Prefabricated bridge support and design method thereof

Abstract

This invention discloses a prefabricated bridge bearing and its design method. The bearing includes an upper bearing plate assembly, a flat sliding plate, a spherical crown, a spherical sliding plate, and a lower bearing plate assembly. The upper bearing plate stop is assembled, disassembled, and longitudinally adjusted via pre-tightened bolts, which can compensate for misalignment between the upper and lower bearing plates. The lower bearing plate assembly uses a high-performance concrete base plate instead of a steel base plate, with a pot ring threaded to the spherical base. The lower bearing plate stop is rotatable. Bearings of the same model but different functions share the same core component, and only the stop needs to be replaced to switch functions. The design method first determines the core parameters such as the vertical bearing capacity of the bearing, and then quantitatively determines the installation dimensions of each component and the overall shape step by step, clarifying the design calculation standards. This invention adopts a prefabricated modular design, optimizes material selection, and combines standardized design methods to improve the bearing's production and installation efficiency and service adaptability, reduce costs, and solve the problems of poor versatility and inability to adapt to installation deviations in traditional bearings.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering component design technology, and more specifically, relates to a prefabricated bridge bearing and its design method. Background Technology

[0002] Bridge bearings are important force-transfer components between the superstructure and substructure of a bridge. They are responsible for reliably transferring the load of the superstructure to the substructure. At the same time, they must also accommodate the displacement and rotation deformation of the bridge caused by factors such as temperature changes, concrete shrinkage and creep, prestressing, and vehicle loads. They are key components to ensure the safety and normal service of the bridge structure.

[0003] Existing bridge bearings mainly consist of five core components: an upper bearing plate, a flat sliding plate, a spherical crown, a spherical sliding plate, and a lower bearing plate. The upper and lower bearing plates are often fabricated as a single piece of steel. However, this type of traditional bridge bearing has many technical defects in its design, production, installation, and service, making it difficult to meet the efficient, economical, and reliable construction requirements of modern bridge engineering. (1) Poor versatility and low production efficiency: For supports of different models and different functions (fixed, unidirectional sliding, bidirectional sliding), it is necessary to customize integrated steel upper and lower seat plates separately. There is no universal component design, the design is highly repetitive, the standardization of production and processing is low, and the overall production efficiency is low. (2) High material cost and low utilization rate: The upper and lower seat plates and the bottom plate are all made of pure steel, which consumes a large amount of steel. The cost of raw materials and processing and manufacturing costs remain high. Furthermore, the materials are not optimized and matched according to the stress characteristics of the components, resulting in low material utilization rate. (3) Inability to adapt to installation and service deviations: During the installation and long-term service of the bearing, the upper and lower bearing plates are prone to misalignment due to factors such as construction errors, concrete shrinkage and creep, and prestressing. The blocks of the traditional integrated bearing are fixed structures and cannot be adjusted, which can easily cause problems such as bearing jamming and uneven local stress, affecting the service performance of the bearing. (4) Insufficient flexibility in component connection: The traditional bearing base and basin ring, and the stop block and basin ring adopt a fixed connection method, which cannot adapt to the slight deflection of the bearing caused by construction errors, which easily causes local stress concentration in the bearing and reduces the service life of the bearing. (5) Low component integration and high construction cost: Each component of the lower seat plate assembly is designed, processed and assembled independently. The core components of different functional supports cannot be used interchangeably and need to be transported and installed separately, which further increases the construction and maintenance costs.

[0004] To address the aforementioned technical challenges, there is an urgent need to develop a bridge bearing with high versatility, a high degree of modularization, low cost, and adaptability to installation and service deviations, along with its design method. Modular and standardized design will improve the production and installation efficiency of the bearing, while adjustable structures will accommodate various deviations. At the same time, optimized material selection will reduce costs and ensure the reliability of the bearing in service. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a prefabricated bridge bearing and its design method. The bearing includes an upper bearing plate assembly, a planar sliding plate, a spherical crown, a spherical sliding plate, and a lower bearing plate assembly. In the upper bearing plate assembly, a pre-tightening component forms a longitudinal sliding fit with the upper bearing plate sliding groove. The upper bearing plate stop block achieves quick assembly and disassembly and longitudinal position adjustment via pre-tightening bolts, compensating for misalignment issues between the upper and lower bearing plates caused by construction errors, concrete shrinkage, and creep. The lower bearing plate assembly uses a high-performance concrete base plate instead of a steel base plate, and the basin ring is threaded to the spherical base basin. The lower seat plate block and the basin ring are rotatably connected by fastening bolts. Fixed, unidirectional and bidirectional sliding bearings of the same model share core components such as the spherical base plate and the base plate. Functional switching can be achieved by simply replacing the lower seat plate block. The corresponding design method determines the core parameters such as the vertical bearing capacity and horizontal bearing capacity of the bearing according to the bridge design requirements. Then, it quantifies and determines the size parameters of each component such as the pre-tightening bolts, upper seat plate, lower seat plate block, base plate, and spherical base plate, as well as the overall shape and installation dimensions of the bearing, in steps. The design calculation standards and matching requirements of each component are clearly defined. This invention adopts a modular prefabricated structure design, which enables rapid switching of bearing functions and standardized production of components. The adjustable and rotatable stop structure adapts to various construction and structural deformation deviations. Combined with the optimized selection of high-performance concrete materials, the amount of steel used is greatly reduced. At the same time, the proposed standardized design method provides a clear quantitative basis for determining the dimensions of each bearing component, effectively improving the production and installation efficiency, service adaptability and structural stability of the bearing. It takes into account both economy and load-bearing reliability, and can solve the technical problems of poor versatility, high cost, inability to adapt to installation deviations and lack of unified quantitative standards in the design process of traditional bridge bearings.

[0006] To achieve the above objectives, one aspect of the present invention provides a prefabricated bridge bearing, comprising an upper bearing plate assembly, a planar sliding plate, a spherical crown, a spherical sliding plate, and a lower bearing plate assembly arranged sequentially from top to bottom; The upper seat plate assembly includes an upper seat plate, two upper seat plate sliding grooves parallel to each other on the upper seat plate, an upper seat plate stop block detachably disposed on the upper seat plate sliding groove, and a pre-tightening member disposed on the upper seat plate sliding groove; the pre-tightening member forms a longitudinal sliding fit with the upper seat plate sliding groove; the upper seat plate stop block and the upper seat plate are fixed by a pre-tightening bolt passing through the upper seat plate stop block and connecting to the pre-tightening member; The lower seat plate assembly includes a basin ring, a base plate disposed at the bottom of the basin ring, and a spherical bottom basin disposed on the base plate inside the basin ring. The upper outer part of the basin ring is milled to form a frustum section, and a lower seat plate block is detachably provided at the frustum section of the basin ring. The planar sliding plate is directly attached and fixed to the lower surface of the upper seat plate of the upper seat plate assembly; The spherical crown is located directly below the flat slide plate, with its top surface closely fitting the lower surface of the flat slide plate and its bottom surface having a spherical structure. The spherical sliding plate is located on the concave spherical surface of the spherical base and cooperates with the spherical structure of the spherical crown, so that the support can rotate freely within the designed rotation angle range and can bear the transmission of vertical loads.

