Replaceable bent steel bar-shear plate combined metal damper and installation method

Abstract

This invention relates to a replaceable bent steel bar-shear plate combined metal damper and its installation method, belonging to the field of bridge engineering technology. It includes a left connecting steel plate, a right connecting steel plate, a bolt fixing plate, high-strength bolts, and an energy dissipation component. The left and right connecting steel plates are respectively connected to a concrete tie beam. Bolt fixing plates are fixed to the left and right connecting steel plates and connected to the energy dissipation component via high-strength bolts. The energy dissipation component, installed between the left and right connecting steel plates, includes bent steel bars and a shear plate. The shear plate is a combination of an "H"-shaped steel plate and bent steel bars at its upper and lower ends. Multiple sets of bent steel bars and at least one shear plate are arranged side-by-side. This invention can improve the seismic performance of bridges, greatly accelerate construction speed, ensure good energy dissipation capacity, and provide post-earthquake replaceability.

Description

Technical Field

[0001] This invention relates to a replaceable bent steel bar-shear plate combined metal damper and its installation method, belonging to the field of bridge engineering technology. Background Technology

[0002] Located between the Circum-Pacific Seismic Belt and the Eurasian Seismic Belt, my country has a wide distribution of high-intensity seismic zones. Therefore, bridge structures in these high-intensity zones are highly susceptible to the effects of earthquakes. For bridges that require the addition of concrete tie beams between piers to increase the stability and lateral stiffness of the piers, once subjected to seismic loads, they are extremely prone to flexural-shear failure at the connection points between the concrete tie beams and the piers, which can lead to the destruction of the entire bridge.

[0003] In bridge pier design, concrete tie beams are typically designed as ductile members. The goal is to ensure that even if failure occurs at the ends of the concrete tie beams, the plastic deformation of the tie beams will absorb seismic loads, protecting other parts of the pier from damage. Therefore, under seismic loading, plastic hinges often form first at the pier-concrete tie beam connection. Once the concrete tie beam fails and loses its structural integrity, the structural system changes, making the entire pier more susceptible to failure. Therefore, adding dampers to the concrete tie beams can improve the seismic performance of the piers and prevent premature failure.

[0004] Common bridge dampers include viscous dampers, friction dampers, and metallic dampers. Viscous dampers provide significant damping force, effectively dissipating energy input to the structure and thus significantly reducing vibration response. However, their performance is affected by environment and temperature, and the internal viscous fluid may leak due to poor sealing or aging, affecting performance and making them unsuitable for complex environments such as high-intensity seismic zones. Friction dampers are inexpensive, have a simple mechanical model, and effectively control lateral displacement; however, their friction force needs to be determined by adjusting the preload, their performance is significantly affected by temperature, and they are difficult to install and maintain in complex terrain such as high-intensity seismic zones. Metallic dampers are energy-dissipating devices made of metal materials, formed into various shapes and installed in bridge tie beams, and have broad application prospects. The development and application of metallic dampers are like equipping bridges with "airbags." During an earthquake, the dampers absorb and dissipate the impact energy of the earthquake to the maximum extent, greatly mitigating the impact and damage caused by the earthquake. Using metal dampers not only offers advantages such as light weight, ease of construction, and replaceability, but also enhances the seismic performance of the structure.

[0005] Common types of metal dampers include shear dampers, bending dampers, and bending-shear dampers. Shear dampers can provide greater stiffness, but the shear plate fails relatively quickly. Bending dampers can generate greater energy dissipation and fail more slowly, but their lateral stiffness is lower than that of shear plates. Existing bending-shear dampers have greater stiffness and energy dissipation capacity, but their replaceability is relatively limited. Further research is needed to explore new types of dampers that are more suitable for complex terrain conditions in high-intensity seismic zones, ensuring that bridge tie beams are protected to a certain extent and easily replaceable after an earthquake. Summary of the Invention

[0006] To address the aforementioned deficiencies in the existing technology, this invention proposes a replaceable bent steel bar-shear plate combined metal damper and its installation method. This replaceable bent steel bar-shear plate combined metal damper can improve the seismic performance of bridges, greatly accelerate construction speed, and ensure good energy dissipation capacity and post-earthquake replaceability.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A replaceable bent steel bar-shear plate combined metal damper includes a left connecting steel plate, a right connecting steel plate, a bolt fixing plate, high-strength bolts, and an energy dissipation component;

[0009] The left and right connecting steel plates are connected to the concrete tie beams respectively. Bolt fixing plates are fixed on the left and right connecting steel plates and connected to the energy dissipation components by high-strength bolts. There are four sets of bolt fixing plates, located on the upper and lower inner sides of the left and right connecting steel plates respectively. Each set of bolt fixing plates includes upper and lower bolt fixing plates.

