Pier-type damping structure and design method thereof

Abstract

The present application relates to the technical fields of vibration and noise control, and discloses a pier-tai type damping structure and a design method thereof. The pier-tai type damping structure comprises a first support, a bearing platform, a pier-tai and a second support. The pier-tai is supported on the top of the bearing platform and has a support end face facing the bearing platform. The second support has a connecting face connected with the pier-tai, and the area of the connecting face is smaller than that of the support end face. The damping pad is arranged between the bearing platform and the pier-tai to isolate the vibration transmission to the upper part. By increasing the bearing area of the pier-tai and uniformly spreading the vertical force of the second support, the bearing strength of the damping pad is reduced by several times, the thickness of the damping pad can be increased, and the vertical stiffness of the damping pad is reduced. In addition, the distributed damping pad has a smaller first shape coefficient and a larger overall second shape coefficient. The vertical stiffness of the damping pad is significantly reduced, the vertical bearing capacity is stable, the damping structure has good low-frequency vibration isolation performance, and has the advantages of simple structure, low cost and the like.

Description

Technical Field

[0001] This invention relates to the field of vibration and noise control technology, and in particular to a pier-type vibration reduction structure and its design method. Background Technology

[0002] The rapid development of subway and other rail transit systems has facilitated convenient travel for people. However, the operation of these systems also induces widespread building vibrations, affecting building quality and living comfort. Subway operation primarily causes vertical vibrations, which are relatively weak, typically ranging from 0.01 to 0.04 m / s². 2 The frequency range of vertical vibration, typically within 1-250Hz, can affect the comfort of a house under vertical vibration frequency resonance.

[0003] Research on vertical vibration reduction technology in buildings mainly focuses on rubber bearings. For example, patent CN216740062U discloses a structure for a deformable and releasable seismic isolation bearing, including an upper pier, a foundation cap, and a seismic isolation bearing. The upper pier is located above the foundation cap, and the seismic isolation bearing is located between the upper pier and the foundation cap. Rubber material is installed in the seismic isolation bearing. An upper flange plate is provided on the upper side of the seismic isolation bearing, and a lower flange plate is provided on the lower side of the seismic isolation bearing. The upper and lower flange plates are fixedly connected to the pre-embedded sleeves in the upper pier and the foundation cap by anchor bars. A pre-embedded steel pad is provided on the bottom surface of the upper pier, and the upper anchor bars pass through the pre-embedded steel pad. The openings on the lower flange plate and the pre-embedded steel pad are matched with the diameter of the anchor bars. An adjustment hole is provided on the upper flange plate, and the size of the adjustment hole is the maximum deformation size of the seismic isolation bearing.

[0004] The aforementioned seismic isolation bearings are constructed by vulcanizing layers of rubber and steel plates together and then placing them on the building to provide horizontal vibration damping. Currently, laminated rubber bearings used in high-intensity areas to isolate horizontal seismic forces are primarily designed to address structural safety issues under horizontal seismic inertial forces. They result in minimal overall horizontal structural deformation, while earthquakes are predominantly horizontal, although their intensity is typically 2-3 m / s². 2 The intensity is relatively high, but the vibration frequency band is relatively narrow, ranging from 1 to 20 Hz; the horizontal isolation technology absorbs horizontal seismic energy through the large horizontal deformation of an entire isolation layer (isolation bearing), but it has a large vertical stiffness and does not have a vertical vibration reduction function.

[0005] Because thicker rubber layers are prone to lateral buckling instability after being compressed and bulging, it is necessary to control the first shape factor S1 (the ratio of the bearing area of ​​a single rubber layer in a laminated rubber bearing to its free side surface area) and the second shape factor S2 (the ratio of the effective side length or diameter of the rubber layer inside the laminated rubber bearing to the total thickness of the rubber). That is, using larger values ​​of S1>15 and S2>5 is necessary to ensure that the rubber bearing obtains a stable vertical bearing capacity.

[0006] One mainstream approach to reducing the vertical stiffness of rubber bearings is the use of thick-layer rubber bearings. By increasing the thickness of a single rubber layer, the free surface area of ​​the rubber is increased, thereby reducing the first shape factor S1 and thus the stiffness of the rubber bearing. However, this method has limited vibration reduction efficiency, and increasing the rubber thickness reduces the second shape factor S2, making the bearing prone to instability. Another mainstream approach is to connect traditional horizontal seismic isolation bearings with steel spring bearings in series to form an integrated double-bearing system, achieving dual control of both horizontal earthquakes and vertical vibrations. However, the significantly increased height of the integrated double-bearing system makes it prone to lateral buckling instability under instantaneous earthquakes and long-term loads, posing a structural safety hazard. Furthermore, the damping of steel components is much lower than that of rubber bearings, making it unable to effectively suppress cyclic vibration responses and quickly return to zero position. Summary of the Invention

[0007] The purpose of this invention is to provide a pier-type vibration reduction structure to solve the problem of low vertical vibration isolation efficiency of existing vibration isolation supports; this invention also provides a vibration reduction structure design method for this pier-type vibration reduction structure.

[0008] To achieve the above objectives, the present invention provides a pier-type vibration reduction structure, including a first support member, a foundation, a pier, and a second support member. The foundation is supported on the top of the first support member, the pier is supported on the top of the foundation, and the second support member is supported on the top of the pier. The pier has a support end face facing the foundation, and the second support member has a connecting surface connected to the pier. The area of ​​the connecting surface is smaller than the area of ​​the support end face.