[0007] Furthermore, the upper seat plate sliding groove includes two upper seat plate sliding groove openings with rectangular cross sections arranged in parallel and spaced apart, and a sliding groove channel with an inverted T-shaped cross section disposed between the two upper seat plate sliding groove openings; The sliding direction section of the preload is an inverted T-shaped section, and the bottom surface is a rectangular section, forming a longitudinal sliding fit with the sliding groove channel; The upper surface of the pre-tightening component has bolt holes, and the upper and lower surfaces of the upper seat plate block have multiple through bolt holes; the number of pre-tightening components is the same as the number of through bolt holes on the upper seat plate block.

[0008] Furthermore, the basin ring is a cylindrical hollow steel tube structure with threads on its inner wall, which are adapted to the threads on the cylindrical side of the spherical bottom basin to achieve assembly and fastening. The outer wall of the cylinder above the frustum section is threaded, and a fastening threaded hole is drilled radially at the corresponding position. The lower seat plate has a strip-shaped threaded hole on its side; The fastening bolt passes through the threaded hole of the lower seat plate block and engages with the fastening threaded hole on the frustum section, connecting the lower seat plate block and the basin ring into a whole. The lower seat plate stop can be rotated within the range of the threaded hole of the stop by tightening or loosening the fastening bolt; The outer wall of the basin ring is provided with multiple anchoring lugs at intervals; The base plate is a cylindrical high-performance concrete structure. The spherical base is a steel structure with cylindrical sides and a concave spherical top surface. The upper surface of the spherical base has a platform section at its edge, and the lower surface is a plane.

[0009] Furthermore, the prefabricated bridge bearing is available in three forms: fixed bearing, unidirectional sliding bearing, and bidirectional sliding bearing; the inner surface of the lower bearing plate block facing the center of the bearing is provided with a lower bearing plate guide strip, which forms a sliding guide fit with the side of the upper bearing plate block. When the support is a one-way sliding support, there are two lower support plate guide strips on the lower support plate block in the longitudinal direction of the bridge; the two lower support plate guide strips on the left and right form a guide channel, which only allows the upper support plate block to slide in the longitudinal direction of the bridge and restricts the transverse displacement of the bridge. When the support is a fixed support, the lower support plate guide strip on the lower support plate block is provided on all four sides in the longitudinal and transverse directions of the bridge, which surrounds and limits the upper support plate block from all sides, so that the displacement of the support in any direction on the horizontal plane is restricted, and complete fixation is achieved. When the support is a two-way sliding support, the lower support plate block is not installed, and the upper support plate block has no lateral constraint in the horizontal direction.

[0010] A second aspect of the present invention provides a design method for prefabricated bridge bearings, used to design the prefabricated bridge bearings, comprising: S1: Based on the bridge design requirements, determine the vertical bearing capacity, horizontal bearing capacity, design displacement, and design rotation angle of the prefabricated bridge bearings; S2: Determine the type, quantity, and dimensions of the upper bearing plate of the pre-tightening bolts based on the horizontal bearing capacity and design displacement of the prefabricated bridge bearing; S3: Determine the dimensional parameters of the lower bearing plate block based on the horizontal bearing capacity of the prefabricated bridge bearing; the dimensional parameters of the lower bearing plate block include height and planar dimensions. S4: Determine the height of the upper bearing plate stop based on the size parameters of the lower bearing plate stop and the design rotation angle of the prefabricated bridge bearing. S5: Determine the design dimensions of the base plate based on the vertical bearing capacity of the prefabricated bridge bearing; S6: Determine the size of the spherical base plate based on the vertical bearing capacity of the prefabricated bridge bearing and the design dimensions of the base plate; S7: Determine the overall external dimensions and installation dimensions of the prefabricated bridge bearing based on the design parameters of the upper bearing plate, pot ring, and base plate.

[0011] Further, step S2 includes: The number of pre-tightening bolts is initially selected based on the horizontal bearing capacity of the support. The bolts are then selected according to the horizontal bearing capacity: 5 bolts for 0-1000kN, 8 bolts for 1000-5000kN, and 10 bolts for 5000-10000kN. The initial selection is then checked against the shear strength calculation formula for the pre-tightening bolts to ensure that the number of bolts meets the shear resistance requirements of the horizontal load on the support. The final number of pre-tightening bolts is then determined. Based on the verified number of pre-tightened bolts, the design value of horizontal bearing capacity, and the mechanical performance parameters of the bolts, determine the type of pre-tightened bolts and clarify the core technical indicators such as the nominal diameter, pitch, length, and material of the bolts; Based on the design displacement requirements of the support, and combined with the longitudinal sliding fit relationship between the pre-tightening components and the upper plate sliding groove, the groove length and channel size parameters of the upper plate sliding groove are determined, and the arrangement spacing and installation space of the pre-tightening bolts and pre-tightening components are matched. Based on the design parameters of the upper plate sliding groove, the arrangement requirements of the pre-tightening bolts and pre-tightening components, and the force transmission requirements of the vertical bearing capacity of the support, the planar dimensions and thickness of the upper plate are comprehensively determined to ensure that the structural strength and stiffness of the upper plate meet the requirements of the support for stress and sliding deformation. To prevent jamming when the pre-tightening component mates with the upper seat plate sliding groove, the height of the pre-tightening component is determined based on the vertical dimension of the upper seat plate sliding groove. The height of the pre-tightening component is 1-2 mm smaller than the vertical dimension of the upper seat plate sliding groove, ensuring that the pre-tightening component can slide freely longitudinally within the upper seat plate sliding groove.

[0012] Further, step S3 includes: Determine the length of the guide bar for the lower seat plate stop, ensuring that the guide bar length matches the diameter of the flat slide plate; Based on the horizontal bearing capacity of the support, the compressive strength of the material used for the lower support plate block, and the determined guide strip length, the design height of the lower support plate block is calculated using the formula: Lower support plate block height = Horizontal bearing capacity / Compressive strength / Guide strip length. Based on the guide strip length, stop block design height, and the functional requirements of horizontal guidance and limiting of the support, the planar dimensions of the lower seat plate stop block and the matching dimensions of the irregular structure are comprehensively determined to ensure that it meets the requirements of horizontal force on the support and the matching requirements with the upper seat plate stop block.

