JP6835492B2 - Seismic isolation structure - Google Patents

Description

The present invention relates to a seismic isolation structure.

The seismic isolation structure is a system that reduces seismic motion input by lengthening the natural period and concentrates deformation on the seismic isolation layer to efficiently absorb seismic energy. In recent years, society has become safe and secure. From the viewpoint of increasing demand and BCP (Business Continuity Plan), there are an increasing number of cases where even super high-rise buildings are equipped with a seismic isolation structure to be seismically isolated (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-137109

On the other hand, especially when a super high-rise building with a large aspect ratio is seismically isolated, the influence of the higher-order mode is large, and even if the seismic isolation structure is used, the response in the superstructure (upper floor, upper layer) is amplified. However, the response acceleration and the interlayer deformation angle increase.

As a result, the seismic isolation effect is diminished due to the greater influence of the higher-order mode, and as a result, the cross section of the superstructure cannot be narrowed down even if seismic isolation is performed, and the number of skeletons cannot be reduced. In addition, the closer to the top layer, the higher the acceleration, so there is a problem from the viewpoint of comfort and security.

Furthermore, it has been proposed and put into practical use to add a dynamic mass (also called an inertial mass device, an inertial connecting element, etc.) to the seismic isolation layer for the purpose of reducing the response, but simply adding the dynamic mass is excessive. On the contrary, there is a problem that the response acceleration increases at the time of input.

In view of the above circumstances, an object of the present invention is to provide a seismic isolation structure having higher performance seismic isolation performance and capable of responding to a larger seismic motion.

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 serving as a mode control mechanism in the seismic isolation layer of a building, and the dynamic mass has a higher-order stimulus function based on the mode control theory. Its mass is adjusted to be small, and an overload prevention mechanism is provided by connecting in series with the dynamic mass, and it is one of the basic seismic isolation layers, or intermediate with the basic seismic isolation layer. It is characterized in that a plurality of the seismic isolation layers of the seismic isolation layer are provided, and the dynamic mass and the overload prevention mechanism are provided on the basic seismic isolation layer and / or the intermediate seismic isolation layer .

Further, in the seismic isolation structure of the present invention, it is more desirable 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 is provided with 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 even more desirable to be.

Further, in the seismic isolation system of the present invention, be added to the dynamic mass necessary for mode control, the relief force F _r of response acceleration in the long period side with seismic isolation period is not increased, the long period side It is desirable that the load relief rate α _{r is set by using a load relief rate α r} that can reduce the response on the short cycle side without increasing the response of, and the load relief rate α r is 0 <α _r ≦ 0.5.

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

In addition, by adopting a mode-controlled seismic isolation structure, the response near the top floor can be significantly reduced. As a result, it is possible to increase the added value of the building.

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

Further, even in an existing seismic isolated building, the present invention can be realized by retrofitting a damper, and the seismic performance can be easily and surely improved.

Therefore, according to the seismic isolation structure of the present invention, by adopting the mode control seismic isolation structure, the response performance of the super high-rise seismic isolation can be improved, the habitability on the upper floors can be improved, and the number of skeletons can be significantly reduced. Becomes possible.

