A tunnel lining mechanical test device and test method

Abstract

The present application relates to the technical field of tunnel model test, and especially relates to a tunnel lining mechanical test device and a test method. The tunnel lining mechanical test device comprises a loading assembly and a supporting assembly. The loading assembly comprises a counterforce frame and a servo loading mechanism. The counterforce frame is annular. Multiple loading mechanisms are arranged on the inner side of the counterforce frame. The bottom side of the counterforce frame is provided with multiple telescopic supports. The supporting assembly is arranged in the annular counterforce frame and is used for supporting a lining model. The supporting assembly comprises a supporting platform and multiple adjustable supports arranged below the supporting platform. The test device can be suitable for multiple tunnel structures, greatly reduces the cost of the device, and improves the test efficiency.

Description

Technical Field

[0001] This invention relates to the field of tunnel model testing technology, and in particular to a tunnel lining mechanical testing device and method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In the field of transportation engineering, whether it is a highway tunnel or a subway tunnel, a series of tunnel lining defects will inevitably occur during construction and operation due to factors such as geological conditions, traffic loads, and construction quality. The safe development and operation of tunnel lining projects require a lot of scientific research, and tunnel lining mechanical model tests are an important way to study the mechanical properties of tunnels.

[0004] Currently, tunnel model tests mainly involve large-scale similarity model tests, primarily using either surrounding rock similarity materials or not. While using surrounding rock similarity materials can effectively simulate the pressure of the surrounding rock in tunnel lining, the workload is enormous for large-scale tests, and the controllability of the mechanical properties of these materials is low, significantly impacting the consistency of the test results. The method of simulating surrounding rock pressure without using similar materials involves arranging numerous servo loading mechanisms around the lining. This method offers advantages such as less workload and higher controllability, but the cost of the testing equipment is higher.

[0005] The inventors discovered that there are certain differences in the lining shape of highway tunnels and rail transit tunnels, and that the existing test devices severely limit their applicability due to the inherent limitations of their structure. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a tunnel lining mechanical testing device that is applicable to various tunnel structures, significantly reduces device costs, and improves testing efficiency.

[0007] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0008] A mechanical testing device for tunnel lining includes: a loading component and a support component; the loading component includes a reaction frame and a servo loading mechanism, the reaction frame is annular, a plurality of the loading mechanisms are disposed inside the reaction frame, and the bottom side of the reaction frame has a plurality of retractable supports; the support component is disposed inside the annular reaction frame for supporting the lining model, and includes a support platform and a plurality of adjustable supports disposed under the support platform.

[0009] Preferably, the reaction frame includes a frame structure, which is a ring structure, with multiple baffles arranged in a circular array along the side wall of the frame structure, and fixing holes for installing the loading mechanism are provided on the baffles.

[0010] Preferably, the retractable support includes a baffle fixed to the ground, a connecting seat connected to the frame structure, and a double-ended bolt. The double-ended bolt is disposed between the baffle and the connecting seat and is threadedly connected to the baffle and the connecting seat. The threads at both ends of the double-ended bolt have opposite directions of rotation.

[0011] Preferably, the loading mechanism includes a movable hinge support and a servo hydraulic jack. The movable hinge support is installed inside the reaction frame. The first end of the servo hydraulic jack is rotatably connected to the movable hinge support, and the second end is used to load the lining model.

[0012] Preferably, a loading plate is provided at the second end of the servo hydraulic jack, and the loading area of ​​the loading plate is larger than the loading area of ​​the servo hydraulic jack.

[0013] Preferably, a pressure sensor is provided between the servo hydraulic jack and the loading plate.

[0014] Preferably, the support platform has positioning holes whose shape matches the shape of the inner hole of the lining model.

[0015] Preferably, the support platform is provided with a sliding support unit for supporting the lining model. The sliding support unit provides fixed support or sliding support for the lining model. The sliding support unit includes a support base, a height adjustment knob, a roller, and a support. The extension length of the support is adjusted by adjusting the height adjustment knob. When the extension length of the support is greater than the height of the roller, the support is in a bearing state, and the sliding support unit provides fixed support for the lining model. When the extension length of the support is less than the height of the roller, the roller is in a supporting state, and the sliding support unit provides sliding support for the lining model.

