Mechanical performance test device capable of simulating voiding of plate-type rubber support and use method thereof

Abstract

This invention discloses a mechanical performance testing device and method for simulating the detachment of a plate rubber bearing. The device includes a loading beam, a support platform, a loading head, a plate rubber bearing, a bearing mounting platform, a hinge assembly, a push-pull mechanism, a horizontal displacement adjustment mechanism, and a control system. The support platform has a bearing mounting platform at its top left end, a plate rubber bearing at its top, a loading head at its top, and a loading beam at its top. The support platform is hinged to the right end of the loading beam. The fixed end of the push-pull mechanism is embedded in the support platform, and its output end is hinged to the bottom of the loading beam. One end of the horizontal displacement adjustment mechanism is horizontally fixed to the support platform, and its other end is detachably connected to the side wall of the bearing mounting platform. The control system is connected to both the push-pull mechanism and the horizontal displacement adjustment mechanism. The device simulates the bearing compression performance under eccentric detachment conditions and the bearing compression and shear performance under displacement detachment conditions in actual bridges.

Description

Technical Field

[0001] This invention belongs to the field of experimental device technology, and more specifically, relates to a mechanical property testing device and its usage method for simulating the detachment of a plate rubber bearing. Background Technology

[0002] Plate rubber bearings for highway bridges are key force-transmitting components connecting the superstructure and substructure of bridges. They play a crucial role in supporting loads, adapting to structural deformation, and transmitting forces. Their operational stability directly determines the overall load-bearing performance, structural safety, and service life of the bridge. During actual bridge operation, plate rubber bearings often experience localized voiding due to various factors such as improper control of bearing pad height differences, insufficient dimensions of the wedge blocks at the bottom of the beam when the beam has a slope, and foundation settlement. In engineering practice, to address this voiding problem, a visual inspection of the bearing is usually conducted first, followed by maintenance or replacement measures based on the inspection rating. However, currently, there is a lack of reliable experimental evidence and theoretical support for quantifying the impact of voiding on the bearing's stiffness and the mechanical properties of the bridge superstructure.

[0003] The common solution in the current engineering field is to empirically reduce the stiffness of the support after it is detached and then input it into the bridge finite element model for mechanical calculation. However, the authenticity and reliability of this empirical stiffness reduction relationship are always questionable. It cannot accurately reflect the actual stress characteristics of the support in the detached state, which can easily lead to deviations in the bridge mechanical analysis results and affect the scientific nature of bridge safety assessment and maintenance decisions.

[0004] The root cause of these problems lies in the significant differences in stiffness variation and actual stress state of plate rubber bearings under eccentric or displaced void conditions compared to their intact state. Currently, systematic experimental research on the mechanical properties of bearings under such void conditions is scarce. One key limiting factor is the extreme lack of specialized testing equipment capable of accurately simulating and testing the compressive performance of bearings under void conditions. Existing testing equipment, such as universal testing machines and presses, can only test the bearing under central compression conditions and cannot simulate the complex boundary conditions caused by void defects, such as eccentric compression and localized pressure. This makes it difficult to reproduce the void stress state of the bearing in actual operation and fails to provide reliable experimental data support for revealing the void mechanism and establishing a scientific void evaluation system. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a mechanical performance testing device and method for simulating the cavitation of plate rubber bearings. Through integrated control system, it enables flexible switching and precise adjustment of the bearing's compression performance under biased cavitation conditions and its compression and shear performance under displacement cavitation conditions, adapting to different testing requirements. For the bearing compression performance under biased cavitation conditions, the control system drives a push-pull mechanism to achieve stepless precision adjustment and locking of the loading beam's inclination angle. Different preset inclination angles θ can be flexibly set to simulate different degrees of biased cavitation. Multiple biased condition tests can be completed without disassembling and adjusting the main structure of the device. For simulating the bearing compression and shear performance under displacement cavitation conditions, the control system can... The control system drives the horizontal displacement adjustment mechanism, enabling stepless precision adjustment and locking of the horizontal displacement of the bearing mounting platform and plate rubber bearing. Different preset horizontal displacements d can be flexibly set to accurately simulate different degrees of displacement and voiding. The operation is convenient and efficient. Throughout the entire test process, loading, displacement adjustment, data acquisition, data processing, and curve generation are all integrated and controlled by the control system, which has a high degree of automation. This effectively reduces manual intervention and avoids human error, significantly shortening the test preparation and operation time and improving test efficiency. It also ensures the consistency and repeatability of the test process for different batches and under different working conditions, ensuring the stability and reliability of the test data. This provides a solid guarantee for subsequent comparative analysis of the impact of two voiding conditions on the mechanical properties of the bearing.

[0006] To achieve the above objectives, according to one aspect of the present invention, a mechanical performance testing device for simulating the detachment of a plate rubber bearing is provided, comprising a loading beam, a support platform, a loading head, a plate rubber bearing, a bearing mounting platform, a hinge assembly, a push-pull mechanism, a horizontal displacement adjustment mechanism, and a control system; wherein... The support platform is provided with a support mounting platform at the top left end, a plate rubber support is provided at the top of the support mounting platform, a loading head is provided at the top of the plate rubber support, and a loading beam is provided at the top of the loading head. The support platform and the right end of the loading beam are hinged together by a hinge assembly. The fixed end of the push-pull mechanism is embedded in the support platform, and its output end is hinged to the bottom of the loading beam. The push-pull mechanism is located on the left side of the hinge seat. The loading beam is driven to rotate around the hinge assembly by the push-pull mechanism, so that the loading beam forms an inclined posture, thereby realizing the simulation of the bearing compression performance under the biased pressure and voiding condition of the plate rubber bearing. One end of the horizontal displacement adjustment mechanism is horizontally fixedly installed on the support platform, and the other end is detachably connected to the side wall of the support mounting platform. It is used to push and pull the support mounting platform to drive the plate rubber support to generate a predetermined horizontal displacement, thereby realizing the simulation of the support compression and shear performance under the displacement and detachment condition of the plate rubber support. The control system is connected to the push-pull mechanism and the horizontal displacement adjustment mechanism respectively. It is used to receive the preset test parameters and output precise control commands to control the push-pull mechanism and the horizontal displacement adjustment mechanism to simulate the compression performance of the plate rubber bearing under the biased detachment condition and the compression and shear performance of the bearing under the displacement detachment condition.

