Vibration damping system

Abstract

To provide a vibration control system capable of eliminating the deterioration of the vibration control effect of a BMD caused by the operation limit of an elevator and exhibiting the vibration control effect higher than before.SOLUTION: The non-core portion 22 has a soft layer portion 31 located in a middle portion in a height direction of the high-rise building 2, a lower layer portion 4 located below the soft layer portion 31, and an upper layer portion 5 located above the soft layer portion 31, and the core portion 21 is connected to the lower layer portion 4 and is provided up to a height reaching the upper layer portion 5. The soft layer part 31 has a horizontal rigidity smaller than those of the lower layer part 4 and the upper layer part 5, connects the lower layer part 4 and the upper layer part 5 so as to be relatively movable in the horizontal direction, and is configured so that a vibration period of a region combining the soft layer part 31 and the upper layer part 5 and a vibration period of a region combining the lower layer part 4 and the core part 21 are synchronized with each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vibration damping system. [Background technology]

[0002] A known vibration control system constructed in high-rise buildings is the Building Mass Damper (BMD), which provides a soft layer in the middle layer that has lower horizontal rigidity than the other layers, and reduces vibration by synchronizing the vibration period of the entire layer located above the layer on which the soft layer is constructed with the vibration period of the entire layer located below the layer on which the soft layer is constructed (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-163678 [Patent Document 2] Japanese Patent Application Publication No. 2023-009484 Summary of the Invention [Problem to be solved by the invention]

[0004] When a vibration control system like the one described above is installed in a high-rise building, elevators that pass through the soft floors are restricted in their operation due to their displacement. Therefore, to reduce the restriction on elevator operation, the stiffness or damping of the soft floors must be increased, which results in a problem of impairing the vibration control effect of the vibration control system.

[0005] Therefore, an object of the present invention is to provide a vibration control system that can eliminate the reduction in the vibration control effect of BMD caused by elevator operation restrictions and can exert a higher vibration control effect than conventional systems. [Means for solving the problem]

[0006] In order to achieve the above object, a vibration control system according to the present invention is provided in a high-rise building, The structure has a core portion and a non-core portion adjacent to the core portion, and the non-core portion has a soft layer portion located in the middle of the structural building in the height direction, a lower layer portion located below the soft layer portion, and an upper layer portion located above the soft layer portion, and the core portion is connected to the lower layer portion and is provided at a height reaching the upper layer portion, and the soft layer portion has lower horizontal rigidity than the lower layer portion and the upper layer portion, and connects the lower layer portion and the upper layer portion so that they can move relative to each other in the horizontal direction, and is configured so that the vibration period of the area combining the soft layer portion and the upper layer portion is synchronized with the vibration period of the area combining the lower layer portion and the core portion.

[0007] In the present invention, the flexible section connects the lower and upper sections to allow relative horizontal displacement, and the vibration period of the area where the flexible section and upper section are combined is synchronized with the vibration period of the area where the lower section and core section are combined. This allows a high-rise building to form a vibration system in which the area where the flexible section and upper section are combined and the area where the lower section and core section are combined cancel each other out when vibrations caused by earthquakes or wind occur, allowing part of the high-rise building to be used as a mass damper. Since the flexible section is located in the non-core section and not in the core section, large displacement of the core section at its intermediate section in the height direction can be prevented. Therefore, by providing an elevator in the core section, the frame does not require a seismic isolation elevator, and the deformation restrictions of the flexible section are relaxed, thereby optimizing the stiffness and damping of the flexible section and further enhancing the vibration control effect of conventional BMDs, demonstrating particularly high vibration control effectiveness against small and medium-sized earthquakes.

[0008] In the vibration control system according to the present invention, an upper side of the upper layer portion may be connected to the core portion. In the vibration control system according to the present invention, the upper side of the upper layer and the core may be connected via a stiffness / damping element.

