Seismic design method of high pier with hinged tie beam and energy dissipation diagonal brace

Abstract

The present application belongs to the field of engineering design, and particularly relates to a high pier seismic system with hinged tie beams and energy dissipation braces and a seismic design method. The method sets an anti-seismic system containing hinged intermediate tie beams and multi-layer buckling-restrained braces, and a new anti-seismic design method is proposed based on the new structure. In the new anti-seismic design method, by inputting known design conditions, such as the design parameters of the bridge double-column high pier, the design ground motion, the anti-seismic performance target and the like, the design parameters of the buckling-restrained braces arranged at different layers can be quickly determined to meet the established anti-seismic performance target without complex and time-consuming nonlinear seismic response calculation and parameter analysis. The anti-seismic system provided by the present application can overcome the deficiency of the reinforced concrete double-column high pier form bridge in the anti-seismic performance, the new design method greatly simplifies the anti-seismic design process of the bridge pier, improves the efficiency of the buckling-restrained brace parameter design, and is convenient for practical engineering application.

Description

Technical Field

[0001] This invention belongs to the field of engineering design, specifically relating to a high pier seismic system with hinged tie beams and energy-dissipating braces, a seismic design method and system for bridges using hinged tie beams and buckling-restrained braces, and a design and construction method for seismic-resistant bridge piers. Background Technology

[0002] To adapt to the terrain characteristics of mountainous areas, reinforced concrete double-column high-pier bridges are widely used in western my country. Their main feature is the use of multi-layered concrete tie beams to increase the lateral stiffness of the piers. However, past earthquake disasters have shown that the tie beam-pier joint is susceptible to seismic damage, severely weakening the vertical and lateral load-bearing capacity of the piers. How to design a new structural form for bridge piers that can reduce seismic damage to the beam-column joint has become a pressing technical challenge for those skilled in the art.

[0003] Buckling-restrained bracing (CRB) can significantly reduce the seismic response of bridge piers in seismic design and reinforcement, and its sacrificial energy dissipation characteristics can effectively protect the main pier from severe seismic damage. However, for high piers with two columns, multiple layers of bracing are often required in the overall structure. Determining the parameters of each layer of bracing generally requires extensive parameter analysis, which is time-consuming and labor-intensive, making it unsuitable for designers to apply in actual engineering projects. Therefore, how to solve the problem of the high difficulty in parameter design of high pier structures with two columns using multiple layers of buckling-restrained bracing is a technical challenge that urgently needs to be addressed in this field. Summary of the Invention

[0004] To address the issues of insufficient seismic performance of existing reinforced concrete double-column high-pier bridges and the significant structural design challenges of double-column high-pier bridges with multi-layer buckling-restrained bracing, this invention proposes a high-pier seismic resistance system and seismic design method with hinged tie beams and energy-dissipating bracing.

[0005] This invention is achieved using the following technical solution:

[0006] A seismic-resistant system for high piers with hinged tie beams and energy-dissipating braces is applied to the piers of bridges employing a double-column high-pier structure. This seismic-resistant system is a truss structure composed of multiple tie beams and multiple buckling-restrained braces. The tie beams are evenly distributed along the pier elevation direction between the cap beam and the pier abutment. The buckling-restrained braces are sequentially distributed between the cap beam and tie beams, between tie beams, and between the tie beams and the pier abutment at each level. The ends of each tie beam and buckling-restrained brace are detachably and fixedly connected to the bridge piers via hinged connections.

[0007] This invention also includes a seismic design method for bridges employing hinged tie beams and buckling-restrained braces. This method decomposes the aforementioned high-pier seismic system with hinged tie beams and energy-dissipating braces into two parallel structures: a pure double-column high-pier structure and a multi-layer buckling-restrained brace truss. Based on the deformation coordination and stress synergy theory between the two structures, the key parameters of the multi-layer buckling-restrained brace are rapidly determined.

[0008] Specifically, the seismic design method provided by the present invention includes the following steps:

[0009] S1: Obtain the basic design parameters and design seismic motion parameters of the double-column high pier of the bridge based on the design information; including: pier structural dimensions, equivalent structural mass of each part, design seismic motion displacement response spectrum S(T), and pier transverse first-order vibration mode. And the initial design displacement d0 of the bridge pier.

[0010] S2: Based on the structural dimensions of the pier, the equivalent mass of each part of the structure, and the first transverse vibration mode of the pier. Calculate the equivalent mass M of the double-column high pier of the bridge.

[0011] S3: Combining the flexural stiffness EI of the pier section and the first transverse vibration mode of the pier. Calculate the lateral elastic stiffness k of a double-column high pier without buckling restraint bracing. p .

