Vibration control structure and design method of vibration control structure

Abstract

To provide a vibration control structure capable of improving a vibration control function, and a design method of the vibration control structure.SOLUTION: A vibration control structure includes: a structure provided above a surface layer ground of a predetermined range to be a vibration control object; and a connection part connecting the structure and the surface layer ground. The connection part has a rigidity function and a damping function based on a mass of the surface layer ground between the structure and the surface layer ground so that the structure acts as a mass body to control vibration of the surface layer ground.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vibration-damping structure and a method for designing a vibration-damping structure. [Background technology]

[0002] Conventionally, for example, Patent Document 1 discloses a vibration control structure in which a first building and a second building built on the surface ground are connected by a connecting part, and a vibration control damper is provided between the connecting part and the first building. In such a vibration control structure, a vibration control function acts between the first building and the second building built on the surface ground. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-102530 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although such vibration-damping structures attenuate the vibration of the building itself, there is a need to improve the vibration-damping function from a new perspective. [Means for solving the problem]

[0005] A vibration control structure that solves the above problem comprises a structure that is located above a predetermined range of surface ground that is the target of vibration control, and a connection part that connects the structure to the surface ground, and the connection part has a rigidity function and a damping function based on the mass of the surface ground between the structure and the surface ground so that the structure acts as a mass body that controls the vibration of the surface ground.

[0006] A design method for a vibration-control structure that solves the above-mentioned problems includes estimating the mass of a predetermined range of surface ground that is the target of vibration control, and determining the mass of a structure located above the surface ground, and the stiffness function and damping function of a connection part connecting the structure and the surface ground, based on the mass of the surface ground, so that the structure acts as a mass body that controls the vibration of the surface ground. [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the vibration damping function. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing a vibration damping system according to a first embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing the function of the vibration damping structure of the first embodiment. [Figure 3] FIG. 3 is a flowchart showing the vibration damping structure design process of the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing the relationship between the frequency of vibration to the surface ground and the response magnification in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] An embodiment of a vibration-damping structure and a method for designing a vibration-damping structure will be described. <Vibration Control Structure 10> As shown in Fig. 1, the vibration control structure 10 is installed on a surface ground 91. The surface ground 91 is a layer of ground deposited near the ground surface 91A. The surface ground 91 is a layer of ground located above an engineering ground 92.

[0010] The engineering ground 92 is good ground that serves as the basis for earthquake motion design. The engineering ground 92 may be ground with an S-wave velocity of 300 to 700 m / s, for example. The engineering ground 92 is also called an engineering bedrock.

[0011] The surface ground 91 is softer than the engineering ground 92. Therefore, the surface ground 91 is subject to greater vibrations due to earthquakes than the engineering ground 92. The surface ground 91 may be ground that is within 30 m deep from the earth's surface and has an S-wave velocity of, for example, 100 m / s or more and less than 300 m / s.

[0012] In addition to the vibration control structure 10, a building 93 may be provided on the ground surface 91A of the surface ground 91. Vibrations caused by an earthquake are transmitted to the building 93 from the surface ground 91. The building 93 does not have to be connected to the vibration control structure 10.

[0013] The vibration-damping structure 10 is a structure that improves vibration-damping function. In particular, the vibration-damping structure 10 is a structure that can improve vibration-damping function for a predetermined range of the surface ground 91. The vibration-damping structure 10 may be configured as a mass damper for a predetermined range of the surface ground 91. The vibration-damping structure 10 may be configured as a tuned mass damper for a predetermined range of the surface ground 91. In other words, the vibration-damping structure 10 controls vibrations of the natural frequency for a predetermined range of the surface ground 91.

[0014] The vibration-damping structure 10 may be provided around the building 93. In this way, the vibration-damping structure 10 can attenuate earthquake vibrations transmitted from the surface ground 91 to the building 93 by improving the vibration-damping function for the surface ground 91 itself within a predetermined range.