(A) is a diagram showing a seismic isolation structure according to the first embodiment of the present invention, and (b) is a diagram showing a normal seismic isolation structure. (A) is a diagram showing a stimulus function in a primary mode, a secondary mode, and a tertiary mode by providing a seismic isolation structure according to the first embodiment of the present invention, and (b) is a normal seismic isolation structure. It is a figure which shows the stimulus function in the primary mode, the secondary mode, and the tertiary mode of. It is sectional drawing which shows an example of the dynamic mass (inertial mass device) with an overload prevention mechanism. It is a figure which shows the model of the dynamic mass (inertial mass device) 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 the analysis result, and is the figure which shows the acceleration response spectrum. It is a figure which shows the analysis result, and is the figure which shows the displacement response spectrum. It is a figure which shows the analysis result, and is the figure which shows the stimulus function of the superstructure of a building. It is a figure which shows the waveform of the input seismic motion used for analysis. It is a figure which shows the pseudo velocity response spectrum of the input seismic motion used for analysis. It is a figure which shows the change of the stimulus function by the mode control of the system including the seismic isolation layer. It is a figure which shows the acceleration response magnification in the 25th floor. Input seismic motion: It is a figure which shows the maximum response value in El Centro NS (Lv2). Input seismic motion: It is a figure which shows the maximum response value in K-NET Yokohama NS (double). It is a figure which shows the building which provided the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the building which provided the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the stimulus function in the primary mode, the secondary mode, the tertiary mode, and the quaternary mode by providing the seismic isolation structure according to the second embodiment of the present 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 when the foundation seismic isolation layer is provided with a dynamic mass, and is the absolute acceleration when each input seismic motion is input to the S structure provided with the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the interlayer deformation angle, and the layer displacement. It is a figure which shows the analysis result when the foundation seismic isolation layer is provided with a dynamic mass, and is the absolute acceleration when each input seismic motion is input to the RC structure provided with the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the interlayer deformation angle and layer displacement. It is a figure which shows the analysis result when the intermediate seismic isolation layer is provided with a dynamic mass, and is the figure which shows the absolute acceleration, the interlayer deformation angle, and the layer shear force coefficient when each input seismic motion is input. It is a figure which shows the modification example of the seismic isolation structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the absolute acceleration, the interlayer deformation angle, and the layer displacement when the seismic isolation structure of FIG. 22 is provided.

Hereinafter, the seismic isolation structure according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 14.

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 skyscraper. Further, the building 1 of the present embodiment is provided with a basic seismic isolation layer 2 at the lower part, and the seismic isolation structure A is formed by the basic seismic isolation layer 2.

The seismic isolation layer 2 of the seismic isolation structure A is provided with an arbitrary seismic isolation bearing (seismic isolation device) 3 and a damping device 4. For example, one or more of laminated rubber, sliding bearings, and linear sliders are used as seismic isolation bearings, and oil dampers, lead dampers (including LRB contained in laminated rubber), steel dampers, and friction dampers are used as damping devices. Either or more of these are used together. Further, as the seismic isolation device, a device having a damping element (function of the damping device) such as a lead plug-containing laminated rubber or a high-damping laminated rubber may be used, and the damping device may be omitted. Furthermore, a wind lock mechanism (wind lock mechanism) that enables the function / performance to be adjusted and changed according to the magnitude of the wind load, for example, by locking or releasing the damper with a solenoid valve based on the signal of the anemometer. It is preferable to use a damper with a).

The seismic isolation structure A of the present embodiment is different from the conventional seismic isolation structure B shown in FIG. 1 (b), and has a dynamic mass (inertial mass device, inertial connecting element, etc.) as a mode control mechanism in the basic seismic isolation layer 2. It is configured by adding 5.

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

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 (second-order or higher) stimulation coefficient is extremely small. It is configured by adjusting the mass (inertial mass) and manipulating it so that the higher-order mode is not excited. Note that FIG. 2B shows the stimulation function of the conventional / normal seismic isolation structure B in which the shaking becomes large in the higher-order mode.

As a result, in the building 1 provided with the seismic isolation structure A of the present embodiment, the excitation of the higher-order mode is suppressed even during an earthquake, the response of the superstructure above the foundation seismic isolation layer 2 is suppressed, and the response is larger than before. It will be possible to improve.

Here, the dynamic mass 5 of the present embodiment will be described with an example.

As shown in FIG. 3, the dynamic mass 5 of the present embodiment has, 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. By incorporating them in a state of being coaxially opposed to each other and rotating one rotary weight 13 by these two sets of ball screw mechanisms, the displacement expanding function and the speed increasing function with respect to the rotary weight 13 are exhibited by themselves. It is configured.

