Roadbed model test device and method for simulating bidirectional subway reciprocating load

Abstract

The invention discloses a roadbed model test device and method for simulating bidirectional subway reciprocating load, and belongs to the technical field of geotechnical engineering foundation tests, the device comprises a reaction frame, a model system, a loading assembly, a moving assembly and a control and acquisition system; the model system is used for simulating a subway track roadbed and is arranged at the bottom of the reaction frame; the loading assembly is mounted on the reaction frame and is used for applying a dynamic load to the model system; the moving assembly is installed on the side, close to the loading assembly, of the counter-force frame and used for moving the loading assembly. And the control and acquisition system is used for controlling the loading component to load, controlling the moving component to move and acquiring monitoring data. The problems that a model test cannot simulate the influence of principal stress shaft rotation on foundation deformation caused when a subway moves and roadbed deformation caused by bidirectional subway reciprocating motion are solved, and meanwhile simulation of roadbed model tests under different stress rotation fixed angles can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical engineering foundation testing, and in particular to a roadbed model testing device and method simulating bidirectional subway reciprocating loads. Background Art

[0002] As my country's urbanization process continues to deepen, more and more cities are beginning to build a comprehensive three-dimensional transportation network that serves the new development pattern. Subways are favored by more cities for their low-carbon, environmentally friendly, safe, reliable, convenient and fast characteristics. In the early days of subway construction, the impact of subway dynamic loads on the roadbed soil was often ignored, resulting in problems such as uneven roadbed settlement, affecting subway structure and operational safety. Therefore, more new projects began to focus on the impact of subway reciprocating motion on the roadbed during operation.

[0003] Subway subgrade soil is a typical anisotropic material, so the deformation of the subgrade is not only affected by the magnitude of the principal stress value, but also the direction of the principal stress value cannot be ignored. Existing invention patents CN201410658846.4 "A method for determining the dynamic load of subway operating trains and the long-term settlement of tunnels", CN201810645400.6 "A test device for simulating double-line subway operation vibration", CN202110127247.X "Simulation box and test method for simulating long-term tunnel settlement under subway operation load" all take into account the influence of the change of the principal stress value caused by the subway operation load on the subgrade deformation. However, when the subway is in reciprocating motion, such as Figure 1 As shown in , the direction of the principal stress generated by the subway at points A, B, and C on the soil below point B is constantly changing, but the above devices do not consider the influence of the rotation of the principal stress axis caused by the subway during movement, and therefore ignore the roadbed deformation caused by the change in the direction of the principal stress value caused by the rotation of the principal stress axis. In addition, the above devices do not consider the roadbed deformation caused by the reciprocating motion of the subway in two directions, which may lead to a large difference between the roadbed deformation obtained in the test and the actual roadbed deformation of the subway.

[0004] The geological conditions in different regions of my country vary greatly, and the subway train selections in different cities are also different. However, they all have to solve the problem of the principal stress axis rotation of the roadbed under the dynamic load of the bidirectional subway. Therefore, a complete and generally applicable roadbed model test device and method for simulating bidirectional subway reciprocating loads under various conditions is urgently needed to guide subway project construction. Summary of the invention

[0005] The purpose of the present invention is to provide a roadbed model test device and method for simulating bidirectional subway reciprocating loads, so as to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides a roadbed model test device simulating bidirectional subway reciprocating load, comprising:

[0007] reaction frame;

[0008] A model system, used for simulating a subway track subgrade, wherein the model system is arranged at the bottom of the reaction frame;

[0009] A loading assembly, mounted on the reaction frame, and used to apply a dynamic load to the model system;

[0010] A moving assembly is installed on a side of the reaction frame close to the loading assembly, and the moving assembly is used to move the loading assembly;

[0011] The control and acquisition system is used to control the loading component to load, control the moving component to move, and collect monitoring data.

[0012] Preferably, the model system includes a model box, a roadbed and track 2; the model box is placed below the reaction frame, and the two ends of the model box are fixedly connected to the two ends of the reaction frame respectively; the roadbed is arranged in the model box, the track 2 is placed on the surface of the roadbed, and the end of the loading assembly away from the reaction frame is slidably matched with the track 2.

[0013] Preferably, rubber gaskets are provided at both ends of the second track, and the rubber gaskets are used to prevent the loading assembly from directly colliding with the model box.

[0014] Preferably, a track 1 is provided on the reaction frame, and an end of the loading assembly close to the reaction frame is slidably matched with the track 1.

[0015] Preferably, the loading assembly is provided with two groups for simulating two subway trains passing back and forth; the loading assembly comprises a servo cylinder, a suspension column and a subway loading model; both ends of the upper part of the suspension column are provided with wing-shaped suspensions, the servo cylinder is suspended on the track one through the wing-shaped suspensions on the suspension column, and the moving assembly is in transmission cooperation with the suspension column; the subway loading model is arranged at the bottom of the servo cylinder, and the subway loading model is in sliding cooperation with the track two.