[0009] With this configuration, relative displacement between the upper layer portion and the core portion can be suppressed. [Effects of the Invention]

[0010] According to the present invention, the reduction in the vibration damping effect of the BMD caused by elevator operation restrictions can be eliminated, and a higher vibration damping effect than conventional can be achieved. [Brief explanation of the drawings]

[0011] [Figure 1] (a) is a diagram showing an example of a high-rise building in which a vibration control system (without connection) according to an embodiment is adopted, (b) is a diagram showing an example of a high-rise building in which a vibration control system (with connection) according to an embodiment is adopted, and (c) is a diagram showing an example of a high-rise building in which a conventional vibration control system is adopted. [Figure 2] 10 is a graph showing the acceleration response magnification curve of the lower part of the soft layer. [Figure 3] 10 is a graph showing a response ratio curve at the time of optimum stiffness and optimum damping. [Figure 4] FIG. 1 is a diagram showing a vibration model of a Tuned Mass Damper (TMD), which is a device that suppresses vibration of an object by adding an auxiliary mass to the object and tuning to the vibration of the object. [Figure 5] 1A is a diagram showing a multi-mass system model, and FIG. 1B is a diagram showing a first-order contracted mass system model. [Figure 6] FIG. 10 is a diagram showing fixed vectors of a two-mass system. [Figure 7] 10 is a graph showing the results of earthquake response analysis (notified wave Kobe phase L2). [Figure 8] 1 is a graph showing the results of earthquake response analysis (KA1 wave). DETAILED DESCRIPTION OF THE INVENTION

[0012] A vibration damping system according to an embodiment of the present invention will be described below with reference to FIGS. As shown in Figures 1(a) and 1(b), the vibration control system 1 according to this embodiment is employed in a high-rise building 2. In this embodiment, the high-rise building 2 also includes a super high-rise building and an ultra-high-rise building. The high-rise building 2 has a core portion 21 and a non-core portion 22. In a plan view in the vertical direction, the non-core portion 22 is arranged to surround the outer periphery of the core portion 21. Figure 1(a) shows a high-rise building 2A that employs a vibration control system 1A in which the core section 21 and non-core section 22 are not connected. Figure 1(b) shows a high-rise building 2B that employs a vibration control system 1B in which the core section 21 and non-core section 22 are connected at the top floor. Both of the above vibration control systems 1A and 1B are vibration control systems according to embodiments of the present invention.

[0013] The non-core portion 22 is provided across the entire vertical length of the high-rise building 2. The non-core portion 22 has a middle floor portion 3, a lower floor portion 4, and an upper floor portion 5. The middle floor portion 3 is a series of multiple floors (story) located in the middle portion of the high-rise building 2 in the height direction. The lower floor portion 4 is a floor (story) lower than the middle floor portion 3 in the high-rise building 2. The upper floor portion 5 is a floor (story) higher than the middle floor portion 3 in the high-rise building 2. The core portion 21 is provided across the entire vertical length of the high-rise building 2. An elevator 6 that is not a seismic isolation elevator is provided in the core portion 21. 1(c) shows a high-rise building 102 that employs a conventional vibration control system 101. The conventional vibration control system 101 does not have a core part, but instead has a seismic isolation elevator 106.

[0014] Returning to Figures 1(a) and (b), the intermediate layer 3 connects the lower layer 4 and the upper layer 5. The intermediate layer 3 is not joined to the core 21. The intermediate layer 3 and the core 21 are capable of relative displacement. The lower layer 4 is joined to the core 21. The lower layer 4 and the core 21 are not capable of relative displacement. The upper layer 5 is joined to the core 21 by an expansion joint. The upper layer 5 and the core 21 are capable of relative displacement within the range of displacement of the expansion joint. In the vibration control system 1A shown in Fig. 1(a), the upper floor 5 and the top floor of the core part 21 are not connected. In the vibration control system 1B shown in Fig. 1(b), the upper floor 5 and the top floor of the core part 21 are connected via a slab 7 or the like, and relative displacement between the upper floor 5 and the core part 21 that is greater than or equal to a predetermined value is restrained.

[0015] The middle floor 3 is set to a flexible floor 31 that has lower horizontal rigidity than the lower floor 4 and upper floor 5. The vibration periods of the lower floor 4 and core 21 in the high-rise building 2 are configured to be in sync with the vibration periods of the flexible floor 31 (middle floor 3) and upper floor 5. In the vibration control system 1 according to this embodiment, by making the middle floor 3 a flexible floor 31 that has lower horizontal rigidity than the lower floor 4 and upper floor 5, a vibration system is formed in which the lower floor 4 and upper floor 5 are in sync. In the vibration control system 1, the upper floor 5 of the high-rise building 2 is used as a mass damper to tune with the lower floor 4 and core 21.