[0007] Furthermore, a plurality of first grooves are provided at the bottom left end of the loading beam, and a first vertical displacement adjustment mechanism is fixedly assembled in each of the plurality of first grooves. The first vertical displacement adjustment mechanism is connected to the control system, and the output end of the first vertical displacement adjustment mechanism is fixedly connected to the loading head.

[0008] Furthermore, the right end of the support platform is provided with several second grooves, and a second vertical displacement adjustment mechanism is fixedly installed in each of the second grooves. The output end of the second vertical displacement adjustment mechanism abuts against the bottom of the support mounting platform, and the second vertical displacement adjustment mechanism is connected to the control system.

[0009] Furthermore, the hinge assembly includes a first hinge seat and a second hinge seat. One end of the first hinge seat is fixedly mounted to the top right end of the support platform, and one end of the second hinge seat is fixedly mounted to the bottom right end of the loading beam. The end of the first hinge seat away from the support platform and the end of the second hinge seat away from the loading beam are hinged by a pivot pin, forming a hinge fulcrum for the loading beam to rotate around the support platform.

[0010] Furthermore, the push-pull mechanism, the horizontal displacement adjustment mechanism, the first vertical displacement adjustment mechanism, and the second vertical displacement adjustment mechanism all adopt electric pull rods or servo electric cylinders.

[0011] Furthermore, the compression performance testing device also includes a measurement component, which includes an inclination sensor, a displacement sensor, a pressure sensor, a position sensor, a force sensor, and a distributed strain gauge. The inclination sensor, displacement sensor, pressure sensor, position sensor, force sensor, and distributed strain gauge are all connected to the control system signal. The tilt sensor is installed at the bottom of the loading beam to collect the tilt angle of the loading beam in real time. The displacement sensor is located between the support mounting platform and the loading head, and is used to detect the vertical compression deformation of the plate rubber support in real time. The pressure sensor is located between the output end of the first vertical displacement adjustment mechanism and the loading head, and between the output end of the second vertical displacement adjustment mechanism and the support mounting platform, and is used to collect the pressure loads acting on the plate rubber support by the first vertical displacement adjustment mechanism and the second vertical displacement adjustment mechanism in real time. The position sensor is integrated inside the horizontal displacement adjustment mechanism and is used to detect the amount of displacement of the plate rubber support when it is horizontally displaced. The force sensor is located at the output end of the horizontal displacement adjustment mechanism and is used to measure the horizontal load applied by the horizontal displacement adjustment mechanism to the support mounting platform. The distributed strain gauge is arranged between the support mounting platform and the plate rubber bearing to collect stress distribution data of the plate rubber bearing in real time under bias and void conditions.

[0012] Furthermore, the loading head is a replaceable structure, and its shape and size can be flexibly replaced according to the test requirements to simulate the actual contact state between the plate rubber support and different upper structures.

[0013] According to a second aspect of the present invention, a method for using a mechanical performance testing device capable of simulating the detachment of a plate rubber bearing is provided. This method utilizes the aforementioned mechanical performance testing device and includes the following steps: S100: According to the test requirements, select the appropriate specifications of plate rubber support and the matching loading head, position and install the plate rubber support on the upper surface of the support platform, fix the loading head to the output end of the first vertical displacement adjustment mechanism, and install, debug and calibrate the sensors in the measurement assembly. S200: The control system drives the push-pull mechanism and the second vertical displacement adjustment mechanism to simulate the compression performance test of the plate rubber support under the bias pressure and void condition. S300: The horizontal displacement adjustment mechanism and the first vertical displacement adjustment mechanism are driven by the control system to simulate the compression and shear performance test of the plate rubber support under the condition of displacement and voiding. S400: By comparing and analyzing the load-compression (P-δ) curves of plate rubber bearings under different eccentric pressure and displacement void states, as well as the bearing shear performance curves under different vertical loads and void displacements, the mechanical property variation law of plate rubber bearings can be obtained.

[0014] Further, step S200 specifically includes: S210: The control system drives the push-pull mechanism to rotate the loading beam around the hinge assembly to a preset tilt angle θ, and then drives the second vertical displacement adjustment mechanism to make the loading head and the upper surface of the plate rubber support form an inclined fit, realizing the initial bias pressure release state. S220: Controls the second vertical displacement adjustment mechanism to push the support mounting platform to drive the plate rubber support to rise, and synchronously collects vertical load P, compression δ, loading beam inclination angle θ and support bottom distributed stress σ data in real time through the measurement component and transmits them to the control system. S230: The control system processes the collected data in real time and generates the load-compression curve at the corresponding tilt angle θ; S240: Adjust the loading beam to different inclination angles θ by using the push-pull mechanism, and repeat steps S210 to S230 to obtain multiple sets of support compression performance curves under different inclination angles and biased cavitation conditions.