[0016] Preferably, an oil and electricity pipeline structure is provided on the outside of the reaction frame, the oil and electricity pipeline structure including an oil pipe structure and an electrical circuit structure, the oil pipe structure and the electrical circuit structure being wound around the outside of the frame structure.

[0017] This invention also provides a test method for the above-mentioned tunnel lining mechanical test device, including: designing the device size according to the test requirements, adjusting the height and angle of the reaction frame and support platform, and installing a servo loading mechanism; after the servo loading mechanism is installed, installing the corresponding lining model on the support platform, and determining the position of the lining model through positioning holes; after the lining model is installed, applying corresponding constraints and loading to the lining model through servo control; after the test is completed, retracting the corresponding constraints and loading, transporting the tested lining model, and completing one test process.

[0018] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0019] 1. In the test apparatus of this invention, multiple telescopic supports are provided on the bottom side of the outer reaction frame, and multiple adjustable supports are provided on the bottom side of the inner support platform. The relative height of the reaction frame and the support platform can be flexibly adjusted through the cooperation of the telescopic and adjustable supports to meet the test requirements of lining models with different longitudinal dimensions. Furthermore, by adjusting the multiple telescopic (or adjustable) supports to different heights, the loading cross-section of the servo loading mechanism can be made to form a predetermined angle with the lining model. Simultaneously, by selecting different positions of the servo loading mechanism for loading, various loading methods can be provided to meet the test requirements of different lining profiles. The cooperation of the adjustable supports and adjustable brackets allows for convenient adjustment of the relative height and relative angle of the reaction frame and the support platform, providing sufficient strength while facilitating observation of the test process. It is applicable to tunnel models of different forms and sizes, including highway tunnels and subway tunnels, meeting various test requirements.

[0020] 2. The reaction frame of the present invention is equipped with baffles and multiple positioning holes, and the lining model test can be carried out by individual or combined loading at four positions: arch top, arch shoulder, arch foot and invert arch through different positioning holes.

[0021] 3. The servo loading mechanism of the present invention is provided with a movable hinge support between itself and the reaction frame, and integrates a pressure gauge and a hydraulic jack, which facilitates precise control of the load and adaptive adjustment of the loading direction during the loading process.

[0022] 4. This invention sets up multiple sliding support units on the support platform. The sliding support units switch different support states at different test stages. Before the test, they are adjusted to a fixed support state, and during the test, they are adjusted to a sliding support state. The setting of rollers ensures that the boundary condition friction of the lining model is minimized during the test, which effectively reduces the test error.

[0023] 5. The oil and electricity pipeline structure of this invention is fixed to the outside of the reaction frame in a circular shape, which can not only realize the corresponding functions, but also simplify the complexity of the model test device structure, reduce the test space, and improve the stability of the test device. It maximizes the use of test space while meeting the requirements for hydraulic oil supply and electromechanical control.

[0024] 6. The oil and electricity pipeline structure of the present invention is fixed to the outside of the reaction frame in a circular structure, which can not only realize the corresponding functions, but also simplify the complexity of the model test device structure, reduce the test space, and improve the stability of the test device.

[0025] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0028] Figure 1 This is a schematic diagram of the overall experimental apparatus according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the hidden reaction frame according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the reaction frame according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the servo loading mechanism according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the support components according to an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the sliding support unit according to an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the oil and electricity pipeline structure according to an embodiment of the present invention;

[0035] In the diagram: 1. Reaction frame; 1-1. Frame structure; 1-2. Fixing hole; 1-3. Telescopic support; 2. Servo loading mechanism; 2-1. Movable hinge support; 2-2. Servo hydraulic jack; 2-3. Pressure sensor; 2-4. Loading plate; 3. Support assembly; 3-1. Support platform; 3-2. Adjustable support; 3-3. Positioning hole; 3-4. Sliding support unit; 3-4-1. Support seat; 3-4-2. Height adjustment knob; 3-4-3. Roller; 3-4-4. Support; 5. Oil and electricity pipeline structure; 5-1. Oil pipe structure; 5-2. Circuit structure; 6. Lining model.