[0013] Further, step S4 includes: S41: Based on the actual motion state of the support during service, clarify the lateral guiding fit relationship between the upper support plate block and the lower support plate block, and define the fit boundary requirements between the two. S42: Based on the height and planar dimensions of the lower seat plate block, and combined with the design rotation angle of the support, simulate and calculate the vertical spatial force and deformation boundary of the upper seat plate block under the coupled working conditions of maximum design displacement and design rotation angle. S43: Based on the simulation calculation results of step S42, determine the minimum design height of the upper seat plate block to ensure that the lower surface of the upper seat plate block is always higher than the lower surface of the lower seat plate block under all working conditions of design displacement and design rotation angle, so as to meet the guiding fit requirements and have no structural interference.

[0014] Further, step S6 includes: S61: Based on the vertical bearing capacity of the support and the design value of the compressive strength of the flat sliding plate, calculate and determine the diameter of the flat sliding plate 2 as the basic parameter for the size design of the spherical bottom basin; S62: Based on the diameter of the flat sliding plate, determine the spherical radius of the spherical base according to the standard of 1.5 times the diameter of the flat sliding plate; S63: Based on the design height of the concave spherical surface of the spherical base, add a dimensional allowance of 5-10mm to calculate and determine the overall height of the spherical base; S64: Match the planar design dimensions of the base plate to determine the planar dimensions of the spherical base basin, ensuring that the two are properly assembled and that vertical force transmission is smooth.

[0015] Further, step S7 includes: S71: Review the planar dimensions and thickness of the upper seat plate, the outer diameter, height, and frustum section dimensions of the basin ring, and the planar dimensions and height parameters of the base plate; clarify the outer boundaries and assembly connection dimensions of each component. S72: Based on the assembly relationship between the upper and lower seat plate assemblies, and the thickness dimensions of the flat sliding plate, spherical crown, and spherical sliding plate, calculate the overall vertical installation height of the support, reserve assembly gaps for components, and ensure the smoothness of vertical force transmission. S73: Based on the maximum planar contour of the upper seat plate and the pot ring, and combined with the arrangement dimensions of the anchoring ear plate and the lower seat plate block, determine the overall planar installation dimensions of the support to meet the connection and installation requirements between the support and the bridge superstructure and piers. S74: Based on the vertical height and planar dimensions of the bearing, as well as the installation space and connection requirements at the bridge engineering site, the overall external shape and installation dimensions of the prefabricated bridge bearing are finally determined.

[0016] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: (1) The present invention divides the support into modular structures such as upper support plate assembly and lower support plate assembly. Fixed, unidirectional sliding and bidirectional sliding supports of the same model adopt the same spherical base plate, base plate, basin ring and anchoring ear plate. Functional switching can be achieved by simply replacing or adding or removing the lower support plate block, which greatly improves the versatility of components and the degree of production standardization. At the same time, each component adopts assembly connection methods such as threads and bolts to achieve quick assembly and disassembly and on-site adjustment, reducing the difficulty of installation and construction. In addition, the base plate uses high-performance concrete to replace the steel base plate to form a steel pipe concrete composite structure, which greatly saves the amount of steel used and reduces the overall cost of the support from multiple dimensions such as raw materials, production and construction.

[0017] (2) In the bearing design stage, the present invention fully considers the superposition effect of bidirectional displacement / rotation in the calculation of design displacement and design rotation angle, so that the final design value of the bearing covers the maximum deformation in both positive and negative directions. It can effectively adapt to the bidirectional displacement caused by temperature expansion and contraction, concrete shrinkage and creep, prestressing, and foundation settlement of the bridge, as well as the bidirectional rotation deformation caused by the deflection of the superstructure and uneven settlement of the foundation. At the same time, through the adjustable design of the upper bearing plate stop and the rotatable design of the lower bearing plate stop, it can compensate for the misalignment of the upper and lower bearing plates and the bearing deflection caused by construction errors and structural deformation, avoid bearing jamming and local stress concentration, and ensure the rationality of the bearing under all working conditions and the structural stability.

[0018] (3) The prefabricated bridge bearing design method proposed in this invention determines the size parameters of the pre-tightening bolts, upper bearing plate, lower bearing plate block, upper bearing plate block, base plate, and spherical base plate, as well as the overall shape and installation dimensions of the bearing, step by step according to the core parameters such as vertical bearing capacity, horizontal bearing capacity, design displacement, and design rotation angle. The calculation basis of each step is clear and the design logic is clear. Quantitative design standards and matching requirements are formulated for key load-bearing components. At the same time, the design process takes into account the compatibility of component assembly, the smoothness of structural force transmission, and the deformation guidance and limiting function, providing a standardized process for the design of bearings of different specifications and functions, effectively improving the bearing design accuracy, ensuring that the dimensions of each component of the bearing are matched and the force is coordinated, and fully meeting the vertical force transmission, horizontal guidance, and deformation adaptation requirements of bridge engineering. Attached Figure Description

[0019] Figure 1 This is a partial cross-sectional structural schematic diagram (first view) of a prefabricated bridge bearing according to an embodiment of the present invention. Figure 2 This is a partial cross-sectional structural schematic diagram (second perspective) of a prefabricated bridge bearing according to an embodiment of the present invention. Figure 3 This is an exploded structural diagram of the components of the upper bearing plate assembly of a prefabricated bridge bearing according to an embodiment of the present invention. Figure 4 This is an exploded structural diagram of the components of the lower bearing plate assembly when the prefabricated bridge bearing is a single-phase bearing, according to an embodiment of the present invention. Figure 5 This is an exploded structural diagram of the components of the lower bearing plate assembly when the prefabricated bridge bearing is a fixed bearing, according to an embodiment of the present invention. Figure 6 This is a flowchart illustrating a design method for prefabricated bridge bearings according to an embodiment of the present invention.

[0020] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-upper seat plate assembly, 11-upper seat plate, 12-upper seat plate sliding groove, 121-upper seat plate sliding groove opening, 122-sliding groove channel, 13-upper seat plate stop, 14-pre-tightening component, 15-pre-tightening bolt; 2-flat sliding plate; 3-spherical crown; 4-spherical sliding plate; 5-lower seat plate assembly, 51-basin ring, 511-frustum section, 512-fastening threaded hole, 52-anchoring ear plate, 53-base plate, 54-spherical bottom basin, 55-lower seat plate stop, 551-stop threaded hole, 56-fastening bolt. Detailed Implementation

[0021] 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. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, when an element is referred to as "fixed to," "set on," or "provided on" another element, it can be directly on or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to or indirectly connected to the other element. The terms "mounted," "connected," "linked," and "provided with" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] like Figures 1-3As shown, one aspect of the present invention provides a prefabricated bridge bearing, including an upper bearing plate assembly 1, a planar sliding plate 2, a spherical crown 3, a spherical sliding plate 4, and a lower bearing plate assembly 5. The planar sliding plate 2 is disposed on the lower surface of the upper bearing plate assembly 1, the spherical crown 3 is disposed below the planar sliding plate 2, and the spherical sliding plate 4 is fitted onto the lower surface of the spherical crown 3 and cooperates with the lower bearing plate assembly 5. This enables vertical force transmission and angular adaptation. The components are tightly assembled and connected, and the bearing also has displacement adjustment and deflection adaptation functions. Furthermore, different functional bearings can be switched by replacing a single component, adapting to the diverse usage needs of bridge engineering. The present invention enables modular and prefabricated design of the bearing, improves the versatility of components and production and installation efficiency, reduces material and construction costs, and avoids problems such as bearing jamming and stress concentration by adjusting the structure to adapt to construction and service deviations, thereby improving the service reliability and service life of the bearing.