[0009] It also includes vibration damping pads, which are arranged between the bearing platform and the pier, and the vibration damping pads are in frictional engagement with the bearing platform and with the pier.

[0010] Preferably, the vibration damping pad includes multiple pad units, and each pad unit is spaced apart between the bearing platform and the pier.

[0011] Preferably, the connecting surface has a first edge, the supporting end face has a second edge, and the line connecting the first edge and the second edge forms an angle with the supporting end face, the angle ranging from 35 to 75 degrees.

[0012] Preferably, both the connecting surface and the supporting end surface are rectangular, and the first edge and the second edge are the sides of the rectangle.

[0013] Preferably, the vibration damping pad is made of either rubber or polyurethane.

[0014] The present invention also provides a design method for abutment-type vibration reduction structure, used in any of the above-mentioned technical solutions for abutment-type vibration reduction structures, comprising the following steps:

[0015] S1. Establish a finite element model of the overall building structure and analyze the vertical vibration response of the overall building structure using the finite element model;

[0016] S2, set the height of the pier as... The angle between the base and the pier is This forms the design dimensions of the pier platform, among which ;

[0017] S3. Based on the overall building structure and the plan dimensions of the pier, calculate and obtain the bearing strength of the vibration damping pad, and determine whether the bearing strength of the vibration damping pad meets the requirements. If yes, proceed to step S4; otherwise, proceed to step S2.

[0018] The compressive strength of the vibration damping pad meets the requirements.

[0019] ,

[0020] in, The calculated value of the bearing strength of the vibration damping pad. Design value of the bearing strength of the vibration damping pad For the bearing load of the vibration damping pad, To ensure the vibration damping pads can withstand the bending moment transmitted from the piers, Let be the section bending coefficient of the pier / abutment in the bending moment direction. It is the smaller of the area of ​​the supporting end face of the pier and the area of ​​the vibration damping pad;

[0021] S4. Calculate the punching shear bearing capacity of the pier and determine whether the punching shear bearing capacity of the pier meets the performance requirements. If yes, proceed to step S5; otherwise, proceed to step S2.

[0022] The punching shear bearing capacity of the piers and abutments meets the requirements.

[0023] ,

[0024] in, This is the design value for punching force. , This refers to the area of ​​the unfavorable side of the punching shear failure cone of the pier. This is the design value for the axial tensile strength of concrete; The effective height of the punching shear failure cone of the pier. The distance from the resultant point of the reinforcing steel bars at the bottom of the pier to the bottom surface of the pier is denoted as . ; For the pier The length of the unfavorable side of the cone at the height of the punching failure; The coefficient of influence of punching section height, when When less than 800, Take 1.0, when When it is greater than 2000mm, Take 0.9, when When the diameter is between 800 and 2000 mm, use linear interpolation.

[0025] S5, the plan dimensions of the foundation cap are the same as those of the pier cap. Calculate the shear bearing capacity of the foundation cap to obtain its height.

[0026] The shear bearing capacity of the pile cap meets the requirements.

[0027] , ,

[0028] in, The distance from the edge of the first support member Cross-sectional area between the point and the side of the foundation With the bearing strength of the vibration damping pad The product; This is the design value for the axial tensile strength of concrete; To verify the effective area of ​​the vertical section of the foundation at the cross-section, The effective height of the foundation, The distance from the resultant point of the stressed reinforcement at the top of the pile cap to the top surface of the pile cap is given by: , The design height of the foundation; This is a coefficient affected by the height of the shear section. ,when Take when less than 800 =800mm, when When it is greater than 2000mm, take =2000mm;

[0029] S6, set the planar distribution and thickness of the vibration damping pads to obtain the vertical stiffness of the designed vibration damping pads. This ensures that the thickness of the vibration damping pad meets the requirements.

[0030] ,

[0031] in, The second shape factor of the overall vibration damping pad. It is equal to the ratio of the shortest side length of the overall planar length of the vibration damping pad to the thickness of the vibration damping pad;

[0032] The vertical stiffness value of the vibration damping pad meets the requirements.

[0033] ,

[0034] ,

[0035] ,

[0036] ,

[0037]

[0038] in, For the first Vertical stiffness of the block damping pad unit; For the first The area of ​​the block damping pad unit; For the first The block damping pad unit takes into account the modified elastic modulus of small volume compression; The bulk modulus of elasticity of the vibration damping pad material. 2 GPa; For the first The block damping pad element takes into account the modified elastic modulus of material and boundary constraints; The elastic modulus of the vibration damping pad material; For the first The first shape factor of the block damping pad unit, ; For the first The area of ​​the block damping pad unit, For the first The perimeter of the block damping pad unit, The thickness of the vibration damping pad; ; Shear modulus of the vibration damping pad material; For the hardness and shear modulus of vibration damping pad material Correction factor, Take a value of 0.6-0.9, and the shear modulus The larger The smaller; This is the boundary constraint influence coefficient, whose value is no greater than 1. The weaker the constraint effect on the upper and lower surfaces of the vibration damping pad, the greater the influence coefficient. The smaller;

[0039] S7, Calculate the vertical natural frequency of the vibration damping pad. Determine whether the vibration wave meets the vibration reduction performance requirements after passing through the vibration damping pad. If yes, execute S8; otherwise, execute S6.

