Building structure

Abstract

To reduce response acceleration of a building while suppressing deformation of a base isolation layer at the time of earthquake occurrence.SOLUTION: A building structure 100 has a main frame part 120 which has a first attenuation device 152 provided in a base isolation layer 50 and has a base isolation structure, and a core part 110 which is constructed with a gap with the main frame part 120, is joined to a node part FA of a higher mode of a natural frequency mode of the main frame part 120, has a second attenuation device 162 provided in the base isolation layer 50, and has a base isolation structure, wherein the core part 110 has such rigidity that deformation of a second base isolation layer 54 of the core part 110 in the higher mode becomes 0 or approximately 0.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to building structures. [Background technology]

[0002] Patent Document 1 discloses technology relating to a vibration-damping structure that has a function of absorbing vibration energy caused by external forces such as earthquakes internally, particularly a vibration-damping structure suitable for use in high-rise structures. In this prior art, at least a part of the walls in the portions corresponding to the loops of the multiple natural vibration modes of the structure is configured to be freely movable in the horizontal direction, the natural periods of these walls themselves are made to approximately coincide with the natural periods of the respective vibration modes of the structural parts, and the walls are provided with a damping function that damps their own horizontal vibrations.

[0003] Patent Document 2 discloses a technology related to a structure for improving the earthquake resistance performance of a building. In this prior art, a seismic isolation layer equipped with a seismic isolation device such as laminated rubber is provided on any floor of a building, and the entire floor above the seismic isolation layer is supported by the seismic isolation device, and a vibration control device such as a damper is installed at any position of the upper floor supported by the seismic isolation device. The entire upper floor supported by the seismic isolation device is divided into a lower floor section directly supported by the seismic isolation device and a higher floor section connected to the lower floor in a tower-like shape, and the vibration control device is installed only in the higher floor section.

[0004] Patent Document 3 discloses technology related to seismic isolation structures such as seismic isolated buildings. This prior art includes one seismic isolation structure and another seismic isolation structure that are supported by seismic isolation devices and constructed independently, and connects the one seismic isolation structure and the other seismic isolation structure with a vibration control device that includes a spring element and a damping element. In addition, the seismic isolation device that supports either the one seismic isolation structure or the other seismic isolation structure is a sliding bearing.

[0005] Patent Document 4 discloses technology relating to seismic isolation structures. This prior art technology includes a core part and a main building part adjacent to the core part, and is configured with a multi-layer seismic isolation structure consisting of a base isolation layer provided at least in the lower part of the core part and the main building part, and an intermediate seismic isolation layer provided in the middle part of the main building part, and a connected vibration control structure in which the core part and the main building part are connected by a vibration control device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 01-165885 [Patent Document 2] Japanese Patent Application Publication No. 11-117568 [Patent Document 3] JP 2017-125324 A [Patent Document 4] JP 2018-009442 A Summary of the Invention [Problem to be solved by the invention]

[0007] In a building with a seismic isolation structure, if the input level of earthquake motion exceeds the expected level due to a major earthquake, the deformation of the seismic isolation layer will increase, i.e., the horizontal relative displacement of the building will increase, and there is a risk that the building will exceed the horizontal clearance and collide with the retaining wall. Such a collision can be prevented by increasing the damping force of the damping devices, such as oil dampers, installed in the seismic isolation layer and suppressing the deformation of the seismic isolation layer. However, suppressing the deformation of the seismic isolation layer increases the acceleration response of the building and reduces the seismic isolation effect.

[0008] In this way, it can be said that there is a trade-off between suppressing deformation of the seismic isolation layer during an earthquake and reducing the response acceleration of the building.

[0009] In view of the above, an object of the present invention is to reduce the response acceleration of a building while suppressing deformation of the seismic isolation layer during an earthquake. [Means for solving the problem]

[0010] The first aspect is a building structure having a first building part of a seismic isolation structure in which a first damping device is provided in the seismic isolation layer, and a second building part of a seismic isolation structure constructed at a distance from the first building part and joined to a node of a higher mode of the natural vibration mode of the first building part, in which a second damping device is provided in the seismic isolation layer, wherein the second building part has a rigidity such that deformation of the seismic isolation layer of the second building part in the higher mode is zero or approximately zero.

[0011] In the building structure of the first embodiment, the second building section of the seismic isolation structure is joined to the joint of the higher mode of the first building of the seismic isolation structure. The second building section has a rigidity such that the deformation of the seismic isolation layer of the second building section in the higher mode is zero or approximately zero. Therefore, in the movement due to the higher mode, the second building section hardly deforms, so the deformation or velocity input to the second damping device is zero or approximately zero, and the damping force is also zero or approximately zero. As a result, the second damping device highly damps the first building section in the primary mode to suppress the deformation of the seismic isolation layer, and prevents overdamping in the higher mode to reduce the response acceleration. Therefore, it is possible to reduce the acceleration response of the first building section while suppressing the deformation of the seismic isolation layer of the first building section during an earthquake.

[0012] A second aspect is the building structure according to the first aspect, wherein the second damping device has a higher damping performance than the first damping device.

[0013] In the building structure of the second aspect, since the second damping device has a higher damping performance than the first damping device, the second damping device suppresses deformation of the seismic isolation layer with higher damping for the first mode of the first building part, compared to a case in which the second damping device has a lower damping performance than the first damping device. Also, the second damping device suppresses deformation of the seismic isolation layer and prevents overdamping for higher modes, thereby suppressing the response acceleration of the first building.