[0016] The soft layer portion 31 is softened so that its horizontal rigidity is smaller than that of the upper layer portion 5 and the lower layer portion 4, for example, by the following methods (a) to (c). (a) The soft layer 31 is constructed with a seismic isolation device. (b) The floor height of each floor of the soft floor section 31 (middle floor section 3) is made greater than the floor height of each floor of the upper floor section 5 and the lower floor section 4. (c) At least some of the end joints of the beams and columns on each floor of the soft story 31 are pin joints.

[0017] The horizontal stiffness and damping of the soft layer 31 are set so that the vibration period of the lower layer 4 and core 21 is synchronized with the vibration period of the soft layer 31 (middle layer 3) and upper layer 5. For example, this is set using the "fixed point theory" used in TMD design. In this embodiment, since the core 21 is provided above and below the soft layer 31 (penetrating the soft layer 31), the horizontal stiffness and damping of the soft layer 31 are set using the combined effective mass of the core 21 and lower layer 4 and the effective mass of the upper layer 5 using the "fixed point theory."

[0018] Specifically, the horizontal stiffness and damping of the soft layer 31 are calculated using the following procedure. Note that if the lower layer 4 and the upper layer 5 are connected via the core 21, the characteristics of the vibration system will differ accordingly, and adjustments will be necessary to achieve optimal synchronization. Specifically, for example, based on the calculated stiffness and damping, the horizontal stiffness and damping are changed to a certain extent to create an acceleration response magnification curve for the lower part of the soft layer as shown in Figure 2, and the optimum values ​​(stiffness at which two fixed points are at the same height as in Figure 3, and damping at which the response magnification is maximized at a fixed point) are selected. Figure 2 depicts a curve where only the damping magnification is changed, but the stiffness magnification is also changed.

[0019] As shown in Figure 4, in general, when designing a TMD, a two-mass system is constructed by adding the mass of the TMD to a mass point consisting of the primary effective mass of the entire high-rise building 2, and then fixed point theory is applied to determine the period (rigidity) of the TMD. For example, in a pendulum-type TMD, tuning is achieved using the suspension length. In a rail-type TMD or a type where the weight is supported by a bearing, tuning is achieved using the rigidity of a restoring material such as a coil spring or laminated rubber.

[0020] In this embodiment, as shown in Fig. 5(a), the tuned stiffness is achieved by regarding the horizontal stiffness of each layer of the soft layer 31 as a spring connected in series. Furthermore, to find the optimal tuning condition for horizontal stiffness based on fixed point theory, the primary effective mass and primary effective stiffness are found in the region combining the middle layer 3 (soft layer 31) and the upper layer 5, and the primary effective mass and primary effective stiffness are found in the region combining the lower layer 4 and the core 21. A linear contracted two-mass system is constructed as shown in Fig. 5(b) to calculate the effective mass ratio.

[0021] The effective mass ratio of the first-order contracted two-mass system is, first, the first-order effective mass 1M in the area that combines the middle layer 3 and the upper layer 5. U is calculated from the following formula (1), and the primary effective mass 1M B is calculated from the following equation (2). Then, from the following equation (3), the effective mass ratio of the two mass system of linear contraction is 1M U / 1M B Calculate.

[0022]

number

[0023] For this linearly contracted two-mass system, the optimal value is derived in fixed point theory, as with TMD, and the horizontal stiffness of the middle layer 3 (soft layer 31) is determined so that the period of the mass points consisting of the middle layer 3 and upper layer 5, which are converted into mass dampers, satisfies the optimal tuning period. In an actual high-rise building 2, adjustments are made to approach the horizontal rigidity of the determined soft story 31 by adjusting the cross section of the structural members, the end joint conditions, or by adding or omitting earthquake-resistant elements such as braces.

[0024] In other words, the horizontal stiffness to be set for each floor of the soft story 31 should be set to the same period or effective horizontal stiffness as that of the contracted two-mass system that is optimally tuned. However, the specific value must be found by performing eigenvalue analysis multiple times through trial and error. In this embodiment, in order to avoid such a complicated work, it is possible to obtain the design parameters by approximate calculation. An approximate calculation method for determining the horizontal stiffness of the soft layer portion 31 is shown below.