[0024] Furthermore, such as Figures 1-3 As shown, the upper seat plate assembly 1 includes an upper seat plate 11, two upper seat plate sliding grooves 12 parallelly spaced on the upper seat plate 11, an upper seat plate stop block 13 detachably disposed on the upper seat plate sliding groove 12, and a pre-tightening member 14 disposed on the upper seat plate sliding groove 12; the upper seat plate sliding groove 12 includes two upper seat plate sliding groove openings 121 with rectangular cross sections arranged parallelly spaced and a sliding groove channel 122 with an inverted T-shaped cross section disposed between the two upper seat plate sliding groove openings 121; the sliding direction cross section of the pre-tightening member 14 is an inverted T-shaped cross section, and the bottom surface is a rectangular cross section, forming a longitudinal sliding fit with the sliding groove channel 122; the pre-tightening member 14 can slide freely longitudinally within the upper seat plate sliding groove 12, and the length of the upper seat plate sliding groove opening 121 is slightly greater than the lateral length of the pre-tightening member 14. Figure 3The length (horizontal length) allows the preload 14 to enter the upper seat plate sliding groove channel 122 through the upper seat plate sliding groove opening 121; the upper surface of the preload 14 has bolt holes, and the upper and lower surfaces of the upper seat plate stop 13 have multiple through bolt holes; the number of preload 14 is the same as the number of through bolt holes on the upper seat plate stop 13; the preload bolt 15 passes through the through bolt holes on the upper seat plate stop 13 and connects with the preload 14 in the upper seat plate sliding groove 12, thereby fixing the preload 14 in the upper seat plate sliding groove 12; loosening the preload bolt 15 can adjust the longitudinal position of the upper seat plate stop 13; the number of preload 14 can be set according to requirements; the upper seat plate stop... Block 13 can be quickly assembled and disassembled by loosening or tightening the pre-tightening bolt 15, and can flexibly adjust its own longitudinal position. This effectively solves the problem of misalignment of the upper and lower seat plates caused by factors such as construction deviation, concrete shrinkage and creep, and prestressing. Specifically, when the support is initially installed, the upper seat plate and the lower seat plate are precisely aligned. Subsequently, due to the above factors, the upper and lower seat plates are prone to spatial displacement, causing the upper seat plate stop block to deviate from the preset temperature displacement change center. At this time, simply loosen the pre-tightening bolt 15 and adjust the position of the pre-tightening member 14 in the upper seat plate sliding groove 12 to reset the upper seat plate stop block 13 to the temperature displacement change center and restore the normal working state of the support. Furthermore, such as Figure 4 and Figure 5 As shown, the lower seat plate assembly 5 includes a basin ring 51, a base plate 53 disposed at the bottom of the basin ring 51, and a spherical bottom basin 54 disposed on the base plate 53 inside the basin ring 51; the upper outer part of the basin ring 51 is milled to form a frustum section 511, and a lower seat plate stop 55 is detachably provided at the frustum section 511 of the basin ring 51; the lower seat plate stop 55 cooperates with the basin ring 51 and is locked and fixed as a whole by fastening bolts 56; the basin ring 51 is a cylindrical hollow steel tube structure, and its inner side wall is threaded, which is adapted to the thread on the cylindrical side of the spherical bottom basin 54 to achieve assembly and fastening; the outer cylindrical side wall above the frustum section 511 is threaded. A fastening threaded hole 512 is drilled radially at the corresponding position; a strip-shaped stop threaded hole 551 is opened on the side of the lower seat plate stop 55; the fastening bolt 56 passes through the stop threaded hole 551 of the lower seat plate stop 55 and cooperates with the fastening threaded hole 512 on the frustum section 511 to connect the lower seat plate stop 55 and the basin ring 51 into a whole; the lower seat plate stop 55 can rotate within the range of the stop threaded hole 551 by tightening and loosening the fastening bolt 56; the present invention allows the lower seat plate stop 55 to rotate within a certain range (stop bolt hole) by tightening and loosening the fastening bolt 56, adapting to the support deflection phenomenon caused by construction errors; the number of fastening bolts 56 depends on the situation.

[0025] Furthermore, such as Figure 4 and Figure 5As shown, the outer wall of the basin ring 51 is provided with multiple anchoring lugs 52 at intervals; the base plate 53 is a cylindrical high-performance concrete structure, located at the bottom of the basin ring 51, which is equivalent to replacing the pure steel base plate with steel pipe concrete, greatly saving materials and costs; the spherical bottom basin 54 is a steel structure with cylindrical sides and a concave spherical surface on the upper surface; to ensure processing efficiency, the edge of the upper surface is provided with a platform section 541, and the lower surface is a plane. Its cylindrical side is fastened to the inner side of the basin ring 51 by threads, and the concave spherical surface of the spherical sliding plate 4 of the bottom basin 54 is matched with the spherical crown 3.

[0026] Furthermore, the prefabricated bridge bearings include three types: fixed bearings, unidirectional sliding bearings, and bidirectional sliding bearings; the lower bearing plate stop types of the unidirectional bearings and fixed bearings are respectively as follows: Figure 4 and Figure 5 As shown; the lower seat plate stop 55 is a detachable part of the overall support component; the same type of unidirectional, bidirectional and fixed support can use the same spherical base 54, base plate 53, basin ring 51 and anchoring lug 52 to form the same assembly, only one component of the lower seat plate stop 55 needs to be changed to complete the assembly. The ability to switch between unidirectional sliding, fixed, and bidirectional sliding functions of the support greatly improves production and installation efficiency and significantly reduces costs. The lower support plate stop 55 has a lower support plate guide strip on its inner surface facing the center of the support, forming a sliding guide fit with the side of the upper support plate stop 13, guiding and limiting the upper support plate stop 13, extending vertically along the bridge direction. When the support is a unidirectional sliding support, the lower support plate stop 55 has two lower support plate guide strips in the bridge direction; the left and right lower support plate guide strips form a guide channel, allowing only the upper support plate stop 13 to slide along the bridge direction. When the support is a fixed support, the lower plate guide strip on the lower plate stop 55 is provided on all four sides in the longitudinal and transverse directions, which surrounds and limits the upper plate stop 13 from all sides, so that the displacement of the support in any direction on the horizontal plane is limited, and complete fixation is achieved; when the support is a bidirectional sliding support, the lower plate stop 55 is not installed, and the upper plate stop 13 has no lateral constraint in the horizontal direction, so the support can slide freely in both the longitudinal and transverse directions.