[0014] The third aspect is a building structure having a first building section of a seismic isolation structure in which a first damping device is provided in the seismic isolation layer, and a second building section constructed at a distance from the first building section and joined via a second damping device to a node in a higher mode of the natural vibration mode of the first building section, wherein the second building section has a rigidity at the joint with the first building section such that the relative displacement between the first building section and the second building section in the higher mode is zero or approximately zero.

[0015] In the building structure of the third aspect, the second building section is joined to the joint of the first building section of the seismic isolation structure in the higher mode via the second damping device. The second building section has a rigidity at the joint with the first building section such that the relative displacement between the first building section and the second building section in the higher mode is 0 or approximately 0. Therefore, in the movement due to the higher mode, the second building section is hardly deformed, so the deformation or velocity input to the second damping device is 0 or approximately 0, and the damping force is also 0 or approximately 0. As a result, the second damping device highly damps the first building section in the primary mode to suppress the deformation of the seismic isolation layer, and prevents overdamping in the higher mode to reduce the response acceleration. Therefore, it is possible to reduce the acceleration response of the first building section while suppressing the deformation of the seismic isolation layer of the first building section during an earthquake.

[0016] A fourth aspect is the building structure according to the third aspect, wherein the second damping device has a higher damping performance than the first damping device.

[0017] In the building structure of the fourth aspect, the second damping device has a higher damping performance than the first damping device, and therefore the second damping device suppresses the deformation of the seismic isolation layer by providing higher damping for the first mode of the first building part, and also suppresses the deformation of the seismic isolation layer and prevents overdamping for higher modes to suppress the response acceleration of the first building part. Effect of the Invention

[0018] According to the present invention, it is possible to reduce the response acceleration of a building while suppressing deformation of the seismic isolation layer during an earthquake. [Brief description of the drawings]

[0019] [Figure 1] 1A is a cross-sectional view taken along line 1A-1A in FIG. 1B, which is a schematic diagram of a seismic isolation structure to which the building structure of the first embodiment is applied, and FIG. 1B is a cross-sectional view taken along line 1B-1B in FIG. [Diagram 2] 2 is a graph showing a primary mode displacement of a natural vibration mode of a main frame part in the seismic isolation structure of FIG. 1. [Diagram 3] 2 is a graph showing a secondary mode displacement of the natural vibration mode of the main frame of the seismic isolation structure of FIG. 1. [Figure 4] 2A is a diagram of an analytical model of a comparative example, and FIG. 2B is a diagram of an analytical model of the seismic isolation structure of FIG. 1 . [Diagram 5] 5 is a graph of an acceleration transfer function and a graph of a displacement transfer function analyzed using the analytical model of FIG. 4(A) and the analytical model of FIG. 4(B). [Figure 6] 2 is a cross-sectional view corresponding to FIG. 1, which shows a schematic illustration of a seismic isolation structure to which a building structure according to a first modified example of the first embodiment is applied. [Figure 7] 2 is a cross-sectional view corresponding to FIG. 1, which shows a schematic illustration of a seismic isolation structure to which a building structure according to a second modified example of the first embodiment is applied. [Figure 8] 1A is a graph showing the third mode displacement corresponding to FIG. 3 in a seismically isolated structure to which the building structure of the third modified example of the first embodiment of FIG. 1B is applied, and FIG. 1B is a cross-sectional view corresponding to FIG. 1 which shows a schematic diagram of the seismically isolated structure of the third modified example. [Figure 9] 1A is a graph showing a second mode displacement corresponding to FIG. 3 in a structure to which the building structure of the second embodiment of FIG. 1B is applied, and FIG. 1B is a cross-sectional view corresponding to FIG. 1 which shows a schematic diagram of the structure of the second embodiment. [Figure 10] 1A is a graph showing a second mode displacement corresponding to FIG. 3 in a structure to which a building structure according to a modified example of the second embodiment of FIG. 2B is applied, and FIG. 1B is a cross-sectional view corresponding to FIG. 1 which shows a schematic diagram of the structure according to the modified example. [Figure 11]1(A) is a cross-sectional view corresponding to FIG. 1(A) taken along line 11A-11A in (B) which shows a schematic diagram of a seismic isolation structure to which a fourth variant of the first embodiment is applied, and (B) is a cross-sectional view corresponding to FIG. 1(B) taken along line 11B-11B in (A). [Figure 12] 1(A) is a cross-sectional view corresponding to FIG. 1(A) taken along line 12A-12A in (B) which shows a schematic diagram of a seismic isolation structure to which the fifth variant of the first embodiment is applied, and (B) is a cross-sectional view corresponding to FIG. 1(B) taken along line 12B-12B in (A). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] First Embodiment A seismic isolation structure to which the building structure of the first embodiment is applied will be described. In each drawing, hatching showing a cross section is omitted to avoid the drawing becoming complicated.

[0021] [structure] First, the structure of the seismic isolation structure will be described.

