JP7440441B2 - Seismic isolation structure - Google Patents

Description

The present invention relates to a seismic isolation structure.

A seismic isolation structure is configured to reduce vibration response by reducing seismic energy input into the structure from the ground using a seismic isolation device (for example, see Patent Document 1). Even in high-rise and super-high-rise structures, the use of base isolation structures can effectively reduce vibration response during earthquakes.

JP2020-94390A

In high-rise and super-high-rise structures with seismic isolation structures, when vibrations in high-order modes such as secondary and tertiary occur, the response acceleration increases in the upper floors compared to the lower floors, amplifying the shaking, and the higher floors become A so-called whiplash phenomenon that causes a large shaking may occur. For this reason, high-rise and super-high-rise structures with seismic isolation structures have a problem in that the high-rise areas are not comfortable to live in.

Therefore, an object of the present invention is to provide a seismic isolation structure that can improve the seismic resistance of the entire structure while reducing the response acceleration of the high-rise section and improving livability.

In order to achieve the above object, the seismic isolation structure according to the present invention includes a seismic isolation layer between a high-rise section that is the top part of a high-rise or super-high-rise structure and a lower layer below the high-rise section. the lower layer part has a lower core part and a lower core adjacent part adjacent to the lower core part, the lower core part is set to have greater rigidity than the lower core adjacent part, The high-rise part is set to have greater rigidity than the lower-layer part, and has a natural period of 2 seconds or less and 30% or less of the natural period of the lower-layer part, and the seismic isolation period of the high-rise part is set to be the same as the period of the lower part. The difference is more than 20% .

In the present invention, since the lower part has the lower core part, the structure has a highly rigid mandrel, and the vibration response during an earthquake can be reduced. In addition, by providing a seismic isolation layer between the upper and lower floors, it is possible to reduce the seismic energy transmitted from the lower to the upper floors, and the vibration response of the upper floors can be reduced. At the same time, the upper floors can be used as building mass.

In the present invention, the stiffness of the upper layer is greater than that of the lower layer, and the natural period of the upper layer is 2 seconds or less and 30% or less of the natural period of the lower layer. As a result, in the present invention, it is possible to reduce the so-called whiplash phenomenon in which the high-rise section shakes significantly, and it is possible to reduce the response acceleration of the high-rise section and improve livability, as well as improve the seismic isolation effect. .

Furthermore, in the present invention, the structure is such that the high-rise part (building mass portion) is not synchronized with the lower-layer part by shifting the seismic isolation period of the high-rise part by 20% or more with respect to the period of the lower-story part. As a result, variations in the load and rigidity of the structure can be tolerated, and the robustness of the structure can be improved. Furthermore, although the primary vibration mode becomes larger compared to the case of pinpoint tuning, the short-period secondary vibration mode can be lowered. As a result, it is possible to suppress the resonance of the secondary vibration mode for earthquake motions that generally have a large short-period acceleration component, and it is possible to suppress the resonance of the secondary vibration mode, which is not limited to high-rise areas caused by the secondary vibration mode, compared to pinpoint tuning. The response acceleration of the lower layer can also be reduced.

Further, in the seismic isolation structure according to the present invention, the high-rise section has a high-rise core section and a high-rise core adjacent section adjacent to the high-rise core section, and the high-rise core section is an RC core wall of RC construction. may be provided, and the rigidity may be set to be greater than that of the adjacent portion of the high-rise core.

With such a configuration, the rigidity of the high-rise section can be increased, and the swinging of the top section can be suppressed and the seismic isolation effect can be maximized. Furthermore, the weight of the high-rise section can be increased, and the building mass effect of the structure can be improved.

Moreover, in the seismic isolation structure according to the present invention, an AMD may be provided in the high-rise section.

With such a configuration, the response acceleration of the entire structure can be further reduced by controlling the movement of the building mass portion using the active vibration damping device. In particular, by applying AMD when shaking due to wind loads or shaking after an earthquake occurs, it is possible to efficiently reduce the response acceleration and shaking of the entire structure.

Furthermore, the seismic isolation structure according to the present invention may include a locking mechanism that restricts the seismic isolation function of the seismic isolation layer.