[0012] S4: Based on the design seismic motion displacement response spectrum S(T), generated at a characteristic period of T. * Seismic displacement d of double-column high pier * .

[0013] S5: Determine whether the initial design displacement d0 in S1 is less than d*: If yes, correct the initial design displacement d0; otherwise, assume that the structural period satisfies the principle of equal displacement and use it as the pier design displacement d.

[0014] The correction steps for the initial design displacement d0 are as follows:

[0015] S51: Assume an elastic displacement value d1, which satisfies: d1 <d0;

[0016] S52: Obtain the structural period T1 corresponding to the design displacement d1 by designing the seismic motion displacement response spectrum S(T).

[0017] S53: Calculate the corresponding displacement correction coefficient R using the following formula, taking into account the structural period T1. d1 :

[0018]

[0019] In the above formula, μ DTo design the displacement ductility coefficient.

[0020] S54: Determine R d1 Is the error between ×d1 and d0 less than 5%? If yes, the correction is complete. Use R... d1 Correct d0;

[0021] Otherwise, re-assume the elastic displacement value d2 = d / R d1 Then return to step S52 to continue iterative correction.

[0022] S6: The elastic stiffness K of the double-column high pier with buckling restraint bracing is calculated by combining the design displacement d obtained from the iterative convergence with the design ground motion response spectrum S(T).

[0023] S7: Assuming that the diagonal braces of each layer are connected in series, determine the elastic stiffness k of the multi-layer buckling-restrained diagonal brace truss structure according to the formula for the stiffness relationship between connected members. b And calculate the design elastic stiffness k of the buckling restraint braces in each layer. bi and horizontal design displacement Δ bi .

[0024] S8: Combine the design of elastic stiffness k with buckling restraint braces in each layer. bi and horizontal design displacement Δ bi Calculate the minimum effective length L of the buckling restraint brace required for each layer. bi and the cross-sectional area A of the diagonal brace bi .

[0025] As a further improvement of the present invention, in step S2, the formula for calculating the equivalent mass M of the double-column high pier of the bridge is as follows:

[0026]

[0027] In the above formula, m s m c and m c These represent the mass of the main beam, the mass of the cap beam, and the equivalent mass of the lower pier column, respectively; H represents the pier height; EI represents the flexural stiffness of the pier column section; and x represents the pier's ground elevation.

[0028] As a further improvement of the present invention, in step S3, the lateral elastic stiffness k of the double-column high pier... p The calculation formula is as follows:

[0029]

[0030] As a further improvement of the present invention, in step S53, the displacement ductility coefficient μ D It is a manually set constant related to the engineering scenario.

[0031] As a further improvement of the present invention, in step S6, the formula for calculating the elastic stiffness K of the double-column high pier is as follows:

[0032]

[0033] In the above formula, n represents the number of stories in the multi-story buckling-restrained braced truss structure; k bi denoted by , where represents the design elastic stiffness of the buckling-restrained brace of the i-th layer, and n represents the total number of layers in the multi-layer buckling-restrained brace truss structure.

[0034] As a further improvement of the present invention, in step S7, the formula for the stiffness relationship between the series components is as follows:

[0035]

[0036] In the above formula, c is the proportionality coefficient; k bj The design elastic stiffness of the buckling-restrained brace of the j-th layer, i≠j; H j H j-1 H i and H i-1 denoted as the heights of the buckling restraint braces of the j-th, j-1, i-th, and i-1-th layers, respectively.

[0037] As a further improvement of the present invention, in step S8, the minimum effective length L of the buckling restraint brace is... bi and the cross-sectional area A of the diagonal brace bi The constraint equations satisfied are as follows:

[0038]

[0039] In the above formula, L represents the total length of the buckling-restrained brace; μ b ε is the allowable displacement ductility coefficient of the brace, the value of which is determined by the allowable strain of the core material; θ is the inclination angle of the brace; ε y E represents the yield strain of the core material of the diagonal brace. b This indicates the elastic modulus of the bracing material.

[0040] The present invention also includes a seismic design system for bridges employing articulated tie beams and buckling-restrained braces, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the seismic design method for bridges employing articulated tie beams and buckling-restrained braces as described above, and then obtains the key parameters of the multi-layer buckling-restrained braces that meet the seismic design objectives based on the basic design parameters of the bridge engineering and the design ground motion parameters.

[0041] This invention also includes a design and construction method for earthquake-resistant bridge piers, comprising the following steps:

[0042] (1) The bridge piers are designed as double-column high piers with a high pier seismic system with hinged tie beams and energy-dissipating diagonal braces as described above, and the basic design parameters and design ground motion parameters of the bridge project are determined.