[0022] The seismic isolation structure 10 to which the building structure 100 of this embodiment shown in Fig. 1(B) is applied is configured with a building main body 30 as an example of an upper structure and a seismic isolation pit section 20 as an example of a lower structure, and is a structure of a base isolation structure with a seismic isolation layer 50 between the building main body 30 and a base plate 22 of the seismic isolation pit section 20. The seismic isolation pit section 20 is configured with a base plate 22 and a retaining wall 24 provided on the outer periphery of the base plate 22.

[0023] The building structure 100 is composed of a seismic isolation layer 50, a first seismic isolation bearing 150, a first damping device 152, a second seismic isolation bearing 160, a second damping device 162, a main frame section 120 as an example of a first building section, and a core section 110.

[0024] The building main body 30 is configured to have a main frame section 120 as an example of a first building section, and a core section 110 as an example of a second building section. The main frame section 120 has a greater horizontal rigidity than the main frame section 120, but is not limited to this. In the present embodiment, the core section 110 is provided with shared facilities such as stairs, elevator shafts, and pipe spaces, but is not limited to these.

[0025] The main frame section 120 has a void section 122 in the center of the lower part of the building (see also FIG. 1(A)). The core section 110 is constructed in the void section 122 with a distance L between it and the main frame section 120, and the upper end section 112 is rigidly joined to the upper end 124 of the void section 122.

[0026] In addition, "core section 110 is constructed with a gap between it and main structure section 120 within open space section 122" means that "core section 110 and main structure section 120 are insulated from each other for structural calculation purposes except at upper end 124 of open space section 122," and the two may be connected by an expansion joint or the like at a point other than upper end 124.

[0027] An upper end 124 of the void section 122 is a node FA that coincides or approximately coincides with the position of a node F2 (see FIGS. 2 and 3) of the secondary mode of the natural vibration mode in the main frame section 120. Therefore, the core section 110 is rigidly joined to the node FA that coincides or approximately coincides with the position of the node F2 of the secondary mode in the main frame section 120.

[0028] A first seismic isolation bearing 150, a second seismic isolation bearing 160, a first damping device 152, and a second damping device 162 are installed in the seismic isolation layer 50. The first seismic isolation bearing 150 and the first damping device 152 are installed directly below the main frame section 120, and the second seismic isolation bearing 160 and the second damping device 162 are installed directly below the core section 110.

[0029] In addition, the portion of the seismic isolation layer 50 where the first seismic isolation bearing 150 and the first damping device 152 are installed directly below the main frame section 120 is referred to as the first seismic isolation layer 52, and the portion where the second seismic isolation bearing 160 and the second damping device 162 are installed directly below the core section 110 is referred to as the second seismic isolation layer 54.

[0030] The core portion 110 has a rigidity such that the deformation of the second seismic isolation layer 54 of the core portion 110 in the secondary mode is 0 or approximately 0. In addition, the second damping device 162 has a higher damping performance than the first damping device 152.

[0031] In addition, the term "damping performance" refers to the damping coefficient in the case of velocity-dependent damping devices such as oil dampers and viscous dampers, and refers to the area that the hysteresis traces up to a certain deformation in the case of displacement-dependent damping devices such as hysteresis dampers. This also applies to the following descriptions.

[0032] The main frame section 120 is supported by a first seismic isolation bearing 150, and the core section 110 is supported by a second seismic isolation bearing 160. The rigidity of the second seismic isolation bearing 160 is set to be smaller than the rigidity of the first seismic isolation bearing 150, but is not limited to this.

[0033] In addition, when the first seismic isolation bearing 150 and the second seismic isolation bearing 160 are each composed of a plurality of seismic isolation bearings, the total rigidity of the plurality of seismic isolation bearings constituting the second seismic isolation bearing 160 is set to be smaller than the total rigidity of the plurality of seismic isolation bearings constituting the second seismic isolation bearing 160. From another perspective, the rigidity of the second seismic isolation layer 54 is set to be smaller than the rigidity of the first seismic isolation layer 52.

[0034] In this embodiment, the first seismic isolation bearing 150 is composed of a plurality of laminated rubber bearings, and the second seismic isolation bearing 160 is composed of a plurality of sliding bearings, but this is not limited to this.

[0035] The first damping device 152 is connected to the base plate 22 and the bottom 128 of the main frame portion 120, and the second damping device 162 is connected to the base plate 22 and the bottom 118 of the core portion 110. The second damping device 162 has a higher damping performance than the first damping device 152, but is not limited to this.

[0036] In addition, when the first damping device 152 and the second damping device 162 are composed of damping devices such as multiple dampers, the total damping performance of the multiple damping devices that constitute the second damping device 162 is set to be higher than the total damping performance of the second damping device 162.

[0037] In this embodiment, the damping performance of the second damping device 162 is set to be higher than the damping performance of the first damping device 152 by adjusting the number of damping devices, such as oil dampers, that constitute the first damping device 152 and the second damping device 162, but this is not limited to this.

[0038] Here, the graphs in FIG. 2 and FIG. 3 will be explained.

[0039] Fig. 2 shows the horizontal displacement of the main frame portion 120 and the core portion 110 in the primary mode of the natural vibration modes of the main frame portion 120. Fig. 3 shows the horizontal displacement of the main frame portion 120 and the core portion 110 in the secondary mode of the natural vibration modes of the main frame portion 120.