[0025] (Step 1) Assuming the Ai distribution, the horizontal stiffness of the high-rise building 2 is determined by determining the number of stories in the upper floor 5 and the middle floor 3 (soft floor 31), and the primary effective mass of the area combining the middle floor 3 and the upper floor 5 is calculated using the following equation (4).

[0026]

number

[0027] (Step 2) The primary effective mass of the region including the lower layer portion 4 and the core portion 21 is calculated using the following formula (5).

[0028]

number

[0029] (Step 3) The first-order effective mass ratio is calculated using the following equation (6).

[0030]

number

[0031] (Step 4) The optimum frequency ratio λ is calculated using the following equation (7). opt Ask for.

[0032]

number

[0033] (Step 5) Using the following equation (8), the primary period of the lower layer 4 is 1T B Calculate the following roughly. Here, 1T B indicates the primary period of the entire high-rise building 2, n indicates the total number of stories, and k indicates the number of stories in the lower part 4.

[0034]

number

[0035] (Step 6) Using the following equation (9), the first period of the upper layer 5 is 1T U Calculate the following roughly. Here, β=(h / n)^0.25, and h indicates the number of layers in the upper layer portion 5 (h=nk).

[0036]

number

[0037] (Step 7) Using the following equation (10), the optimal (first-order) effective stiffness 1Ku ,оpt and the optimum (first) period 1Tu of the upper layer 5 is calculated using the following equation (11).,opt Ask for.

[0038]

number

[0039] (Step 8) Using the following equation (12), τ(=1T u / 1T u,opt ) is calculated, and the tuning stiffness coefficient ζ when only the middle layer portion 3 is made soft is calculated using the following equations (13)-(17). The ratio of the eigenvectors of a two-mass system as shown in Figure 6 is defined as r = r2 / r1.

[0040]

number

[0041] (Step 9) The horizontal stiffness of each layer of the intermediate layer 3 is roughly calculated by multiplying each layer of the intermediate layer 3 by the tuning stiffness coefficient ζ of the intermediate layer 3 calculated by equation (17). In this way, the horizontal rigidity of each layer of the soft layer portion 31 (middle layer portion 3) is determined.

[0042] To verify the effectiveness of the vibration control system of this embodiment, a 220-meter-tall, 47-story building was designed with the soft layer between the 31st and 32nd floors, adjusting the soft layer parameters to prevent excessive soft layer and core deformation. An earthquake response analysis was conducted using the L2 earthquake of the Kobe phase of the notified earthquake and KA1 earthquake motion, which simulates the earthquake motion at Shinjuku Station, assuming the Nankai Trough. The Kobe earthquake is a notified earthquake based on Ministry of Construction Notification No. 1461. KA1 contains many long-period components. Figure 7 shows a comparison of the acceleration, story deformation angle, and story shear force of the earthquake response analysis results for the L2 earthquake of the Kobe phase of the notified earthquake. Figure 8 shows a comparison of the acceleration, story deformation angle, and story shear force of the earthquake response analysis results for KA1. Note that the "no connection" in Figures 7 and 8 refers to the case where the core 21 and upper floors 5 are not connected, as in the vibration control system 1A shown in Figure 1(a). "With connection" in Figures 7 and 8 is a case where the core section 21 and the upper section 5 are connected by a slab 7, as in the vibration control system 1B shown in Figure 1(b). "Conventional BMD" in Figures 7 and 8 is a case where the conventional vibration control system 101 shown in Figure 3(c) is used.

[0043] Focusing on the acceleration, story drift angle, and story shear force when inputting the L2 earthquake wave phase (notified Kobe earthquake phase) shown in Figure 7, comparing the conventional BMD and the connected and unconnected models of the vibration control system of the present invention, it can be seen that the vibration control system of the present invention has the same vibration control effect as the conventional BMD for the notified Kobe earthquake wave phase. Furthermore, focusing on the acceleration, story drift angle, and story shear force when inputting the KA1 earthquake wave phase (notified Kobe earthquake phase) shown in Figure 8, it can be seen that the vibration control system of the present invention significantly reduces seismic response compared to the conventional BMD. This is because the vibration control system of the present invention does not require displacement restrictions in the soft layer, thereby reducing the deviation of the soft layer parameters from their optimal values, thereby improving the vibration control effect of the vibration control system.