[0043] (2) Using the seismic design method of bridges with hinged tie beams and buckling-restrained braces as described above, the key parameters of multi-layer buckling-restrained braces that meet the seismic design objectives are obtained based on the basic design parameters and the design ground motion parameters.

[0044] (3) Procurement or prefabrication of various structural components in the high pier seismic system with hinged tie beams and energy-dissipating diagonal braces according to key parameters.

[0045] (4) After the construction of the double-column high pier structure of the main body of the bridge is completed, the prefabricated structural components are installed according to the design drawings to complete the construction of the bridge piers, which include a high pier seismic system with hinged tie beams and energy dissipation braces.

[0046] The technical solution provided by this invention has the following beneficial effects:

[0047] (1) This invention proposes to use hinged tie beams and buckling-restrained braces instead of traditional concrete tie beams on double-column high piers of bridges, which releases the rotational constraint between beam and column. On the one hand, it enhances the lateral deformation capacity of the pier, which is conducive to the deformation of the energy-dissipating braces to play a shock-absorbing effect. On the other hand, it can also avoid earthquake damage to the nodes and ensure that the pier has sufficient bearing capacity during and after the earthquake.

[0048] (2) This invention proposes a simplified method for rapidly determining the parameters of multi-layer buckling-restrained bracing based on displacement for bridge double-column high pier structures using hinged tie beams and buckling-restrained bracing. The design steps provided can quickly determine the design parameters of the bracing required for different layers of the double-column high pier with sufficient accuracy. It does not require complex and time-consuming nonlinear seismic response calculations and parameter analysis, which greatly improves design efficiency and facilitates practical engineering applications for designers.

[0049] (3) The seismic system of hinged tie beams + multi-layer buckling-restrained braces proposed in this invention has a simple structure and is easy to construct. It allows the braces and the main piers to be better decoupled, so that each can play its seismic role without causing excessive adverse effects on the other. In addition, the seismic system of hinged tie beams + multi-layer buckling-restrained braces designed in this invention can be applied to both new and existing bridges to improve their seismic performance, and it is also easy to maintain and repair in the later stages. Attached Figure Description

[0050] Figure 1 This is a case study of a double-column high-pier structure bridge pier using H-shaped concrete tie beams and an engineering case involving tie beam fracture.

[0051] Figure 2 This is a structural schematic diagram of the high pier seismic-resistant system with hinged tie beams and energy-dissipating diagonal braces provided in Embodiment 1 of the present invention.

[0052] Figure 3 This is a flowchart illustrating the steps of the seismic design method for a bridge employing hinged tie beams and buckling-restrained braces, as provided in Embodiment 2 of the present invention.

[0053] Figure 4 A schematic diagram of the structure of a bridge using a new seismic-resistant system in Embodiment 2 of the present invention.

[0054] Figure 5 The flowchart of the iterative update process of the design displacement in Embodiment 2 of the present invention.

[0055] Figure 6 This is a schematic diagram of the three-story, double-column high pier structure used in the 30-meter span simply supported beam bridge tested in the experiment.

[0056] Figure 7 To test the displacement response spectrum of the designed ground motion in the experiment and the actual seismic wave that matches it.

[0057] Figure 8 To compare the maximum displacement demand response of the pier top before and after the design in the test experiment.

[0058] Figure 9 To compare the time history curves of the pier top displacement before and after the design in the test experiment.

[0059] Figure 10 The peak displacement ductility coefficient response of each layer of buckling-restrained bracing in the test experiment was determined.

[0060] Figure 11 This is a schematic diagram of the hysteresis curves of the buckling-restrained braces in each layer after the design in the test experiment. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0062] Example 1

[0063] This embodiment provides a seismic-resistant system for high piers with hinged tie beams and energy-dissipating diagonal braces, which is applied to the piers of bridges employing a double-column high-pier structure. In traditional bridge engineering using double-column supported piers, such as... Figure 1As shown, when the bridge piers are double-column high piers, a concrete tie beam is usually designed between the two piers. The tie beam and the two pier columns are cast as a single unit during construction, jointly bearing the load generated by the bridge above the piers. However, if the seismic performance of the piers is insufficient, the tie beam is prone to fracture during an earthquake. The high pier seismic-resistant system with hinged tie beams and energy-dissipating braces provided in this embodiment is mainly used to replace... Figure 1 The concrete tie beams in the bridge pier structure, this new high-pier seismic system with hinged tie beams and energy-dissipating diagonal braces, will improve the seismic performance of bridges while maintaining the same structural characteristics. Figure 1 Compared to the traditional bridge pier structure, the solution in this embodiment will bring about innovations in multiple aspects, including structural design, construction, lifespan, safety monitoring, and maintenance of bridge engineering.