[0010] The energy-dissipating component is installed between the left and right connecting steel plates and includes bent steel bars and a shearing plate. When the relative deformation of the left and right connecting steel plates is small, the deformation of the shearing plate, due to its higher rigidity, is preferentially concentrated in the middle of the shearing plate. When the relative displacement is large, the middle part of the shearing plate is sheared, and the bent steel bars continue to perform bending deformation, maintaining their connection and energy-dissipating function. The shearing plate is a combination of an "H"-shaped steel plate and bent steel bars at the upper and lower ends. Multiple sets of bent steel bars and at least one shearing plate are arranged side by side. Both ends of the bent steel bars are provided with reserved bolt holes, and the bolt fixing plates are also provided with corresponding reserved bolt holes. The two ends of the bent steel bars are fixed to each set of bolt fixing plates through the reserved bolt holes, the reserved bolt holes, and high-strength bolts.

[0011] Furthermore, the bent steel strip is divided into upper and lower groups, and both ends of the bent steel strip in the upper and lower groups are clamped between the upper and lower bolt fixing plates of each group by high-strength bolts.

[0012] Furthermore, the bent steel bar is arc-shaped, with the arc-shaped protrusions of the upper and lower sets of bent steel bars arranged opposite each other. The formula for calculating the bending strength of the bent steel bar is: W = bh 2 / 6, where b is the flange width and h is the height; the formula for calculating torsional strength is W t =2b 3 h / 3L, where L is the length of the bent steel bar. The purpose of the curved steel bar is to make it more aesthetically pleasing than ordinary straight steel bars, and to provide good ductility and deformation capacity when subjected to seismic loads.

[0013] Furthermore, the shearing plate is positioned in the middle of multiple sets of bent steel bars, and the multiple sets of bent steel bars are symmetrically arranged on both sides of the shearing plate.

[0014] Furthermore, the number of shear plates and bent steel bars is calculated based on the strength and stiffness of the tie beam in the corresponding bridge structure. The stiffness and strength of the entire damper must be 0.8 times that of the corresponding concrete tie beam to ensure that the damper structure is weaker than the tie beam structure, so that the damage is concentrated at the damper location. The arrangement of the shear plates and bent steel bars should be adjusted in conjunction with the number of shear plates and bent steel bars, but it should be ensured that the shear plates and bent steel bars of the entire damper are symmetrically distributed to avoid out-of-plane failure caused by improper construction.

[0015] Furthermore, the bent steel bars are in groups of 2, 4, 6, or 8.

[0016] Furthermore, the cross-section of the middle section of the left and right limbs of the "H"-shaped steel plate is larger than the cross-section of its upper and lower ends.

[0017] Furthermore, both the left connecting steel plate and the right connecting steel plate are welded together with the bolt fixing plate.

[0018] Furthermore, the "H"-shaped steel plate in the shearing plate is integrally formed or welded together with the bent steel strips at the upper and lower ends.

[0019] The installation method for the above-mentioned replaceable bent steel bar-shear plate combined metal damper includes the following steps:

[0020] S1. The piers and concrete tie beams are fabricated in the processing plant. The tie beams are pre-embedded with bolts and the installation positions of the combined metal dampers are reserved.

[0021] S2. The left connecting steel plate, the right connecting steel plate, and the bolt fixing plate are processed and manufactured in the processing plant. Bolt holes are reserved on the bolt fixing plate. The left connecting steel plate and the right connecting steel plate are bolted together by the screws embedded in the concrete tie beam. The reserved space between the left connecting steel plate and the right connecting steel plate is ensured to facilitate the installation of energy-consuming components.

[0022] S3. In the processing plant, the bent steel bars and shearing plates are manufactured, and pre-drilled bolt holes are made at both ends of the bent steel bars. The pre-drilled bolt holes on the bent steel bars and shearing plates are aligned with the pre-drilled bolt holes on the bolt fixing plates, and then connected with high-strength bolts. This ensures that when the shearing plates are subjected to loads and the concrete tie beams of the pier columns move relative to each other, the left and right limbs of the middle "H"-shaped steel can move relative to each other, forming plastic deformation and dissipating energy.