[0040] FIG. 2 shows that the core portion 110 is rigidly joined to a node FA (see upper end 124 in FIG. 1) that coincides or nearly coincides with a node F2 of the secondary mode of the natural vibration mode in the main frame portion 120.

[0041] FIG. 3 shows that the horizontal displacement of the core portion 110 in the secondary mode of the natural vibration mode of the main frame portion 120 is zero.

[0042] The specifications of the analytical model in FIG. 4(B) used to calculate the graphs in FIG. 2 and FIG. 3 are as follows:

[0043] In the analysis model shown in Fig. 4(B), the main frame section 120 is a 30-mass model, the mass of each story is 2000t, the floor height of each story is 4m, the natural period when the foundation is fixed is 2.4s, and the rigidity distribution is a trapezoidal distribution in which the rigidity of the top story is 0.3 times that of story 1. The core section 110 has a mass 0.5 times and a rigidity 5.0 times that of the main frame section 120, and is connected to the 18th story of the main frame section 120.

[0044] A rigidity was added to the first seismic isolation bearing 150 (first seismic isolation layer 52) so that the natural period would be 6.0 s when the main frame portion 120 and the core portion 110 were assumed to be one mass point, and an extremely small rigidity was added to the second seismic isolation bearing 160 (second seismic isolation layer 54).

[0045] The analysis results based on the analytical model will be described later.

[0046] [Action and Effects] Next, the operation and effects of this embodiment will be described.

[0047] The core portion 110 of the seismic isolation structure 10 to which the building structure 100 of this embodiment is applied is joined to a node FA that coincides or nearly coincides with a node F2 of the secondary mode of the natural vibration mode of the main frame portion 120. The core portion 110 also has a rigidity such that the deformation of the second seismic isolation layer 54 of the core portion 110 in the secondary mode is zero or nearly zero. Therefore, in the movement due to the secondary mode during an earthquake, the core portion 110 hardly deforms, so the deformation or velocity input to the second damping device 162 is zero or nearly zero, and the damping force is also zero or nearly zero.

[0048] As a result, as shown in Fig. 2, the second damping device 162 provides high damping for the first mode to suppress deformation of the seismic isolation layer 50, i.e., suppresses the horizontal relative displacement of the main frame portion 120, and prevents collision with the retaining wall 24. On the other hand, as shown in Fig. 3, the second damping device 162 prevents overdamping for the second mode, increases the displacement of the main frame portion 120, and reduces the response acceleration. Therefore, it is possible to reduce the acceleration response of the main frame portion 120 while suppressing excessive deformation of the seismic isolation layer 50 during an earthquake, particularly a massive earthquake.

[0049] Furthermore, since the second damping device 162 has a higher damping performance than the first damping device 152 , the second damping device 162 provides higher damping for the primary mode of the main frame section 120 and suppresses deformation of the seismic isolation layer 50 .

[0050] (Analysis results of the analysis model) Next, the analysis results of the analytical model will be described.

[0051] Fig. 4(A) is an analytical model of a base isolation structure of a comparative example. The upper structure of the analytical model of the comparative example is a 30 mass point model, similar to the analytical model of the base isolation structure 10 of this embodiment to which the building structure 100 is applied (see Fig. 4(B)), with the mass of each story being 2000t, the floor height being 4m, and the natural period when the foundation is fixed being 2.4s. The stiffness distribution of the upper structure is a trapezoidal distribution in which the stiffness of the top story is 0.3 times that of the bottom story, and the damping constant of the main frame part 120 is 1.5%. The natural period of the seismic isolation layer is 6.0s when the upper structure is assumed to be a single mass point, and the damping constant h at this time is used as a parameter.

[0052] FIG. 4(B) shows an analytical model of the seismic isolation structure 10 of this embodiment to which the building structure 100 is applied as described above.

[0053] A damping constant h equivalent to 10% of the damping constant was added to the first seismic isolation bearing 150 (first seismic isolation layer 52) of the main frame portion 120, and the remaining amount was added to the second seismic isolation bearing 160 (second seismic isolation layer 54) of the core portion 110. The rigidity of the second seismic isolation bearing 160 (second seismic isolation layer 54) of the core portion 110 was set to an extremely small value.

[0054] 5 shows the acceleration transfer function (top absolute acceleration / ground acceleration) and the displacement transfer function (deformation of seismic isolation layer / ground displacement) in the analytical model of the comparative example and the analytical model to which the building structure 100 is applied. It also shows the results of analysis in the cases of damping constants of 20% (h=20%), 40% (h=40%), and 60% (h=60%).

[0055] The damping coefficient of the main frame section 120 can be calculated for each story by the following formula using the damping constant h of the main frame section 120 itself excluding the first damping device 152.

[0056] ci=2hki / ω ci: Attenuation coefficient of the i layer h: Damping constant of the main structure (h=1.5% in this example) ki: stiffness of the i-th story of the main frame ω: Primary circular frequency of the main structure (2π / T (T is the natural period when the foundation is fixed)) i: Main frame floor

[0057] The damping coefficient of the first damping device 152 installed in the first seismic isolation layer 52 can be calculated using the following formula. In this study, the same value as the damping coefficient calculated for the comparative example is also given to the analysis model of the seismic isolation structure 10.