[0044] On the other hand, when comparing the results of the vibration control system without coupling with the results of the vibration control system with coupling in Figures 7 and 8, it can be said that the vibration control system without coupling is able to reduce the response by about 10%, but this is not a significant difference. As a result, by providing an elevator in the core section of the vibration control system of this invention, a seismic isolation elevator is no longer necessary, and it is possible to bring the stiffness and damping of the soft layer closer to the optimum values ​​and further improve the vibration control effect of conventional BMD.

[0045] Next, the operation and effect of the vibration control system according to this embodiment will be described. In the vibration control system 1 according to this embodiment, the flexible layer 31 connects the lower layer 4 and the upper layer 5 so that they can be displaced relative to each other in the horizontal direction. The vibration period of the area including the flexible layer 31 and the upper layer 5 is synchronized with the vibration period of the area including the lower layer 4 and the core layer 21. This allows a high-rise building 2 to form a vibration system in which the area including the flexible layer 31 and the upper layer 5 and the area including the lower layer 4 and the core layer 21 cancel each other out when vibrations caused by earthquakes or wind occur. This allows a portion of the high-rise building 2 to be used as a mass damper. The flexible layer 31 is provided in the non-core layer 22, but not in the core layer 21, preventing large displacement of the core layer 21 in the middle of its height. Therefore, by providing the elevator 6 in the core layer 21, the frame does not require a seismic isolation elevator. This optimizes the stiffness and damping of the flexible layer 31, further enhancing the vibration control effect of conventional BMDs. By providing the core portion 21, the deformation restriction of the soft layer portion 31 is relaxed, so that a higher vibration control effect can be achieved, especially for small and medium-sized earthquakes, than conventional BMD.

[0046] In the vibration control system 1, the upper side of the upper layer 5 is connected to the core portion 21, so that the relative displacement between the upper layer 5 and the core portion 21 can be suppressed.

[0047] Although the embodiment of the vibration control system according to the present invention has been described above, the present invention is not limited to the above embodiment and can be modified as appropriate within the scope of the invention. For example, the upper side of the upper floor 5 and the core part 21 do not have to be connected by a slab 7. When the upper floor 5 and the core part 21 are connected, the position and number of connections may be set appropriately. For example, the upper floor 5 and the core part 21 may be connected by a slab 7 on each floor. The upper floor 5 and the core part 21 may also be connected by a member instead of the slab 7.

[0048] The upper floor 5 and the core part 21 may be connected via stiffness / damping elements such as springs and dampers. Such a configuration can suppress relative displacement between the upper floor 5 and the core part 21. When the upper floor 5 and the core part 21 are connected via damping elements, the installation locations and number of the damping elements may be set appropriately. For example, a damping element may be provided between the upper floor 5 and the core part 21 on each floor. The damping element between the upper floor 5 and the core part 21 may be provided whether the upper floor 5 and the core part 21 are connected by a slab 7 or not.

[0049] The soft layer portion 31 may be composed of one floor or multiple floors.

[0050] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The vibration control system according to this embodiment can contribute to achieving one of the 17 SDGs, such as goal 9, "Create indispensable infrastructure for industry, innovation and sustainable development." [Explanation of symbols]

[0051] 1. Vibration control system 2 High-rise buildings 3. Middle Class 4 Lower part 5. Upper Management 6. Elevator 7. Slab 21 Core 22 Non-core section 31 Soft layer part

Claims

1. Installed in high-rise buildings, A core portion, a non-core portion provided adjacent to the core portion, The non-core portion includes a soft layer portion located in the middle of the height direction of the high-rise building, A lower layer portion located below the soft layer portion; An upper layer portion located above the soft layer portion, the core portion is connected to the lower layer portion and is provided to a height reaching the upper layer portion, The soft layer portion has lower horizontal rigidity than the lower layer portion and the upper layer portion, and connects the lower layer portion and the upper layer portion so that they can move relatively in the horizontal direction; A vibration control system configured so that the vibration period of the region combining the soft layer portion and the upper layer portion is synchronized with the vibration period of the region combining the lower layer portion and the core portion.

2. The vibration control system according to claim 1 , wherein an upper side of the upper layer portion is connected to the core portion.

3. 3. The vibration control system according to claim 2, wherein the upper side of the upper layer and the core are connected via a stiffening and damping element.

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