[0023] S4. When the bent steel bar or shear plate is deformed or damaged under earthquake action, it can be replaced. The high-strength bolts can be disassembled and reinstalled, and new bent steel bars or shear plates can be replaced. This enables the replaceable bent steel bar-shear plate combined metal damper to achieve sustainable operation, restore the temporary working capacity of the bridge pier, and facilitate the deployment of post-earthquake rescue work.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] This invention proposes a combined metal damper of bent steel bars and shear plates, which is installed at the concrete tie beam and connected by high-strength bolts. The damper absorbs seismic load energy through the vertical shear deformation of the shear plates and the bending deformation of the bent steel bars, ensuring that the concrete tie beam does not suffer serious damage and concentrating the damage at the damper location. Furthermore, after damage occurs, the damper can be quickly removed and replaced with a new one, achieving rapid installation and replaceability. This enables the tie beam piers to temporarily serve after an earthquake, facilitating timely post-earthquake rescue operations.

[0026] Under seismic loads, the pier and the concrete tie beam move relative to each other, causing the energy dissipation components to deform and thus dissipate energy. The deformation of the entire energy dissipation component is divided into two stages. When the relative deformation of the left and right connecting steel plates is small, the deformation of the shear plate, due to its higher stiffness, is preferentially concentrated in the middle of the shear plate. When the relative displacement is large, the middle part of the shear plate shears off, and the bent steel bar continues to exert its bending deformation effect, maintaining its connection and energy dissipation function. When the actual seismic load is applied, the relative displacement between the pier and the concrete tie beam is first borne by the shear plate, and then by the bent steel bar, thereby achieving the purpose of dissipating seismic energy. This avoids the failure of the concrete tie beam root due to large bending and shear loads, and transfers the failure to the bent steel bar-shear plate combined metal damper, improving the seismic performance of the pier. At the same time, the bent steel bar-shear plate combined metal damper is connected by bolts, which has advantages over traditional concrete tie beams, such as light weight, quick and convenient installation, and post-earthquake replacement. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the left and right connecting steel plate structure of the present invention;

[0029] Figure 3 This is a schematic diagram of the energy-consuming component structure of the present invention;

[0030] Figure 4 This is a detailed schematic diagram of the bending steel bar and shearing plate of the present invention;

[0031] Figure 5 An elevation view of a single bent steel bar;

[0032] Figure 6 A top view of a single bent steel bar;

[0033] Figure 7 The bending moment diagrams are shown for the right end of the bent steel bar under different loads.

[0034] Figure 8 This is a schematic diagram of the shearing plate dimensions;

[0035] Figure 9 The diagram illustrates the equivalent stiffness, where (a) is a cast-in-place tie beam and (b) is a replaceable tie beam.

[0036] Figure 10 To optimize the Pareto curve. Detailed Implementation

[0037] The following is in conjunction with the appendix Figure 1-10 The present invention will be further described in detail below to facilitate a clear understanding of the invention, but these descriptions do not constitute a limitation thereof.

[0038] Example 1

[0039] As attached Figure 1-4 As shown, a replaceable bending steel bar-shear plate combined metal damper of this embodiment includes a left connecting steel plate 1, a right connecting steel plate 2, a bolt fixing plate 3, a high-strength bolt 4, and an energy dissipation component.

[0040] The left connecting steel plate 1 and the right connecting steel plate 2 are respectively connected to the concrete tie beam. Bolt fixing plates 3 are fixed on the left connecting steel plate 1 and the right connecting steel plate 2, and are connected to the energy dissipation components by high-strength bolts 4. There are four sets of bolt fixing plates 3, located at the upper and lower inner sides of the left connecting steel plate 1 and the right connecting steel plate 2, respectively. Each set of bolt fixing plates 3 includes upper and lower bolt fixing plates 3. In this embodiment, the left connecting steel plate 1 and the right connecting steel plate 2 are welded together with the bolt fixing plates 3.