[0058] c=2hk / ω k: Stiffness of the seismic isolation layer ω: Primary circular frequency of the seismic isolation structure (period when the superstructure is assumed to be one mass point)

[0059] The aforementioned "damping coefficient equivalent to 10% of the damping constant" is a value calculated using the above formula with h = 0.1, and this value is added to the first damping device 152 of the first seismic isolation layer 52 of the main frame portion 120. In addition, when the overall damping constant h is 60%,

[0060] h=0.6-0.1 =0.5

[0061] This damping constant h adds a damping coefficient of 50% to the second damping device 162 of the second seismic isolation layer 54 of the core portion 110.

[0062] As can be seen from Figure 5, the analytical model of the comparative example and the analytical model of the seismic isolation structure 10 to which the building structure 100 is applied are given the same damping coefficient, so the damping constant of the analytical model of the seismic isolation structure 10 is smaller than that of the analytical model of the comparative example.

[0063] Therefore, at h=20%, the peaks of the first mode in both the acceleration transfer function and the displacement transfer function of the analytical model of the seismic isolation structure 10 are slightly larger.

[0064] However, since the amount of deformation input to the second damping device 162 is larger in the analytical model of the seismic isolation structure 10 than in the analytical model of the comparative example, the effect is enhanced, and at h=40% and h=60%, the primary peaks of both the acceleration transfer function and the displacement transfer function are smaller than those in the analytical model.

[0065] In the analysis model of the comparative example, the secondary peak of the acceleration transfer function tends to increase with an increase in the damping constant h. In contrast, in the analysis model of the base-isolated structure 10, the degree of increase in the secondary peak of the acceleration transfer function due to an increase in the damping constant h is suppressed, and the amplitude in the frequency band around the secondary peak is smaller than that of the comparative example.

[0066] Furthermore, the displacement transfer function of the analysis model to which the seismic isolation structure 10 of this embodiment is applied increases in the high frequency band, but a separately performed earthquake response analysis has confirmed that the deformation of the first seismic isolation layer 52 of the main frame section 120 does not increase, and that the displacement response reduction effect is greater than that of the analysis model of the comparative example.

[0067] [Variations] Next, modified examples of this embodiment will be described. Note that, in the drawings of each modified example, hatching indicating a cross section is omitted in order to avoid the drawings becoming complicated.

[0068] (First Modification) The seismic isolation structure 11 to which the first modified building structure 101 shown in Figure 6 is applied is composed of a building main body 31 as an example of an upper structure and a seismic isolation pit portion 20 as an example of a lower structure, and is a structure with a base isolation structure having a seismic isolation layer 50 composed of a first seismic isolation layer 52 and a second seismic isolation layer 54 between the building main body 31 and the base 22 of the seismic isolation pit portion 20.

[0069] The building main body 31 is configured to have a main frame section 121 as an example of a first building section, and a core section 111 as an example of a second building section. The core section 111 has greater horizontal rigidity than the main frame section 121, but is not limited to this. The main frame section 121 has a void section 122 provided in the center of the lower part of the building. The core section 111 is constructed within the void section 122 with a distance L between it and the main frame section 121, and the middle section 113 is rigidly joined to an upper end 124 of the void section 122.

[0070] Furthermore, the core portion 111 is constructed up to the uppermost story of the main frame portion 121, and is rigidly joined to the main frame portion 121 from the upper end 124 to the uppermost story. In other words, the core portion 111 is rigidly joined to the main frame portion 121 from the middle portion 113 to the upper end portion 114.

[0071] In addition, the core portion 111 may be connected to the main frame portion 121 by an expansion joint or the like, other than between the intermediate portion 113 and the upper end portion 114.

[0072] In the present modified example, the core portion 111 of the seismic isolation structure 11 is joined to a node FA that coincides or nearly coincides with a node F2 of the secondary mode of the natural vibration mode of the main frame portion 121. Moreover, the core portion 111 has a rigidity such that the deformation of the second seismic isolation layer 54 of the core portion 111 in the secondary mode is zero or nearly zero.

[0073] Therefore, it is possible to reduce the acceleration response of the main frame portion 121 while suppressing excessive deformation of the seismic isolation layer 50 during an earthquake, particularly a major earthquake.

[0074] Moreover, the core portion 111 is rigidly joined to the main frame portion 121 from the middle portion 113 to the upper end portion 114. This suppresses displacement of the core portion 111, and makes it possible to narrow the distance L between the main frame portion 121 and the core portion 111 in the void portion 122.

[0075] (Second Modification) The seismic isolation structure 12 to which the second modified building structure 102 shown in Figure 7 is applied is composed of a building main body 32 as an example of an upper structure and a seismic isolation pit portion 20 as an example of a lower structure, and is a structure with a base isolation structure having a seismic isolation layer 50 composed of a first seismic isolation layer 52 and a second seismic isolation layer 54 between the building main body 32 and the base 22 of the seismic isolation pit portion 20.

[0076] In the building main body 32, a truss structure 190 is provided on an upper end 124 of the open space 122 in the main frame section 123. An upper end section 112 of the core section 110 is rigidly joined to the truss structure 190.

[0077] In the present modified example, the core portion 110 of the seismic isolation structure 12 is joined to a node FA that coincides or nearly coincides with a node F2 of the secondary mode of the natural vibration mode of the main frame portion 123. Moreover, the core portion 110 has a rigidity such that the deformation of the second seismic isolation layer 54 of the core portion 110 in the secondary mode is zero or nearly zero.