[0040] The vertical natural frequency of the vibration damping pad satisfies

[0041]

[0042] in, To support the weight of the vibration damping pad, Equal to the bearing load of the vibration damping pad Ratio to gravitational acceleration , This is the vertical stiffness value of the vibration damping pad;

[0043] S8, the determined pier-type vibration reduction structure is arranged in the finite element model of the overall building structure;

[0044] S9, perform the overall vertical vibration response of the pier-type vibration reduction structure, and determine whether the overall structural vibration response after vibration reduction meets the requirements of the vibration reduction effect. If yes, proceed to step S10; otherwise, proceed to step S6.

[0045] S10: Draw and output the design drawings of the pier-type vibration reduction structure.

[0046] Preferably, in step S7, when determining the vertical natural frequency of the vibration damping pad, a local finite element model is established connecting the pier, vibration damping pad, and foundation in sequence. The response loss of the vibration wave before and after passing through the vibration damping pad is analyzed and compared to evaluate the vibration damping performance of the vibration damping pad. The response loss meets the following requirements:

[0047]

[0048] in, The frequency of the vibration wave, For frequency The corresponding input acceleration; For frequency The corresponding output acceleration.

[0049] Compared with existing technologies, the pier-type vibration damping structure and its design method of this invention have the following advantages: the area of ​​the connecting surface is smaller than the area of ​​the supporting end face, thereby increasing the bearing area of ​​the pier; the vertical pressure of the second support member is evenly diffused through the pier, causing the bearing strength of the vibration damping pad to be reduced by a factor of two, thus increasing the thickness of the vibration damping pad and reducing its vertical stiffness. Furthermore, while reducing the strength requirements of the vibration damping pad, it also leverages the characteristic of the vibration damping pad material having a lower elastic modulus under low pressure, further reducing the vertical stiffness of the vibration damping pad and ensuring its filtering effect on low-frequency vertical vibrations; the vibration damping pad is arranged between the pier and the foundation, and the vibration damping pad uses a covering support. By arranging the vibration damping pads on the end faces, the vibration damping pads can completely isolate the abutment and pier, preventing vibration from being directly transmitted to the pier via the abutment. Increasing the area of ​​the supporting end faces of the upper pier effectively increases the area and side length of the vibration damping pads. While reducing the first shape factor of the vibration damping pads, it ensures that the vibration damping pads have a large overall second shape factor, giving them an efficient effect in filtering low-frequency vibrations and a stable vertical bearing capacity. The vibration damping pads are friction-fitted with the piers and abutments. During on-site construction, the vibration damping pads can be assembled simply by placing them on the abutments and then placing the piers on the vibration damping pads. This simplifies the installation process, reduces manufacturing and assembly costs, and facilitates widespread adoption. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the pier-type vibration reduction structure of the present invention;

[0051] Figure 2 yes Figure 1 The damping pad of the pier-type vibration reduction structure is an integral structural diagram;

[0052] Figure 3 yes Figure 1 The vibration damping pads of the pier-type vibration damping structure are distributed in the schematic diagram.

[0053] Figure 4 This is a flowchart of the design method for the pier-type vibration reduction structure of the present invention;

[0054] Figure 5 This is a schematic diagram of the punching shear bearing capacity calculation method of the pier in step S4 of the pier-type vibration reduction structure design method of the present invention.

[0055] Figure 6 This is a schematic diagram of the method for calculating the shear bearing capacity of the pier cap in step S5 of the design method for the pier-type vibration reduction structure of the present invention.

[0056] In the figure, 1 is the first support member, 2 is the foundation, 3 is the pier, 31 is the support end face, 4 is the second support member, 41 is the connecting surface, 5 is the vibration damping pad, and 51 is the pad unit. Detailed Implementation

[0057] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0058] A preferred embodiment of the pier-type vibration reduction structure of the present invention is as follows: Figures 1 to 3 As shown, the pier-type vibration reduction structure includes a first support member 1, a foundation 2, a pier 3, a second support member 4, and a vibration reduction pad 5.

[0059] The first support member 1, the foundation 2, the pier 3, and the second support member 4 are arranged sequentially from bottom to top. The first support member 1 is used to support the building's foundation or other basic structure. The foundation 2 is supported on top of the first support member 1, the pier 3 is supported on top of the foundation 2, and the second support member 4 is supported on top of the pier 3. The first support member 1, foundation 2, pier 3, and second support member 4 are located on the same vertical line to ensure vertical force transmission. In this embodiment, both the first support member 1 and the second support member 4 are column walls. In other embodiments, the first support member 1 and the second support member 4 can also be other building support structures. In this embodiment, the foundation 2 can be a pile foundation, in which case the first support member 1 is specifically a pile of the building, supported on the building's foundation, and the vibration damping pad 5 rests on the top surface of the foundation 2. In other embodiments, the foundation 2 and the first support member 1 can also be a bedrock layer with sufficient bearing capacity. In this case, the first support member 1 is the foundation of the bedrock layer, and the foundation 2 is the top support surface of the bedrock layer.