[0064] Specifically, such as Figure 2 As shown, the high pier seismic system with hinged tie beams and energy-dissipating braces provided in this embodiment is a truss structure composed of multiple tie beams and multiple buckling-restrained braces (energy-dissipating braces). The tie beams are evenly distributed along the pier elevation direction between the cap beam and the pier abutment; the buckling-restrained braces are sequentially distributed between the cap beam and tie beams, between tie beams, and between the tie beams and the pier abutment on each floor.

[0065] It is particularly important to emphasize that in this embodiment, the ends of each tie beam and buckling-restrained brace in the seismic resistance system are detachably and fixedly connected to the bridge piers via hinges. This seismic resistance system is an auxiliary facility installed between the two piers after the main pier columns are constructed, rather than being cast integrally with the pier columns.

[0066] After rigorous engineering design and calculation, the embodiment provided is as follows: Figure 2 Structure and Figure 1 Compared to similar structures, this design enhances the lateral deformation capacity of the piers, facilitating the vibration reduction effect of the energy-dissipating braces. Furthermore, it prevents seismic damage to the joints, ensuring sufficient load-bearing capacity of the piers during and after earthquakes. The relevant performance indicators will be verified in the design section below.

[0067] Example 2

[0068] The high-pier seismic-resistant system with hinged tie beams and energy-dissipating braces provided in Embodiment 1, which improves the structure of traditional bridge piers with concrete tie beams, has also revolutionized the seismic design of bridge structures. For example, traditional solutions include engineering cases of double-column high-pier bridges with multi-layered bracing. In the design phase of these projects, engineers often need complex and tedious steps to determine the parameters of bracing or other components that meet seismic and other requirements. This process is time-consuming and labor-intensive, placing a significant workload on designers. However, by adopting the high-pier seismic-resistant system with hinged tie beams and energy-dissipating braces provided in Embodiment 1 of this invention, the difficulty of seismic design for bridge engineering can be greatly simplified.

[0069] In this embodiment, the double-column high pier of the bridge is taken as the design object. After setting up a high pier seismic resistance system with hinged tie beams and energy-dissipating braces to replace the traditional concrete tie beams, the buckling-restrained braces are set on the multi-layer tie beams to form a multi-layer buckling-restrained brace double-column high pier lateral seismic resistance system. This embodiment can decompose the seismic resistance system into two parallel structures: a pure double-column high pier and a multi-layer buckling-restrained brace truss. Based on the deformation coordination and force synergy theory between the two, a new seismic design method is proposed to quickly determine the parameters of the multi-layer buckling-restrained brace under a specified design objective.

[0070] The principle of equal displacement and the theory of displacement compatibility are the two main bases for the design method proposed in this embodiment. The principle of equal displacement states that within a certain structural period, the elastoplastic displacement of a certain elastoplastic system under the design earthquake is equal to the elastic displacement of an elastic system with the same initial elastic stiffness. The theory of displacement compatibility assumes that the multi-layered braced truss structure and the unstretched double-column pier structure have the same displacement pattern. Therefore, the seismic-resistant system in this invention can be decoupled into two parallel systems—the multi-layered braced truss and the unstretched double-column pier—for correlation analysis during structural design.

[0071] Specifically, such as Figure 3 As shown, the seismic design method for bridges employing hinged tie beams and buckling-restrained braces provided in this embodiment includes the following steps:

[0072] S1: Obtain the basic design parameters and design seismic motion parameters of the double-column high pier of the bridge based on the design information; including: pier structural dimensions, equivalent structural mass of each part, design seismic motion displacement response spectrum S(T), and pier transverse first-order vibration mode. And the initial design displacement d0 of the bridge pier.

[0073] Specifically, the structural dimensions of the bridge piers include the total height H of the piers. For example... Figure 4 As shown, the structural equivalent mass of each part includes the mass m of the main beam. s The mass of the cap beam is m c and the equivalent mass m of the lower pier columnc The design ground motion displacement response spectrum is a spectral data calculated from the ground motion records of an earthquake. It is used to characterize the relationship between the maximum absolute acceleration, velocity, and displacement of a single-degree-of-freedom system during an earthquake and its natural period T. This data can be used to calculate the seismic displacement of a double-column pier at a specified period. To simplify the design, this embodiment also assumes that the displacement envelope of the double-column pier under seismic loading is linearly proportional to its first mode shape, even if it affects the design objectives.