[0078] Therefore, it is possible to reduce the acceleration response of the main frame portion 123 while suppressing excessive deformation of the seismic isolation layer 50 during an earthquake, particularly a major earthquake.

[0079] Moreover, the upper end of the core section 110 is rigidly joined to a truss structure 190 provided on the main frame section 123. This suppresses displacement of the core section 110, and makes it possible to narrow the distance L between the main frame section 123 and the core section 110 in the void section 122.

[0080] (Third Modification) The seismic isolation structure 13 to which the third modified building structure 103 shown in Figure 8 (B) is applied is composed of a building main body 33 as an example of an upper structure and a seismic isolation pit portion 20 as an example of a lower structure, and is a structure with a base isolation structure having a seismic isolation layer 50 composed of a first seismic isolation layer 52 and a second seismic isolation layer 54 between the building main body 33 and the base 22 of the seismic isolation pit portion 20.

[0081] The building main body 33 is configured to have a main frame section 220 as an example of a first building section, and a core section 210 as an example of a second building section. The core section 210 has greater horizontal rigidity than the main frame section 220, but is not limited to this. The main frame section 220 has a void section 222 in the center of the lower part of the building. The core section 210 is constructed with a gap L between it and the main frame section 220 within the void section 222, and an upper end section 212 is rigidly joined to an upper end 224 of the void section 222.

[0082] In addition, the core portion 210 may be connected to the main frame portion 220 at a portion other than the upper end portion 212 by an expansion joint or the like.

[0083] An upper end 224 of the void section 222 is a node FB that coincides or approximately coincides with the position of a node F3 (see FIG. 8(A)) in the tertiary mode of the natural vibration mode of the main frame section 220. Therefore, the core section 210 is rigidly joined to the main frame section 220 at the node FB that coincides or approximately coincides with the node F3 in the tertiary mode.

[0084] In this modification, the seismic isolation structure 13 has the core portion 210 joined to a node portion FB that coincides or substantially coincides with a node F3 of the tertiary mode of the natural vibration mode of the main frame portion 220. The core portion 210 has a rigidity such that the deformation of the second seismic isolation layer 54 of the core portion 210 in the tertiary mode is zero or substantially zero.

[0085] Therefore, it is possible to reduce the acceleration response of the main frame section 220 while suppressing excessive deformation of the seismic isolation layer 50 during an earthquake, particularly a major earthquake.

[0086] In addition, since the core portion 210 is rigidly joined to the node FB that coincides or approximately coincides with the node F3 of the third mode of the main frame portion 220, the stiffness of the core portion 210 is reduced. Therefore, it is easy to increase the horizontal stiffness of the core portion 210.

[0087] (Fourth Modification) The seismic isolation structure 14 to which the fourth modified building structure 104 shown in Figure 11 (B) is applied is composed of a building main body 34 as an example of an upper structure and a seismic isolation pit portion 20 as an example of a lower structure, and is a structure with a base isolation structure having a seismic isolation layer 50 composed of a first seismic isolation layer 52 and a second seismic isolation layer 54 between the building main body 34 and the base 22 of the seismic isolation pit portion 20.

[0088] The building main body 34 is configured to have a main frame section 240 as an example of a first building section, and a core section 230 as an example of a second building section. The core section 230 has greater horizontal rigidity than the main frame section 220, but is not limited to this. The main frame section 240 has a recess 242 in the lower part of the building (see also FIG. 11(A)). The core section 230 is constructed within the recess 242 with a distance L between it and the main frame section 220, and the upper end section 232 is rigidly joined to the upper end 244 of the recess 242.

[0089] In addition, the core portion 230 may be connected to the main frame portion 240 at a portion other than the upper end portion 232 by an expansion joint or the like.

[0090] An upper end 244 of the recess 242 is a node FA that coincides or approximately coincides with the position of a node F2 in the secondary mode of the natural vibration mode of the main frame portion 240. Therefore, the core portion 230 is rigidly joined to the main frame portion 240 at the node FA that coincides or approximately coincides with the node F2 in the secondary mode.

[0091] In this modification, the core portion 230 of the seismic isolation structure 14 is joined to a node FA that coincides or nearly coincides with a node F2 of the secondary mode of the natural vibration mode of the main frame portion 240. The core portion 230 has a rigidity such that the deformation of the second seismic isolation layer 54 of the core portion 230 in the secondary mode is zero or nearly zero.

[0092] Therefore, it is possible to reduce the acceleration response of the main frame section 240 while suppressing excessive deformation of the seismic isolation layer 50 during an earthquake, particularly a major earthquake.

[0093] (Fifth Modification) The seismic isolation structure 15 to which the building structure 105 of the fifth modified example shown in Figure 12 (B) is applied is composed of a building main body 35 as an example of an upper structure and a seismic isolation pit portion 20 as an example of a lower structure, and is a structure with a base isolation structure having a seismic isolation layer 50 composed of a first seismic isolation layer 52 and a second seismic isolation layer 54 between the building main body 35 and the base 22 of the seismic isolation pit portion 20.