[0060] The pier 3 has a supporting end face 31 facing the foundation 2, which is the bottom surface of the pier 3. The second support member 4 has a connecting surface 41 that connects to the pier 3. This connecting surface 41 is the horizontal cross-section at the connection between the second support member 4 and the pier 3. The area of ​​the connecting surface 41 is smaller than the area of ​​the supporting end face 31, thus increasing the area of ​​the supporting end face 31 of the pier 3. The force of the second support member 4 can be evenly distributed through the pier 3, thereby increasing the bearing capacity of the vibration damping pad 5. The vertical stiffness of the vibration damping pad 5 can be reduced by increasing its thickness, which can also reduce the strength requirements of the vibration damping pad 5. In addition, the lower elastic modulus of the vibration damping pad 5 material under low pressure can be utilized to further reduce the vertical stiffness of the vibration damping pad 5 and obtain good low-frequency vibration isolation performance.

[0061] Vibration damping pads 5 are arranged between the foundation 2 and the pier 3. The vibration damping pads 5 and the foundation 2, and the vibration damping pads 5 and the pier 3, are in frictional fit. The vibration damping pads 5 cover the support end face 31. Friction, adhesion, and the constraint forces of the buildings on both sides are used between the vibration damping pads 5 and the pier 3 and foundation 2 to balance the inertial forces under earthquakes, ensuring that the second support member 4 will not misalign with the foundation 2 under horizontal earthquakes. This eliminates the need for other horizontal limiting and fixing components, simplifying the assembly of the foundation 2, pier 3, and vibration damping pads 5.

[0062] The vibration damping pad 5 covers the area between the support end face 31 and the bearing platform 2. With the same thickness, the length of the short side of the vibration damping pad 5 is increased. Compared with the existing rubber bearings where the side length or diameter of the rubber pad is small, S2 is generally more than 40 (much greater than 5), which can ensure that the vibration damping pad 5 has a very stable vertical bearing capacity and anti-lateral buckling capacity.

[0063] The vibration damping pad 5 is made of a single material and has no internal steel plates or other structures. The first and second shape factors of the vibration damping pad 5 are adjusted by adjusting its thickness, thereby adjusting its low-frequency vibration isolation performance. The vibration damping pad 5 is placed on the pier 2, and the abutment 3 rests directly on the vibration damping pad 5, which greatly simplifies the installation process of the vibration damping pad 5.

[0064] The area of ​​the connecting surface 41 of the pier-type vibration damping structure is smaller than the area of ​​the supporting end face 31, thereby increasing the bearing area of ​​the pier 3. The vertical pressure of the second support member 4 is evenly diffused through the pier 3, causing the bearing strength of the vibration damping pad 5 to be reduced by a factor of two. The vibration damping pad 5 is arranged between the pier 2 and the pier 3, and the vibration damping pad 5 is arranged in a way that covers the supporting end face 31. The vibration damping pad 5 can completely isolate the pier 2 and the pier 3, so that vibration will not be directly transmitted to the pier 3 through the pier 2, increasing the supporting end of the upper pier 3. The increased area of ​​surface 31 effectively increases the area of ​​vibration damping pad 5 and its side length. While reducing the first shape factor of vibration damping pad 5, it ensures that vibration damping pad 5 has a large second shape factor, thus enabling vibration damping pad to have stable vertical bearing capacity. Vibration damping pad 5 is in friction fit with pier 3 and foundation 2. During on-site construction, it is only necessary to place vibration damping pad 5 on foundation 2 and then place pier 3 on vibration damping pad 5 to complete the assembly. This simplifies the installation process of vibration damping pad 5, reduces manufacturing and assembly costs, and facilitates its promotion.

[0065] Preferably, the vibration damping pad 5 includes multiple pad units 51, and each pad unit 51 is distributed at intervals between the pier cap 2 and the abutment 3.

[0066] The vibration damping pad 5 is composed of multiple pad units 51, with a gap between adjacent pad units 51, so that the side of each pad unit 51 forms the free side surface of the vibration damping pad 5, effectively increasing the total free side surface area of ​​the vibration damping pad 5. Under the same pressure conditions, the free side surface area can be increased by several times or tens of times compared to traditional rubber bearings, that is, the first shape factor S1 is significantly reduced, the vertical stiffness is significantly reduced, and the lower the frequency of the vibration damping pad 5, the better the isolation effect of high-frequency vibration, and the more effectively it can isolate and reduce environmental vibration in most frequency bands.

[0067] Preferably, the connecting surface 41 has a first edge, the supporting end surface 31 has a second edge, and the line connecting the first edge and the second edge forms an angle with the supporting end surface 31, the angle ranging from 35 to 75 degrees.

[0068] The line connecting the first edge of the connecting surface 41 and the second edge of the supporting end surface 31 forms an angle with the supporting end surface 31, so that the ratio of the height of the pier 3 to the distance from the outer edge of the second support member 4 to the edge of the pier 3 is about 0.7-4, which ensures that the planar dimensions of the pier 3 are enlarged, effectively and evenly distributing the vertical force of the second support member 4 to the pressure-bearing damping pad 5, and reducing the pressure-bearing strength of the damping pad 5.

[0069] Preferably, both the connecting surface 41 and the supporting end surface 31 are rectangular, and the first edge and the second edge are the sides of the rectangle.