[0036] The distances or dimensions between parts have been exaggerated to show their positions; the diagram is for illustrative purposes only. Detailed Implementation

[0037] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0038] Existing testing devices mainly suffer from three problems: First, the longitudinal dimension of the tunnel model cannot be adjusted. Due to the limitations of the testing device's structure, the longitudinal dimension of the lining model required for the test is also fixed, which severely limits the applicability of the testing device. Second, the tunnel model has a single profile shape. The lining profiles of highway tunnels, rail transit tunnels, and subway tunnels differ greatly. Existing testing devices either have a fixed shape or the loading position cannot be adjusted, limiting the testing range of the model. Third, the loading method of the lining model is simple and differs greatly from actual engineering, and the loading method cannot simulate the load-bearing form of the lining under specific conditions.

[0039] Based on the above problems, this invention proposes a mechanical testing device for tunnel lining, such as... Figures 1-7 As shown, the system includes a loading component and a support component 3. The loading component includes a reaction frame 1 and a servo loading mechanism 2. The reaction frame 1 is annular, and multiple loading mechanisms are disposed inside the reaction frame 1. The bottom side of the reaction frame 1 has multiple retractable supports 1-3. The support component is disposed inside the annular reaction frame 1 to support the lining model 6, and includes a support platform 3-1 and multiple adjustable supports 3-2 disposed below the support platform 3-1. The reaction frame 1 is mainly used for fixing the servo loading mechanism and the oil and electricity pipelines. The servo loading mechanism 2 is detachable and connected to the fixing hole of the reaction frame 1 for applying loads during the test.

[0040] In the testing apparatus of this invention, multiple telescopic supports are provided on the bottom side of the outer reaction frame, and multiple adjustable supports are provided on the bottom side of the inner support platform. The relative height of the reaction frame and the support platform can be flexibly adjusted through the cooperation of the telescopic and adjustable supports to meet the testing requirements of lining models with different longitudinal dimensions. Furthermore, by adjusting the multiple telescopic (or adjustable) supports to different heights, the loading cross-section of the servo loading mechanism can be made to form a predetermined angle with the lining model to achieve inclined loading. Simultaneously, selecting different positions of the servo loading mechanism for loading can provide various loading methods and meet the testing requirements of different lining profiles. The cooperation of the adjustable supports and adjustable brackets allows for convenient adjustment of the relative height and relative angle of the reaction frame and the support platform, providing sufficient strength while facilitating observation of the testing process. It is applicable to tunnel models of different forms and sizes, including highway tunnels and subway tunnels, meeting diverse testing needs.

[0041] like Figure 3As shown, the reaction frame 1 includes a frame structure 1-1, fixing holes 1-2, and a telescopic support 1-3. In this embodiment, the frame structure 1-1 is a circular steel structure with 30 empty spaces on the side of the circular ring. Each empty space contains a fixing hole 1-2. The frame structure 1-1 is fixed to the ground by the telescopic support 1-3, which has a telescopic function and includes a baffle fixed to the ground, a connecting seat connected to the frame structure, and a double-ended bolt. The double-ended bolt is located between the baffle and the connecting seat and is threadedly connected to the baffle and the connecting seat. The threads at both ends of the double-ended bolt have opposite directions. The height and angle of the reaction frame can be adjusted by rotating the telescopic support 1-3, facilitating tests of different scales. The fixing holes of the reaction frame can provide different fixing positions for the servo loading mechanism. The baffle and multiple fixing holes allow for individual or combined loading tests of the lining model at four locations: the arch crown, arch shoulder, arch foot, and invert arch. It can also be used to install other test devices.