[0074] S2: Based on the structural dimensions of the pier, the equivalent mass of each part of the structure, and the first transverse vibration mode of the pier. Calculate the equivalent mass M of the double-column high pier of the bridge. In this embodiment, the formula for calculating the equivalent mass M of the double-column high pier of the bridge is as follows:

[0075]

[0076] In the above formula, m s m c and m c These represent the mass of the main beam, the mass of the cap beam, and the equivalent mass of the lower pier column, respectively; H represents the pier height; EI represents the flexural stiffness of the pier column section; and x represents the pier's ground elevation.

[0077] S3: Combining the flexural stiffness EI of the pier section and the first transverse vibration mode of the pier. Calculate the lateral elastic stiffness k of a double-column high pier without buckling restraint bracing. p The lateral elastic stiffness k of the double-column high pier p The calculation formula is as follows:

[0078]

[0079] S4: Based on the design seismic motion displacement response spectrum S(T), generated at a characteristic period of T. * Seismic displacement d of double-column high pier * .

[0080] S5: In the bridge piers of this embodiment that adopt a high-pier seismic resistance system with hinged tie beams and energy-dissipating diagonal braces, the structural design should meet the following conditions:

[0081] When the structural period is greater than the characteristic period of the response spectrum, the principle of equal displacement is satisfied, and the elastoplastic displacement is equal to its corresponding elastic displacement; when the structural period is less than the characteristic period of the response spectrum, the principle of equal energy is satisfied, and the elastic displacement needs to be corrected to obtain the actual elastoplastic displacement.

[0082] Therefore, as Figure 5As shown, the design scheme requires determining whether the initial design displacement d0 in S1 is less than d*: if so, the initial design displacement d0 is corrected; otherwise, the structural period is considered to satisfy the principle of equal displacement, and it is taken as the design displacement d of the pier.

[0083] The correction steps for the initial design displacement d0 are as follows:

[0084] S51: Assume an elastic displacement value d1, which satisfies: d1 <d0;

[0085] S52: Obtain the structural period T1 corresponding to the design displacement d1 by designing the seismic motion displacement response spectrum S(T).

[0086] S53: Calculate the corresponding displacement correction coefficient R using the following formula, taking into account the structural period T1. d1 :

[0087]

[0088] In the above formula, μ D The displacement ductility coefficient is designed. The displacement ductility coefficient μ D It is a manually set constant related to the engineering scenario.

[0089] S54: Determine R d1 Is the error between ×d1 and d0 less than 5%? If yes, the correction is complete. Use R... d1 Correct d0; otherwise, re-assume the elastic displacement value d2 = d / R. d1 Then return to step S52 to continue iterative correction.

[0090] S6: The elastic stiffness K of the double-column pier with buckling-restrained bracing is calculated by combining the design displacement d obtained from iterative convergence with the design ground motion response spectrum S(T). In this embodiment, the formula for calculating the elastic stiffness K of the double-column pier is as follows:

[0091]

[0092] In the above formula, n represents the number of stories in the multi-story buckling-restrained braced truss structure; k bi denoted by , where represents the design elastic stiffness of the buckling-restrained brace of the i-th layer, and n represents the total number of layers in the multi-layer buckling-restrained brace truss structure.

[0093] S7: Assuming that the diagonal braces of each layer are connected in series, determine the elastic stiffness k of the multi-layer buckling-restrained diagonal brace truss structure according to the formula for the stiffness relationship between connected members. b And calculate the design elastic stiffness k of the buckling restraint braces in each layer. bi and horizontal design displacement Δ bi The formula for the stiffness relationship between series members is as follows:

[0094]

[0095] In the above formula, c is the proportionality coefficient; k bj The design elastic stiffness of the buckling-restrained brace of the j-th layer, i≠j; H j H j-1 H i and H i-1 denoted as the heights of the buckling restraint braces of the j-th, j-1, i-th, and i-1-th layers, respectively.

[0096] S8: Combine the design of elastic stiffness k with buckling restraint braces in each layer. bi and horizontal design displacement Δ bi Calculate the minimum effective length L of the buckling restraint brace required for each layer. bi and the cross-sectional area A of the diagonal brace bi In this embodiment, the minimum effective length L of the buckling-restrained brace is... bi and the cross-sectional area A of the diagonal brace bi The constraint equations satisfied are as follows:

[0097]

[0098] In the above formula, L represents the total length of the buckling-restrained brace; μ b ε is the allowable displacement ductility coefficient of the brace, the value of which is determined by the allowable strain of the core material; θ is the inclination angle of the brace; ε y E represents the yield strain of the core material of the diagonal brace. b This indicates the elastic modulus of the bracing material.