[0015] Furthermore, the support compression performance test in step S300 specifically includes: The control system controls the push-pull mechanism to keep the loading beam in a horizontal state; The control system controls the horizontal displacement adjustment mechanism to drive the support mounting platform and the plate rubber bearing to generate a preset horizontal displacement d, so that a local area of ​​the plate rubber bearing is suspended outside the loading head, forming a displaced and freed state. The control system controls the first vertical displacement adjustment mechanism to push the loading head to apply a vertical load to the plate rubber support, and the measuring components collect the load P, compression δ and horizontal displacement d in real time. The control system calculates the displacement distance L, suspension length A, and detachment rate S in real time, and generates the load-compression (P-δ) curves for the corresponding horizontal displacement d. By adjusting the horizontal displacement adjustment mechanism through the control system, the bearing mounting platform drives the plate rubber bearing to produce different horizontal displacements d. By repeating the above steps, multiple sets of bearing compression performance curves under different displacement and voiding degrees are obtained. The support compression performance test in step S300 specifically includes: The control system controls the push-pull mechanism to keep the loading beam in a horizontal state; The control system controls the horizontal displacement adjustment mechanism to drive the support mounting platform and the plate rubber support to generate a preset horizontal displacement d, so that a local area of ​​the plate rubber support is suspended outside the loading head, forming a preset displacement and free state. The control system controls the first vertical displacement adjustment mechanism to push the loading head to apply a preset vertical load to the plate rubber support and keep the vertical load stable. The load P and horizontal displacement d are collected in real time by the measuring component. After the vertical load stabilizes, the horizontal displacement adjustment mechanism is controlled by the control system to drive the support mounting platform to move the plate rubber bearing horizontally back and forth, thereby applying a horizontal back and forth shear load to the plate rubber bearing. Throughout the entire process of applying horizontal reciprocating shear load, horizontal load and horizontal displacement data are collected in real time by the measuring components, and the collected data are transmitted to the control system in real time. The control system processes the collected test data to generate the horizontal shear hysteresis curve of the plate rubber bearing under vertical load and free displacement. By adjusting the first vertical displacement adjustment mechanism through the control system, different vertical loads are applied to the plate rubber bearing by the loading head, and the horizontal displacement adjustment mechanism is controlled to cause the bearing mounting platform to drive the plate rubber bearing to produce different horizontal displacements d. By repeating the above steps, multiple sets of bearing shear performance curves under different vertical loads and free displacements are obtained.

[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 mechanical performance testing device for simulating the detachment of plate rubber bearings of the present invention can accurately and quantitatively simulate the bearing compression performance under eccentric detachment conditions, the bearing compression under displacement detachment conditions, and the defect conditions under shear in the same device. The test boundary conditions are highly consistent with the actual operation scenarios of bridge engineering, effectively solving the problem that the existing test methods can only simulate a single detachment condition and are out of touch with reality. It fills the gap in the field of dedicated test methods that can simultaneously simulate two core detachment conditions, and improves the practicality and pertinence of the test.

[0017] 2. The mechanical performance testing device for simulating the detachment of plate rubber bearings of the present invention, through integrated control system, can flexibly switch and precisely control the bearing compression performance under eccentric detachment conditions and the bearing compression and shear performance under displacement detachment conditions, adapting to different testing needs. For the bearing compression performance under eccentric detachment conditions, the control system can drive a push-pull mechanism to achieve stepless precision adjustment and locking of the loading beam inclination angle, and can flexibly set different preset inclination angles θ to simulate different degrees of eccentric detachment. Multiple sets of eccentric condition tests can be completed without disassembling and adjusting the main structure of the device. For the simulation of bearing compression and shear performance under displacement detachment conditions, the control system can drive horizontal displacement adjustment. The mechanism enables stepless precision adjustment and locking of the horizontal displacement of the bearing mounting platform and plate rubber bearing. Different preset horizontal displacements d can be flexibly set to accurately simulate different degrees of displacement and voiding. The operation is convenient and efficient. Throughout the test, loading, displacement adjustment, data acquisition, data processing, and curve generation are all integrated and controlled by the control system, which has a high degree of automation. This effectively reduces manual intervention and avoids human error, which not only significantly shortens the test preparation and operation time and improves test efficiency, but also ensures the consistency and repeatability of the test process for different batches and under different working conditions. This ensures the stability and reliability of the test data and provides a solid guarantee for subsequent comparative analysis of the impact of two voiding conditions on the mechanical properties of the bearing.

[0018] 3. The mechanical performance testing device for simulating the detachment of plate rubber bearings of the present invention achieves automated and synchronized acquisition and processing of test data through the coordinated cooperation of the control system and the measuring components. The measuring components collect data in real time on vertical load P, horizontal load, bearing compression displacement δ, loading beam inclination angle θ, horizontal displacement d, and bearing bottom distributed stress σ, and transmit the collected data to the control system. The control system plots load-compression (P-δ) curves under different inclination angles θ, load-compression (P-δ) curves under different horizontal displacements d, and bearing shear performance curves under different vertical loads and detachment displacements, providing comprehensive and accurate multi-dimensional data support for establishing a bearing mechanical model and deeply analyzing the mechanism of detachment disease.

[0019] 4. The mechanical performance test device of the present invention, which can simulate the detachment of plate rubber bearings, can directly analyze the influence mechanism of detachment or displacement on the bearing's compressive stiffness and stress distribution through the obtained test data. The calibrated stiffness reduction relationship can provide a reliable test basis for the correction of bridge finite element models and the safety assessment of bearings.

[0020] 5. The mechanical performance testing device of the present invention, which can simulate the detachment of plate rubber bearings, relies on the modular design of the device. By changing the loading head and adapting to different sizes of bearing mounting platforms, it can meet the testing needs of various specifications of plate rubber bearings without adjusting the core testing process. It is suitable for routine laboratory testing scenarios and facilitates routine testing. Attached Figure Description

[0021] Figure 1 This is a front view of the overall structure of a mechanical performance testing device for simulating the detachment of a plate rubber bearing, according to an embodiment of the present invention. Figure 2 This is a state diagram simulating the compression performance of a plate rubber bearing under the biased delamination condition, according to an embodiment of the present invention, which is a mechanical performance testing device that can simulate the delamination of a plate rubber bearing. Figure 3 This is a diagram illustrating the compression state of a bearing under the displacement and dislocation condition of a mechanical performance testing device for simulating the dislocation of a plate rubber bearing, according to an embodiment of the present invention. Figure 4 This is a diagram showing the shear state of a bearing under the displacement and detachment condition of a mechanical performance testing device that can simulate the detachment of a plate rubber bearing, according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the displacement and voiding parameters of a plate rubber bearing in a mechanical performance testing device that can simulate the voiding of a plate rubber bearing, according to an embodiment of the present invention. Figure 6 This is a comparison of load-compression curves under different bias angles for a mechanical performance test device that can simulate the detachment of a plate rubber bearing, according to an embodiment of the present invention. Figure 7This is a comparison of load-compression curves under different displacements and voids of a mechanical performance testing device for simulating the voiding of a plate rubber bearing, according to an embodiment of the present invention. Figure 8 This is a comparison diagram of horizontal load-horizontal displacement curves under different displacements and voids of a mechanical performance test device for simulating the voiding of a plate rubber bearing, according to an embodiment of the present invention. Figure 9 This is a flowchart illustrating the usage of a mechanical performance testing device for simulating the detachment of a plate rubber bearing, according to an embodiment of the present invention.