[0041] The energy-consuming component is installed between the left connecting steel plate 1 and the right connecting steel plate 2, and includes bent steel bars 5 and a shearing plate 6. The shearing plate 6 is an assembly composed of an "H"-shaped steel plate and bent steel bars 5 at both the upper and lower ends. The "H"-shaped steel plate is welded to the bent steel bars 5 at both ends. For example... Figure 3-4 As shown, the "H"-shaped steel plate has a cross-section in the middle of its left and right limbs that is larger than its top and bottom cross-sections. Multiple sets of bent steel bars 5 and at least one shear plate 6 are arranged side by side. Both ends of the bent steel bars 5 are provided with pre-drilled bolt holes 8, and the bolt fixing plate 3 is also provided with corresponding pre-drilled bolt holes 7. The two ends of the bent steel bars 5 are fixed to each set of bolt fixing plates 3 through the pre-drilled bolt holes 8, the pre-drilled bolt holes 7, and high-strength bolts 4.

[0042] The curved steel strip 5 is divided into upper and lower groups, and both ends of the upper and lower groups of curved steel strip 5 are clamped between the upper and lower bolt fixing plates 3 of each group by high-strength bolts 4. In this embodiment, the curved steel strip 5 is arc-shaped, and the arc-shaped protrusions of the upper and lower groups of curved steel strip 5 are arranged opposite each other.

[0043] like Figure 3As shown, the shear plate 6 is positioned in the middle of multiple sets of bent steel bars 5, which are symmetrically arranged on both sides of the shear plate 6. The number of shear plates 6 and bent steel bars 5 is calculated based on the strength and stiffness of the tie beam in the corresponding bridge structure. The stiffness and strength of the entire damper must be 0.8 times that of the corresponding concrete tie beam to ensure that the damper structure is weaker than the tie beam structure, thus concentrating damage at the damper location. The arrangement of the shear plates 6 and bent steel bars 5 should be adjusted according to their number, but it must be ensured that the shear plates 6 and bent steel bars 5 are symmetrically distributed throughout the damper to avoid out-of-plane failure due to improper construction. In this embodiment, there are specifically four sets of bent steel bars 5.

[0044] Example 2

[0045] like Figure 5-9 As shown, the specific design method is as follows:

[0046] According to the design principle of ensuring strong column-weak beam seismic resistance, the aim is to concentrate damage at high energy-dissipating structural locations. The general principle is to ensure that the damper yields before the tie beam, and the tie beam yields before the pier column, thus guaranteeing that failure occurs first at the damper location, then the tie beam, and finally the pier column. Meanwhile, many scholars achieve the priority yielding process of the damper by increasing the flexural and shear capacity of the non-damped beam segment, and by appropriately reducing the flexural capacity of the damper segment to achieve a reasonable yielding sequence. In this design, a damper reduction factor of 0.8 is used.

[0047] 1. Determine the reasonable internal force requirement M for the combined energy-dissipating structure. T

[0048] M T =0.8×M (1)

[0049] In the formula, M T M represents the required bending moment for the damper, and M is the maximum bending moment that the tie beam can withstand at the location of the damper.

[0050] 2. Assume that the five dimensional parameters of the bent steel bar are l, r, t, h, and b, which correspond to the length, radius, half the thickness, sag, and width of the bent steel bar (5), respectively. Write the force equation for the bent steel bar.

[0051] like Figure 5-6 As shown, the equation of the curve for bending the steel bar is:

[0052] x 2 +(rhy) 2 =r 2 (2)

[0053] Where x is the x-coordinate of a point on the curve of the bent steel bar, and y is the x-coordinate of a point on the curve of the bent steel bar.

[0054] When the end of the bent steel bar exhibits unit displacement and unit rotation, the force method is used to solve the problem based on its boundary conditions. The typical equation of the force method is:

[0055]

[0056] In the formula, δ 11 δ 22 δ 33 Main coefficient, δ ii (i = 1, 2, 3) represents the unit redundant unknown force. The displacement along its own direction caused when acting alone; δ 12 δ 13 δ 21 δ 23 δ 31 δ 32 As the secondary coefficient, δ ij (i = 1, 2, 3; j = 1, 2, 3) represents the unit redundant unknown force. The effect along X when acting alone i Displacement in the direction of (i≠j); Δ 1c Δ 2c Δ 3c For the free term, Δ ic (i = 1, 2, 3) represents the load along X caused by the external load acting alone. i Displacement in direction; X1 is the rotation angle applied to the right end of the bent steel bar, X2 is the horizontal displacement applied to the right end of the bent steel bar, X3 is the vertical displacement applied to the right end of the bent steel bar; θ is the rotation angle occurring at the right end of the bent steel bar, Z is the horizontal displacement at the right end of the bent steel bar, and Δ is the vertical displacement at the right end of the bent steel bar.

