A complex load test system for large-span arch bridge models

Abstract

The present invention relates to the technical field of bridge loading tests, and specifically to a novel complex force loading test system for a super-long span arch bridge model, comprising an electro-hydraulic servo multi-point multi-directional loading system, a control system, and a test system. A plurality of spaced-apart load-bearing reaction frames are connected by a continuous beam, at least one of the electro-hydraulic servo actuators of the load-bearing reaction frames is a static servo actuator and at least one is a dynamic servo actuator. The load-bearing reaction frames are equipped with automatically elevating frame beams, and a horizontal loading beam is installed inside the load-bearing reaction frames. Servo actuators are installed on the frame beams and the continuous beams, and the servo actuators are used for vertical loading, and the servo actuators installed on the horizontal loading beams are used for horizontal loading. The control system is used to control the servo actuators. The present invention can perform complex multi-point multi-directional static and dynamic combined scale model loading tests on super-long span arch bridges.

Description

Technical Field

[0001] The invention relates to the technical field of bridge loading tests, in particular to a novel complex force loading test system for a super-large span arch bridge model. Background Art

[0002] In recent years, there have been numerous reports of bridge collapses and safety hazards in large buildings around the world. While enjoying the development of science and technology, mankind is also facing huge challenges in structural engineering safety. The research and development of powerful large-scale loading test systems that can simulate the real and complex stresses of structures is currently a key issue worldwide.

[0003] Because it is difficult to obtain complete and reliable data on overall structural performance using standard specimens or small-scale models, modern structural testing must transition from traditional single-component testing to testing of entire structures and full-scale testing to meet these objective requirements. Furthermore, even multi-parameter computer analysis is difficult for structures composed of different materials, necessitating tests close to the actual structure or full-scale testing to ensure safety. Simultaneously, the rapid development of science and technology, particularly computer technology, electronics, automatic control technology, and hydraulic servo technology, has provided a solid foundation for the development of structural testing and monitoring technology, providing strong support for the design, testing, and monitoring of various complex structures and promoting the advancement of structural design theory. Consequently, countries around the world are actively engaged in the development and research of large-scale structural testing equipment.

[0004] At present, vertical static multi-point loading is mainly used in bridges in China. However, there are no successful cases in China for dynamic loading tests in other directions such as horizontal directions under vertical multi-point loading conditions. However, this type of test is an important development direction in the field of structural test loading and has important promoting significance for scientific research in civil engineering disciplines. Summary of the Invention

[0005] The purpose of the present invention is to address the problems existing in the prior art and provide a novel complex force loading test system for extra-large span arch bridge models. By adjusting the static servo actuator, dynamic servo actuator and load-bearing reaction frame, complex multi-point and multi-directional static and dynamic scale model loading tests can be performed on extra-large span arch bridges.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A new type of complex force loading test system for extra-large span arch bridge models includes an electro-hydraulic servo multi-point multi-directional loading system, a control system and a test system. The electro-hydraulic servo multi-point multi-directional loading system includes a plurality of spaced-apart load-bearing reaction frames, and the plurality of load-bearing reaction frames are connected by continuous beams. The electro-hydraulic servo multi-point multi-directional loading system also includes an electro-hydraulic servo actuator, at least one of the servo actuators is a static servo actuator and at least one is a dynamic servo actuator. The load-bearing reaction frame is equipped with a frame beam that can be automatically raised and lowered, and a horizontal loading beam is installed inside the load-bearing reaction frame. The frame beam, the horizontal loading beam and the continuous beam are all equipped with the servo actuator. The servo actuators installed on the frame beam and the continuous beam are used for vertical loading, and the servo actuator installed on the horizontal loading beam is used for horizontal loading. The control system is used to control the servo actuator.

[0008] Among them, the extra-large span arch bridge described in the present invention refers to a highway bridge with a total span length of multiple spans greater than 1000m or a single span span greater than 150m, as well as a railway bridge with a bridge length greater than 500m.

[0009] The static servo actuator (static loading) of the present invention can simulate the short-term load and constant load effects of an arch bridge, while the dynamic servo actuator (dynamic loading) can simulate live load effects such as earthquake forces and vehicle loads. The present invention uses servo actuators installed on reaction frame beams and continuous beams for vertical loading, simulating the ultimate load-bearing capacity of an arch bridge and its load-bearing capacity during the operational phase. Simultaneously, the present invention uses servo actuators installed on horizontal loading beams for horizontal loading, simulating the load-bearing capacity of a bridge under horizontal loads (e.g., wind loads and earthquake loads). The loading position of the servo actuator can be adjusted by using an automatically raised and lowered reaction frame beam, and multi-point loading can be achieved by installing multiple servo actuators.