[0042] like Figure 2 , Figure 4 As shown, the servo loading mechanism 2 includes a movable hinge support 2-1, a servo hydraulic jack 2-2, a pressure sensor 2-3, and a loading plate 2-4. The movable hinge support 2-1 is fixed to the fixing hole 1-2 by bolts. Since fixing holes 1-2 are provided at different positions on the outside of the frame structure 1-1, the position of the servo loading mechanism 2 can be flexibly adjusted according to the test requirements. The servo hydraulic jack 2-2 is controlled by a servo motor to control the pressure, facilitating the adjustment of the load. The movable hinge support can set the initial direction of model loading and can also adaptively adjust the loading direction in real time according to the lining deformation to ensure the perpendicularity of the loading direction. The pressure sensor 2-3 and the loading plate 2-4 are fixed to one end of the servo hydraulic jack 2-2. The pressure sensor 2-3 can collect the load magnitude in real time and provide real-time feedback on the loading status. The loading plate 2-4 is located between the pressure sensor 2-3 and the lining model. Since the servo hydraulic jack is a point loading method, it is not suitable for lining loading. Therefore, by setting the loading plate 2-4, the point loading is changed to surface loading, improving the accuracy of the test.

[0043] In another preferred embodiment of the invention, such as Figure 5 and Figure 6As shown, the support assembly 3 includes a support platform 3-1, an adjustable support 3-2, a positioning hole 3-3, and a sliding support unit 3-4. The sliding support unit 3-4 includes a support base 3-4-1, a height adjustment knob 3-4-2, a roller 3-4-3, and a support 3-4-4. The support platform 3-1 is cut from a single piece of steel plate, and its bottom is fixed to the ground via the adjustable support 3-2, allowing for height adjustment. A positioning hole 3-3 is provided at the top, the shape of which matches the shape of the inner hole of the lining model 6, facilitating the installation and positioning of the lining model and the passage of internal wiring.

[0044] The upper part of the support platform 3-1 is equipped with 5 sets of sliding support units 3-4, which are mainly used to support the lining model. The principle of the sliding support unit is the same as that of the roller. The extension length of the support can be freely adjusted by adjusting the height adjustment knob. When the extension length of the support is greater than the height of the roller, the support is in the bearing state and the sliding support unit is in the fixed state to ensure the stability of the lining model. When the extension length of the support is less than the height of the roller, the roller is in the supporting state and the sliding support unit is in the sliding state.

[0045] Existing testing devices suffer from significant boundary friction of the lining model during testing, severely impacting the stress state and altering its stress characteristics, thus failing to achieve satisfactory test results. Therefore, this invention addresses this issue by incorporating multiple sliding support units on a support platform. These units switch between different support states at different test stages: a fixed support state before the test and a sliding support state during the test. The use of rollers ensures minimal boundary friction of the lining model during the test, effectively reducing experimental errors.

[0046] like Figure 7 As shown, the oil-electric pipeline structure 5 includes an oil pipe structure 5-1 and a circuit structure 5-2. The oil pipe structure and the circuit structure are fixed to the outside of the reaction frame 1 in a circular manner. This not only enables the oil-electric transmission of different servo hydraulic servo loading mechanisms, but also has a simple and aesthetically pleasing effect, maximizing the use of the test space.

[0047] The test method of the aforementioned tunnel lining mechanical testing device mainly includes three steps: adjusting the loading position, adjusting the height and angle of the lining model, and test loading and monitoring. The device dimensions are designed according to the test requirements, the height of the reaction frame and support platform are adjusted, and the servo loading mechanism is installed appropriately. After the servo loading mechanism is installed, the corresponding lining model is installed on the support platform, and the lining model is positioned by comparing its position with the contour of the positioning holes. After the lining model is installed, corresponding constraints and loading are applied to the lining model through servo control. After the test is completed, the corresponding constraints and loading are removed, the corresponding sensors are removed, and the tested lining model is moved, completing one test process. Specifically, the following steps are included:

[0048] (1) Loading position adjustment: There are significant differences in the loading position and loading method for different tests. According to the test design, different loading points will be set for different model tests. For example, in the test plan, loading is performed at the top of the arch. If the loading position is incorrect, it will affect the test process and produce incorrect test results. Before the test begins, the number and position of the servo loading mechanism should be adjusted in advance according to the test requirements. The servo loading mechanism is fixed in different positions with bolts, and the number and position of the servo loading mechanism are flexibly adjusted. The loading direction is also adjusted by using the movable hinge support.