[0022] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-loading beam, 101-first groove, 2-support platform, 201-step structure, 202-second groove, 3-loading pressure head, 4-plate rubber support, 5-support mounting platform, 6-hinge assembly, 601-first hinge seat, 602-second hinge seat, 7-push-pull mechanism, 8-horizontal displacement adjustment mechanism, 9-first vertical displacement adjustment mechanism, 10-second vertical displacement adjustment mechanism, 11-tilt sensor, 12-displacement sensor, 13-control system. Detailed Implementation

[0023] 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.

[0024] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0025] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0026] In this patent, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0027] Example 1 like Figure 1-3As shown, this embodiment of the invention provides a mechanical performance testing device for simulating the detachment of a plate rubber bearing, including a loading beam 1, a support platform 2, a loading head 3, a plate rubber bearing 4, a bearing mounting platform 5, a hinge assembly 6, a push-pull mechanism 7, a horizontal displacement adjustment mechanism 8, and a control system 13; wherein, the support platform 2 has a bearing mounting platform 5 at its left top, the bearing mounting platform 5 has a plate rubber bearing 4 at its top, the plate rubber bearing 4 has a loading head 3 at its top, and the loading head 3 has a loading beam 1 at its top; the support platform 2 and the right end of the loading beam 1 are hinged together by the hinge assembly 6, the fixed end of the push-pull mechanism 7 is embedded in the support platform 2, and its output end is hinged to the bottom of the loading beam 1, and the push-pull mechanism 7 is located on the left side of the hinge assembly 6, driving the loading beam 1 to rotate around the hinge assembly 6 through the push-pull mechanism 7, so that the loading beam 1 forms an inclined posture, thereby realizing the detachment of the plate rubber bearing 4. Simulation of bearing compression performance under biased detachment conditions; one end of the horizontal displacement adjustment mechanism 8 is horizontally fixedly installed on the support platform 2, and the other end is detachably connected to the side wall of the bearing mounting platform 5. It is used to push and pull the bearing mounting platform 5, thereby causing the plate rubber bearing 4 to generate a predetermined horizontal displacement, thus realizing the simulation of bearing compression and shear performance under the displacement detachment conditions of the plate rubber bearing 4; the control system 13 is electrically connected to the push-pull mechanism 7 and the horizontal displacement adjustment mechanism 8 respectively, and is used to receive the preset test parameters and output precise control commands. It controls the push-pull mechanism 7 to realize stepless precision adjustment and locking of the tilt angle of the loading beam 1, thereby accurately simulating the bearing compression performance under different degrees of biased detachment conditions; at the same time, it adjusts the pushing stroke of the horizontal displacement adjustment mechanism 8 to realize the quantitative control of the horizontal displacement of the bearing mounting platform 5 and the plate rubber bearing 4, and accurately reproduces the bearing compression and shear performance under the displacement detachment conditions with different displacement amounts. The working condition simulation of this invention closely matches actual engineering conditions, accurately reproducing the compression performance of plate rubber bearings under eccentric compression and void conditions, and the compression and shear performance of bearings under displacement and void conditions. This effectively solves the technical problem that existing testing devices can only simulate a single void type and are disconnected from actual bridge operation conditions. It can realistically reflect the stress state of the bearing under actual scenarios such as beam settlement, load imbalance, and expansion / contraction displacement. The integrated structural design offers significant advantages, integrating three performance simulation mechanisms onto the same support platform. Test types can be quickly switched without disassembling or replacing test components, significantly reducing workload and shortening the test cycle. It also avoids the need for duplicate equipment purchases, saving testing costs and improving equipment utilization. The push-pull mechanism and horizontal displacement adjustment mechanism enable stepless precise adjustment, ensuring the authenticity and reliability of test data. The bearing mounting platform is adaptable to various bearing specifications, and with the control system, automated operation is achieved, reducing human error and operator workload. The device adopts a modular design, is compact, and suitable for laboratory environments. By changing different sized loading heads and bearing mounting platforms, it can meet the testing needs of various specifications of plate rubber bearings.

[0028] Furthermore, a plurality of first grooves 101 are provided at the bottom left end of the loading beam 1. Each of the first grooves 101 is fixedly fitted with a first vertical displacement adjustment mechanism 9. The first vertical displacement adjustment mechanism 9 is connected to the control system 13, and its output end is fixedly connected to the loading head 3. This allows for precise control of the vertical position of the loading head 3, enabling it to apply a uniform and stable vertical pressure load to the plate rubber support 4. It can also cooperate with the horizontal displacement adjustment mechanism 8 to achieve… Simulation of the compression and shear performance of the plate rubber bearing 4 under displacement and detachment conditions; through precise control of the vertical displacement of the first vertical displacement adjustment mechanism 9, the vertical force applied to the bearing by the loading head 3 is ensured to be evenly distributed, avoiding test errors caused by force deviation and ensuring the stability of the loading process; through the coordinated linkage of this mechanism and the horizontal displacement adjustment mechanism 8, the composite force requirements of "vertical load + horizontal displacement" under displacement and detachment conditions can be accurately matched, improving the realism and accuracy of the simulation of the compression and shear performance of the bearing under displacement and detachment conditions.

[0029] Furthermore, the right end of the support platform 2 has several second grooves 201, each of which is fixedly fitted with a second vertical displacement adjustment mechanism 10. The output end of the second vertical displacement adjustment mechanism 10 abuts against the bottom of the support mounting platform 5. The second vertical displacement adjustment mechanism 10 is connected to the control system 13 and is used to perform stepless precision control of the vertical position of the support mounting platform 5, so that the support mounting platform 5 can apply a uniform and stable vertical pressure load to the plate rubber support 4 placed on it, and can form a coordinated linkage with the push-pull mechanism 7 to accurately realize the plate rubber support. Simulation of the compression performance of rubber bearing 4 under eccentric pressure and voiding conditions; the second vertical displacement adjustment mechanism 10 can achieve precise control of the vertical position of the bearing mounting platform 5, thereby ensuring that the vertical load is uniformly and stably transmitted to the plate rubber bearing 4, avoiding stress concentration and bearing force distortion caused by uneven load distribution, and ensuring the authenticity and accuracy of the test data; this mechanism works in conjunction with the push-pull mechanism 7 to accurately match the composite force requirements of "vertical load + tilting of the loading beam" under eccentric pressure and voiding conditions, and can flexibly adjust the degree of eccentricity, significantly improving the accuracy and fit of the simulation of eccentric pressure and voiding conditions.