[0015] The vibration control structure 10 includes a support portion 11 and a structure 12. The support portion 11 is provided on the ground surface 91A. The support portion 11 extends upward from the ground surface 91A. In other words, the support portion 11 extends upward from the surface ground 91. The support portion 11 is configured to support the structure 12. The support portion 11 has a rigidity function in the vertical direction.

[0016] The structure 12 is provided above the surface ground 91, which is the target of vibration control. The structure 12 is supported by the support portion 11. The structure 12 is provided at a position away from the surface ground 91 while being supported by the support portion 11. The structure 12 has a mass that allows the structure 12 to act as a mass body that controls the vibration of the surface ground 91. The mass of the structure 12 that acts as a mass body that controls the vibration of a predetermined range of the surface ground 91 may have a mass ratio to the mass of the surface ground 91 of 0.01 or more and 0.2 or less. The structure 12 may be used as a plaza. The structure 12 may be used as an observation deck.

[0017] The vibration-damping structure 10 includes a connection portion 13. The vibration-damping structure 10 may include multiple connection portions 13. The connection portion 13 is provided on the ground surface 91A. The connection portion 13 extends upward from the ground surface 91A. In other words, the connection portion 13 extends upward from a predetermined range of the surface ground 91. The connection portion 13 is configured to connect the predetermined range of the surface ground 91 and the structure 12. The connection portion 13 may extend upward in a spiral shape. The connection portion 13 may be used as a passage connecting the ground surface 91A and the structure 12.

[0018] The connection part 13 has a stiffness function and a damping function in the horizontal direction between the structure 12 and the surface ground 91. In particular, the connection part 13 has a stiffness function and a damping function between the structure 12 and a predetermined range of the surface ground 91 so that the structure 12 acts as a mass body that damps vibrations of the surface ground 91 in a predetermined range. In addition, the stiffness function and the damping function are determined based on the mass of the surface ground 91.

[0019] <10 Functions of Vibration Control Structure> 1 and 2, the connection portion 13 may include a first connection portion 21 and a second connection portion 22. The connection portion 13 may include a plurality of first connection portions 21 and a plurality of second connection portions 22.

[0020] The first connection portion 21 has a function of providing horizontal rigidity between the structure 12 and a predetermined range of the surface ground 91. The first connection portion 21 may be made of, for example, a steel pipe. The first connection portion 21 may be made of, for example, an iron plate.

[0021] The second connection portion 22 has a damping function in the horizontal direction between the structure 12 and a predetermined range of the surface ground 91. The second connection portion 22 may be configured by using, for example, a damping brace. The damping brace may have a built-in damper.

[0022] <Vibration control structure design process> Next, the vibration control structure design process will be described with reference to FIGS. As shown in FIG. 3, in step S10, a surface ground mass estimation step is performed. The surface ground mass estimation step is a step of estimating the mass of the surface ground 91, which is the target of vibration control. The surface ground mass estimation step is a step of estimating the mass of the surface ground 91 based on the results of a geological survey of the surface ground 91, with the site area on which the vibration control structure 10 is to be constructed, etc., being set as a predetermined area. In particular, the surface ground mass estimation step is a step of estimating the mass of the surface ground 91 in a predetermined area. To give a specific example, the predetermined area may be an area of, for example, 100 m square and 10 m, which is an example of a depth from the ground surface to the engineering ground 92, in addition to the site area on which the vibration control structure 10 is to be constructed. Also, for example, if the surface ground 91 is estimated to have a modulus of 18 kN / m based on the results of a geological survey, 2 In this case, the mass m of the surface ground 91 in a predetermined range b may be calculated as 1,800,000 kN.

[0023] In step S11, a structural material quantity determination step is performed. The structural material quantity determination step is a step of determining the mass of the structure 12. In particular, the structural material quantity determination step is a step of determining the mass of the structure 12 such that the structure 12 acts as a mass body that damps the vibrations of the surface ground 91. Furthermore, the structural material quantity determination step is a step of determining the mass of the structure 12 based on the mass of the surface ground 91.