[0016] Preferably, a pressure sensor is provided in the servo cylinder, and the pressure sensor is used to record the dynamic load applied to the roadbed by the subway loading model; a laser ranging sensor is provided on the reaction frame, and the laser ranging sensor is used to record the vertical deformation of the roadbed as a whole; the pressure sensor and the laser ranging sensor are both connected to the control and acquisition system.

[0017] Preferably, the moving assembly is arranged corresponding to the loading assembly, and the moving assembly includes a stepper motor, a support seat and a threaded rod; the stepper motor and the support seat are respectively fixed at two ends of the reaction frame, one end of the threaded rod is connected to the stepper motor, and the other end of the threaded rod has no thread at the end; an opening one is provided in the middle of the suspension column, and an opening two is provided on the support seat, the threaded rod passes through the opening one in the middle of the suspension column, and the end of the threaded rod without a thread is inserted into the opening two on the support seat.

[0018] Preferably, the control and acquisition system includes a hydraulic servo system, inlet and outlet oil pipes, wires and an operation console; the hydraulic servo system is connected to the servo cylinder through the inlet and outlet oil pipes, the operation console is connected to the pressure sensor and the laser ranging sensor through the wires, the operation console is connected to the hydraulic servo system through the wires, and the operation console is connected to the stepper motor through wires.

[0019] A roadbed model test method simulating bidirectional subway reciprocating load is based on a roadbed model test device simulating bidirectional subway reciprocating load. The test steps are as follows:

[0020] I. Load roadbed soil into the model box and compact the soil to form a roadbed, level the surface of the paved roadbed, place the track 2 on the leveled roadbed, place rubber gaskets on both sides of the track 2, and the rubber gaskets can be glued to the side walls of the model box;

[0021] II. Operate the console to control the hydraulic servo system to extend the servo cylinder until the subway loading model contacts the track II;

[0022] III. The operating console controls the stepper motor to rotate the threaded rod, so that the two sets of servo cylinders move forward and backward until the subway loading model contacts the rubber gasket;

[0023] IV. Input the subway moving speed, number of cycles, vertical load amplitude, load frequency, and cyclic load ratio in the operation console. The operation console controls the rotation direction and speed of the stepper motor to control the left and right cyclic reciprocating motion of the two sets of subway loading models. The operation console controls the servo cylinder through the hydraulic servo system to apply the corresponding vertical load amplitude, load frequency, and cyclic load ratio to the roadbed through the subway loading model;

[0024] V. The roadbed deformation data during the left-right cyclic reciprocating motion and vertical vibration of the subway loading model is recorded by a laser ranging sensor, and the average value of the data measured by the laser ranging sensor is used as the roadbed deformation.

[0025] A roadbed model test method under different stress rotation fixed angles is based on a roadbed model test device simulating bidirectional subway reciprocating loads. The test steps are as follows:

[0026] I. Load the roadbed soil into the model box and compact the soil to form a roadbed, level the surface of the paved roadbed, and place the track 2 on the leveled roadbed;

[0027] II. Operate the console to control the hydraulic servo system to extend the servo cylinder until the subway loading model contacts the track II;

[0028] III. The operating console controls the stepper motor to rotate the threaded rod, and moves the two sets of servo cylinders to fixed positions according to the required stress deflection angle;

[0029] IV. Input the vertical load amplitude, load frequency, and cyclic load ratio into the operation console, and the operation console controls the servo cylinder through the hydraulic servo system to apply the corresponding vertical load amplitude, load frequency, and cyclic load ratio to the roadbed through the subway loading model;

[0030] V. The roadbed deformation data during the vertical vibration of the subway loading model is recorded by a laser ranging sensor, and the average value of the data measured by the laser ranging sensor is used as the roadbed deformation.

[0031] Compared with the prior art, the present invention has the following advantages and technical effects:

[0032] The roadbed model test device for simulating bidirectional subway reciprocating loads provided by the present invention solves the problem that the model test cannot simulate the influence of the principal stress axis rotation caused by the movement of the subway on the foundation deformation, and the roadbed deformation caused by the reciprocating movement of the bidirectional subway. At the same time, the present invention can also realize the simulation of the roadbed model test under different stress rotation fixed angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a schematic diagram of the principal stress direction of the subgrade soil unit subjected to subway moving load;

[0035] Figure 2 It is a schematic plan view of a roadbed model test device simulating bidirectional subway reciprocating load in the present invention;

[0036] Figure 3It is a three-dimensional schematic diagram of the model system in the present invention;

[0037] Figure 4 It is a schematic diagram of the connection between the suspension column and the track 2 in the present invention;