Further, the dynamic mass 5 is provided with connecting tools 14 at both ends 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 an upper structure. , The first nut 16 screwed to 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 has a lower structure. A second nut 18 connected to and screwed to the second nut 18 is rotatably provided 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 arranged to face each other at a center with a distance from each other, and the first nut 16 and the second nut 18 A cylindrical rotary weight 13 is arranged between them. Further, both ends of the rotary weight 13 are non-rotatably connected to the tip surfaces of the first nut 16 and the second nut 18, respectively.

Further, in the dynamic mass 5 of the present embodiment, a weight support sleeve 19 is arranged 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 the amount of rotation of both nuts is the same.

In the weight support sleeve 19, the tips of the first screw shaft 15 and the second screw shaft 17 are connected to each other via the sleeve 20 so that they cannot rotate relative to each other and can be displaced relative to each other in the axial direction. The entire 1 nut 16, the 2nd nut 18, and the weight support sleeve 19 can rotate integrally with respect to the 1st screw shaft 15 and the 2nd screw shaft 17 while being displaced relative to each other in the axial direction.

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

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

The transmission torque limiting 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 integrally 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 relatively rotated (idle) with respect to the weight support sleeve 19 to limit the torque transmission.

Specifically, an annular friction plate 22 is fixed to the front portion of the pressing block arranged to face the end surface of the rotary weight 13, and the friction plate 22 is pressed forward on the end surface of the rotary weight 13. I try to press against it.

In the present embodiment, the pressing block 23 is pressed by the adjusting bolt 24 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 with respect to the block, the pressing force of the friction plate 22 against the rotary weight 13 (that is, the frictional force between the friction plate 22 and the rotary weight 13) can be freely and widely adjusted. 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 naturally rotate (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 peaked at a constant value, and the peaking torque is reached. When the friction plate 22 reaches the limit, 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 (idle), whereby the overload prevention function against excessive acceleration is exhibited. To torque.

Since the peaking 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 exerts the following effects.

(1) By using two sets of ball screw mechanisms with different leads together, the displacement of each ball screw mechanism (the amount of movement of the screw shaft with respect to the nut) with respect to the relative displacement of both ends of the dynamic mass 5 can be greatly expanded. At the same time, the torque reaction force generated at both ends can be significantly reduced, the burden on the structural frame can be reduced, and an effective inertial mass device provided with the transmission torque limiting mechanism 21 as an overload prevention mechanism can be realized.

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

(3) Conventionally, bearings, cylinders, and the like are required as component parts in addition to the ball screw mechanism, but these are unnecessary, the number of component parts 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 reduce the actual reed of the ball screw mechanism, it is not necessary to make the diameter of the ball bearing too small. Therefore, it is possible to secure an appropriate reed according to the diameter of the screw shaft, so that the load bearing performance can be improved. No problem arises.

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

Then, in the seismic isolation structure A of the present embodiment, as described above, the mode control (mode control so that the higher-order stimulus function is as close to 0 as possible) is performed so that the higher-order stimulus coefficient is set to 0 (zero). The dynamic mass 5 is arranged only in the seismic isolation layer 2. As a result, the response of the superstructure is reduced.

Further, when a large deformation of the seismic isolation layer 2 or the like and an excessive acceleration are input to the dynamic mass 5, there is a possibility that the seismic motion is directly transmitted through the rigid body mode, but in the present embodiment, it is shown in FIG. As described above, since the friction element is connected in series with the dynamic mass 5 to provide an overload prevention function, the friction element slides out in response to an excessive input, enabling mode control with reduced rigid body mode. To do.

That is, by connecting the 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.

Further, 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 laminated rubber 3, an oil damper 4, and a wind lock mechanism, and it is more effective to adopt this structure. It is possible to exert the mode control effect.