[0024] The structural material amount determination step may be a step of determining the mass of the structure 12 at a predetermined mass ratio μ compared to the mass of the surface ground 91. As a specific example, the predetermined mass ratio μ may be 0.2. Also, for example, when the predetermined mass ratio μ is 0.2 and the mass m of the surface ground 91 is b is calculated to be 1,800,000 kN, the mass m a is calculated to be 360,000 kN.

[0025] The structural material amount determination step may include a step of determining the size of the structure 12 based on the mass of the structure 12. Furthermore, the structural material amount determination step may comprehensively determine the mass of the structure 12, the size of the structure 12, and the mass of the support portion 11 for supporting the structure 12. As a specific example, the diameter and number of columns of the support portion 11 may be determined based on the mass and size of the structure 12.

[0026] In step S12, a stiffness function determination step is performed. The stiffness function determination step is a step of determining the stiffness function of the connection part 13 based on the mass of the surface ground 91 and the mass of the structure 12. In particular, the stiffness function determination step is a step of determining the stiffness function of the connection part 13 so that the structure 12 acts as a mass body that damps the surface ground 91. In other words, the stiffness function determination step is a step of determining the stiffness function of the connection part 13 based on the mass of the surface ground 91 so that the structure 12 acts as a mass body that damps the surface ground 91.

[0027] For details, mass m of surface ground 91 b and a predetermined mass ratio μ and an angular frequency ω of the surface ground 91. b The stiffness function of the connection part 13 may be determined based on the above. Specifically, the stiffness function of the connection part 13 is determined by the following equation (1): a may be determined. In this case, the stiffness k a may be calculated as 61622500 kN / m.

[0028]

number

[0029] In step S13, a damping function determination step is performed. The damping function determination step is a step of determining the damping function of the connection part 13 based on the mass of the surface ground 91 and the mass of the structure 12. In particular, the damping function determination step is a step of determining the damping function of the connection part 13 so that the structure 12 acts as a mass body that damps the surface ground 91. In other words, the damping function determination step is a step of determining the damping function of the connection part 13 based on the mass of the surface ground 91 so that the structure 12 acts as a mass body that damps the surface ground 91.

[0030] For details, mass m of surface ground 91 b and a predetermined mass ratio μ and an angular frequency ω of the surface ground 91. b The damping function of the connection part 13 may be determined based on the above. Specifically, the optimal damping rate h aopt may be determined, where the decay rate h aopt may be calculated as 0.25. In addition, the optimal damping coefficient c as the damping function of the connecting portion 13 is calculated by Equation 3. a may be determined, where the damping coefficient c a may be calculated as 2355000kN·s / m.

[0031]

number

[0032]

number

[0033] Then, based on the rigidity function of the connection portion 13 determined in the rigidity function determination process and the damping function determined in the damping function determination process, the number and rigidity function of the first connection portions 21 and the number and damping function of the second connection portions 22 are determined.

[0034] In this way, the structural material quantity determination process, stiffness function determination process, and damping function determination process are processes for determining the mass of the structure 12, the stiffness function, and the damping function of the connection part 13 based on the mass of the surface ground 91 so that the structure 12 acts as a mass body that damps the surface ground 91.

[0035] As shown in Figure 4, when the vibration control structure 10 is not installed on the surface ground 91 as in the conventional case, the response magnification increases at the natural frequency transmitted to the surface ground 91, as shown in graph 30. Therefore, as a result of the vibration control structure design process being carried out, when the vibration control structure 10 is installed on the surface ground 91, the increase in the response magnification is suppressed at the natural frequency transmitted to the surface ground 91, as shown in graph 31.

[0036] <Actions and Effects of the First Embodiment> The operation and effects of the embodiment will be described. (1) The connection portion 13 has a stiffness function and a damping function based on the mass of the surface ground 91 between the structure 12 and the surface ground 91 so that the structure 12 acts as a mass body that damps the vibration of the surface ground 91. Therefore, the structure 12 acts as a mass body that damps the vibration of the surface ground 91, thereby improving the damping function for the surface ground 91 itself. Therefore, the damping function can be improved.