[0027] Furthermore, such as Figures 1-4As shown, the planar sliding plate 2, the spherical crown 3, and the spherical sliding plate 4 are arranged in a stacked manner from top to bottom between the upper seat plate assembly 1 and the lower seat plate assembly 5, serving as the core transition components for vertical force transmission and corner adaptation of the support. Specifically, the planar sliding plate 2 is directly attached to and fixed to the lower surface of the upper seat plate 11 of the upper seat plate assembly 1, forming a surface contact with the upper seat plate 11, and serving as a sliding transition layer between the upper seat plate 11 and the spherical crown 3, adapting to the relative sliding during horizontal displacement of the support. The spherical crown 3 is located directly below the planar sliding plate 2, with its top surface touching the lower surface of the planar sliding plate 2. The spherical sliding plate 4, with its tightly fitted bottom surface and spherical structure, forms a spherical fit with the upper plate 11, and is the core component for achieving the designed rotation angle of the support. The spherical sliding plate 4 is tightly fitted to the spherical bottom surface of the spherical crown 3, and its lower surface is a concave spherical structure adapted to the spherical crown 3. The spherical sliding plate 4 is entirely laid on the concave spherical surface of the upper surface of the spherical base 54 of the lower plate assembly 5, precisely fitting with the concave spherical surface of the spherical base 54. Through the spherical fit between the spherical crown 3 and the spherical sliding plate 4, the support can rotate freely within the designed rotation angle range, while simultaneously bearing the vertical load. The three components—the planar sliding plate 2, the spherical crown 3, and the spherical sliding plate 4—connect the upper plate 11 and the spherical base 54 through a layered and fitted arrangement. This achieves a smooth transfer of vertical load from the upper plate assembly 1 to the lower plate assembly 5, and also adapts to the horizontal displacement and angular deformation requirements of the support through planar sliding and spherical fit, respectively.

[0028] like Figure 6 As shown, a second aspect of the present invention provides a design method for prefabricated bridge bearings, comprising the following steps: S1: Based on the bridge design requirements, determine the vertical bearing capacity, horizontal bearing capacity, design displacement, and design rotation angle of the prefabricated bridge bearings; S2: Determine the type and quantity of preload bolts 15 and the dimensions of the upper bearing plate 11 based on the horizontal bearing capacity and design displacement of the prefabricated bridge bearing; S3: Determine the dimensional parameters of the lower bearing plate block 55 based on the horizontal bearing capacity of the prefabricated bridge bearing; the dimensional parameters of the lower bearing plate block 55 include height and planar dimensions. S4: Determine the height of the upper plate stop 13 based on the size parameters of the lower plate stop 55 and the design rotation angle of the prefabricated bridge bearing. S5: Determine the design dimensions of the base plate 53 based on the vertical bearing capacity of the prefabricated bridge bearing; S6: Determine the dimensions of the spherical base plate 54 based on the vertical bearing capacity of the prefabricated bridge bearing and the design dimensions of the base plate 53; S7: Determine the overall external dimensions and installation dimensions of the prefabricated bridge bearing based on the design parameters of the upper bearing plate 11, the pot ring 51 and the base plate 53. Further, step S1 includes: Based on the bridge's span, superstructure self-weight, live load level, and core design requirements of the bridge system, calculate and determine the vertical bearing capacity that the supports need to withstand, and clarify the design limits for vertical force transmission of the supports. Based on the temperature variation range, seismic fortification intensity, wind load and horizontal deformation requirements of the bridge structure in the area where the bridge is located, calculate and determine the horizontal bearing capacity that the bearings need to bear, and define the design standards for the horizontal force of the bearings. Based on the displacement of the bridge caused by factors such as temperature expansion and contraction, concrete shrinkage and creep, prestressing and foundation settlement, calculate and determine the design displacement of the bearings, and clarify the allowable horizontal sliding displacement limit of the bearings. Based on the flexural deformation of the bridge superstructure, the uneven settlement of the foundation, and the stress-deformation characteristics of the structure, the design rotation angle of the support is calculated and determined, and the allowable rotation angle limit of the support is defined. Furthermore, in step S1, the vertical bearing capacity, horizontal bearing capacity, design displacement, and design rotation angle are all calculated and determined according to the current industry standards for highway bridge engineering. The vertical bearing capacity is the design value of the maximum total vertical load that the support needs to withstand. Taking into account the self-weight of the bridge superstructure, live load (including impact coefficient), additional loads, etc., and calculated according to the stress distribution coefficient of the bridge support, the formula for calculating the vertical bearing capacity in step S1 is as follows: in, For permanent load partial factors; The standard value of the self-weight load of the bridge superstructure (kN). The standard value of the self-weight load of bridge deck ancillary facilities (kN); The vertical force distribution coefficient for a single support is determined by the bridge system (simply supported, continuous, rigid frame, etc.) and the number of supports. For variable load partial factors; The standard value of vehicle live load (kN); The vehicle impact coefficient is determined according to the bridge span. For simply supported beam bridges with a span L < 5m, it is taken as 0. For 5m ≤ L ≤ 150m, it is linearly interpolated according to the standard. For additional load partial factors; The standard value (kN) of additional vertical loads such as temperature stress and prestressing secondary stress is given. For conventional small-to-medium span bridges, if additional vertical loads are neglected, the formula for calculating the vertical bearing capacity in step S1 can be simplified as follows: ; The horizontal bearing capacity is the design value of the maximum total horizontal load that the support must withstand, including the horizontal force due to temperature deformation, the horizontal force due to earthquake, the horizontal force due to wind load, the braking force, etc., and is calculated by superimposing the loads under the most unfavorable working conditions. The formula for calculating the horizontal bearing capacity in step S1 is: in, For temperature and horizontal force partial factors; This is the wind load partial factor; For seismic action partial factors; For braking force partial factor; This is the standard value of the horizontal force for temperature deformation; This represents the standard value of the horizontal force under wind load. This represents the standard value of the horizontal force during an earthquake. This refers to the standard value of vehicle braking force. The maximum value of the calculation results is taken for both normal use and seismic fortification conditions (normal use condition (temperature + wind load) and seismic fortification condition (earthquake + braking force)).