[0010] Therefore, the present invention has the ability to dynamically and statically load the extra-large span arch bridge model, can realize multi-point and multi-directional loading tests on the extra-large span arch bridge model, and complete the simulated loading of vertical train loads and horizontal wind loads.

[0011] As a preferred solution of the present invention, the horizontal loading beam includes a horizontal loading longitudinal beam and a horizontal loading cross beam connected to each other.

[0012] As a preferred solution of the present invention, the horizontal loading beam is also installed between the multiple bearing reaction frames.

[0013] As a preferred solution of the present invention, the horizontal loading beam and the bearing reaction frame are detachably connected, and the installation height of the horizontal loading beam is adjustable, so as to facilitate adjustment of the loading position.

[0014] As a preferred solution of the present invention, the horizontal loading beam is installed with at least one static servo actuator and at least one dynamic servo actuator, so as to facilitate dynamic and static loading through the horizontal loading beam.

[0015] As a preferred solution of the present invention, the continuous beam is installed with at least two servo actuators, and the installation position of the servo actuator on the continuous beam is adjustable to facilitate adjustment of the loading position.

[0016] As a preferred solution of the present invention, the continuous beam is fixedly connected to the frame cross beam, and the continuous beam is arranged horizontally, and can be raised and lowered by the lifting of the frame cross beam.

[0017] As a preferred solution of the present invention, the electro-hydraulic servo multi-point multi-directional loading system further includes a dynamic oil separator and pipelines.

[0018] As a preferred solution of the present invention, the control system includes multiple control channels, each control channel is equipped with two closed-loop control circuits of test force and displacement. The control system can control multiple servo actuators to load simultaneously, improve the synchronization of load loading, and improve test accuracy.

[0019] As a preferred solution of the present invention, the test system includes test instruments such as load sensors, strain gauges, and displacement gauges to complete internal force, strain, and other tests on the extra-long span arch bridge model.

[0020] The present invention also discloses a complex force loading test method for a super-long span arch bridge model, which uses any of the novel complex force loading test systems for super-long span arch bridge models, and comprises the following steps:

[0021] Step 1: Fix and install the load-bearing reaction frame, connect multiple load-bearing reaction frames through a continuous beam; install the horizontal loading beam;

[0022] Step 2: Install the servo actuator on the frame beam, the horizontal loading beam, and the continuous beam;

[0023] Step 3: Carry out a loading test on the specimen and adjust the load size through the control system;

[0024] Step 4: Test the internal forces of the arch model using load sensors; test the structural strain of the arch model using strain gauges; and obtain real-time data on the load-strain and load-deformation relationship curves of key parts of the test model by posting luminous marking points on the arch ribs and using a camera measurement system to observe the arch deflection and structural deformation.

[0025] As a preferred solution of the present invention, by adjusting the loading position, tonnage, loading time, loading direction and load size of the servo actuator, it is used for the ultimate bearing capacity and full life cycle design theory and durability evaluation test of extra-large span arch bridges.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] 1. The present invention has the ability to perform dynamic and static loading on extra-long span arch bridge models, can realize multi-point and multi-directional loading tests on extra-long span arch bridge models, complete simulated loading of vertical train loads and horizontal wind loads, and has the function of maintaining stable loading outputs of other actuators under the working condition that the displacement of the specimen at the action point of a single actuator surges after reaching yield.

[0028] 2. By adjusting the loading position, tonnage, loading time, loading direction and load size of the servo actuator, it is used for the ultimate bearing capacity and full life cycle design theory and durability evaluation test of extra-long span arch bridges.

[0029] 3. This invention is capable of dynamic and static loading of plate-type structures such as walls, including shear walls and corrugated steel webs, for load-bearing capacity and fatigue performance testing, as well as stability testing. Utilizing horizontal loading beams and frame crossbeams, bidirectional loading tests can be performed on plate-type structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a three-dimensional structural schematic diagram of a complex force loading test system for a novel extra-large span arch bridge model described in the present invention.

[0031] Figure 2 It is a front view of a complex force loading test system for a novel extra-large span arch bridge model described in the present invention.