[0030] Furthermore, the hinge assembly 6 includes a first hinge seat 601 and a second hinge seat 602. One end of the first hinge seat 601 is fixedly mounted to the top right end of the support platform 2, and one end of the second hinge seat 602 is fixedly mounted to the bottom right end of the loading beam 1. The end of the first hinge seat 601 away from the support platform 2 and the end of the second hinge seat 602 away from the loading beam 1 are hinged by a pivot pin, forming a hinge fulcrum for the loading beam 1 to rotate around the support platform 2. By using the first hinge seat 601 and the second hinge seat 602... The 602 and the split assembly structure of the shaft pin are convenient to assemble and precise in positioning, which can ensure the reliability of the connection of the hinge and effectively avoid problems such as loosening and jamming at the hinge during the test, ensuring the smoothness and stability of the rotation of the loading beam 1. The hinge structure design can realize the flexible rotation of the loading beam 1 around the shaft pin, precisely matching the motion requirements of the push-pull mechanism 7 to drive the loading beam 1 to tilt and simulate the bias pressure and voiding condition, ensuring that the tilt angle of the loading beam 1 can be precisely controlled according to the test preset, and improving the accuracy of the bias pressure and voiding condition simulation.

[0031] Furthermore, the push-pull mechanism 7, the horizontal displacement adjustment mechanism 8, the first vertical displacement adjustment mechanism 9, and the second vertical displacement adjustment mechanism 10 all adopt electric pull rods or servo electric cylinders. Each mechanism uniformly uses electric pull rods or servo electric cylinders as drive execution units, which have high positioning accuracy, fast response speed, and stable output. They can realize stepless precision adjustment of displacement and load and reliable self-locking, effectively avoiding motion impact and load fluctuation, and ensuring the stability of the support compression performance under biased detachment conditions and the stability of the simulated support compression and shear performance under displacement detachment conditions, as well as the repeatability of the test data.

[0032] Furthermore, the mechanical property testing device also includes a measurement component, which includes an inclination sensor 11, a displacement sensor 12, a pressure sensor, a position sensor, a force sensor, and a distributed strain gauge. The inclination sensor 11, displacement sensor 12, pressure sensor, position sensor, and distributed strain gauge are all connected to the control system signal. The tilt sensor 11 is installed at the bottom of the loading beam 1 to collect the tilt angle of the loading beam 1 in real time; the displacement sensor 12 is installed between the support mounting platform 5 and the loading head 3 to detect the vertical compression deformation of the plate rubber bearing 4 in real time; the pressure sensor is installed between the output end of the first vertical displacement adjustment mechanism 9 and the loading head 3, and between the output end of the second vertical displacement adjustment mechanism 10 and the support mounting platform 5, to collect the pressure loads exerted on the plate rubber bearing 4 by the first vertical displacement adjustment mechanism 9 and the second vertical displacement adjustment mechanism 10 in real time; the position sensor is integrated inside the horizontal displacement adjustment mechanism 8 to detect the horizontal displacement of the plate rubber bearing 4 in real time; the force sensor is installed at the output end of the horizontal displacement adjustment mechanism 8 to measure the horizontal load applied by the horizontal displacement adjustment mechanism 8 to the support mounting platform 5; the distributed strain gauge is arranged between the support mounting platform 5 and the plate rubber bearing 4 to collect the stress distribution data of the plate rubber bearing 4 in real time; through The multi-sensor collaborative acquisition method can synchronously, in real time, and with high precision acquire multi-dimensional test parameters such as the inclination angle of the loaded beam, the vertical deformation of the support, the magnitude of the vertical applied load, the horizontal applied load, the horizontal displacement distance, and the stress distribution inside the support. This enables full-parameter quantitative monitoring of key indicators of the support's compressive performance under eccentric pressure and voiding conditions, and its compressive and shear performance under displacement and voiding conditions, significantly improving the integrity and reliability of test data. The closed-loop linkage between the sensors and the control system enables automatic data acquisition, transmission, and processing, effectively reducing manual intervention and human error, and improving the degree of automation and testing efficiency. Distributed strain measurement can accurately reflect the non-uniform stress characteristics of the support under mechanical performance simulation experiments, providing reliable data support for revealing the mechanical performance of the support under operational conditions and establishing mechanical calculation models. The modular integrated arrangement of the sensors ensures reliable installation and positioning, strong anti-interference capabilities, and adaptability to long-term cyclic loading conditions, guaranteeing stable testing processes and continuous data, significantly improving the testing accuracy and engineering applicability of the device.

[0033] Furthermore, the loading head 3 is a replaceable structure, and its shape and size can be flexibly replaced according to test requirements to simulate the actual contact state between the plate rubber bearing 4 and different superstructures such as the beam bottom steel plate and concrete pad. The replaceable loading head structure allows for matching the corresponding contact surface form according to different test conditions and bearing types, realistically reproducing the contact boundary conditions between the bearing and different components in actual engineering, significantly improving the fit between test conditions and engineering reality. The replaceable design allows for adaptation without modifying the main structure of the device, effectively improving the versatility and applicability of the test, meeting the test needs of multiple specifications and scenarios. Simultaneously, it is easy to assemble and disassemble, and its positioning is reliable, shortening test preparation time, improving test efficiency, reducing test tooling costs, and enhancing the overall practicality and expandability of the device.