Here, the mode control controls 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 the super high-rise seismic isolation, in this embodiment, as shown in FIG. 5, the mass point system including the seismic isolation layer 2 is separated from the mass point equivalent to the primary mode of the superstructure and the seismic isolation layer 2. The dynamic mass 5 required for mode control is obtained by the equation (1) by reducing the mass to a two-mass system. 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 eigenvectors ({η (vector)} ⊥ { _{n r (vector)}).}

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

Therefore, for the purpose of mitigating the effect, we decided to connect a friction element modeled in perfect bilinear in series with it, change the sliding load, create a response spectrum, and verify the effect.

The starting load is referred to as a relief load _Fr, and the load F borne by the dynamic mass on the long period side thereof is assumed by the equation (2). Further, the load relief rate α _r is defined by using _{F r as the equation (3).} Further, m is the mass of one mass system.

Then, _{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 seismic motion obtained by doubling the observation wave K-NET Yokohama NS of the day is obtained under the condition of the 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, as α _r is smaller in both (a) and (b), the response on the long-period side becomes smaller and approaches the result without dynamic mass, and the ground motion acceleration in the rigid body mode It was confirmed that the communication was relaxed. Moreover, it was also confirmed that the input reduction effect on the short cycle side was not significantly reduced.

On the other hand, in the results of the displacement response spectrum of FIG. 7, it was confirmed that the response tended to decrease over the entire period band, and when α _r = 0.25, the response decreased in both (a) and (b). The existence was recognized.

_{From these results, regarding acceleration, 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, and even if the dynamic mass required 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 can be set on the long cycle side with a seismic isolation cycle.

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 was an equivalent shear type multi-mass model, and the superstructure was elastic. The structural attenuation was 1% with respect to the primary.

FIG. 8 shows the stimulus function of the superstructure. Since the mode control targets a linear model, the bearing material of the seismic isolation layer is composed only of natural rubber-based laminated rubber. However, an oil damper was added as a damping element so that the deformation of the seismic isolation layer would not be excessive. The dynamic mass required for mode control obtained as a two-mass point reduction system is about 8000 tons from the equation (1).

The analysis cases were usually seismic isolation case 1, case 2 with a dynamic mass with friction element added, and _{case 3 with α r} = ∞, and complex eigenvalue analysis and seismic response analysis were performed. Further, the input seismic motion was the same as described above, and the input seismic motion shown in FIGS. 9 and 10 was input for the waveform and the pseudo velocity response spectrum.
In addition, (b) K-NET Yokohama NS has a predominant cycle in the vicinity of 1 to 2 seconds, and has a feature that it is easy to excite the higher-order mode of high-rise seismic isolation.

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

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

In addition, from the response results, it was confirmed that the maximum deformation of the mode-controlled seismic isolation layer of Case 1 of normal seismic isolation and Case 2 to which a dynamic mass with a friction element was added was almost the same. Further, in the case of El Centro NS (Lv2), the response acceleration of the case 2 to which the dynamic mass with the friction element is added is higher than that of the case 1 of the normal seismic isolation, but is lower than that of the case 3 where _{α r = ∞.} It was confirmed that. In K-NET Yokohama NS (twice), it was confirmed that the response acceleration and the interlayer deformation angle were reduced more remarkably. In this way, the mode control effect was confirmed in the seismic response analysis.

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

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

Next, the seismic isolation structure according to the second embodiment of the present invention will be described with reference to FIGS. 15 to 21. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Similar to 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 skyscraper. On the other hand, in the seismic isolation structure A and the building 1 of the present embodiment, as shown in FIGS. 15 and 16, the basic seismic isolation layer 2 is provided at the lower part, and the intermediate seismic isolation layer 30 is provided at the predetermined level. It is composed of a step (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 is provided at the upper part of the two-stage seismic isolation structure A. Since there are two seismic isolation layers 2 and 30, the vibration mode is increased by one compared to the normal seismic isolation structure (in the case of only the basic seismic isolation layer 2). Therefore, while the response of the upper structure (upper layer portion) is greatly reduced, the response of the lower structure (lower layer portion) is increased as compared with the normal seismic isolation structure B.