[0070] In this embodiment, the connecting surface 41 and the supporting end surface 31 are rectangular. Rectangles are a standard structure for columns and walls in buildings, making construction simple and convenient. In other embodiments, the connecting surface 41 and the supporting end surface 31 can be concentrically arranged circles, in which case the first edge and the second edge are points on the circumference of the connecting surface 41 and the supporting end surface 31 in the same vertical plane; in other embodiments, the connecting surface can also be an L-shaped or other irregularly shaped plane.

[0071] Preferably, the vibration damping pad 5 is made of either rubber or polyurethane.

[0072] The vibration damping pad 5 is made of flexible material, and these two materials are commonly used in vertical vibration isolation. Existing vibration damping supports often use steel spring supports or laminated rubber supports (rubber sheets and steel sheets are alternately overlapped and vulcanized). In this embodiment, the vibration damping pad 5 is made of a single material, which has a low elastic modulus, relatively low load-bearing capacity, and relatively large deformation capacity. However, because the large-sized pier 3 and foundation 2 provide strong lateral constraints on the upper and lower surfaces of the vibration damping pad 5, they form a clamping effect on the upper and lower surfaces of the vibration damping pad 5, appropriately enhancing the elastic modulus and load-bearing capacity of the vibration damping pad 5 component, thus meeting the requirements of simultaneously filtering vertical vibrations and resisting horizontal tangential loads.

[0073] Vibration damping pad 5 uses a single material, ensuring reliable production quality and precision. It can be mass-produced and standardized on a large scale. Moreover, its overall structure is very simple, allowing for quick installation, environmentally friendly construction, low overall cost, and easy market promotion.

[0074] This invention also provides a design method for abutment-type vibration reduction structures, applicable to any of the abutment-type vibration reduction structures described above, such as... Figures 4 to 6 As shown, it includes the following steps:

[0075] S1. Establish a finite element model of the overall building structure and analyze the vertical vibration response of the overall building structure using the finite element model;

[0076] S2, set the height of pier 3 as... The angle between the base of the pier and the bottom of the platform is This forms the planar dimensions of the designed pier 3, among which... ;

[0077] S3. Based on the overall building structure and the planar dimensions of the pier 3, calculate and obtain the bearing strength of the vibration damping pad 5, and determine whether the bearing strength of the vibration damping pad 5 meets the requirements. If yes, proceed to step S4; otherwise, proceed to step S2.

[0078] The compressive strength of the vibration damping pad 5 meets the requirements.

[0079] ,

[0080] in, The calculated value of the bearing strength of vibration damping pad 5. The design value of the bearing strength of the vibration damping pad 5. For the bearing load of vibration damping pad 5, To ensure that the vibration damping pad 5 can withstand the bending moment transmitted by the pier 3, Let be the section bending coefficient of pier 3 in the bending moment direction. The smaller of the area of ​​the support end face 31 of the pier 3 and the area of ​​the vibration damping pad 5 is used.

[0081] S4. Calculate the punching shear bearing capacity of pier 3 and determine whether the punching shear bearing capacity of pier 3 meets the performance requirements. If yes, proceed to step S5; otherwise, proceed to step S2.

[0082] The punching shear bearing capacity of pier 3 meets the requirements.

[0083] ,

[0084] Among them, such as Figure 5 As shown, This is the design value for punching force. , The area of ​​the unfavorable side of the punching shear failure cone of pier 3; This is the design value for the axial tensile strength of concrete; The effective height of the punching shear failure cone of pier 3. The distance from the resultant point of the stressed reinforcement at the bottom of pier 3 to the bottom surface of pier 3 is denoted as . ; For pier 3 The length of the unfavorable side of the cone at the height of the punching failure; The coefficient of influence of punching section height, when When less than 800, Take 1.0, when When it is greater than 2000mm, Take 0.9, when When the diameter is between 800 and 2000 mm, use linear interpolation.

[0085] S5. The plan dimensions of the foundation 2 are the same as those of the pier 3. Calculate the shear bearing capacity of the foundation 2 to obtain its height.

[0086] The shear bearing capacity of pile cap 2 meets the requirements.

[0087] , ,

[0088] Among them, such as Figure 6 As shown, The edge of the first support member 1 Cross-sectional area between the point and the side of the foundation 2 With the bearing strength of the vibration damping pad 5 The product; This is the design value for the axial tensile strength of concrete; To verify the effective area of ​​the vertical section of the foundation at the cross-section, The effective height of pier 2 The distance from the resultant point of the top reinforcing steel bars of pile cap 2 to the top surface of pile cap 2 is: , The design height of foundation 2; This is a coefficient affected by the height of the shear section. ,when Take when less than 800 =800mm, when When it is greater than 2000mm, take =2000mm, and There is a one-to-one correspondence, and the two are linearly related;

[0089] S6, set the planar distribution form and thickness of the vibration damping pad 5 to obtain the designed vertical stiffness of the vibration damping pad 5. This ensures that the thickness of the vibration damping pad 5 meets the requirements.

[0090] ,

[0091] in, The second shape factor of the overall vibration damping pad 5. It is equal to the ratio of the shortest side length of the overall planar length of the damping pad 5 to the thickness of the damping pad 5;

[0092] The vertical stiffness value of vibration damping pad 5 meets the requirements.