[0032] Figure 3 It is a top view of a complex force loading test system for a novel extra-large span arch bridge model described in the present invention.

[0033] Figure 4 It is a front view of the load-bearing reaction frame described in the present invention.

[0034] Figure 5 It is a schematic diagram of loading the entire arch bridge using a complex force loading test system for a novel extra-large span arch bridge model described in the present invention.

[0035] Figure 6 This is a schematic diagram of the installation of the camera and luminous sign of the present invention Figure 1 .

[0036] Figure 7 This is a schematic diagram of the installation of the camera and luminous sign of the present invention Figure 2 .

[0037] Figure 8 This is the installation diagram of the displacement meter and micrometer of the present invention. Figure 1 .

[0038] Figure 9 This is the installation diagram of the displacement meter and micrometer of the present invention. Figure 2 .

[0039] Icon: 11-first load-bearing reaction frame, 12-second load-bearing reaction frame, 13-third load-bearing reaction frame,

[0040] 101-frame beam, 102-frame column, 103-horizontal loading longitudinal beam, 104-first horizontal loading beam, 105-automatic lifting system, 106-working platform, 107-camera, 108-luminous sign, 109-bracket, 110-displacement meter, 111-micrometer,

[0041] 21-static electro-hydraulic servo actuator, 22-first dynamic electro-hydraulic servo actuator, 23-second dynamic electro-hydraulic servo actuator,

[0042] 3-Continuous beam, 4-Second horizontal loading beam, 5-Reaction foundation, 6-Arch bridge, 7-Reaction frame. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below with reference to the accompanying drawings.

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present 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 only used to explain the present invention and are not intended to limit the present invention.

[0045] Example 1

[0046] like Figure 1-Figure 3 As shown in the figure, a new type of complex force loading test system for extra-long span arch bridge model includes a servo actuator, multiple load-bearing reaction frames arranged at intervals, a dynamic oil distributor, pipelines, and dynamic and static control systems.

[0047] Specifically, in this embodiment, the servo actuator includes one static electro-hydraulic servo actuator 21, one first dynamic electro-hydraulic servo actuator 22, and eight second dynamic electro-hydraulic servo actuators 23. The static electro-hydraulic servo actuator 21 can be a 300-ton static electro-hydraulic servo actuator, the first dynamic electro-hydraulic servo actuator 22 can be a 100-ton dynamic electro-hydraulic servo actuator, and the second dynamic electro-hydraulic servo actuator 23 can be a 25-ton dynamic electro-hydraulic servo actuator. The 300-ton static electro-hydraulic servo actuator is connected to the frame crossbeam 101 via auxiliary equipment. The 100-ton dynamic electro-hydraulic servo actuator can be connected to the frame crossbeam 101. The 25-ton dynamic electro-hydraulic servo actuator can be installed at any position within the load-bearing reaction frame for multi-point and multi-directional loading.

[0048] The 300-ton static electro-hydraulic servo actuator is primarily used for mechanical property testing of large bridge components and nodes. It is used to achieve vertical loading within the load-bearing reaction frame and includes the actuator body, front ball joint and rear flange connection, built-in magnetostrictive displacement sensor, spoke-type high-precision load sensor, and corresponding connectors. The 100-ton dynamic electro-hydraulic servo actuator is primarily used for fatigue testing of large bridge components and includes the actuator body, servo valve, load sensor, displacement sensor, front and rear high-precision ball joints, and other supporting components. The 25-ton dynamic electro-hydraulic servo actuator is primarily used for multi-point and multi-directional dynamic loading testing of large bridge components and includes the actuator body, servo valve, load sensor, displacement sensor, front and rear high-precision ball joints, and other supporting components.

[0049] The dynamic and static control system consists of two sets of four-channel controllers, each with four control channels, which can control up to eight actuators to load simultaneously and jointly complete coordinated loading tests. The controller is connected to the controller network to achieve interchangeable coordinated loading control of the two sets of system actuators, completing more complex structural component loading tests. It can achieve full digital closed-loop control of eight actuators. Each channel is equipped with two closed-loop control loops for test force and displacement. The two control modes can switch smoothly under any circumstances to meet the dynamic and static loading requirements of the test. The control system can accept data from external force or displacement sensors (except for the sensors of the actuator itself) for closed-loop control. The test parameters can be transmitted to the data acquisition system in the form of digital or analog output for analysis and calculation of test results.