[0099] Based on the above process, it can be seen that the seismic design method for bridges using articulated tie beams and buckling-restrained braces provided in this embodiment can quickly determine the design parameters of buckling-restrained braces installed at different layers based on known design conditions, such as the design parameters of the bridge's double-column high piers, the design ground motion, and seismic performance targets, without the need for complex and time-consuming nonlinear seismic response calculations and parameter analyses, thus meeting the predetermined seismic performance targets. The proposed design method greatly simplifies the seismic design process for bridges with double-column high piers and multiple layers of buckling-restrained braces, improves the efficiency of buckling-restrained brace parameter design, and facilitates practical engineering applications.

[0100] Example 3

[0101] This embodiment provides a seismic design system for bridges employing hinged tie beams and buckling-restrained braces, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the seismic design method for bridges employing hinged tie beams and buckling-restrained braces as described in Embodiment 2, and then obtains the key parameters of the multi-layer buckling-restrained braces that meet the seismic design objectives based on the basic design parameters of the bridge project and the design ground motion parameters.

[0102] The seismic design system for bridges employing articulated tie beams and buckling-restrained braces provided in this embodiment is essentially a computer device. This computer device can automatically complete the data processing procedures described in Embodiment 2 based on instructions. Furthermore, under the premise of meeting predetermined seismic performance targets, and based on input design conditions such as design parameters of the bridge's double-column high piers, design ground motion, and seismic performance targets, it automatically completes all mathematical calculations and parameter analysis processes, and quickly outputs the required design parameters for the buckling-restrained braces in different layers of the high-pier seismic system with articulated tie beams and energy-dissipating braces.

[0103] In this embodiment, the computer equipment referred to in the seismic design system can be a smartphone, tablet, laptop, desktop computer, rack server, blade server, tower server, or cabinet server (including independent servers or server clusters composed of multiple servers) capable of executing programs.

[0104] The computer device in this embodiment includes, but is not limited to, a memory and a processor that can be interconnected via a system bus. In this embodiment, the memory (i.e., the readable storage medium) includes flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory can be an internal storage unit of the computer device, such as the hard disk or RAM of the computer device. In other embodiments, the memory can also be an external storage device of the computer device, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc. Of course, the memory can also include both internal storage units and external storage devices of the computer device. In this embodiment, the memory is typically used to store the operating system and various application software installed on the computer device. Furthermore, the memory can also be used to temporarily store various types of data that have been output or will be output.

[0105] In some embodiments, the processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip. The processor is typically used to control the overall operation of a computer device.

[0106] Simulation Experiment

[0107] To verify the effectiveness of the high pier seismic resistance system with hinged tie beams and energy-dissipating diagonal braces provided by this invention and its corresponding seismic design method, the technicians formulated the following simulation experiment, using a typical bridge design case for simulation, and tested the relevant performance of the designed seismic resistance structure.

[0108] 1. Design process simulation

[0109] In this embodiment, the following is selected: Figure 6 The following table shows the seismic design of a 25-meter span simply supported T-beam bridge with three-story, double-column high piers. The known design parameters for the scenario are as follows:

[0110] Table 1: Known Scene Parameters in the Bridge Pier Case Study of This Experiment

[0111]

[0112] See attached document Figure 3 The seismic design steps for a multi-layer buckling-restrained bracing system with a hinged tie beam and double-column high piers in this embodiment are as follows:

[0113] (1) Obtain the known basic design parameters as shown in Table 1.

[0114] (2) The equivalent mass of the three-story double-column high pier is calculated to be M = 833 tons. The lateral elastic stiffness of the double-column pier without diagonal bracing is kp = 17377 kN / m.

[0115] (3) The structural displacement d* = 0.39 m was calculated at the characteristic period T* = 1.125 s of the reaction spectrum.

[0116] (4) Since d* is greater than d, we assume a smaller elastic displacement, d1 = 0.13m.

[0117] (5) Calculate the structural period T1 = 0.585s when d1 = 0.13m, calculate the displacement correction factor Rd1 = 1.69, and the corrected displacement is Rd1 × d1 = 0.22m. Since the corrected displacement still differs from the initial design displacement of 0.16m, assume d2 = d / Rd1 = 0.095m again, and repeat step 5. After two iterations, the final calculation results are obtained: d3 = 0.078m, T3 = 0.452s, Rd3 = 2.12, Rd3 × d3 = 0.164m < d × (1 + 5%).