[0093] ,

[0094] ,

[0095] ,

[0096] ,

[0097]

[0098] in, For the first Vertical stiffness of 5 units of the block vibration damping pad; For the first The area of ​​5 units of the block vibration damping pad; For the first The modulus of elasticity of the block damping pad 5-unit is modified considering the small volume compression. The bulk modulus of elasticity of the material of the vibration damping pad 5 is... 2 GPa; For the first The modified elastic modulus of the block damping pad element is considered in terms of material and boundary constraints. The elastic modulus of the vibration damping pad 5 material; For the first The first shape factor of the 5-unit block vibration damping pad. ; For the first The area of ​​the block vibration damping pad unit 51, Let be the perimeter of the nth vibration damping pad unit 51. The thickness of the vibration damping pad 5; ; The shear modulus of the vibration damping pad 5 material; The hardness and shear modulus of the vibration damping pad material 5 Correction factor, Take a value of 0.6-0.9, and the shear modulus The larger The smaller; This is the boundary constraint influence coefficient, whose value is no greater than 1. The weaker the constraint effect on the upper and lower surfaces of the vibration damping pad, the greater the influence coefficient. The smaller;

[0099] S7, Calculate the vertical natural frequency of vibration damping pad 5. Determine whether the vibration wave meets the vibration reduction performance requirements after passing through the vibration damping pad 5. If yes, execute S8; otherwise, execute S6.

[0100] The vertical natural frequency of the vibration damping pad 5 satisfies

[0101]

[0102] in, The vibration damping pad bears the weight of 5. Equal to the bearing load of the vibration damping pad Ratio to gravitational acceleration , This is the vertical stiffness value of the vibration damping pad 5;

[0103] S8, the determined pier-type vibration reduction structure is arranged in the finite element model of the overall building structure;

[0104] S9. Perform the vertical vibration response of the overall structure with the pier-type vibration reduction structure, and determine whether the vibration response of the overall structure after vibration reduction meets the requirements of the vibration reduction effect. If yes, proceed to step S10; otherwise, proceed to step S6.

[0105] S10: Draw and output the design drawings of the pier-type vibration reduction structure.

[0106] In this embodiment, a finite element model of the overall building structure is established in step S1. The vertical vibration response of the overall building structure can be analyzed through the finite element model and compared with the overall structural vibration response of the pier-type vibration reduction structure in step S8 to determine whether the vibration reduction structure meets the vibration reduction requirements.

[0107] In step S2, the included angle of the base of pier 3 is designed. The angle between the line connecting the first edge and the second edge of the support end face 31 and the support end face 31 is such that the ratio of the height of the pier 3 to the distance from the outer edge of the second support member 4 to the edge of the pier 3 is approximately 0.7-4. This ensures that the planar dimensions of the pier 3 are enlarged, effectively distributing the vertical force of the second support member 4 evenly to the pressure-bearing damping pad 5, thereby reducing the pressure-bearing strength of the damping pad 5.

[0108] In step S3, the compressive strength of the vibration damping pad 5 affects its compressive capacity. Based on the compressive strength of the vibration damping pad 5, it can be verified whether the height of the pier 3 and the angle between the bottom of the pier 3 in step S2 meet the design requirements. The calculated value of the compressive strength of the vibration damping pad 5 is lower than the design value. The design value is the theoretical maximum value of the vibration damping pad 5. This ensures that the vibration damping pad 5 meets the design requirements.

[0109] In step S4, the unfavorable side of the punching shear failure cone of pier 3, that is, the side in the direction of the punching shear force when pier 3 is subjected to punching shear force, is also the side with a larger area of ​​the punching shear failure cone, such as... Figure 5 of As shown.

[0110] In this embodiment, the shorter side dimension of the pier 3 plane is... Width greater than the second support member 4 plus twice the effective height of the pier 3 At that time, the punching shear bearing capacity of pier 3 was checked according to the method in step S4, and the punching shear angle of pier 3 with the vibration damping pad 5 fully covered was taken as . The vibration damping pad 5 uses a distributed arrangement of multiple pad units 51, and the punching angle of the pier 3 is taken as... Because the punching angle formed by the line connecting the inner edge of the damping pad 5 as the starting point to the edge of the second support 4 as the midpoint may be... scope.

[0111] When the short side dimension of the pier 3 plane The width of the second support member 4 is less than or equal to twice the effective height of the pier 3. At that time, the shear bearing capacity of pier 3 was checked according to the calculation method in step S5. Because the short side dimension of pier 3 in plane... Width greater than the second support member 4 plus twice the effective height of the pier 3 At that time, the punching shear of pier 3 failed before the shear failure, so only the punching shear bearing capacity needed to be checked. Less than or equal to the width of the wall column plus twice the effective height of the pier. At this time, shear failure occurs before punching failure, so only the shear bearing capacity needs to be checked.

[0112] Normally, only one of punching shear resistance and shear resistance needs to be checked. Generally, punching shear resistance is checked for pier 3, while for pile cap 2, since the size of the first support member 1 below is larger than the size of the second support member 4 on pier 3, only shear resistance needs to be checked when the shear resistance is unfavorable. Therefore, S4 and S5 involve the calculation methods for punching shear resistance of pier 3 and shear resistance of pile cap 2, respectively.