With such a configuration, by restraining the seismic isolation function, it is possible to quickly bring the shaking to a halt in the case of relatively small shaking. In particular, it is possible to restrain shaking caused by wind loads, improving livability and maintaining building functions such as the operation of seismic isolation elevators.

Moreover, in the seismic isolation structure according to the present invention, the weight of the high-rise portion may be 15% or more of the weight of the entire structure.

With such a configuration, the building mass effect can be improved and the robustness can also be improved.

According to the present invention, it is possible to reduce response acceleration in a high-rise area and improve livability.

FIG. 1 is a side view of a structure provided with a seismic isolation structure according to an embodiment of the present invention. FIG. 3 is a side view of another side of the structure. It is a top view of a lower layer part. FIG. 3 is a plan view of a high-rise section. It is a figure which shows the relationship between the displacement of a seismic isolation layer, the operation|movement of a seismic isolation ELV, and a lock mechanism. It is a graph which shows the comparison of the interstory deformation angle of the building mass plan of this embodiment, and a damping plan. It is a graph which shows the comparison of the response acceleration of the building mass plan of this embodiment, and a damping plan. It is a graph which shows the relationship between a natural period and an acceleration response magnification. It is a graph showing a comparison of response results when a pulse wave is input when an AMD is provided and when an AMD is not provided. It is a graph showing a comparison of the interlayer deformation angles of each layer when the weight of BMD is 15% and 25% of the whole building weight.

Hereinafter, a seismic isolation structure according to an embodiment of the present invention will be described based on FIGS. 1 to 4.
As shown in FIGS. 1 and 2, the base isolation structure 1 according to this embodiment is employed in a super high-rise structure 2. In the structure 2 of this embodiment, it is assumed that the lower floor (referred to as lower part 3) is used as an office, and the upper floor (referred to as upper part 4) is used as a hotel, residence, or the like. A seismic isolation layer 6 is provided between the lower part 3 and the upper part 4.

The lower layer part 3 is formed to have substantially the same external shape throughout the vertical direction. As shown in FIG. 3, the lower layer portion 3 includes a lower core portion 31 located at the center in a plane, and a lower core adjacent portion 32 adjacent to the periphery of the lower core portion 31. In this embodiment, the lower core adjacent portion 32 is provided so as to surround the lower core portion 31 . An elevator, stairs, etc. are installed in the lower core part 31, and a store, an office, etc. are installed in the lower core adjacent part 32.

As shown in FIGS. 1 and 2, the lower core portion 31 is provided with a core frame 33 having a predetermined rigidity, and is also provided with a vibration damping device 34 such as a vibration damper or an oil damper. The lower core portion 31 is set to have greater rigidity than the lower core adjacent portion 32. The lower core portion 31 is designed such that the lower layer has a larger shape in plan view than the upper layer, and is set to have greater rigidity. The lower core portions 31 of each layer are arranged so as to be continuous in the vertical direction.

The high-rise portion 4 is formed to have substantially the same external shape throughout the vertical direction. As shown in FIG. 4, the high-rise section 4 has a rectangular outer shape in plan view having short sides and long sides. The horizontal direction in which the long sides of this rectangle extend is defined as the long side direction (direction of arrow X in the figure), and the horizontal direction in which the short sides extend is defined as the short side direction (direction of arrow Y in the figure). As shown in FIG. 1, the high-rise portion 4 is smaller in plan view than the lower-layer portion 3. As shown in FIG. The high-rise portion 4 is disposed above the central portion of the lower layer portion 3 in plan view, and above the lower core portion 31 .

As shown in FIGS. 1, 2, and 4, the high-rise section 4 includes a high-rise core section 41 located at the center in a plane, and a high-rise core adjacent section 42 adjacent to the periphery of the high-rise core section 41. There is. In this embodiment, the high-rise core adjacent section 42 is provided so as to surround the high-rise core section 41 . Elevators, stairs, etc. are installed in the high-rise core part 41, and hotel rooms, residences, etc. are installed in the high-rise core adjacent part 42. The high-rise core section 41 is provided with an RC core wall 43 made of RC. In FIG. 4, the RC core wall 43 is shown by hatching. The high-rise core adjacent portion 42 is constructed of a steel frame structure. The high-rise core portion 41 is set to have greater rigidity than the high-rise core adjacent portion 42. The high-rise core portions 41 of each layer are arranged so as to be continuous in the vertical direction. In this embodiment, a rooftop garden 45 is provided on the rooftop slab 44 of the high-rise section 4.

