2), the response acceleration of case 2 with a dynamic mass with a friction element increases compared to case 1 of normal seismic isolation, but is reduced from case 3 where α _r = ∞. It was confirmed. In K-NET Yokohama NS (twice), the response acceleration and the interlayer deformation angle were significantly reduced. Thus, the mode control effect was confirmed also in the seismic response analysis.

  Therefore, in the seismic isolation structure A of the present embodiment, the dynamic mass 5 is provided in the base seismic isolation layer 2 and a friction element is provided in series with the dynamic mass 5 as an overload prevention, so that the rigid body mode is used directly. The transmitted acceleration can be reduced. In addition, by applying a mode control method, it is possible to suppress higher-order modes and effectively reduce responses such as acceleration and interlayer deformation angle of the superstructure of a super high-rise base-isolated building.

  Therefore, according to the seismic isolation structure A of the present embodiment, by adopting the mode control seismic isolation structure, the response performance of the super high-rise seismic isolation can be improved, the comfortability on the upper floors can be improved, and the number of housings can be greatly reduced. It becomes possible to plan.

  Next, with reference to FIGS. 15 to 21, a seismic isolation structure according to a second embodiment of the present invention will be described. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  As in the first embodiment, the seismic isolation structure A of the present embodiment is provided in a building having a large aspect ratio, such as a high-rise building. On the other hand, the seismic isolation structure A and the building 1 of the present embodiment are provided with a basic seismic isolation layer 2 at the lower part and an intermediate seismic isolation layer 30 at a predetermined level, as shown in FIGS. It consists of a tiered (double) seismic isolation system.

  Here, in order to improve the seismic isolation performance of the super high-rise building 1, not only the basic seismic isolation layer 2 but also the intermediate seismic isolation layer 30 on the upper part is provided with a two-stage seismic isolation system A By having two seismic isolation layers 2 and 30, the vibration mode is increased by one compared with the normal base isolation structure (in the case of only the base isolation layer 2). For this reason, while the response of the upper structure (upper layer part) is greatly reduced, the response of the lower structure (lower layer part) is increased as compared with the normal seismic isolation structure B.

  In addition, when a dynamic mass 5 without a relief mechanism is installed in the basic seismic isolation layer 2, there are cases where the input seismic motion is transmitted as it is due to its rigid body mode and the response increases. Further, it is necessary to configure the ELV char and the like to follow the deformation by providing the seismic isolation layer 30 on the intermediate floor.

  On the other hand, in the seismic isolation structure A of the present embodiment, as shown in FIGS. 15 and 16, regarding the increased vibration mode which is a factor that increases the response of the lower structure, the lower base seismic isolation layer 2 and / or Alternatively, the dynamic mass 5 is added to the intermediate seismic isolation layer 30 and its mode is controlled to decrease, thereby reducing the response of the upper structure and the lower structure.

  Specifically, in the seismic isolation structure A of this embodiment, the influence of the secondary mode, which is a weak point of the two-stage seismic isolation, is suppressed by the mode control using the dynamic mass 5, and the lower structure and the upper part are suppressed. Reduce structure response.

  Furthermore, by installing the dynamic mass 5 in the upper middle seismic isolation layer 30, it is avoided that the input acceleration from the ground is directly transmitted by the rigid body mode.

  Here, the simulation performed in order to confirm the superiority of the seismic isolation structure A of this embodiment is demonstrated. In order to grasp the influence of the rigidity of the superstructure, the seismic performance of the S and RC high-rise buildings 1 equipped with the seismic isolation structure A of the present embodiment was confirmed, and the seismic isolation structure A of the present embodiment The superiority of the seismic isolation structure A of this embodiment was confirmed by comparing with the case where it is not provided.

  First, the S building was an office building with a natural period T1 = 3.04 seconds, a height H = 108.8 m, and 28 layers, and the analysis model was a mass system equivalent shear spring model. The RC building was an apartment with a natural period of T1 = 2.47 seconds, a height of H = 92.8 m, and 29 layers, and the analysis model was a mass system equivalent shear spring model.

  Further, as shown in FIG. 16, an intermediate seismic isolation layer 30 is provided so that the lower structure has five layers, the upper structure has 23 layers of S structure and 24 layers of RC structure. The 200% strain period of the base seismic isolation layer 2 was about 5 seconds for the S building and about 4 seconds for the RC building, and the intermediate seismic isolation layer 30 was set bilinearly equivalent to that. In this analysis model, the influence of the increase in the frictional force after relief was eliminated by making the mass element acceleration-force relationship non-linear.

  Next, the specifications of the dynamic mass 5 are as shown in Table 2, Table 3, and Table 4.

  Kanto Earthquake Site Wave, Notification Kobe NS (Lv2), Notification Kanto EW (Lv2) were used for the input ground motion.

Next, the analysis result will be described.
FIG. 17 shows a case where a dynamic mass is added to the base seismic isolation layer in the S building (FIG. 17A) and the RC building (FIG. 17B), respectively, and the dynamic mass. The result of having compared the stimulus function when not adding is shown.

  In addition, FIG. 18 shows a case in which dynamic mass is added to the base seismic isolation layer in the S building (FIG. 18A) and the RC building (FIG. 18B), respectively, and the mode control is performed. -The result of comparing the frequency response magnification at the top of the building without adding mass is shown.

Further, in FIG. 19, each of the S buildings (ordinary double seismic isolation building, seismic isolation building provided with dynamic mass according to the present invention and mode control, seismic isolation building with basic isolation only) Results of comparison of absolute acceleration, interlaminar deformation angle, and interlaminar displacement when input seismic motion (notification Kobe, notification Kanto, Kanto earthquake site wave) is input.
In addition, in FIG. 20, each RC building (ordinary double seismic isolated building, seismic isolated building with a dynamic mass according to the present invention and mode controlled, and base isolated only) The result of comparing absolute acceleration, interlayer deformation angle, and layer displacement when input seismic motion is input is shown.