[0037] (2) Furthermore, by using a connection part 13 that connects the structure 12 and the surface ground 91, the vibration control function can be improved without significantly affecting the existing building 93, for example, by significantly renovating the existing building 93.

[0038] (3) The first connection portion 21 has a rigidity function between the structure 12 and the surface ground 91. The second connection portion 22 has a damping function between the structure 12 and the surface ground 91. Therefore, the first connection portion 21 can be designed to have a rigidity function, and the second connection portion 22 can be designed to have a damping function. In this way, the first connection portion 21 and the second connection portion 22 can be designed with separate functions, allowing the rigidity function and damping function to function efficiently. Therefore, the vibration control function can be improved.

[0039] (4) The connection part 13 is provided as a passage between the structure 12 and the surface ground 91. This allows access to the structure 12 located above the surface ground 91, enabling effective use of the structure 12. This provides new added value to users of the structure 12.

[0040] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0041] The structure 12 may have a light-transmitting area. This can prevent the structure 12 from blocking sunlight. The structure 12 may be configured to switch a predetermined area between a light-transmitting area and a light-blocking area. This makes it possible to adjust the sunlight conditions.

[0042] The plurality of connecting portions 13 may include connecting portions that have both a stiffening function and a damping function in the horizontal direction. The plurality of connecting portions 13 may also include connecting portions that do not have both a stiffening function and a damping function in the horizontal direction.

[0043] The connecting portion 13 may include a ramp as a passageway. The connecting portion 13 may include a staircase as a passageway. The connecting portion 13 may include an escalator. The vibration-damping structure 10 may have a passage between the structure 12 and the surface ground 91 other than the connection part 13. The vibration-damping structure 10 may have an elevator between the structure 12 and the surface ground 91 other than the connection part 13.

[0044] A passage may be provided between the structure 12 and the building 93. This allows for flexible access to the structure 12. The structure 12 may be provided on the top of the building 93.

[0045] At least any combination of the structural material quantity determination step, stiffness function determination step, and damping function determination step may be performed simultaneously. The structural material quantity determination step, stiffness function determination step, and damping function determination step may be performed in any order.

[0046] The vibration control structure 10 may have a structure including a plurality of combinations of the structure 12 and the connection portion 13 . The phrase "at least any" used herein means one or more of the desired options. As an example, when the number of options is two, the phrase "at least any" used herein means only one option or both options. As another example, when the number of options is three or more, the phrase "at least any" used herein means only one option or any combination of two or more options.

[0047] [Note] The technical concepts grasped from the above-described embodiment and modified examples will be described below. (A) The connection portion has a rigidity function and a damping function in the horizontal direction between the structure and the surface ground.

[0048] (B) The connection portion includes a passageway connecting the ground surface of the surface ground and the structure. (C) Estimate the mass of the surface ground based on the results of geological adjustment of the surface ground. [Explanation of symbols]

[0049] 10...vibration control structure, 11...support part, 12...structure, 13...connection part, 21...first connection part, 22...second connection part, 91...surface ground, 92...engineered ground, 93...building.

Claims

1. a structure that is located above a predetermined range of surface ground that is a vibration control target; a connection portion that connects the structure and the surface ground, A vibration-damping structure in which the connection portion has a rigidity function and a damping function based on the mass of the surface ground between the structure and the surface ground, so that the structure acts as a mass body that damps the vibration of the surface ground.

2. The vibration damping structure according to claim 1, The connection portion has a first connection portion and a second connection portion, The first connection portion has a rigidity function between the structure and the surface ground, The second connection portion is a vibration control structure having a damping function between the structure and the surface ground.

3. Estimating the mass of the surface ground within a predetermined range that is the target of vibration control; A design method for a vibration-damping structure, comprising: determining the mass of a structure, and the stiffness and damping functions of a connection part connecting the structure and the surface ground, based on the mass of the surface ground, so that the structure located above the surface ground acts as a mass body that damps the vibration of the surface ground.

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