The high-rise section 4 is configured to be movable relative to the lower-level section 3 through the seismic isolation layer 6, and thus functions as a building mass (BMD). The high-rise section 4 (building mass) is designed to have a weight of 10 to 50% of the weight of the entire structure 2. The high-rise section 4 of this embodiment is designed to have a weight of approximately 15% or more of the weight of the entire structure 2.

The high-rise section 4 is provided with three AMDs 51, 52, and 53 (Active Mass Dampers). In this embodiment, the three AMDs 51, 52, and 53 are each provided with a rooftop garden 45 on the rooftop slab 44 of the high-rise section 4. The three AMDs 51, 52, and 53 are referred to as a first AMD 51, a second AMD 52, and a third AMD 53. The first AMD 51 and the third AMD 53 are configured to be able to vibrate in the short side direction. The second AMD 52 is configured to be able to vibrate in the long side direction. The first AMD 51 is provided at an intermediate portion in the short side direction of one end of the high rise portion 4 in the long side direction. The third AMD 53 is provided at an intermediate portion in the short side direction at the other end in the long side direction of the high-rise section 4 . The second AMD 52 is provided at an intermediate portion in the short side direction at one end in the long side direction of the high-rise section 4 . By providing AMDs (first AMD 51 and third AMD 53) that can vibrate in the short side direction at both ends in the long side direction, eccentricity and twisting when the high-rise section 4 vibrates as a building mass can be prevented. can.

As shown in FIGS. 1 and 2, the seismic isolation layer 6 is provided with a seismic isolation device 61 such as laminated rubber, and a locking mechanism 62 that restrains the seismic isolation function of the seismic isolation device 61. The locking mechanism 62 restricts the seismic isolation function of the seismic isolation device 61 according to wind speed, acceleration, the amount of displacement of the high-rise section 4 with respect to the lower section 3, and the like. The structure 2 is provided with sensors (not shown) that detect wind speed, acceleration, displacement amount of the high-rise section 4 with respect to the lower-section section 3, and the like. The structure 2 is provided with an elevator (hereinafter referred to as a seismic isolation ELV 63) that penetrates the seismic isolation layer 6. The operating conditions of the seismic isolation ELV 63 are determined according to the displacement of the seismic isolation layer 6. FIG. 5 shows the displacement of the seismic isolation layer and the operation of the seismic isolation ELV 63 and the locking mechanism 62.

The seismic isolation structure 1 according to the present embodiment includes a building mass (hereinafter referred to as BMD) formed by the high-rise section 4, AMDs 51, 52, 53 (hereinafter referred to as AMD), and a locking mechanism 62 (hereinafter referred to as locking mechanism). and are structured so that they are interrelated.

(Control during earthquakes)
(1) In the event of an earthquake, in order to maximize BMD and ensure high seismic performance and livability, the seismic isolation layer is not locked by a locking mechanism and is left free (see Figure 5).

(2) In order to prevent the seismic isolation ELV from stopping due to frequent earthquakes, the seismic isolation layer is composed of laminated rubber containing lead plugs in addition to natural laminated rubber and oil dampers, and the displacement of the seismic isolation layer is set as the operating condition for the seismic isolation ELV. The displacement is suppressed to below. However, the amount of lead shall be such that the residual deformation of the seismic isolation layer is suppressed to below the seismic isolation ELV movable condition when a large shaking occurs.
For example, in the case of Tokyo, frequent earthquakes refer to seismic motions observed in the past 20 years (1999 to 2020) near the construction site, excluding the Tohoku Pacific Coast Earthquake that occurred on March 11, 2011. Showing an earthquake.
The seismic isolation layer will be designed so that the displacement of the seismic isolation layer during frequent earthquakes will be 40 mm or less. Further, the lead diameter and the rubber diameter are adjusted so that the residual deformation due to the lead plug is less than 20 mm.

(3) According to the above, the movement of the BMD is controlled by the AMD to improve the BMD effect so that the BMD effect is not reduced especially in response to small shaking or after-earthquake shaking.