[0113] In step S5, the planar dimensions of the foundation 2 are the same as those of the pier 3. Therefore, once the planar dimensions of the pier 3 are determined, the planar dimensions of the foundation 2 are naturally the same as those of the pier 3. Thus, the shorter side dimension of the pier 3 is... Equivalent to the short side dimension of the foundation 2; when calculating the shear bearing capacity of the foundation 2, the compressive strength calculation of the vibration damping pad 5 can refer to step S3.

[0114] In step S6, the thickness of the vibration damping pad 5 meets the following requirements. This ensures that the vibration damping pad 5 has a very stable vertical load-bearing capacity and anti-lateral buckling capacity. The first shape factor of the 5-unit block damping pad That is, the area of ​​the vibration damping pad is 5. With a vibration damping pad 5 circumference and thickness The ratio of products; the material of the vibration damping pad 5 is generally an almost incompressible material, therefore .

[0115] In step S7, the vertical natural frequency of the damping pad 5 is calculated. The vertical natural frequency affects the response loss of the vibration wave before and after passing through the damping pad 5, thereby verifying the vertical vibration filtering effect of the damping pad 5. Figure 1 As shown, the wavy line represents the transmission of vibration, and the thickness of the line indicates the magnitude of the intensity. It is clear that after being filtered by the vibration damping pad 5, the vibration of the second support 4 is significantly reduced.

[0116] Preferably, in step S7, when determining the vertical natural frequency of the vibration damping pad 5, a local finite element model is established connecting the pier 3, vibration damping pad 5, and foundation 2 in sequence. The response loss of the acceleration input and output values ​​before and after the vibration wave passes through the vibration damping pad 5 is analyzed and compared to evaluate the vibration damping performance of the vibration damping pad 5. The response loss meets the following requirements.

[0117]

[0118] in, The frequency of the vibration wave, For frequency The corresponding input acceleration; For frequency The corresponding output acceleration.

[0119] In this embodiment, a local finite element model is established by sequentially connecting the pier 3, the vibration damping pad 5, and the foundation 2. The response loss of the acceleration input and output values ​​of the vibration wave before and after passing through the vibration damping pad 5 is analyzed and compared to evaluate the vibration damping performance of the vibration damping pad 5. The corresponding results are obtained through finite element analysis, and the results are accurate and easy to verify.

[0120] In this application, the overall second shape factor S2 of the damping pad 5 is generally above 40, much greater than 5, which ensures that the damping pad 5 has a very stable vertical bearing capacity and anti-lateral buckling capacity, and allows for the design of a thicker damping pad 5, thereby obtaining a smaller vertical stiffness and good low-frequency vibration isolation performance.

[0121] In summary, this invention provides a pier-type vibration damping structure and its design method. The area of ​​its connecting surface is smaller than the area of ​​the supporting end face, thereby increasing the bearing area of ​​the pier. The vertical pressure of the second support member is evenly diffused through the pier, causing the bearing strength of the vibration damping pad to decrease several times over. Therefore, the thickness of the vibration damping pad can be increased, and its vertical stiffness reduced. Furthermore, while reducing the strength requirement of the vibration damping pad, the material's lower elastic modulus under low pressure is utilized to further reduce the vertical stiffness of the vibration damping pad, ensuring its filtering effect on low-frequency vertical vibrations. The vibration damping pad is arranged between the pier and the support cap, and it adopts a square shape covering the supporting end face. The arrangement of the vibration damping pads completely isolates the abutment and pier, preventing vibration from being directly transmitted to the pier via the abutment. Increasing the support end area of ​​the upper pier effectively increases the area and side length of the vibration damping pads. While reducing the first shape factor of the vibration damping pads, it ensures that the vibration damping pads have a large overall second shape factor, giving them a highly efficient effect in filtering low-frequency vibrations and a stable vertical bearing capacity. The vibration damping pads are friction-fitted with the pier and abutment. During on-site construction, the installation process can be completed simply by placing the vibration damping pads on the abutment and then placing the pier on the vibration damping pads. This simplifies the installation process, reduces manufacturing and assembly costs, and facilitates widespread adoption.