[0057] The basic structure is selected for calculation. Since there are no external loads on the basic structure and redundant constraints have been removed, therefore Δ 1c =0, Δ 2c =0, Δ 3c If the value is 0, then calculate M1, M2, and M3 respectively:

[0058] Where M1 is the bending moment at the left end when the right end of the bent steel bar experiences a rotation angle X1; M2 is the bending moment at the left end when the right end of the bent steel bar experiences a horizontal displacement X2; and M3 is the bending moment at the left end when the right end of the bent steel bar experiences a vertical displacement X3. For example... Figure 7 As shown.

[0059] The coefficients can be obtained from the calculation formula:

[0060]

[0061] The bending strength of the bent steel bar is calculated, and the bending strength calculation expression for a single bent steel bar 5 is finally obtained according to the following formula:

[0062] Assuming the number of bent steel bars 5 is n, then the bending moment borne by a single bent steel bar 5 is:

[0063] Based on the cross-sectional dimensions, M c It can be expressed by the following formula:

[0064]

[0065] In the formula, σ y Let b be the yield stress of the steel used for bending the steel bar, b be the width of the bending steel bar, and h be the sag of the bending steel bar.

[0066] The results of the combined force method equations can then be used to perform M c calculate:

[0067] M1X1 + M2X2 + M3X3 = M c (5)

[0068] 3. Using Matlab multi-objective optimization, the results satisfying the objective functions of maximizing bending moment and minimizing volume were obtained. A genetic algorithm was used for analysis, and based on the Pareto optimization results, many sets of results for the bending steel bar's parameters l, r, t, h, and b were obtained. Results for all five parameters were presented.

[0069]

[0070] In the formula, V0 is the total volume of the bent steel bar.

[0071] 4. Determine the shear plate parameters

[0072] After solving the multi-objective function, five sets of key parameters for the bending steel bar are initially determined. Next, the internal forces that the shear plate can provide need to be determined based on the total internal force requirements, and then the shear plate parameters are solved. Finally, the damper stiffness needs to be checked based on the stiffness of the cast-in-place bridge pier, and the damper parameter values ​​are ultimately determined.

[0073] M T =2nmax(M) c )+M sy (7)

[0074]

[0075] In the formula, M T M represents the total bending resistance of the damper, n is the number of bending steel bars, and M is the total bending resistance of the damper. c M provides bending resistance to bent steel bars sy The bending load-bearing capacity provided for the shear plate.

[0076] Shear strength F of shear plate sy The shear strength of the bent steel bar can be calculated using equation (9) as F. fy It can be calculated using equation (10). The resultant force of the shear plate and the bent steel bar is Q. The total shear strength of the damper is Q. T Satisfying Q T =F sy +nF fy .like Figure 8 As shown.

[0077]

[0078] In addition to meeting strength requirements, the damper must also meet stiffness requirements to ensure that the pier structure has a certain ability to resist deformation. The damper stiffness includes the shear plate stiffness K. sy and bending steel bar stiffness K dy For the shear plate K sy In terms of stiffness, the size of the central shearing block directly determines the stiffness of the shearing plate, and therefore its stiffness can be seen in equation (11). The stiffness K of the bending steel bar dy It can be seen that formula (12)

[0079]

[0080] In the formula, t1 is the thickness of the shear plate; k is the shear shape coefficient, taken as 1.2; τ sy G represents the shear stress of the material. s The shear strain modulus of the steel plate can be taken as 0.385E. s E s I represents the elastic modulus of steel. s It is the moment of inertia of the bent steel bar.

[0081] A schematic diagram of stiffness calculation is shown below. Figure 9 As shown.

[0082] Overall damper stiffness K dy This is equivalent to the sum of n bent steel bars connected in parallel with a shear plate, therefore equation (13) can be used for calculation. Furthermore, the stiffness K of the tie beam segment can be replaced. P It can be calculated by equation (14), where K c For the segmental stiffness of the tie beam, the stiffness K of the cast-in-place tie beam can be used as a reference. CIP The calculation is as shown in equation (15). Finally, the damper value is verified to meet the stiffness requirements by formula (16), where β d Let β be the stiffness reduction factor for the tie beam. d When the value is 1, it is assumed that the stiffness is not reduced, and the stiffness of the tie beam can be replaced to be equal to that of the cast-in-place tie beam.