[0034] Example 2 like Figure 1-7 As shown, this invention provides a method for using a mechanical performance testing device that can simulate the detachment of a plate rubber bearing. The method utilizes this mechanical performance testing device, and the specific steps are as follows: S100: According to the test requirements, select the appropriate specifications of plate rubber support 4 and the matching loading head 3, position and install the plate rubber support 4 on the upper end face of the support mounting platform 5, fix the loading head 3 to the output end of the first vertical displacement adjustment mechanism 9, and install, debug and calibrate the sensors in the measurement assembly. S200: The control system 13 drives the push-pull mechanism 7 and the second vertical displacement adjustment mechanism 10 to simulate the compression performance test of the plate rubber support 4 under the bias pressure and void condition. S300: The horizontal displacement adjustment mechanism 8 and the first vertical displacement adjustment mechanism 9 are driven by the control system 13 to simulate the compression and shear performance test of the plate rubber support 4 under the condition of displacement and voiding. S400: By comparing and analyzing the load-compression (P-δ) curves of plate rubber bearing 4 under different eccentric pressure and displacement void states, as well as the bearing shear performance curves under different vertical loads and void displacements, the mechanical property variation law of plate rubber bearing 4 is obtained.

[0035] Further, step S200 specifically includes: S210: The control system 13 drives the push-pull mechanism 7 to rotate the loading beam 1 around the hinge assembly 6 to a preset tilt angle θ, and then drives the second vertical displacement adjustment mechanism 10 to make the loading head 3 and the upper surface of the plate rubber support 4 form an inclined fit, realizing the initial bias pressure release state. S220: Disconnect the horizontal displacement adjustment mechanism 8 from the support mounting platform 5, control the second vertical displacement adjustment mechanism 10 to push the support mounting platform 5 to drive the plate rubber support 4 to rise, and synchronously collect the vertical load P, compression δ, loading beam inclination angle θ and support bottom distributed stress σ data in real time through the measurement component and transmit them to the control system 13. S230: The control system 13 processes the collected data in real time and generates the load-compression (P-δ) curve at the corresponding tilt angle θ; S240: Adjust the loading beam 1 to different inclination angles θ by using the push-pull mechanism 7, and repeat steps S210 to S230 to obtain multiple sets of support compression performance curves under different inclination angles and biased cavitation conditions.

[0036] Through the above experiments, we can obtain the following results: Figure 6 This is a comparison of the load-compression curves of a certain plate rubber bearing 4 when it becomes detached at different inclination angles.

[0037] Furthermore, the support compression performance test in step S300 specifically includes: The control system 13 controls the push-pull mechanism 7 to keep the loading beam in a horizontal state; The horizontal displacement adjustment mechanism 8 is controlled by the control system 13 to drive the support mounting platform 5 and the plate rubber support 4 to generate a preset horizontal displacement d, so that a local area of ​​the plate rubber support 4 is suspended outside the loading head 3, forming a displaced and freed state. The control system 13 controls the first vertical displacement adjustment mechanism 9 to push the loading head 3 to apply a vertical load to the plate rubber support 4, and the load P, compression δ and horizontal displacement d are collected in real time by the measuring component. The control system 13 calculates the displacement distance L, suspension length A and detachment rate S in real time, and generates the load-compression (P-δ) curve under the corresponding horizontal displacement d. By adjusting the horizontal displacement adjustment mechanism 8 through the control system 13, the bearing mounting platform 5 drives the plate rubber bearing 4 to produce different horizontal displacements d. By repeating the above steps, multiple sets of bearing compression performance curves under different displacement and voiding degrees are obtained.

[0038] Through the above experiments, we can obtain the following results: Figure 7 This is a comparison chart of the load-compression curves of the plate rubber bearing 4 when it is dislodged under different displacements.

[0039] Furthermore, the conversion relationships between the displacement distance L, suspension length A, and voiding rate S in the displacement and voiding test are as follows: Displacement distance: ; Void removal rate: ; Where: R is the radius of the plate rubber bearing 4, L is the displacement distance, and S is the void ratio.

[0040] Furthermore, the support compression performance test in step S300 specifically includes: The control system 13 controls the push-pull mechanism 7 to keep the loading beam in a horizontal state; The horizontal displacement adjustment mechanism 8 is controlled by the control system 13 to drive the support mounting platform 5 and the plate rubber support 4 to generate a preset horizontal displacement d, so that a local area of ​​the plate rubber support 4 is suspended outside the loading head 3, forming a preset displacement and free state. The control system 13 controls the first vertical displacement adjustment mechanism 9 to push the loading head 3 to apply a preset vertical load to the plate rubber support 4 and keep the vertical load stable. The load P and horizontal displacement d are collected in real time by the measuring component. After the vertical load stabilizes, the horizontal displacement adjustment mechanism 8 is controlled by the control system 13 to drive the support mounting platform 5 to move the plate rubber support 4 horizontally back and forth, thereby applying a horizontal back and forth shear load to the plate rubber support 4. Throughout the entire process of applying horizontal reciprocating shear load, horizontal load and horizontal displacement data are collected in real time by the measuring components, and the collected data are transmitted to the control system 13 in real time. The control system 13 processes the collected test data to generate the horizontal shear hysteresis curve of the plate rubber support 4 under vertical load and free displacement. By adjusting the first vertical displacement adjustment mechanism 9 through the control system 13, the loading head 3 applies different vertical loads to the plate rubber bearing 4, and the horizontal displacement adjustment mechanism 8 is controlled to cause the bearing mounting platform 5 to drive the plate rubber bearing 4 to generate different horizontal displacements d. By repeating the above steps, multiple sets of bearing shear performance curves under different vertical loads and free displacements are obtained.

[0041] Through the above experiments, we can obtain the following results: Figure 8 This is a comparison of the horizontal force load and horizontal shear displacement curves of the plate rubber bearing 4 under different displacements under a vertical load of 500KN.