[0122] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A design method for a pier-type vibration damping structure, applied to a pier-type vibration damping structure, the pier-type vibration damping structure comprising a first support member, a foundation, a pier, and a second support member, wherein the foundation is supported on the top of the first support member, the pier is supported on the top of the foundation, the second support member is supported on the top of the pier, the pier has a support end face facing the foundation, and the second support member has a connecting surface connected to the pier, the area of ​​the connecting surface being smaller than the area of ​​the support end face; the pier-type vibration damping structure further comprises a vibration damping pad, the vibration damping pad being arranged between the foundation and the pier, and the vibration damping pad and the foundation, and the vibration damping pad and the pier having a frictional fit, characterized in that... The design method for the pier-type vibration reduction structure includes the following steps: S1. Establish a finite element model of the overall building structure and analyze the vertical vibration response of the overall building structure using the finite element model; S2, set the height of the pier as... The angle between the base and the pier is This forms the design dimensions of the pier platform, among which ; S3. Based on the overall building structure and the plan dimensions of the pier, calculate and obtain the bearing strength of the vibration damping pad, and determine whether the bearing strength of the vibration damping pad meets the requirements. If yes, proceed to step S4; otherwise, proceed to step S2. The compressive strength of the vibration damping pad meets the requirements. ， in, The calculated value of the bearing strength of the vibration damping pad. Design value of the bearing strength of the vibration damping pad For the bearing load of the vibration damping pad, To ensure the vibration damping pads can withstand the bending moment transmitted from the piers, Let be the section bending coefficient of the pier / abutment in the bending moment direction. It is the smaller of the area of ​​the supporting end face of the pier and the area of ​​the vibration damping pad; S4. Calculate the punching shear bearing capacity of the pier and determine whether the punching shear bearing capacity of the pier meets the performance requirements. If yes, proceed to step S5; otherwise, proceed to step S2. The punching shear bearing capacity of the piers and abutments meets the requirements. ， in, This is the design value for punching force. , This refers to the area of ​​the unfavorable side of the punching shear failure cone of the pier. This is the design value for the axial tensile strength of concrete; The effective height of the punching shear failure cone of the pier. The distance from the resultant point of the reinforcing steel bars at the bottom of the pier to the bottom surface of the pier is denoted as . ; For the pier The length of the unfavorable side of the cone at the height of the punching failure; The coefficient of influence of punching section height, when When less than 800, Take 1.0, when When it is greater than 2000mm, Take 0.9, when When the diameter is between 800 and 2000 mm, use linear interpolation. S5, the plan dimensions of the foundation cap are the same as those of the pier cap. Calculate the shear bearing capacity of the foundation cap to obtain its height. The shear bearing capacity of the pile cap meets the requirements. ， ， in, The distance from the edge of the first support member Cross-sectional area between the point and the side of the foundation With the bearing strength of the vibration damping pad The product; This is the design value for the axial tensile strength of concrete; To verify the effective area of ​​the vertical section of the foundation at the cross-section, The effective height of the foundation, The distance from the resultant point of the stressed reinforcement at the top of the pile cap to the top surface of the pile cap is given by: , The design height of the foundation; This is a coefficient affected by the height of the shear section. ,when Take when less than 800 =800mm, when When it is greater than 2000mm, take =2000mm; S6, set the planar distribution and thickness of the vibration damping pads to obtain the vertical stiffness of the designed vibration damping pads. This ensures that the thickness of the vibration damping pad meets the requirements. ， in, The second shape factor of the overall vibration damping pad. It is equal to the ratio of the shortest side length of the overall planar length of the vibration damping pad to the thickness of the vibration damping pad; The vertical stiffness value of the vibration damping pad meets the requirements. ， ， ， ， in, For the first Vertical stiffness of the block damping pad unit; For the first The area of ​​the block damping pad unit; For the first The block damping pad unit takes into account the modified elastic modulus of small volume compression; The bulk modulus of elasticity of the vibration damping pad material. 2 GPa; For the first The block damping pad element takes into account the modified elastic modulus of material and boundary constraints; The elastic modulus of the vibration damping pad material; For the first The first shape factor of the block damping pad unit, ; For the first The area of ​​the block damping pad unit, For the first The perimeter of the block damping pad unit, The thickness of the vibration damping pad; ; Shear modulus of the vibration damping pad material; For the hardness and shear modulus of vibration damping pad material Correction factor, Take a value of 0.6-0.9, and the shear modulus The larger The smaller; This is the boundary constraint influence coefficient, whose value is no greater than 1. The weaker the constraint effect on the upper and lower surfaces of the vibration damping pad, the greater the influence coefficient. The smaller; S7, Calculate the vertical natural frequency of the vibration damping pad. Determine whether the vibration wave meets the vibration reduction performance requirements after passing through the vibration damping pad. If yes, execute S8; otherwise, execute S6. The vertical natural frequency of the vibration damping pad satisfies in, To support the weight of the vibration damping pad, Equal to the bearing load of the vibration damping pad Ratio to gravitational acceleration , This refers to the vertical stiffness value of the vibration damping pad; S8, the determined pier-type vibration reduction structure is arranged in the finite element model of the overall building structure; S9. Perform the vertical vibration response of the overall structure with the pier-type vibration reduction structure, and determine whether the vibration response of the overall structure after vibration reduction meets the requirements of the vibration reduction effect. If yes, proceed to step S10; otherwise, proceed to step S6. S10: Draw and output the design drawings of the pier-type vibration reduction structure.

2. The design method for the pier-type vibration reduction structure according to claim 1, characterized in that, In step S7, when determining the vertical natural frequency of the vibration damping pad, a local finite element model is established connecting the pier, vibration damping pad, and foundation in sequence. The response loss of the vibration wave before and after passing through the vibration damping pad is analyzed and compared to evaluate the vibration damping performance of the pad. The response loss meets the following requirements. in, The frequency of the vibration wave, For frequency The corresponding input acceleration; For frequency The corresponding output acceleration.

3. The design method for the pier-type vibration reduction structure according to claim 1, characterized in that, The vibration damping pad includes multiple pad units, which are spaced apart between the bearing platform and the pier.

4. The design method for the pier-type vibration reduction structure according to claim 1, characterized in that, The connecting surface has a first edge, the supporting end face has a second edge, and the line connecting the first edge and the second edge forms an angle with the supporting end face, the angle ranging from 35 to 75 degrees.

5. The design method for the pier-type vibration reduction structure according to claim 4, characterized in that, Both the connecting surface and the supporting end surface are rectangular, and the first edge and the second edge are the sides of the rectangle.

6. The design method for the pier-type vibration reduction structure according to claim 1, characterized in that, The vibration damping pad is made of either rubber or polyurethane.

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