[0050] The load-bearing reaction frames include a first load-bearing reaction frame 11, a second load-bearing reaction frame 12, and a third load-bearing reaction frame 13. One of these is a 300-ton load-bearing reaction frame (meaning the load-bearing reaction frame can withstand a vertical load of 3000 kN), and the other two are 200-ton load-bearing reaction frames (meaning the load-bearing reaction frame can withstand a vertical load of 2000 kN). The three load-bearing reaction frames adopt a self-balancing structure with a semi-automatic lifting function and are placed on the reaction foundation 5.

[0051] Specifically, such as Figure 4As shown, each bearing reaction frame includes a frame crossbeam 101, a frame column 102, a horizontal loading longitudinal beam 103, a first horizontal loading crossbeam 104, an automatic lifting system 105, a working platform 106, etc., wherein the frame crossbeam 101 and the first horizontal loading crossbeam 104 are both connected to the automatic lifting system 105, and can be hydraulically automatically lifted and lowered by the automatic lifting system 105, and the space can be adjusted by manual locking. The working platform 106 at the bottom of the bearing reaction frame is connected to the reaction foundation 5 by anchor bolts. In this embodiment, the first horizontal loading crossbeam 104 is a short horizontal beam installed inside the bearing reaction frame. Each bearing reaction frame is installed with two first horizontal loading crossbeams 104 of different heights. The two first horizontal loading crossbeams 104 are connected by a vertically arranged horizontal loading longitudinal beam 103. The installation height of the first horizontal loading crossbeam 104 can be adjusted by the automatic lifting system 105.

[0052] The three load-bearing reaction frames are connected by a horizontally arranged continuous beam 3. Specifically, in this embodiment, the continuous beam 3 is connected to the frame beam 101 of each load-bearing reaction frame. The height of the frame beam 101, and thus the height of the continuous beam 3, can be adjusted via an automatic lifting system 105. Two second horizontal loading beams 4 are also provided between the load-bearing reaction frames. These two second horizontal loading beams 4 are long horizontal beams, located at heights of 52250mm and 5500mm from the working level, respectively. The continuous beam 3 is equipped with multiple servo actuators for vertical loading. The servo actuators are adjustable at their mounting positions on the continuous beam 3. The second horizontal loading beams 4 are also equipped with multiple servo actuators for horizontal loading, which may include at least one static servo actuator and at least one dynamic servo actuator.

[0053] Example 2

[0054] A complex load test method for a super-long span arch bridge model is provided, using a novel complex load test system for a super-long span arch bridge model as in Example 1, comprising the following steps:

[0055] Step 1: First, connect the work platform 106 to the reaction foundation 5 via anchor bolts. Then, connect the three load-bearing reaction frames to the work platform 106 via anchor bolts. After installing the load-bearing reaction frames, install the continuous beam 3. Then, install the second horizontal loading beam 4 (long horizontal beam) at a height of 2250mm and 5500mm from the work surface, respectively, and test whether the installation accuracy meets the requirements. After installing the second horizontal loading beam 4, install the horizontal loading longitudinal beam 103 and the first horizontal loading beam 104 (short horizontal beam).

[0056] Step 2: After the structure is installed, install the static and dynamic electro-hydraulic servo actuators. Depending on the load required for the test, the actuator type and tonnage can be changed. The horizontal position and vertical height of the actuators can also be adjusted based on the load position.

[0057] Step 3: Place the test component on the work platform 106. For large components such as long-span bridges, it can be installed across three load-bearing reaction frames. Small components such as K-byte nodes and cross nodes can be installed on a single load-bearing reaction frame. After the test component is installed, the position of the electro-hydraulic servo actuator can be adjusted to apply loads in different positions and directions, and the load magnitude can be adjusted through system control.

[0058] like Figure 5 As shown, Guangxi University uses the new type of complex force loading test system for extra-large span arch bridge model described in the present invention to load the arch bridge 6. By installing corresponding static and / or dynamic electro-hydraulic servo actuators and cooperating with the reaction frames 7 added on both sides, the bearing capacity test and fatigue performance test of the entire arch bridge 6 can be realized.

[0059] Step 4: Test the internal forces of the arch model using load sensors; test the structural strain of the arch model using strain gauges; and obtain real-time data on the load-strain and load-deformation relationship curves of key parts of the test model by posting luminous marking points on the arch ribs and using a camera measurement system to observe the arch deflection and structural deformation.