[0029] In step S1, the design displacement is the maximum allowable horizontal sliding displacement limit of the support. It is calculated by superimposing the displacement due to temperature expansion and contraction, concrete shrinkage and creep, prestressing, and foundation settlement, and then calculating the total design displacement in the most unfavorable direction. The expression is: in, For temperature-induced expansion and contraction displacement; This refers to the displacement due to concrete shrinkage and creep. Apply displacement to the prestress; Based on the settlement displacement; Temperature expansion and contraction displacement The expression is: ,in, The coefficient of linear expansion of the bridge superstructure; Calculate the length (m) of the bridge superstructure. —The maximum temperature variation (°C) in the area where the bridge is located is the difference between the highest and lowest effective temperatures in the local area; Concrete shrinkage and creep displacement The expression is: ,in, The strain is the combined strain of concrete shrinkage and creep. Prestressing displacement The expression is: , —The average cross-sectional stress (MPa) generated by the application of prestress; The elastic modulus of concrete (MPa); Foundation settlement displacement The expression is: , , These are the maximum and minimum settlement (m) of the bridge foundations on both sides of the bearing, calculated according to the geological survey report and foundation design specifications.

[0030] In step S1, the design rotation angle is the maximum allowable rotation angle limit of the support (unit: rad). Taking into account the flexural deformation rotation angle of the superstructure, the uneven settlement rotation angle of the foundation, and the stress deformation rotation angle of the structure, the total rotation angle under the most unfavorable working condition is taken, and the expression is: in, This refers to the flexural deformation angle of the superstructure; Based on the uneven settlement rotation angle; Apply a rotation angle to the prestress; Flexural deformation angle of the superstructure The expression is: , The maximum deflection (m) of the bridge superstructure at mid-span is calculated using structural mechanics methods. Calculate the span (m) for the bridge. Uneven settlement angle of foundation The expression is: , The uneven settlement of the foundation of the pier where the support is located (m); Here is the calculated width (m) of the pier foundation; when the turning angle is small, Calculated using approximate values; Prestressing application angle The expression is: , The amount of corner deformation (m) at the end of the superstructure caused by the application of prestress. The effective length of the prestressed tendon (m); When calculating the design displacement and design rotation in step S1, the superposition effect of bidirectional displacement / rotation must be considered, and the final design value of the support must cover the maximum deformation in both the positive and negative directions.

[0031] Further, step S2 includes: Based on the initial selection of the number of pre-tightening bolts 15 according to the horizontal bearing capacity of the support, the bolts are selected according to the horizontal bearing capacity: 5 bolts for horizontal bearing capacity of 0~1000kN, 8 bolts for 1000~5000kN, and 10 bolts for 5000~10000kN. The initial selection of bolts 15 is then checked according to the shear strength calculation formula of the pre-tightening bolts 15 to ensure that the number of bolts meets the shear resistance requirements of the horizontal force of the support, and the final number of pre-tightening bolts 15 is determined. Based on the verified quantity of preload bolts 15, the design value of horizontal bearing capacity, and the mechanical performance parameters of the bolts, the model of preload bolts 15 is determined, and the core technical indicators such as the nominal diameter, pitch, length, and material of the bolts are clarified. Based on the displacement requirements of the support design, and combined with the longitudinal sliding fit relationship between the pre-tightening member 14 and the upper plate sliding groove 12, the groove length and channel size parameters of the upper plate sliding groove 12 are determined, and the arrangement spacing and installation space of the pre-tightening bolts 15 and the pre-tightening member 14 are matched. Based on the design parameters of the upper plate sliding groove 12, the arrangement requirements of the pre-tightening bolts 15 and pre-tightening components 14, and the force transmission requirements of the vertical bearing capacity of the support, the planar dimensions and thickness of the upper plate 11 are comprehensively determined to ensure that the structural strength and stiffness of the upper plate 11 meet the requirements of the support for stress and sliding deformation. To prevent jamming when the pre-tightening member 14 engages with the upper seat plate sliding groove 12, the height of the pre-tightening member 14 is determined based on the vertical dimension of the upper seat plate sliding groove 12, so that the height of the pre-tightening member 14 is 1-2 mm smaller than the vertical dimension of the upper seat plate sliding groove 12, ensuring that the pre-tightening member 14 can slide freely longitudinally within the upper seat plate sliding groove 12.

[0032] Further, step S3 includes: Determine the length of the guide bar of the lower seat plate stop 55 so that the length of the guide bar is consistent with the diameter of the flat slide plate 2; Based on the horizontal bearing capacity of the support, the compressive strength of the material used for the lower support plate block 55, and the determined guide strip length, the design height of the lower support plate block 55 is calculated using the formula: Lower support plate block height = Horizontal bearing capacity / Compressive strength / Guide strip length. Based on the guide bar length, stop block design height, and the functional requirements of horizontal guidance and limiting of the support, the planar dimensions of the lower seat plate stop block 55 and the matching dimensions of the irregular structure are comprehensively determined to ensure that it meets the requirements of horizontal force on the support and the matching requirements with the upper seat plate stop block 13.

[0033] Further, step S4 includes: S41: Based on the actual motion state of the support during service, clarify the lateral guiding fit relationship between the upper support plate block 13 and the lower support plate block 55, and define the fit boundary requirements between the two. S42: Based on the height and planar dimensions of the lower seat plate block 55, and combined with the support design rotation angle, simulate and calculate the vertical spatial force and deformation boundary of the upper seat plate block 13 under the coupled working conditions of maximum design displacement and design rotation angle. S43: Based on the simulation calculation results of step S42, determine the minimum design height of the upper plate stop 13 to ensure that the lower surface of the upper plate stop 13 is always higher than the lower surface of the lower plate stop 55 under all working conditions of design displacement and design rotation, so as to meet the guiding fit requirements and have no structural interference.

[0034] Further, step S5 includes: S51: Specify the design value of the compressive strength of the high-performance concrete used in the base plate 53. This value shall be selected in accordance with the relevant current specifications for concrete structure engineering. S52: Based on the design value of the vertical bearing capacity of the support and the design value of the compressive strength of high-performance concrete, the minimum planar design size of the base plate 53 is determined by the compressive bearing capacity calculation formula to ensure that the base plate meets the compressive requirements for vertical force transmission. S53: Combining the inner hole size of the basin ring 51, the installation and adaptation requirements of the spherical bottom basin 54, and the overall vertical stiffness requirements of the support, the height of the base plate 53 is comprehensively determined to ensure that it is matched with the rest of the lower base plate assembly and is stable under force.