[0083] K dy=nK fy +K sy (13)

[0084]

[0085] K P =β d K CIP (16)

[0086] In the formula, ΔM and ΔV are the bending deformation and shear deformation under unit load, respectively; L is the length of the cast-in-place tie beam; E t and I t And A t These are the elastic modulus, moment of inertia, and cross-sectional area of ​​the concrete tie beam, respectively; G is the shear modulus of concrete, which can be taken as 0.425E. t .

[0087] Based on the initially determined values, the shear strength and stiffness of the damper are verified to determine whether they meet the design requirements. If they do not meet the requirements, iterative calculations are repeated until the requirements are met.

[0088] Example 2

[0089] Damper design calculations were performed based on the reinforcement details of the tie beams of a highway bridge pier in a high-intensity seismic zone.

[0090] The tie beam has a height of 650mm and a width of 550mm. The main reinforcement of the tie beam is HRB steel bar with a diameter of 14mm.

[0091] According to the formula for calculating the shear resistance of beam inclined sections in the "Code for Design of Concrete Structures GB 50010-2010", we know that:

[0092]

[0093] α cv =0.7 f t =1.71MPa f yv =400MPa A sv =314mm 2 h0 = 608mm

[0094] s = 80mm

[0095] V y =1354.836kN

[0096] Based on the relevant parameters, the following can be calculated:

[0097] V = 2032.254 kN (considering a safety factor of 1.5)

[0098] Calculate the flexural yield strength of the tie beam:

[0099] M y =n×f y ×A S ×h0

[0100] n = 14 f y =400MPa A S =153.94mm 2 h0 = 608mm

[0101] Based on the relevant parameters, we can calculate that: M y =524.134kN·m, then the maximum bending moment M of the tie beam at the damper location is 389.95kN·mm.

[0102] 1. By selecting a strength reduction factor of 0.8, the reasonable internal force requirement M for the combined energy-dissipating structure can be determined. T Q T :

[0103] M T =β×M=0.8×389.95=311.96kN·m

[0104] Q T =β×V=0.8×2032255=1625.8kN

[0105] In the formula, β is the strength reduction factor, and M and V represent the flexural and shear bearing capacities of the concrete tie beam at the damper location, respectively. Since the energy dissipation structure yields before the ordinary concrete section of the tie beam, it can be a number less than 1. The specific value is determined according to the requirements of the actual project. In this example, the reduction factor is calculated using 0.8.

[0106] 2. Determine the dimensions and quantity of the bent steel bars.

[0107] Based on previous calculations, Pareto optimization was used to obtain the Pareto front of a single bent steel bar, and the initial bending moment M of the bent steel bar was obtained. c and volume V o And five dimensional parameters, including l, r, t, h, and b, which correspond to the length, radius, half the thickness, sag, and width of the bent steel strip.

[0108] Based on the bending strength equation and the bending steel bar volume equation, a multi-objective equation set is obtained, as shown in equation (6). Approximate ranges are set for the bending steel bar length l, radius r, half the thickness t, sag h, and width b. These ranges can be initially determined based on actual conditions. MATLAB multi-objective optimization is used to obtain results that satisfy the above objective functions, with a genetic algorithm selected for analysis. Figure 10 As shown, its Pareto optimization curve is obtained, and the points on the curve are the target values ​​M of the corresponding parameters.c and V o Assuming the number of bending steel bars is n, and considering structural factors such as the actual space size for the tie beam arrangement, we intend to select parameter values ​​whose bending moment values ​​are closer to the internal force requirements as preliminary design values ​​for subsequent verification.

[0109] Based on the optimization results, the final dimensions are determined to be [200, 1340, 40, 60, 40], specifically: length l = 200 mm, radius r = 1340 mm, half the thickness t = 40 mm, sag h = 60 mm, and width b = 200 mm. Assuming that 10 bent steel bars are needed to meet the bending moment requirements, subsequent dimensional calculations are performed.

[0110] The shear capacity of a single bent steel bar is:

[0111]

[0112] The total shear capacity V is:

[0113] V = nf fy =132.267×10=1322.67kN

[0114] The required shear bearing capacity of the shear plate is

[0115] F sy =Q T -V=1625.8-1322.67kN=303.13kN

[0116]

[0117] Assuming t1 has the same thickness as the bent steel bar, b2 can be calculated to be 50mm. b1 needs to be further determined after comparing the stiffness. b3 can be determined according to the structural requirements, which require that it does not buckle, and can be the same as b1.