  From the result of comparing these stimulus functions and frequency response magnifications, it was confirmed that the secondary mode is reduced by performing the mode control with a dynamic mass.

  In addition, if the restoring force characteristics of the middle-layer seismic isolation are equivalent to those of the base-isolation, the dynamic mass is provided and mode control is performed, so that the deformation of the intermediate-floor seismic isolation layer becomes smaller than that of the base-isolation. Was confirmed. Thereby, it was confirmed that it becomes advantageous also for deformation follow-up of an ELV shaft or the like.

  In addition, the response acceleration directly under the middle seismic isolation layer increases in the normal double base isolation structure, but if the dynamic mass is provided and mode control is performed, the acceleration directly under the intermediate seismic isolation layer 30 is reduced. It was also confirmed that the effect to be obtained is obtained.

  In addition, it was confirmed that the maximum response value for both S and RC structures is basic seismic isolation> normal double seismic isolation> double seismic isolation with mode control.

  FIG. 21 shows a simulation result when the dynamic mass 5 is provided in the intermediate seismic isolation layer 30 and mode control is performed (see FIG. 15). From the results shown in FIG. 21, it was confirmed that the same effects as those obtained when a dynamic mass was provided in the basic seismic isolation layer were obtained.

  Thus, if the dynamic mass is provided in the intermediate seismic isolation layer and mode control is performed, the relief mechanism becomes unnecessary, and the performance / mechanism required for the apparatus can be simplified. That is, since the burden force does not become excessive, the cost of the apparatus can be reduced accordingly.

  Here, FIGS. 19 and 20 also show the results of absolute acceleration, interlayer deformation angle, and layer displacement when the dynamic mass of the basic seismic isolation layer is all changed to oil dampers as shown in Table 5. Yes. From this result, if all dynamic masses are changed to oil dampers, the deformation of the seismic isolation layer is suppressed and the overall deformation is also reduced, but the input to the superstructure is increased accordingly, and both absolute response acceleration and interlayer deformation angle are increased. It was confirmed that the response increased to the same or higher than the normal double seismic isolation. That is, when all the dynamic masses were changed to oil dampers, it was confirmed that the deformation of the seismic isolation layer was excessively suppressed and the response result was worse than that of the mode control seismic isolation structure of the present embodiment.

  Therefore, the base isolation structure A of the present embodiment includes the base isolation layer 2 and the intermediate isolation layer 30, and the dynamic mass 5 is provided in the base isolation layer 2 and / or the intermediate isolation layer 30. By providing a friction element in series with the dynamic mass 5 as a load prevention, the acceleration directly transmitted by the rigid body mode can be reduced. In addition, by applying a mode control method, it is possible to suppress higher-order modes and effectively reduce responses such as acceleration and interlayer deformation angle of the superstructure of a super high-rise base-isolated building.

  Therefore, also in the seismic isolation structure A of this embodiment, by adopting the mode control seismic isolation structure, it is possible to improve the response performance of the high-rise seismic isolation, improve the comfortability on the upper floor, and greatly reduce the number of frames It becomes possible.

  As mentioned above, although 1st, 2nd embodiment of the seismic isolation structure which concerns on this invention was described, this invention is not limited to said 1st, 2nd embodiment, In the range which does not deviate from the meaning. It can be changed as appropriate.

  For example, as shown in FIG. 22, a spring / damping parallel element may be connected in series with a dynamic mass of a seismic isolation structure that performs mode control. In this case, even if the spring element is connected in series with the dynamic mass, by adding the damping element in parallel with the spring element, as shown in FIG. It becomes possible to exhibit excellent response performance.

  In addition, in a system consisting only of a dynamic mass and a series spring, a vibration system is formed by itself, so there is a risk that resonance will occur and the spring may oscillate, but by adding a spring and a damping element arranged in parallel, This fear can be avoided reliably.

  A plurality of intermediate seismic isolation layers 30 may be provided.

1 Building 2 Base isolation layer (Seismic isolation layer)
3 Seismic isolation device 4 Damping device 5 Dynamic mass (Inertial mass device, Inertial connection element)
10 first ball screw mechanism 11 second ball screw mechanism 12 casing 13 rotary weight 14 connector 15 first screw shaft 16 first nut 17 second screw shaft 18 second nut 19 weight support sleeve 20 sleeve 21 transmission torque limiting mechanism 22 Friction plate (friction element)
23 Press block 24 Adjustment bolt 25 Press plate 30 Middle base isolation layer A Base isolation structure B Conventional base isolation structure

Claims (5)

Dynamic mass of inertial mass device that is a mode control mechanism is provided in the seismic isolation layer of the building,
The seismic isolation structure is characterized in that the dynamic mass is adjusted so that a high-order stimulus function becomes small based on a mode control theory. In the seismic isolation structure according to claim 1,
A seismic isolation structure, wherein an overload prevention mechanism is provided in series with the dynamic mass. In the seismic isolation structure according to claim 1 or 2,
A base-isolated structure comprising a spring / damping parallel element connected in series to the dynamic mass. In the seismic isolation structure according to any one of claims 1 to 3,
The seismic isolation structure, wherein the seismic isolation layer includes the dynamic mass having an overload prevention mechanism, a seismic isolation device made of natural rubber-based laminated rubber, and a wind lock mechanism. . In the seismic isolation structure according to any one of claims 1 to 4,
One of the base isolation layers, or a plurality of base isolation layers including a base isolation layer and an intermediate isolation layer, and the dynamic mass is provided in the base isolation layer and / or the intermediate isolation layer. A seismic isolation structure characterized by being constructed.

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