[0042] The experimental procedures of this invention closely align with engineering realities, accurately and quantitatively reproducing the damage conditions of plate rubber bearings under eccentric compression and displacement-induced voiding conditions, including bearing compression and shear stress. By step-by-step adjusting the beam inclination angle, bearing horizontal displacement, and vertical load, it realistically recreates the voiding stress state of the bearing caused by beam tilting and misalignment during actual bridge operation. This solves the technical problem of existing experimental methods having a single simulated working condition and being disconnected from reality, thus improving the authenticity and relevance of the experiment. The experimental process is highly automated, with the entire process driven by a control system that coordinates the actions of various adjustment mechanisms, achieving integrated closed-loop control of loading, displacement adjustment, data acquisition, data processing, and curve generation. This effectively reduces manual intervention, avoids human error, and significantly improves the accuracy, repeatability, and reliability of experimental data, while also reducing the labor intensity of operators and increasing experimental efficiency. The experimental parameters are precisely controlled and highly flexible. By adjusting different inclination angles θ of the loaded beam, multiple sets of test data under different degrees of eccentric compression and voiding can be obtained. By adjusting different vertical loads and horizontal displacements d of the supports, multiple sets of test data on compressive and shear performance under different degrees of displacement and voiding can be obtained. This allows for a systematic and comprehensive understanding of the influence of voiding degree on the compressive and shear performance of the supports. Compared with single-condition tests, the data coverage is wider and the support is stronger. The data acquisition is comprehensive and the analysis is precise. Through the measurement components, multi-dimensional key parameters such as vertical load, horizontal load, support compressive displacement, beam inclination angle, stress distribution at the bottom of the support, and horizontal displacement are collected simultaneously. Combined with the control system, core indicators such as voiding rate and suspension length are calculated in real time, and load-compression (P-δ) curves and load-horizontal shear displacement are generated simultaneously. This provides complete and reliable test data support for subsequent comparative analysis of the changes in the mechanical properties of the supports and for revealing the mechanism of support voiding defects.

[0043] 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 mechanical property testing device for simulating the detachment of a plate rubber bearing, characterized in that, The system includes a loading beam (1), a support platform (2), a loading head (3), a plate rubber bearing (4), a bearing mounting platform (5), a hinge assembly (6), a push-pull mechanism (7), a horizontal displacement adjustment mechanism (8), and a control system (13); among which, The support platform (2) has a support mounting platform (5) at the top left end, a plate rubber support (4) at the top of the support mounting platform (5), a loading head (3) at the top of the plate rubber support (4), and a loading beam (1) at the top of the loading head (3). The support platform (2) is hinged to the right end of the loading beam (1) through the hinge assembly (6). The fixed end of the push-pull mechanism (7) is embedded in the support platform (2), and its output end is hinged to the bottom of the loading beam (1). The push-pull mechanism (7) is located on the left side of the hinge seat (6). The push-pull mechanism (7) drives the loading beam (1) to rotate around the hinge assembly (6), so that the loading beam (1) forms an inclined posture, thereby realizing the simulation of the bearing compression performance under the biased pressure and void working condition of the plate rubber bearing (4). One end of the horizontal displacement adjustment mechanism (8) is horizontally fixedly installed on the support platform (2), and the other end is detachably connected to the side wall of the support mounting platform (5). It is used to push and pull the support mounting platform (5) to drive the plate rubber support (4) to generate a predetermined horizontal displacement, thereby realizing the simulation of the support compression and shear performance under the displacement and detachment working condition of the plate rubber support (4). The control system (13) is connected to the push-pull mechanism (7) and the horizontal displacement adjustment mechanism (8) respectively. It is used to receive the preset test parameters and output precise control commands to control the push-pull mechanism (7) and the horizontal displacement adjustment mechanism (8) to realize the simulation of the bearing compression performance under the biased detachment condition and the bearing compression and shear performance under the displacement detachment condition of the plate rubber bearing (4).

2. The mechanical property testing device for simulating the detachment of a plate rubber bearing according to claim 1, characterized in that, The bottom left end of the loading beam (1) is provided with a number of first grooves (101), and a first vertical displacement adjustment mechanism (9) is fixedly installed in each of the first grooves (101). The first vertical displacement adjustment mechanism (9) is connected to the control system (13), and the output end of the first vertical displacement adjustment mechanism (9) is fixedly connected to the loading head (3).

3. The mechanical performance testing device for simulating the detachment of a plate rubber bearing according to claim 1, characterized in that, The right end of the support platform (2) has several second grooves (201), and each of the second grooves (201) is fixedly equipped with a second vertical displacement adjustment mechanism (10). The output end of the second vertical displacement adjustment mechanism (10) abuts against the bottom of the support mounting platform (5), and the second vertical displacement adjustment mechanism (10) is connected to the control system (13).

4. The mechanical property testing device for simulating the detachment of a plate rubber bearing according to claim 1, characterized in that, The hinge assembly (6) includes a first hinge seat (601) and a second hinge seat (602). One end of the first hinge seat (601) is fixedly mounted on the top right end of the support platform (2), and one end of the second hinge seat (602) is fixedly mounted on the bottom right end of the loading beam (1). The end of the first hinge seat (601) away from the support platform (2) and the end of the second hinge seat (602) away from the loading beam (1) are hinged by a pivot pin to form a hinge fulcrum for the loading beam (1) to rotate around the support platform (2).

5. A mechanical performance testing device for simulating the detachment of a plate rubber bearing according to any one of claims 1-4, characterized in that, The push-pull mechanism (7), the horizontal displacement adjustment mechanism (8), the first vertical displacement adjustment mechanism (9) and the second vertical displacement adjustment mechanism (10) all adopt electric pull rods or servo electric cylinders.

6. A mechanical property testing device for simulating the detachment of a plate rubber bearing according to any one of claims 1-4, characterized in that, The compression performance testing device also includes a measurement component, which includes an inclination sensor (11), a displacement sensor (12), a pressure sensor, a position sensor, a force sensor, and a distributed strain gauge. The inclination sensor (11), displacement sensor (12), pressure sensor, position sensor, force sensor, and distributed strain gauge are all connected to the control system signal. The tilt sensor (11) is installed at the bottom of the loading beam (1) and is used to collect the tilt angle of the loading beam (1) in real time. The displacement sensor (12) is located between the support mounting platform (5) and the loading head (3) to detect the vertical compression deformation of the plate rubber support (4) in real time. The pressure sensor is located between the output end of the first vertical displacement adjustment mechanism (9) and the loading head (3) and between the output end of the second vertical displacement adjustment mechanism (10) and the support mounting platform (5), and is used to collect the pressure loads of the first vertical displacement adjustment mechanism (9) and the second vertical displacement adjustment mechanism (10) acting on the plate rubber support (4) in real time. The position sensor is integrated inside the horizontal displacement adjustment mechanism (8) and is used to detect the displacement of the plate rubber support (4) in real time when it is dislodged. The force sensor is located at the output end of the horizontal displacement adjustment mechanism (8) and is used to measure the horizontal load applied by the horizontal displacement adjustment mechanism (8) to the support mounting platform (5). The distributed strain gauge is arranged between the support mounting platform (5) and the plate rubber support (4) to collect stress distribution data of the plate rubber support (4) under bias and void conditions in real time.