[0049] (2) Adjustment of the height of the lining model: During the loading test of the lining model, it is generally required that the loading point be in the middle position of the longitudinal direction of the model. If it is not in the middle position, the lining model will be subjected to eccentric load, which will affect the accuracy of the test results. The position of the middle point is different depending on the height of the lining model. Therefore, it is necessary to comprehensively adjust the height of the telescopic support and the adjustable support to adjust the loading point of the lining model to the middle position of the model.

[0050] (3) Test loading and monitoring: Before loading, the height adjustment knob needs to be adjusted to ensure the sliding support unit is in a fixed state. Corresponding monitoring elements are installed on the lining model. At the start of the test, the height adjustment knob is adjusted to make the sliding support unit slide. According to the test loading scheme, the loading size and speed of different servo loading mechanisms are set (in geotechnical tests, loading speed is a crucial parameter affecting test results; a high loading speed will result in overly large test results, while a low loading speed will affect the test progress; therefore, a reasonable testing speed is generally set according to the test requirements and relevant test procedures). The loading process is then adjusted in real-time based on the pressure feedback from the pressure sensor.

[0051] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A mechanical testing device for tunnel lining, characterized in that, include: Loading components and supporting components; The loading component includes a reaction frame and a servo loading mechanism. The reaction frame is ring-shaped, and multiple loading mechanisms are arranged inside the reaction frame. The bottom side of the reaction frame has multiple retractable supports. The support assembly is set inside the annular reaction frame to support the lining model, and includes a support platform and multiple adjustable supports set under the support platform; The support platform is equipped with sliding support units for supporting the lining model. The sliding support units provide fixed support or sliding support for the lining model. The sliding support unit includes a support base, a height adjustment knob, a roller, and a support. The extension length of the support is adjusted by adjusting the height adjustment knob. When the extension length of the support is greater than the height of the roller, the support is in a load-bearing state, and the sliding support unit provides fixed support for the lining model. When the extension length of the support is less than the height of the roller, the roller is in a support state, and the sliding support unit provides sliding support for the lining model.

2. The tunnel lining mechanical testing device as described in claim 1, characterized in that, The reaction frame includes a frame structure, which is a ring structure. Multiple baffles are arranged in a circular array along the side wall of the frame structure, and the baffles are provided with fixing holes for installing the loading mechanism.

3. The tunnel lining mechanical testing device as described in claim 2, characterized in that, The retractable support includes a baffle fixed to the ground, a connecting seat connected to the frame structure, and a double-ended bolt. The double-ended bolt is disposed between the baffle and the connecting seat and is threadedly connected to the baffle and the connecting seat. The threads at both ends of the double-ended bolt have opposite directions of rotation.

4. The tunnel lining mechanical testing device as described in claim 1, characterized in that, The loading mechanism includes a movable hinge support and a servo hydraulic jack. The movable hinge support is installed inside the reaction frame. The first end of the servo hydraulic jack is rotatably connected to the movable hinge support, and the second end is used to load the lining model.

5. The tunnel lining mechanical testing device as described in claim 4, characterized in that, A loading plate is provided at the second end of the servo hydraulic jack, and the loading area of ​​the loading plate is larger than the loading area of ​​the servo hydraulic jack.

6. The tunnel lining mechanical testing device as described in claim 5, characterized in that, A pressure sensor is installed between the servo hydraulic jack and the loading plate.

7. The tunnel lining mechanical testing device as described in claim 1, characterized in that, The support platform has positioning holes whose shape matches the shape of the inner hole of the lining model.

8. The tunnel lining mechanical testing device as described in claim 2, characterized in that, An oil and electricity pipeline structure is provided on the outside of the reaction frame. The oil and electricity pipeline structure includes an oil pipe structure and a circuit structure, which are wound around the outside of the frame structure.

9. A mechanical testing method for tunnel lining, characterized in that, The test is conducted using the tunnel lining mechanical testing apparatus as described in any one of claims 1-8, comprising: Design the device dimensions according to the test requirements, adjust the height and angle of the reaction frame and support platform, and install the servo loading mechanism; After the servo loading mechanism is installed, the corresponding lining model is installed on the support platform, and the position of the lining model is determined by the positioning holes. After the lining model is installed, it is constrained and loaded accordingly through servo control. After the test is completed, the corresponding constraints and loads are removed, and the lining model after the test is moved to complete one test process.

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