Further, when the dynamic mass 5 without a relief mechanism is installed in the foundation seismic isolation layer 2, the input seismic motion is transmitted as it is depending on the rigid body mode, and the response may be increased. Further, it is necessary to provide a seismic isolation layer 30 on the intermediate floor so that the ELV shear and the like can follow the deformation.

On the other hand, in the seismic isolation structure A of the present embodiment, as shown in FIGS. 15 and 16, the increased vibration mode, which is a factor that increases the response of the substructure, is the lower basic seismic isolation layer 2 and / Alternatively, a dynamic mass 5 is added to the intermediate seismic isolation layer 30 to control and reduce the mode thereof to reduce the response of the superstructure and the substructure.

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

Further, by installing the dynamic mass 5 in the upper intermediate seismic isolation layer 30, it is possible to prevent the input acceleration from the ground from being directly transmitted by the rigid body mode.

Here, a simulation performed to confirm the superiority of the seismic isolation structure A of the present embodiment will be described. In order to understand the effect of the rigidity of the superstructure, the seismic isolation performance of the S and RC skyscrapers 1 provided with the seismic isolation structure A of the present embodiment is confirmed, and the seismic isolation structure A of the present embodiment is confirmed. The superiority of the seismic isolation structure A of the present embodiment was confirmed by comparing with the case where the seismic isolation structure A is not provided.

First, the S-structured 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 point system equivalent shear spring model. The RC building was an apartment house with a natural period T1 = 2.47 seconds, a height H = 92.8 m, and 29 layers, and the analysis model was a mass point system equivalent shear spring model.

Further, as shown in FIG. 16, the intermediate seismic isolation layer 30 is provided so that the lower structure has 5 layers, the upper structure has 23 layers in the S structure, and 24 layers in the RC structure. The 200% strain time period of the foundation seismic isolation layer 2 is about 5 seconds for the S building and about 4 seconds for the RC building, and the intermediate seismic isolation layer 30 is set with a bilinear equivalent to that. In this analysis model, the acceleration-force relationship of the mass element was made non-linear, and the effect of increased frictional force after relief was eliminated.

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

For the input seismic motion, the Kanto earthquake site wave, the notification Kobe NS (Lv2), and the notification Kanto EW (Lv2) were used.

Next, the analysis result will be described.
In FIG. 17, a dynamic mass is added to the foundation seismic isolation layer in each of the S structure (Fig. 17 (a)) and RC structure (Fig. 17 (b)) to control the mode, and the dynamic mass. The result of comparing the stimulus functions when is not added is shown.

Further, in FIG. 18, a dynamic mass is added to the foundation seismic isolation layer in each of the buildings of S structure (FIG. 18 (a)) and RC structure (FIG. 18 (b)), and mode control is performed.・ The results of comparing the frequency response magnifications at the top of the building without adding mass are shown.

Further, in FIG. 19, for each of the S-structured buildings (ordinary double seismic isolation building, seismic isolation building in which the dynamic mass according to the present invention is provided and mode control is performed, and seismic isolation building having only basic seismic isolation). The results of comparing the absolute acceleration, inter-story deformation angle, and layer displacement when the input seismic isolation (notification Kobe, notification Kanto, Kanto earthquake site wave) are input are shown.
Further, in FIG. 20, each of the RC buildings (normal double seismic isolation building, seismic isolation building in which the dynamic mass according to the present invention is provided and mode control is performed, and seismic isolation building having only basic seismic isolation) is shown. The result of comparing the absolute acceleration, the inter-story deformation angle, and the layer displacement when the input seismic isolation motion is input is shown.

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

In addition, when the restoring force characteristics of the middle layer seismic isolation are made equivalent to those of the foundation seismic isolation, the deformation of the middle floor seismic isolation layer becomes smaller than the deformation of the foundation seismic isolation by providing a dynamic mass and performing mode control. Was confirmed. As a result, it was confirmed that it is also advantageous for deformation tracking of the ELV shaft and the like.