[0035] Further, step S6 includes: S61: Based on the vertical bearing capacity of the support and the design value of the compressive strength of the flat sliding plate 2, calculate and determine the diameter of the flat sliding plate 2 as the basic parameter for the size design of the spherical bottom basin 54; S62: Based on the diameter of the flat plate 2, determine the spherical radius of the spherical base 54 according to the standard of 1.5 times the diameter of the flat plate 2; S63: Based on the design height of the concave spherical surface of the spherical base 54, add a dimensional allowance of 5-10mm to calculate and determine the overall height of the spherical base 54; S64: Match the planar design dimensions of the base plate 53, determine the planar dimensions of the spherical base 54, and ensure that the two are properly assembled and that vertical force transmission is smooth.

[0036] Further, step S7 includes: S71: Review the planar dimensions and thickness of the upper seat plate 11, the outer diameter, height, and dimensions of the frustum section 511 of the basin ring 51, and the planar dimensions and height parameters of the base plate 53, and clarify the outer boundaries and assembly connection dimensions of each component. S72: Based on the assembly relationship between the upper seat plate assembly 1 and the lower seat plate assembly 5, and the thickness dimensions of the flat sliding plate 2, the spherical crown 3, and the spherical sliding plate 4, calculate the overall vertical installation height of the support, reserve assembly gaps for components, and ensure the smoothness of vertical force transmission. S73: Based on the maximum planar contour of the upper seat plate 11 and the pot ring 51, and combined with the arrangement dimensions of the anchoring ear plate 52 and the lower seat plate stop block 55, determine the overall planar installation dimensions of the support to meet the connection and installation requirements between the support and the bridge superstructure and piers. S74: Taking into account the vertical height and planar dimensions of the bearing, as well as the installation space and connection requirements at the bridge engineering site, the overall shape and installation dimensions of the prefabricated bridge bearing are finally determined to ensure that it is compatible with the installation and stress requirements of the bridge structure.

[0037] Those skilled in the art will readily understand that the above description is merely 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 scope of protection of the present invention.

Claims

1. A prefabricated bridge bearing, characterized in that: It includes, from top to bottom, an upper seat plate assembly (1), a flat sliding plate (2), a spherical crown (3), a spherical sliding plate (4), and a lower seat plate assembly (5); The upper seat plate assembly (1) includes an upper seat plate (11), two upper seat plate sliding grooves (12) parallelly spaced on the upper seat plate (11), an upper seat plate stop block (13) detachably disposed on the upper seat plate sliding groove (12), and a pre-tightening member (14) disposed on the upper seat plate sliding groove (12); the pre-tightening member (14) forms a longitudinal sliding fit with the upper seat plate sliding groove (12); the upper seat plate stop block (13) is fixed to the upper seat plate (11) by passing a pre-tightening bolt (15) through the upper seat plate stop block (13) and connecting it to the pre-tightening member (14); The lower seat plate assembly (5) includes a basin ring (51), a base plate (53) disposed at the bottom of the basin ring (51), and a spherical bottom basin (54) disposed on the base plate (53) inside the basin ring (51). The upper outer part of the basin ring (51) is milled to form a frustum section (511), and a lower seat plate block (55) is detachably provided at the frustum section (511) of the basin ring (51). The planar sliding plate (2) is directly attached to and fixed to the lower surface of the upper seat plate (11) of the upper seat plate assembly (1); The spherical crown (3) is located directly below the planar sliding plate (2), with its top surface closely attached to the lower surface of the planar sliding plate (2) and its bottom surface having a spherical structure; The spherical sliding plate (4) is located on the concave spherical surface of the spherical base (54) and cooperates with the spherical structure of the spherical crown (3), so that the support can rotate freely within the designed rotation angle range and can bear the transmission of vertical load.

2. The prefabricated bridge bearing according to claim 1, characterized in that: The upper seat plate sliding groove (12) includes two upper seat plate sliding groove openings (121) with rectangular cross sections arranged in parallel and spaced apart, and a sliding groove channel (122) with an inverted T-shaped cross section disposed between the two upper seat plate sliding groove openings (121). The sliding direction section of the pre-tightening member (14) is an inverted T-shaped section, and the bottom surface is a rectangular section, forming a longitudinal sliding fit with the sliding groove channel (122); The upper surface of the pretensioner (14) is provided with bolt holes, and the upper and lower surfaces of the upper seat plate block (13) are provided with multiple through bolt holes; the number of pretensioners (14) is the same as the number of through bolt holes on the upper seat plate block (13).

3. A prefabricated bridge bearing according to claim 2, characterized in that: The basin ring (51) is a cylindrical hollow steel pipe structure with threads on its inner wall, which are matched with the threads on the cylindrical side of the spherical bottom basin (54) to achieve assembly and fastening. The outer wall of the cylinder above the frustum section (511) is threaded, and a fastening threaded hole (512) is drilled radially at the corresponding position. The lower seat plate stop (55) has a strip-shaped stop thread hole (551) on its side. The fastening bolt (56) passes through the block thread hole (551) of the lower seat plate block (55) and engages with the fastening thread hole (512) on the frustum section (511) to connect the lower seat plate block (55) and the basin ring (51) into a whole. The lower seat plate stop (55) can rotate within the range of the threaded hole (551) of the stop by tightening or loosening the fastening bolt (56); The outer wall of the basin ring (51) is provided with multiple anchoring lugs (52) at intervals. The base plate (53) is a cylindrical high-performance concrete structure; The spherical bottom basin (54) is a steel structure with cylindrical sides and a concave spherical top surface; The upper surface of the spherical bottom basin (54) is provided with a platform section (541), and the lower surface is a plane.

4. A prefabricated bridge bearing according to any one of claims 1-3, characterized in that: The prefabricated bridge bearings are of three types: fixed bearings, unidirectional sliding bearings, and bidirectional sliding bearings; the lower bearing plate block (55) has a lower bearing plate guide strip on its inner surface facing the center of the bearing, which forms a sliding guide fit with the side of the upper bearing plate block (13). When the support is a one-way sliding support, there are two lower support plate guide strips on the lower support plate block (55) in the longitudinal direction of the bridge; the two lower support plate guide strips on the left and right form a guide channel, which only allows the upper support plate block (13) to slide in the longitudinal direction of the bridge and restricts the transverse displacement of the bridge. When the support is a fixed support, the lower support plate guide strip on the lower support plate block (55) is provided on all four sides in the longitudinal and transverse directions of the bridge, which surrounds and limits the upper support plate block (13) from all sides, so that the displacement of the support in any direction on the horizontal plane is restricted, and complete fixation is achieved. When the support is a two-way sliding support, the lower support plate block (55) is not installed, and the upper support plate block (13) has no lateral constraint in the horizontal direction.