[0060] like Figure 6-7 As shown, when loading arch bridge 6 using the complex load-bearing test system for the new ultra-long-span arch bridge model, the system can be connected to a video measurement system via a dynamic and static control system. The video measurement system, consisting of a camera 107 and a light-emitting marker 108, measures the displacement and rotation of the light-emitting marker 108 with camera 107, which then connects to the dynamic and static control system to enable real-time measurement of the displacement and rotation of the entire arch bridge 6 during load-bearing capacity and fatigue performance tests.

[0061] like Figure 8-9 As shown, when the complex force loading test system of the new extra-large span arch bridge model is loading the arch bridge 6, the bracket 109 is connected to the first load-bearing reaction frame 11, the second load-bearing reaction frame 12, and the third load-bearing reaction frame 13 by bolts, the displacement meter 110 and the micrometer 111 are mounted on the bracket 109, and the dynamic and static control system is connected to the displacement measuring equipment such as the displacement meter 110 and the micrometer 111, so as to realize high-precision real-time testing of the displacement during the load-bearing capacity test and fatigue performance test of the entire arch bridge 6.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A complex load test system for a large-span arch bridge model, characterized by: It includes an electro-hydraulic servo multi-point multi-directional loading system, a control system and a test system. The electro-hydraulic servo multi-point multi-directional loading system includes a plurality of bearing reaction frames arranged at intervals, and the plurality of bearing reaction frames are connected by continuous beams. The electro-hydraulic servo multi-point multi-directional loading system also includes an electro-hydraulic servo actuator, at least one of the servo actuators is a static servo actuator and at least one is a dynamic servo actuator. The bearing reaction frame is equipped with a frame beam that can be automatically raised and lowered, and a horizontal loading beam is installed inside the bearing reaction frame. The frame beam, the horizontal loading beam and the continuous beam are all equipped with the servo actuator, which is installed on the frame beam, The servo actuator of the continuous beam is used for vertical loading, the servo actuator installed on the horizontal loading beam is used for horizontal loading, and the control system is used to control the servo actuator; the horizontal loading beam includes a horizontal loading longitudinal beam and a horizontal loading beam connected to each other, each of the bearing reaction frames is installed with a first horizontal loading beam, and a second horizontal loading beam is installed between multiple bearing reaction frames, the first horizontal loading beam and the bearing reaction frame are detachably connected, and the installation height of the first horizontal loading beam is adjustable, and the second horizontal loading beam is installed with at least one static servo actuator and at least one dynamic servo actuator.

2. The complex load test system for a super-long span arch bridge model according to claim 1 is characterized in that: The continuous beam is equipped with at least two servo actuators, and the installation position of the servo actuator on the continuous beam is adjustable.

3. The complex load test system for a super-long span arch bridge model according to claim 1 is characterized in that: The continuous beam is fixedly connected to the frame cross beam, and the continuous beam is arranged horizontally.

4. The complex load test system for a super-long span arch bridge model according to claim 1 is characterized in that: The electro-hydraulic servo multi-point multi-directional loading system also includes a dynamic oil separator and pipelines.

5. A complex load test system for a super-long span arch bridge model according to any one of claims 1 to 4, characterized in that: The control system includes multiple control channels, each control channel is equipped with two closed-loop control circuits of test force and displacement, and the control system can control multiple servo actuators to load simultaneously.

6. A complex load test system for a super-long span arch bridge model according to any one of claims 1 to 4, characterized in that: The testing system includes a load sensor, a strain gauge, and a displacement gauge.

7. A complex load test method for a special-span arch bridge model, characterized in that: A complex load test system for a super-long span arch bridge model according to any one of claims 1 to 6 is used, comprising the following steps: Step 1: Fix and install the load-bearing reaction frame, connect multiple load-bearing reaction frames through a continuous beam; install the horizontal loading beam; Step 2: Install the servo actuator on the frame beam, the horizontal loading beam, and the continuous beam; Step 3: Carry out a loading test on the specimen and adjust the load size through the control system; Step 4: Test the internal forces of the arch model using load sensors; test the structural strain of the arch model using strain gauges; and obtain real-time data on the load-strain and load-deformation relationship curves of key parts of the test model by posting luminous marking points on the arch ribs and using a camera measurement system to observe the arch deflection and structural deformation.

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