[0094] The building main body 35 is configured to have a high-rise section 260 as an example of a first building section, and a low-rise section 250 as an example of a second building section. The low-rise section 250 has greater horizontal rigidity than the high-rise section 260, but is not limited to this. The low-rise section 250 is set back relative to the high-rise section 260 and constructed with a distance L therebetween (see also FIG. 12(A)), and a protruding section 254 protruding from an upper end section 252 is rigidly joined to a joint section 262 of the high-rise section 260.

[0095] In addition, the low-rise section 250 may be connected to the high-rise section 260 by an expansion joint or the like at a point other than the protruding section 254.

[0096] The joint 262 of the high rise section 260 is a node FA that coincides or approximately coincides with the position of a node F2 in the secondary mode of the natural vibration mode of the high rise section 260. Therefore, the low rise section 250 has a structure in which it is rigidly joined to the high rise section 260 at the node FA that coincides or approximately coincides with the node F2 of the secondary mode.

[0097] In this modification, the seismic isolation structure 15 has the low-rise section 250 joined to a node FA that coincides or nearly coincides with a node F2 of the secondary mode of the natural vibration mode of the high-rise section 260. The low-rise section 250 has a rigidity such that the deformation of the second seismic isolation layer 54 of the low-rise section 250 in the secondary mode is zero or nearly zero.

[0098] Therefore, it is possible to reduce the acceleration response of the upper section 260 while suppressing excessive deformation of the seismic isolation layer 50 during an earthquake, particularly a major earthquake.

[0099] In addition, the building main body 35 in this modified example is composed of a main frame section and a core section having greater horizontal rigidity than the main frame section, and the core section may be constructed by being set back from the main frame section.

[0100] Second Embodiment Next, a seismic isolation structure to which the building structure of the second embodiment is applied will be described. The same members as those in the first embodiment are given the same reference numerals, and duplicated descriptions will be omitted or simplified. In addition, in each drawing of the second embodiment and its modified example, hatching showing a cross section is omitted to avoid the drawings becoming complicated.

[0101] [structure] First, the structure of the seismic isolation structure will be described.

[0102] As shown in Fig. 9(B), a structure 16 to which a building structure 300 of this embodiment is applied has a first building portion 320, a second building portion 310, and a seismic isolation pit portion 20. The first building portion 320 is a base isolation structure having a seismic isolation layer 55 between itself and the base slab 22 of the seismic isolation pit portion 20. The first building portion 320 also has a void portion 322 provided in the center of the lower part of the building.

[0103] The second building section 310 is constructed in an open void 322 with a distance L therebetween from the first building section 320. The second building section 310 is a non-earthquake-isolated building constructed on a base 22. An upper end 312 of the second building section 310 is connected to an upper end 324 of the open void 322 via a second damping device 162.

[0104] An upper end 324 of the open void section 322 is a node FA that coincides or approximately coincides with the position of node F2 (see FIG. 9(A)) in the secondary mode of the natural vibration mode of the first building section 320. Therefore, the first building section 320 is connected to the second building section 310 via the second damping device 162 at the node FA that coincides or approximately coincides with node F2 in the secondary mode.

[0105] In this embodiment, a second seismic isolation bearing 160 is provided between the upper end 312 of the second building section 310 and the upper end 324 of the open void section 322. However, the second seismic isolation bearing 160 does not necessarily have to be provided.

[0106] In addition, the second building portion 310 may be connected to the first building portion 320 by an expansion joint or the like.

[0107] The second damping device 162 provided at the connection portion between the joint FA of the first building section 320 of the structure 16 and the second building section 310 has higher damping performance than the first damping device 152, but is not limited to this.

[0108] The second building section 310 has a rigidity at its joint with the first building section 320 such that the relative displacement between the first building section 320 and the second building section 310 in the secondary mode is zero or approximately zero. In addition, the second damping device 162 has a higher damping performance than the first damping device 152.

[0109] [Action and Effects] Next, the operation and effects of this embodiment will be described.

[0110] The second building section 310 is joined via the second damping device 162 to a node FA that coincides or nearly coincides with a node F2 of the second mode of the natural vibration mode of the first building section 320 of the structure 16 to which the building structure 300 is applied. Moreover, the second building section 310 has a rigidity at the joint with the first building section 320 such that the relative displacement between the first building section 320 and the second building section 310 in the second mode is zero or nearly zero. Therefore, in the movement due to the second mode during an earthquake, almost no relative displacement occurs between the first building section 320 and the second building section 310, so the deformation or velocity input to the second damping device 162 is zero or nearly zero, and the damping force is also zero or nearly zero.

[0111] As a result, the second damping device 162 provides high damping for the primary mode to suppress deformation of the seismic isolation layer 55, and prevents overdamping for the secondary mode, increasing the displacement of the first building section 320 and reducing the response acceleration. Therefore, it is possible to reduce the acceleration response of the first building section 320 while suppressing excessive deformation of the seismic isolation layer 55 during an earthquake, particularly a major earthquake.

[0112] Furthermore, since the second damping device 162 has a higher damping performance than the first damping device 152 , the second damping device 162 provides higher damping for the primary mode of the main frame section 120 and suppresses deformation of the seismic isolation layer 55 .

[0113] [Variations] Next, a modification of this embodiment will be described.

[0114] The structure 17 to which the modified building structure 302 shown in Fig. 10(B) is applied includes a seismic isolation pit portion 20, a first building portion 321, and a second building portion 311. The first building portion 321 is a building with a base isolation structure that includes a seismic isolation layer 56 between the first building portion 321 and the base plate 22 of the seismic isolation pit portion 20.