[0118] 3. Stiffness calculation of cast-in-place tie beams:

[0119]

[0120] Where L is the length of the extended section of the tie beam, taken as 500 mm, k is a shape factor related to the cross-section, taken as 1.2 for rectangular cross-sections, and E and G are the elastic modulus and shear modulus of the tie beam concrete, with concrete G = 0.425E. The stiffness of the cast-in-place tie beam section of length L can be calculated as 4.4843 kN·m.

[0121] 4. Stiffness calculation of series connecting beam-damper:

[0122] The stiffness of the concrete tie beam is K C

[0123]

[0124] make

[0125] K P =β d K CIP

[0126] Where β d This is the stiffness reduction factor, which can be 1 or lower, and is determined according to actual needs. In this example, it is 0.65.

[0127] Therefore, b1 = 5mm.

[0128] During the calculation, multiple iterations are required to verify whether the damper's bending moment, shear force, and stiffness meet the requirements until the design requirements are met and the final parameter calculation is completed.

[0129] Example 3

[0130] The installation method of the replaceable bent steel bar-shear plate combined metal damper in Embodiments 1 and 2 above includes the following steps:

[0131] S1. The piers and concrete tie beams are fabricated in the processing plant. The tie beams are pre-embedded with bolts, and the installation positions for the combined metal dampers are reserved.

[0132] S2. The left connecting steel plate 1, the right connecting steel plate 2, and the bolt fixing plate 3 are processed and manufactured in the processing plant. Bolt fixing plate 3 is provided with bolt holes 7. The left connecting steel plate 1 and the right connecting steel plate 2 are bolted together by the screws embedded in the concrete tie beam. The reserved position between the left connecting steel plate 1 and the right connecting steel plate 2 is ensured to facilitate the installation of energy-consuming components.

[0133] S3. At the processing plant, the bent steel bar 5 and shearing plate 6 are fabricated. Pre-drilled bolt holes 8 are made at both ends of the bent steel bar 5. The pre-drilled bolt holes 8 on the bent steel bar 5 and shearing plate 6 are aligned with the pre-drilled bolt holes 7 on the bolt fixing plate 3, and then connected using high-strength bolts 4. This ensures that when the shearing plate 6 is subjected to load and the concrete tie beam of the pier column undergoes relative movement, the left and right limbs of the middle "H"-shaped steel can move relative to each other, forming plastic deformation and dissipating energy.

[0134] S4. When the bent steel bar 5 or shear plate 6 is deformed or damaged under the action of an earthquake, it can be replaced. The high-strength bolt 4 can be disassembled and reinstalled, and a new bent steel bar 5 or shear plate 6 can be replaced. This enables the replaceable bent steel bar-shear plate combined metal damper to achieve sustainable operation, restore the temporary working capacity of the bridge pier, and facilitate the development of post-earthquake rescue work.

[0135] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the structure of the present invention. The arrangement and quantity of the present invention are not limited to this example and can be optimized according to actual engineering conditions. Any modifications, equivalent changes, and decorations made to the above embodiments based on the technical principles of the present invention, without departing from the scope of the present invention, are still within the scope of the present invention.