Further, in the normal double seismic isolation structure, the response acceleration directly under the intermediate seismic isolation layer increases, but when the mode control is performed by providing a dynamic mass, the acceleration directly below the intermediate seismic isolation layer 30 is reduced. It was also confirmed that the effect of making it is obtained.

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

Note that 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 of FIG. 21, it was confirmed that the same effect as when the dynamic mass was provided in the basic seismic isolation layer can be obtained.

As a result, if a dynamic mass is provided in the intermediate seismic isolation layer to control the mode, the relief mechanism becomes unnecessary, and the performance and mechanism required for the device can be simplified. That is, since the burden is not excessive, it is possible to reduce the cost of the device accordingly.

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

Therefore, in the seismic isolation structure A of the present embodiment, the basic seismic isolation layer 2 and the intermediate seismic isolation layer 30 are provided, and the basic seismic isolation layer 2 and / or the intermediate seismic isolation layer 30 is provided with the dynamic mass 5. 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 the mode control method, it is possible to suppress the higher-order mode and effectively reduce the response such as the acceleration and the interlayer deformation angle of the superstructure of the super high-rise seismic isolated building.

Therefore, also in 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 habitability on the upper floors can be improved, and the number of skeletons can be significantly reduced. Will be possible.

The first and second embodiments of the seismic isolation structure according to the present invention have been described above, but the present invention is not limited to the first and second embodiments described above, and is not deviating from the gist thereof. It can be changed as appropriate.

For example, as shown in FIG. 22, a spring / damping parallel element may be connected in series with the dynamic mass of the seismic isolation structure that performs mode control. In this case, even if the spring element is connected in series with the dynamic mass, the effect of the mode control is not impaired by adding the damping element in parallel with the spring element, as shown in FIG. 23. It is possible to demonstrate excellent response performance.

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

Further, a plurality of intermediate seismic isolation layers 30 may be provided.

1 Building 2 Basic seismic isolation layer (seismic isolation layer)
3 Seismic isolation device 4 Damping device 5 Dynamic mass ((inertial mass device, inertial connecting element)
10 1st ball screw mechanism 11 2nd ball screw mechanism 12 Casing 13 Rotating weight 14 Connector 15 1st screw shaft 16 1st nut 17 2nd screw shaft 18 2nd nut 19 Weight support sleeve 20 Sleeve 21 Transmission torque limiting mechanism 22 Friction plate (friction element)
23 Pressing block 24 Adjusting bolt 25 Pressing plate 30 Intermediate seismic isolation layer A Seismic isolation structure B Conventional seismic isolation structure

Claims (4)

The seismic isolation layer of the building is configured with a dynamic mass of an inertial mass device that serves as a mode control mechanism.
Moreover, the mass of the dynamic mass is adjusted so that the higher-order stimulus function becomes smaller based on the mode control theory .
An overload prevention mechanism is provided by connecting in series to the dynamic mass.
The seismic isolation layer is one of the basic seismic isolation layers, or a plurality of the seismic isolation layers of the basic seismic isolation layer and the intermediate seismic isolation layer are provided, and the dynamic mass is added to the basic seismic isolation layer and / or the intermediate seismic isolation layer. A seismic isolation structure characterized by being provided with the overload prevention mechanism. In the seismic isolation structure according to claim 1,
A seismic isolation structure characterized in that a spring / damping parallel element is provided by connecting in series to the dynamic mass. In the seismic isolation structure according to claim 1 or 2.
The seismic isolation structure is characterized in that the seismic isolation layer is provided with 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. .. In the seismic isolation structure according to any one of claims 1 to 3.
Even if the dynamic mass required for mode control is added, the response acceleration does not increase on the long cycle side with the seismic isolation cycle. The relief load _Fr does not increase the response on the long cycle side and is on the short cycle side. Set using a load relief rate α _{r that can reduce the response,}
The seismic isolation structure is characterized in that the load relief rate α _r is 0 <α _{r ≦ 0.5.}

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