[0115] The second building portion 311 is constructed adjacent to the first building portion 321 with a distance L therebetween. The second building portion 311 is a non-earthquake-isolated building constructed on a base plate 22. An upper end portion 313 of the second building portion 311 is connected to the first building portion 321 via a second damping device 162.

[0116] The portion of the first building part 321 that is connected to the second building part 311 via the second damping device 162 is a node part FA that coincides or approximately coincides with the position of node F2 (see Figure 10 (A)) in the secondary mode of the natural vibration mode of the first building part 321.

[0117] In addition, the second building portion 311 may be connected to the first building portion 321 by an expansion joint or the like.

[0118] The second building portion 311 has a rigidity at its joint with the first building portion 321 such that the relative displacement between the first building portion 321 and the second building portion 311 in the secondary mode is zero or substantially zero.

[0119] Therefore, the second damping device 162 provides high damping for the primary mode to suppress deformation of the seismic isolation layer 56, and prevents overdamping for the secondary mode to increase the displacement of the first building section 321 and reduce the response acceleration. Therefore, it is possible to reduce the acceleration response of the first building section 321 while suppressing excessive deformation of the seismic isolation layer 56 during an earthquake, particularly a massive earthquake.

[0120] <Other> The present invention is not limited to the above embodiment.

[0121] For example, in the above embodiment and modified example, the second building section (core sections 110, 111, 210, 230, low-rise section 250, second building sections 310, 311) is connected to nodes FA and FB that coincide or nearly coincide with node F2 of the second mode or node F3 of the third mode of the natural vibration mode of the first building section (main frame sections 120, 121, 123, 220, 240, high-rise section 260, first building section 320, 321) via rigid joints or second damping device 162, but this is not limited to this. A similar structure may be used for the fourth or higher order modes of the natural vibration mode of the first building section.

[0122] Also, for example, in the above first embodiment and its modified examples, the second building section (core sections 110, 111, 210, 230, low-rise section 250) was supported by the second seismic isolation bearing 160, but this is not limited to this and the configuration may not include the second seismic isolation bearing 160.

[0123] Furthermore, for example, in the above first embodiment and its modified examples, the first building section (main frame sections 120, 121, 123, 210, 220) and the second building section (core sections 110, 111, 210) were both of foundation seismic isolation structure, but this is not limited to this, and the first building section and the second building section may be of intermediate seismic isolation structure, or one of the two may be of foundation seismic isolation structure and the other of the two may be of intermediate seismic isolation structure.

[0124] Also, for example, in the second embodiment and its modified example, the first building portions 320, 321 are of a foundation seismic isolation structure, but this is not limited thereto, and they may be of an intermediate seismic isolation structure.

[0125] Furthermore, the present invention can be embodied in various forms without departing from the spirit and scope of the present invention. A plurality of embodiments and modifications can be implemented in appropriate combination. [Explanation of symbols]

[0126] 50 Seismic isolation layer 55 Seismic isolation layer 56 Seismic isolation layer 100 Building Structure 101 Building Structure 102 Building Structure 103 Building Structure 104 Building Structure 105 Building Structure 110 Core section (example of the second building section) 111 Core section (example of the second building section) 120 Main frame (example of the first building section) 121 Main frame (example of the first building section) 123 Main frame (example of the first building section) 150 First seismic isolation bearing 152 First damping device 160 Second seismic isolation bearing 162 Second damping device 210 Core (an example of the second building) 220 Main frame (example of the first building section) 230 Core (an example of the second building) 240 Main frame (example of the first building section) 250 Lower floors (example of the second building) 260 High-rise section (example of the first building section) 300 Building Structure 302 Building Structure 310 Second Building Section 311 Second Building Section 320 First Building 321 First Building Section

Claims

1. A first building part of a seismic isolation structure constructed on a first seismic isolation layer constituted by a first seismic isolation bearing and a first damping device installed in a substructure, A second building part of a seismic isolation structure constructed at a distance from the first building part on a second seismic isolation layer constituted by installing a second seismic isolation bearing and a second damping device on the lower structure; Equipped with The rigidity of the second seismic isolation bearing is set to approximately 0, The second building section is rigidly connected to a node section which is a node of a higher mode of a natural vibration mode of the first building section, The horizontal rigidity of the second building section is set so that the horizontal deformation amount of the second seismic isolation layer in the higher mode is 0 or approximately 0. Building structure.

2. The second seismic isolation bearing is a sliding bearing, The second damping device has a higher damping performance than the first damping device.

2. The building structure of claim 1.

3. A first building part of a seismic isolation structure constructed on a seismic isolation layer constituted by a first seismic isolation bearing and a first damping device installed in a substructure, A second building section of a non-seismic isolation structure rigidly connected to the lower structure and constructed at a distance from the first building section; Equipped with The second building section has an upper end connected to a node section that is a node of a higher mode of a natural vibration mode of the first building section by a second damping device, The horizontal rigidity of the second building section is set so that the horizontal displacement of the second building section in the higher mode is 0 or approximately 0 from the lower end to the upper end of the second building section. Building structure.

4. The second damping device has a higher damping performance than the first damping device.

4. The building structure of claim 3.

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