5. A design method for prefabricated bridge bearings, characterized in that, For designing prefabricated bridge bearings as described in any one of claims 1-4, comprising: S1: Based on the bridge design requirements, determine the vertical bearing capacity, horizontal bearing capacity, design displacement, and design rotation angle of the prefabricated bridge bearings; S2: Determine the type and quantity of preload bolts (15) and the dimensions of the upper bearing plate (11) based on the horizontal bearing capacity and design displacement of the precast bridge bearing; S3: Determine the dimensional parameters of the lower bearing plate block (55) based on the horizontal bearing capacity of the prefabricated bridge bearing; the dimensional parameters of the lower bearing plate block (55) include height and planar dimensions; S4: Determine the height of the upper plate stop (13) based on the size parameters of the lower plate stop (55) and the design rotation angle of the prefabricated bridge bearing; S5: Determine the design dimensions of the base plate (53) based on the vertical bearing capacity of the prefabricated bridge bearing; S6: Determine the dimensions of the spherical base plate (54) based on the vertical bearing capacity of the prefabricated bridge bearing and the design dimensions of the base plate (53); S7: Determine the overall shape and installation dimensions of the prefabricated bridge bearing based on the design parameters of the upper bearing plate (11), the basin ring (51) and the base plate (53).

6. The prefabricated bridge bearing design method according to claim 5, characterized in that, Step S2 includes: Based on the initial selection of the number of pre-tightening bolts (15) according to the horizontal bearing capacity of the support, select according to the horizontal bearing capacity: 5 bolts for horizontal bearing capacity of 0~1000kN, 8 bolts for 1000~5000kN, and 10 bolts for 5000~10000kN. Then, check the initial selection of the number of bolts according to the calculation formula of the shear strength of the pre-tightening bolts (15) to ensure that the number of bolts meets the shear resistance requirements of the horizontal force of the support, and determine the final number of pre-tightening bolts (15). Based on the number of pre-tightening bolts (15) after verification, the design value of horizontal bearing capacity and the mechanical performance parameters of the bolts, the model of the pre-tightening bolts (15) is determined, and the core technical indicators such as the nominal diameter, pitch, length and material of the bolts are clarified. Based on the displacement requirements of the support design, and combined with the longitudinal sliding fit relationship between the pre-tightening part (14) and the upper plate sliding groove (12), the groove length and channel size parameters of the upper plate sliding groove (12) are determined, and the arrangement spacing and installation space of the pre-tightening bolts (15) and pre-tightening parts (14) are matched. Based on the design parameters of the upper plate sliding groove (12), the arrangement requirements of the pre-tightening bolts (15) and the pre-tightening parts (14), and combined with the force transmission requirements of the vertical bearing capacity of the support, the planar dimensions and thickness dimensions of the upper plate (11) are comprehensively determined to ensure that the structural strength and stiffness of the upper plate (11) meet the requirements of the support for force and sliding deformation. To prevent jamming when the pre-tightening part (14) engages with the upper seat plate sliding groove (12), the height of the pre-tightening part (14) is determined according to the vertical dimension of the upper seat plate sliding groove (12), so that the height of the pre-tightening part (14) is 1-2 mm smaller than the vertical dimension of the upper seat plate sliding groove (12), ensuring that the pre-tightening part (14) can slide freely longitudinally within the upper seat plate sliding groove (12).

7. The prefabricated bridge bearing design method according to claim 5, characterized in that, Step S3 includes: Determine the length of the guide bar of the lower seat plate stop (55) so that the length of the guide bar is consistent with the diameter of the flat slide plate 2; Based on the horizontal bearing capacity of the support, the compressive strength of the material used for the lower support plate block (55) and the determined guide strip length, the design height of the lower support plate block (55) is calculated using the formula: lower support plate block height = horizontal bearing capacity / compressive strength / guide strip length. Based on the length of the guide bar, the design height of the stop block, and the functional requirements of the horizontal guidance and limiting of the support, the planar dimensions of the lower seat plate stop block (55) and the matching dimensions of the irregular structure are comprehensively determined to ensure that it meets the requirements of the horizontal force of the support and the matching requirements with the upper seat plate stop block (13).

8. The prefabricated bridge bearing design method according to claim 5, characterized in that, Step S4 includes: S41: Based on the actual motion state of the support during service, clarify the side guide fit relationship between the upper support plate block (13) and the lower support plate block (55), and define the fit boundary requirements between the two. S42: Based on the height and planar dimensions of the lower seat plate block (55), combined with the support design rotation angle, simulate and calculate the vertical spatial force and deformation boundary of the upper seat plate block (13) under the coupled working conditions of maximum design displacement and design rotation angle. S43: Based on the simulation calculation results of step S42, determine the minimum design height of the upper seat plate block (13) to ensure that the lower surface of the upper seat plate block (13) is always higher than the lower surface of the lower seat plate block (55) under the full working conditions of the support with design displacement and design rotation angle, so as to meet the guiding fit requirements and have no structural interference.

9. The prefabricated bridge bearing design method according to claim 5, characterized in that, Step S6 includes: S61: Based on the vertical bearing capacity of the support and the design value of the compressive strength of the flat sliding plate (2), calculate and determine the diameter of the flat sliding plate 2 as the basic parameter for the size design of the spherical bottom basin (54); S62: Based on the diameter of the flat plate (2), determine the spherical radius of the spherical base (54) according to the standard of 1.5 times the diameter of the flat plate (2); S63: Based on the design height of the concave spherical surface of the spherical base (54), add a dimensional allowance of 5 to 10 mm to calculate and determine the overall height of the spherical base (54); S64: Match the planar design dimensions of the base plate (53), determine the planar dimensions of the spherical base (54), and ensure that the two are properly assembled and that the vertical force transmission is smooth.

10. A design method for prefabricated bridge bearings according to any one of claims 6-9, characterized in that, Step S7 includes: S71: Review the planar dimensions and thickness of the upper seat plate (11), the outer diameter, height, and dimensions of the frustum section (511) of the basin ring (51), and the planar dimensions and height parameters of the base plate (53), and clarify the outer boundary and assembly connection dimensions of each component; S72: Based on the assembly relationship between the upper seat plate assembly (1) and the lower seat plate assembly (5), the thickness dimensions of the planar sliding plate (2), the spherical crown (3), and the spherical sliding plate (4) are superimposed to calculate the overall vertical installation height of the support, reserve the assembly gap of the components and ensure the smoothness of vertical force transmission; S73: Based on the maximum planar contour of the upper seat plate (11) and the pot ring (51), and combined with the arrangement dimensions of the anchor ear plate (52) and the lower seat plate block (55), determine the overall planar installation dimensions of the support to meet the connection and installation requirements of the support with the bridge superstructure and piers. S74: Based on the vertical height and planar dimensions of the bearing, as well as the installation space and connection requirements at the bridge engineering site, the overall external shape and installation dimensions of the prefabricated bridge bearing are finally determined.

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