7. A mechanical property testing device for simulating the detachment of a plate rubber bearing according to any one of claims 1-4, characterized in that, The loading head (3) is a replaceable structure, and its shape and size can be flexibly replaced according to the test requirements to simulate the real contact state between the plate rubber support (4) and different upper structures.

8. A method for using a mechanical property testing device that can simulate the detachment of a plate rubber bearing, characterized in that, The mechanical performance testing device for simulating the detachment of a plate rubber bearing, as described in any one of claims 1-7, is characterized by comprising the following steps: S100: According to the test requirements, select the appropriate specifications of plate rubber support (4) and the matching loading head (3), position and install the plate rubber support (4) on the upper end of the support mounting platform (5), fix the loading head (3) to the output end of the first vertical displacement adjustment mechanism (9), and install, debug and calibrate the sensors in the measurement assembly. S200: The push-pull mechanism (7) and the second vertical displacement adjustment mechanism (10) are driven by the control system (13) to simulate the compression performance test of the plate rubber support (4) under the biased pressure and void condition. S300: The horizontal displacement adjustment mechanism (8) and the first vertical displacement adjustment mechanism (9) are driven by the control system (13) to simulate the compression and shear performance test of the plate rubber support (4) under the displacement and voiding condition. S400: By comparing and analyzing the load-compression (P-δ) curves of the plate rubber bearing (4) under different eccentric pressure and displacement detachment states, as well as the bearing shear performance curves under different vertical loads and detachment displacements, the mechanical performance variation law of the plate rubber bearing (4) is obtained.

9. The method of using the mechanical property testing device for simulating the detachment of a plate rubber bearing according to claim 8, characterized in that, Step S200 specifically includes: S210: Drive the push-pull mechanism (7) through the control system (13) to rotate the loading beam (1) around the hinge assembly (6) to the preset tilt angle θ, and then drive the second vertical displacement adjustment mechanism (10) to make the loading head (3) and the upper surface of the plate rubber support (4) form an inclined fit, so as to achieve the initial bias pressure release state. S220: Control the second vertical displacement adjustment mechanism (10) to push the support mounting platform (5) to drive the plate rubber support (4) to rise, and synchronously collect the vertical load P, compression δ, loading beam inclination angle θ and support bottom distribution stress σ data through the measurement component and transmit them to the control system (13). S230: The control system (13) processes the collected data in real time and generates the load-compression curve at the corresponding tilt angle θ; S240: Adjust the loading beam (1) to different inclination angles θ by using the push-pull mechanism (7), and repeat steps S210 to S230 to obtain multiple sets of support compression performance curves under different inclination angles under biased cavitation conditions.

10. The method of using the mechanical property testing device for simulating the detachment of a plate rubber bearing according to claim 8, characterized in that, The support compression performance test in step S300 specifically includes: The control system (13) controls the push-pull mechanism (7) to keep the loading beam in a horizontal state; The horizontal displacement adjustment mechanism (8) is controlled by the control system (13) to drive the support mounting platform (5) and the plate rubber support (4) to generate a preset horizontal displacement d, so that the local area of ​​the plate rubber support (4) is suspended outside the loading head (3) to form a displacement and free state. The control system (13) controls the first vertical displacement adjustment mechanism (9) to push the loading head (3) to apply a vertical load to the plate rubber support (4), and the load P, compression δ and horizontal displacement d are collected in real time by the measuring component. The control system (13) calculates the displacement distance L, suspension length A and detachment rate S in real time, and generates the load-compression (P-δ) curve under the corresponding horizontal displacement d. By adjusting the horizontal displacement adjustment mechanism (8) through the control system (13), the support mounting platform (5) drives the plate rubber support (4) to generate different horizontal displacements d. Repeat the above steps to obtain multiple sets of support compression performance curves under different displacement and voiding degrees. The support compression performance test in step S300 specifically includes: The control system (13) controls the push-pull mechanism (7) to keep the loading beam in a horizontal state; The horizontal displacement adjustment mechanism (8) is controlled by the control system (13) to drive the support mounting platform (5) and the plate rubber support (4) to generate a preset horizontal displacement d, so that the local area of ​​the plate rubber support (4) is suspended outside the loading head (3) to form a preset displacement and free state. The control system (13) controls the first vertical displacement adjustment mechanism (9) to push the loading head (3) to apply a preset vertical load to the plate rubber support (4) and keep the vertical load stable. The load P and horizontal displacement d are collected in real time by the measuring component. After the vertical load stabilizes, the horizontal displacement adjustment mechanism (8) is controlled by the control system (13) to drive the support mounting platform (5) to move the plate rubber support (4) horizontally back and forth, thereby applying a horizontal back and forth shear load to the plate rubber support (4). Throughout the entire process of applying horizontal reciprocating shear load, horizontal load and horizontal displacement data are collected in real time by the measuring components, and the collected data are transmitted to the control system (13) in real time. The control system (13) processes the collected test data to generate the horizontal shear hysteresis curve of the plate rubber support (4) under vertical load and void displacement. By adjusting the first vertical displacement adjustment mechanism (9) through the control system (13), the loading head (3) applies different vertical loads to the plate rubber bearing (4), and the horizontal displacement adjustment mechanism (8) is controlled to make the bearing mounting platform (5) drive the plate rubber bearing (4) to generate different horizontal displacements d. Repeat the above steps to obtain multiple sets of bearing shear performance curves under different vertical loads and free displacements.

Images