(4) In the event of excessive deformation of the seismic isolation layer due to an unexpected earthquake, the deformation of the seismic isolation layer is controlled using a fail-safe stopper to prevent major damage such as rupture of the seismic isolation device.
For example, the fail-safe concept for earthquakes exceeding level 3 is as follows. The displacement of the seismic isolation layer for level 3 input seismic motion is set at 600 mm or less, but for seismic motion exceeding this, a stopper using a collision buffer material will be installed on the seismic isolation layer.
In addition, if there is no stopper, the displacement of the seismic isolation layer will be kept to 700 mm or less by providing a stopper against an earthquake motion (1.25 times level 3) that would cause the displacement of the seismic isolation layer to be 750 mm.

(Control during wind load)
(5) For winds with a one-year recurrence period or a 50-year recurrence period, the seismic isolation ELV is activated and the seismic isolation layer is locked using a locking mechanism to ensure the habitability of the BMD (e.g., hotel or residence). (See Figure 5).

(6) By installing and moving the AMD in the locked state described above, wind sway is suppressed and comfort is improved. An AMD will be installed at the top of the building to improve habitability during storms. The target values for livability are H-30 at the center of gravity on the hotel floor and H-50 at the corners during a storm with a one-year recurrence period.

In the above-described seismic isolation structure 1 according to this embodiment, since the lower layer portion 3 has the lower core portion 31, it becomes a structure having a highly rigid mandrel, and the vibration response during an earthquake can be reduced. Furthermore, by providing the seismic isolation layer 6 between the high-rise section 4 and the lower-rise section 3, it is possible to reduce the seismic energy transmitted from the lower-rise section 3 to the high-rise section 4, and the vibration of the high-rise section 4 can be reduced. Not only can the response be reduced, but also the high-rise section 4 can be used as a building mass.

In this embodiment, the rigidity of the high-rise section 4 is greater than that of the lower-layer section 3, and the natural period of the high-rise section 4 is 2 seconds or less and 30% or less of the natural period of the lower section 3. Thereby, the so-called whiplash phenomenon in which the high-rise section 4 shakes significantly can be reduced, the response acceleration of the high-rise section 4 can be reduced, and the livability can be improved, as well as the seismic isolation effect can be improved. As shown in FIGS. 6 and 7, the vibration damping structure (see the dashed line of the vibration damping plan in FIGS. 6 and 7) and the structure 2 of the seismic isolation structure 1 of this embodiment (see the broken line of the damping plan in FIGS. 6 and 7) (see the solid line of the building mass plan), in the structure 2 with the base isolation structure of this embodiment, the interstory deformation angle of the entire structure 2 (high-rise section 4 and lower section 3) and the response acceleration of the high-rise section 4 are It can be seen that this can be reduced.

Furthermore, in this embodiment, the seismic isolation period of the high-rise section 4 is shifted from the period of the lower section 3 by 20% or more. As a result, it is possible to create a structure in which the high-rise section 4 (building mass section) is not synchronized with the lower section 3, allowing variations in the load and rigidity of the structure 2, and improving the robustness of the structure 2. can be improved.

In addition, as shown in FIG. 8, in the case of the base isolation structure of this embodiment (see the dashed line of this embodiment in FIG. 8), when the natural period of the high-rise section 4 is pinpoint tuned (see the dashed line of this embodiment in FIG. 8), Although the primary vibration mode becomes larger compared to the optimal tuning (see dashed line), the short-period secondary vibration mode can be lowered. As a result, it is possible to suppress the resonance of the secondary vibration mode for earthquake motions that generally have a large short-period acceleration component, and it is possible to suppress the resonance of the high-rise section 4 caused by the secondary vibration mode rather than pinpoint tuning. First, the response acceleration of the lower layer portion 3 can also be reduced.

Further, in the seismic isolation structure 1 according to the present embodiment, the high-rise section 4 has a high-rise core section 41 and a high-rise core adjacent section 42 adjacent to the high-rise core section 41, and the high-rise core section 41 is made of RC structure. An RC core wall 43 is provided, and is set to have greater rigidity than the high-rise core adjacent portion 42. With such a configuration, the rigidity of the high-rise section 4 can be increased, and the swinging of the top can be suppressed and the seismic isolation effect can be maximized. Moreover, the weight of the high-rise section 4 can be increased, and the building mass effect of the structure 2 can be improved.