Claims

1. A replaceable curved steel bar-shear plate combined metal damper, characterized by: It comprises left connecting steel plate (1), right connecting steel plate (2), bolt fixing plate (3), high-strength bolt (4) and energy dissipation component; The left connecting steel plate (1) and the right connecting steel plate (2) are connected with the concrete tie beam respectively, the left connecting steel plate (1) and the right connecting steel plate (2) are fixed with the bolt fixing plate (3), and are connected with the energy dissipation component through the high-strength bolt (4); wherein, the bolt fixing plate (3) is provided with four groups, which are located on the inner side of the upper and lower ends of the left connecting steel plate (1) and the right connecting steel plate (2) respectively, each group of bolt fixing plate (3) comprises two bolt fixing plates (3) on the upper and lower ends. The energy dissipation component is installed between the left connecting steel plate (1) and the right connecting steel plate (2), and comprises curved steel strip (5) and shear plate (6); the shear plate (6) is a combined body composed of the "H" shaped steel plate and the curved steel strips (5) on the upper and lower ends; a plurality of curved steel strips (5) and at least one shear plate (6) are arranged side by side together; the curved steel strip (5) is provided with curved steel strip reserved bolt holes (8) at both ends, and the bolt fixing plate (3) is also provided with bolt fixing plate reserved bolt holes (7) correspondingly, and the both ends of the curved steel strip (5) are correspondingly fixed on each group of bolt fixing plate (3) through the curved steel strip reserved bolt holes (8), the bolt fixing plate reserved bolt holes (7) and the high-strength bolt (4); The curved steel strip (5) is divided into upper and lower groups, and the both ends of the upper and lower groups of the curved steel strip (5) are clamped between each group of the upper and lower two bolt fixing plates (3) through the high-strength bolt (4); the curved steel strip (5) is arc-shaped, and the arc-shaped convex parts of the upper and lower groups of the curved steel strip (5) are oppositely arranged; the shear plate (6) is arranged at the middle position of the plurality of curved steel strips (5), and the plurality of curved steel strips (5) are symmetrically arranged on both sides of the shear plate (6); the number of the shear plate (6) and the curved steel strip (5) is calculated according to the strength and rigidity of the tie beam in the corresponding bridge structure, and the rigidity and strength of the whole damper should be 0.8 times of the corresponding indexes of the concrete tie beam, so as to ensure that the damper structure is weaker than the tie beam structure, so that the damage is concentrated in the damper position; the arrangement form of the shear plate (6) and the curved steel strip (5) should be adjusted in combination with the number of the shear plate (6) and the curved steel strip (5), but it should be ensured that the shear plate (6) and the curved steel strip (5) of the whole damper are symmetrically distributed, so as to avoid the out-of-plane damage caused by improper structure.

2. The replaceable curved steel bar-shear plate combined metal damper according to claim 1, characterized in that: The curved steel strip (5) is 2, 4, 6 or 8 groups.

3. The replaceable curved steel bar-shear plate combined metallic damper according to claim 1, wherein: The "H" shaped steel plate is provided with left and right limbs, and the middle section of the left and right limbs is larger than the upper and lower end sections.

4. The replaceable curved steel bar-shear plate combined metallic damper according to claim 1, wherein: The left connecting steel plate (1) and the right connecting steel plate (2) are welded with the bolt fixing plate (3).

5. The replaceable curved steel bar-shear plate combined metallic damper according to claim 1, wherein: The "H" shaped steel plate in the shear plate (6) is integrally formed or welded with the curved steel strips (5) on the upper and lower ends.

6. A method of installing the replaceable curved steel bar-shear plate combined metal damper according to any one of claims 1-5, characterized in that, It comprises the following steps: S1, manufacturing the pier column and the concrete tie beam in the processing factory, embedding the screw rod in the concrete tie beam, and reserving the installation position of the combined metal damper; S2, in the processing factory, the left connecting steel plate (1), the right connecting steel plate (2) and the bolt fixing plate (3) are processed and manufactured, and the bolt fixing plate reserved bolt hole (7) is arranged on the bolt fixing plate (3), the left connecting steel plate (1) and the right connecting steel plate (2) are bolted through the screw rod embedded in the concrete beam, and the reserved position between the left connecting steel plate (1) and the right connecting steel plate (2) is ensured, so that the energy consumption component is conveniently installed; S3, in the processing factory, the bent steel strip (5) and the shearing plate (6) are manufactured, and the bent steel strip reserved bolt hole (8) is reserved at both ends of the bent steel strip (5), the bent steel strip reserved bolt hole (8) on the bent steel strip (5) and the shearing plate (6) is positioned and aligned with the bolt fixing plate reserved bolt hole (7) of the bolt fixing plate (3), and is connected by the high-strength bolt (4) respectively; when the shearing plate (6) is subjected to load and the pier concrete beam moves relatively, the left and right limbs of the middle "H" shaped steel can be dislocated, plastic deformation is formed and energy is consumed; S4, when the bent steel strip (5) or the shearing plate (6) is deformed and damaged under the action of earthquake, it can be replaced, the high-strength bolt (4) is disassembled, the new bent steel strip (5) or the shearing plate (6) is replaced, the replaceable bent steel strip-shearing plate combined type metal damper realizes the sustainable working ability, restores the temporary working ability of the pier, and facilitates the development of post-earthquake rescue work.

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