[0118] (6) Calculate the elastic stiffness K = 160878kN / m of the double column pier with diagonal bracing when d3 = 0.078m. Then calculate the elastic stiffness of the buckling restraint diagonal bracing required for each floor as follows: kb1 = 537558kN / m, kb2 = 312787kN / m, kb3 = 479502kN / m, and the horizontal deformations as follows: Δb1 = 0.043m, Δb2 = 0.073m, Δb3 = 0.048m.

[0119] (7) Assuming the allowable displacement ductility coefficient of the buckling restraint brace is μb=5.0, the effective lengths of the braces in each layer are calculated as follows: Lb1=3.27m, Lb2=5.62m, Lb3=3.67m, and the required cross-sectional areas of the braces are as follows: Ab1=1.81×10-2m2, Ab2=1.81×10-2m2, Ab3=1.81×10-2m2.

[0120] 2. Performance Testing

[0121] To verify the rationality of the parameters in the high-pier seismic-resistant system with hinged tie beams and energy-dissipating braces designed using the method of this invention, this experiment uses the nonlinear time history method to calculate the seismic response of the double-column pier structure before and after the design ground motion intensity, and as shown in the figure... Figure 7 As shown, 20 actual seismic waves with mean values ​​matching the design acceleration response spectrum were selected as seismic inputs, and the results were plotted as follows. Figures 8-11 The maximum transverse seismic response of a double-column high-pier bridge with hinged tie beams, designed using the method provided in this invention under seismic wave input, is shown below compared to the design before design.

[0122] Combination Figure 8 and Figure 9 It is known that the seismic displacement requirement of the double-column pier was relatively large before buckling restraint bracing was used, with an average value of 0.453m. After designing multi-layer bracing using the method provided by this invention, the seismic displacement of the double-column pier was effectively controlled, and the average displacement was kept near the design displacement of 0.16m, which met the seismic design target. This proves the effectiveness of this method in controlling the seismic displacement requirement of double-column high piers.

[0123] Further integration Figure 10 and Figure 11 Analysis shows that the maximum displacement ductility coefficient of each layer of buckling-restrained bracing designed using the method of this invention does not exceed the design limit, and each layer of bracing can fully demonstrate strong hysteretic energy dissipation characteristics, proving that the design method provided by this invention can reasonably design the parameters of multi-layer buckling-restrained bracing.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A seismic design method for bridges employing hinged tie beams and buckling-restrained braces, characterized in that: It is used to decompose the high pier seismic system with hinged tie beams and energy dissipation braces into two parallel structures: a pure double-column high pier and a multi-layer buckling-restrained braced truss, under a specified seismic design objective. Based on the deformation coordination and force synergy theory between the two, it can quickly determine the key parameters of the multi-layer buckling-restrained brace. The high pier seismic system with hinged tie beams and energy-dissipating braces is a truss structure composed of multiple tie beams and multiple buckling-restrained braces. Each tie beam is evenly distributed between the cap beam and the pier abutment along the pier elevation direction. The buckling-restrained braces are distributed sequentially between the cap beam and the tie beam, between the tie beams, and between the tie beam and the pier abutment on each floor. The two ends of each tie beam and buckling-restrained brace are detachably and fixedly connected to the pier of the bridge by hinges. The seismic design method includes the following steps: S1: Obtain the basic design parameters and design seismic motion parameters of the bridge's double-column high piers based on the design information; including: pier structural dimensions, equivalent structural mass of each component, and design seismic motion displacement response spectrum. S ( T ), the first transverse vibration mode of the bridge pier and the initial design displacement of the bridge piers. d 0 ; S2: Based on the structural dimensions of the pier, the equivalent mass of each part of the structure, and the first transverse vibration mode of the pier. Calculate the equivalent mass M of a double-column high pier for a bridge; S3: Combined with the flexural stiffness of the pier section EI And the first transverse vibration mode of the bridge pier Calculate the lateral elastic stiffness of a double-column high pier without buckling restraint bracing. k p ; S4: Based on the design seismic motion displacement response spectrum S ( T ) generated in a feature period of T * Seismic displacement of double-column high pier d* ; S5: Determine the initial design displacement in S1 d 0 Is it less than d* : Yes, then the initial design displacement d 0 Make corrections; otherwise, assume the structural period satisfies the principle of equal displacement and use it as the design displacement of the pier. d ; Initial design displacement d 0 The correction steps are as follows: S51: Assuming an elastic displacement value d 1 It satisfies: d 1 < d 0 ; S52: By designing the seismic displacement response spectrum S ( T Obtain the design displacement d 1 Corresponding structural period T 1 ; S53: In conjunction with the aforementioned structural periodicity T 1 The corresponding displacement correction factor can be calculated using the following formula. R d1 : In the above formula, To design the displacement ductility coefficient; S54: Judgment R d1 × d 1 and d 0 Is the error less than 5%? If yes, the correction is complete. R d1 Correction d 0 Otherwise, re-assume the elastic displacement value. d 2 = d / R d1 Then return to step S52 to continue iterative correction; S6: Design displacement obtained from iterative convergence d Combined with the design of the seismic response spectrum S ( T The elastic stiffness K of the double-column high pier with buckling-restrained diagonal bracing was calculated. S7: Assuming that the diagonal braces of each layer are connected in series, determine the elastic stiffness of the multi-layer buckling-restrained diagonal brace truss structure according to the formula for the stiffness relationship between connected members. k b The design elastic stiffness of the buckling-restrained braces in each layer was calculated. k bi and horizontal design displacement Δ bi : S8: Combine the design of elastic stiffness with buckling restraint braces in each layer. k bi and horizontal design displacement Δ bi Calculate the minimum effective length of buckling restraint braces required for each layer. L bi and the cross-sectional area of ​​the diagonal brace A bi .