Further, in the base isolation structure 1 according to the present embodiment, AMDs 51, 52, and 53 are provided in the high-rise section 4. With such a configuration, the movement of the building mass portion can be controlled by the active vibration damping device, and the response acceleration of the entire structure 2 can be further reduced. In particular, by applying the AMDs 51, 52, and 53 when shaking due to wind loads or shaking after an earthquake occurs, the response acceleration and shaking of the entire structure 2 can be efficiently reduced. FIG. 9 shows the response results when a pulse wave is input when an AMD is provided and when an AMD is not provided. As shown in FIG. 9, it can be seen that the response acceleration can be effectively reduced by providing the AMD.

Furthermore, the seismic isolation structure 1 according to the present embodiment includes a locking mechanism 62 that restrains the seismic isolation function of the seismic isolation layer 6. With such a configuration, by restraining the seismic isolation function, it is possible to quickly bring the shaking to a halt in the case of relatively small shaking. In particular, it is possible to restrain shaking caused by wind loads, improving livability and maintaining building functions such as the operation of seismic isolation elevators.

Further, in the seismic isolation structure 1 according to the present embodiment, the weight of the high-rise section 4 is approximately 15% or more of the weight of the entire structure 2. With such a configuration, the building mass effect can be improved and the robustness can also be improved.

Although the embodiments of the seismic isolation structure 1 according to the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit thereof.

For example, in the above embodiment, the high-rise section 4 has a high-rise core section 41 and a high-rise core adjacent section 42 adjacent to the high-rise core section 41, and the high-rise core section 41 has an RC core wall 43 of an RC construction. is provided. On the other hand, the high-rise section 4 may have a configuration other than the above as long as the rigidity is set higher than that of the lower-layer section 3 and the natural period is 2 seconds or less and 30% or less of the natural period of the lower-layer section 3. , the RC core wall 43 may not be provided.

Further, in the above embodiment, the AMDs 51, 52, and 53 are provided in the high-rise section 4, but the AMDs 51, 52, and 53 may not be provided.

Further, in the embodiment described above, a locking mechanism 62 that restricts the seismic isolation function of the seismic isolation layer 6 is provided, but such a locking mechanism 62 may not be provided.

In addition, in the seismic isolation structure 1 according to the present embodiment, the weight of the high-rise section 4 is approximately 15% or more of the weight of the entire structure 2, but the weight ratio of the high-rise section 4 to the structure 2 is other than the above. It's okay. Note that the weight of the high-rise portion 4 may be approximately 15% to 25% of the weight of the entire structure 2. From FIG. 10, it can be seen that the response reduction effect can be achieved by setting the weight of the high-rise section 4 (BMD weight) to approximately 15% to 25% of the weight of the entire structure 2 (the weight of the entire building).

1 Seismic isolation structure 2 Structure 3 Lower part 4 High-rise part 6 Seismic isolation layer 31 Lower core part 32 Lower core adjacent part 41 High-rise core part 42 High-rise core adjacent part 43 RC core wall 62 Lock mechanism

Claims (5)

A seismic isolation layer is provided between a high-rise part that is the top part of a high-rise or super-high-rise structure and a lower part below the high-rise part,
The lower layer portion includes a lower core portion and a lower core adjacent portion adjacent to the lower core portion,
The lower core portion is set to have greater rigidity than the adjacent portion of the lower core,
The high-rise part is set to have greater rigidity than the lower-layer part, and has a natural period of 2 seconds or less and 30% or less of the natural period of the lower-layer part,
A seismic isolation structure in which the seismic isolation period of the upper layer is shifted by 20% or more with respect to the period of the lower layer . The high-rise section has a high-rise core section and a high-rise core adjacent section adjacent to the high-rise core section,
The seismic isolation structure according to claim 1, wherein the high-rise core section is provided with an RC core wall made of RC construction, and has greater rigidity than an adjacent section of the high-rise core. The seismic isolation structure according to claim 1 or 2, wherein the high-rise section is provided with an AMD. The seismic isolation structure according to any one of claims 1 to 3, further comprising a locking mechanism that restrains the seismic isolation function of the seismic isolation layer. The seismic isolation structure according to any one of claims 1 to 4, wherein the weight of the high-rise portion is 15% or more of the weight of the entire structure.

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