2. The seismic design method for bridges employing hinged tie beams and buckling-restrained braces as described in claim 1, characterized in that: In step S2, the formula for calculating the equivalent mass M of the double-column high pier of the bridge is as follows: In the above formula, m s , m c and m p These represent the mass of the main beam, the mass of the cap beam, and the equivalent mass of the lower pier column, respectively; H represents the pier height. x This indicates the height of the bridge pier above the ground.

3. The seismic design method for bridges employing hinged tie beams and buckling-restrained braces as described in claim 2, characterized in that: In step S3, the lateral elastic stiffness of the double-column high pier k p The calculation formula is as follows: ； In the above formula, EI This indicates the flexural stiffness of the pier column section.

4. The seismic design method for bridges employing hinged tie beams and buckling-restrained braces as described in claim 3, characterized in that: In step S53, the displacement ductility coefficient It is a manually set constant related to the engineering scenario.

5. The seismic design method for bridges employing hinged tie beams and buckling-restrained braces as described in claim 3, characterized in that: In step S6, the formula for calculating the elastic stiffness K of the double-column pier is as follows: In the above formula, k bi Indicates the first i Elastic stiffness of layer buckling restraint brace design n This indicates the total number of stories in a multi-layer buckling-restrained braced truss structure.

6. The seismic design method for bridges employing hinged tie beams and buckling-restrained braces as described in claim 5, characterized in that: In step S7, the formula for the stiffness relationship between series members is as follows: In the above formula, c This is the proportionality coefficient; k bj Design elastic stiffness of the buckling-restrained brace of the j-th layer. ; H j , H j-1 , H i , H i-1 They represent the first j , j -1、 i , i -1 is the height of the buckling restraint brace.

7. The seismic design method for bridges employing hinged tie beams and buckling-restrained braces as described in claim 1, characterized in that: In step S8, the minimum effective length of the buckling restraint brace is... L bi and the cross-sectional area of ​​the diagonal brace A bi The constraint equations satisfied are as follows: In the above formula, L Indicates the total length of the buckling-restrained brace; This is the allowable displacement ductility coefficient of the diagonal brace, and its value is determined by the allowable strain of the core material. The angle of inclination of the diagonal brace; The yield strain of the core material of the diagonal brace; E b This indicates the elastic modulus of the bracing material.

8. A seismic design system for bridges employing hinged tie beams and buckling-restrained braces, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, it implements the steps of the seismic design method for bridges using hinged tie beams and buckling-restrained braces as described in any one of claims 1-7, and then obtains the key parameters of the multi-layer buckling-restrained braces that meet the seismic design objectives based on the basic design parameters of the bridge project and the design ground motion parameters.

9. A design and construction method for earthquake-resistant bridge piers, comprising the following steps: (1) The bridge piers are designed as double-column high piers with a high pier seismic system with hinged tie beams and energy dissipation braces, and the basic design parameters and design ground motion parameters of the bridge project are determined. (2) Using the seismic design method for bridges with hinged tie beams and buckling-restrained braces as described in any one of claims 1-7, the key parameters of multi-layer buckling-restrained braces that meet the seismic design objectives are obtained based on the basic design parameters and the design ground motion parameters. (3) Procurement or prefabrication of various structural components in the high pier seismic system with hinged tie beams and energy dissipation braces according to key parameters; (4) After the construction of the double-column high pier structure of the main body of the bridge is completed, the prefabricated structural components are installed according to the design drawings to complete the construction of the bridge pier including the high pier seismic system with the hinged tie beam and energy dissipation brace.

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