[0038] In the figure: 1. reaction frame; 2. model box; 3. roadbed; 4. track one; 5. rubber gasket; 6. track two; 7. servo cylinder; 8. suspension column; 9. subway loading model; 10. wing-shaped suspension; 11. pressure sensor; 12. laser ranging sensor; 13. stepper motor; 14. support seat; 15. threaded rod; 16. opening one; 17. opening two; 18. hydraulic servo system; 19. inlet and outlet oil pipes; 20. wires; 21. operating console. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0040] like Figures 2 to 4 As shown, the present invention provides a roadbed model test device simulating bidirectional subway reciprocating load, comprising:

[0041] Reaction frame 1;

[0042] A model system is used to simulate the subway track subgrade, and the model system is arranged at the bottom of the reaction frame 1;

[0043] A loading component, mounted on the reaction frame 1, and used to apply a dynamic load to the model system;

[0044] A moving assembly is installed on a side of the reaction frame 1 close to the loading assembly, and is used to move the loading assembly;

[0045] The control and acquisition system is used to control the loading component to load, control the moving component to move, and collect monitoring data.

[0046] According to a further optimization scheme, the model system includes a model box 2, a roadbed 3 and a track 6; the model box 2 is placed below the reaction frame 1, and the two ends of the model box 2 are fixedly connected to the two ends of the reaction frame 1 respectively; the roadbed 3 is arranged in the model box 2, and the track 6 is placed on the surface of the roadbed 3, and the end of the loading component away from the reaction frame 1 is slidably matched with the track 6.

[0047] To further optimize the solution, rubber gaskets 5 are provided at both ends of the track 2 6 , and the rubber gaskets 5 are used to prevent the loading assembly from directly colliding with the model box 2 .

[0048] According to a further optimized solution, a track 4 is provided on the reaction frame 1, and an end of the loading assembly close to the reaction frame 1 is slidably matched with the track 4.

[0049] To further optimize the solution, two groups of loading components are provided to simulate two subway trains passing back and forth; the loading components include a servo cylinder 7, a suspension column 8 and a subway loading model 9; wing-shaped suspensions 10 are provided at both ends of the upper part of the suspension column 8, and the servo cylinder 7 is suspended on the track 4 through the wing-shaped suspensions 10 on the suspension column 8, and the moving component is in transmission cooperation with the suspension column 8; the subway loading model 9 is arranged at the bottom of the servo cylinder 7, and the subway loading model 9 is in sliding cooperation with the track 2 6.

[0050] To further optimize the solution, a pressure sensor 11 is provided in the servo cylinder 7, and the pressure sensor 11 is used to record the dynamic load applied to the roadbed 3 by the subway loading model 9; a laser ranging sensor 12 is provided on the reaction frame 1, and the laser ranging sensor 12 is used to record the vertical deformation of the roadbed 3 as a whole; the pressure sensor 11 and the laser ranging sensor 12 are both connected to the control and acquisition system.

[0051] A further optimized solution is provided in which the moving assembly and the loading assembly are arranged correspondingly, and the moving assembly includes a stepper motor 13, a support seat 14 and a threaded rod 15; the stepper motor 13 and the support seat 14 are respectively fixed at both ends of the reaction frame 1, one end of the threaded rod 15 is connected to the stepper motor 13, and the other end of the threaded rod 15 has no thread at the end; an opening 16 is provided in the middle of the suspension column 8, and an opening 2 17 is provided on the support seat 14, the threaded rod 15 passes through the opening 16 in the middle of the suspension column 8, and the end of the threaded rod 15 without a thread is inserted into the opening 2 17 on the support seat 14.

[0052] Further optimization scheme, the control and acquisition system includes a hydraulic servo system 18, an inlet and outlet oil pipe 19, a wire 20 and an operating console 21; the hydraulic servo system 18 is connected to the servo cylinder 7 through the inlet and outlet oil pipes 19, the operating console 21 is connected to the pressure sensor 11 and the laser ranging sensor 12 through the wire 20, the operating console 21 is connected to the hydraulic servo system 18 through the wire 20, and the operating console 21 is connected to the stepper motor 13 through the wire 20.

[0053] Embodiment 1

[0054] A roadbed model test method simulating bidirectional subway reciprocating load is based on a roadbed model test device simulating bidirectional subway reciprocating load. The test steps are as follows:

[0055] I. Load roadbed soil into the model box 2 and compact the soil to form a roadbed 3, level the surface of the paved roadbed 3, place the track 2 6 on the leveled roadbed 3, place rubber gaskets 5 on both sides of the track 2 6, and the rubber gaskets 5 can be glued to the side walls of the model box 2;

[0056] II. The operating console 21 controls the hydraulic servo system 18 to extend the oil cylinder in the servo oil cylinder 7 out of the servo oil cylinder 7 until the subway loading model 9 contacts the track II 6;

[0057] III. The operation console 21 controls the stepper motor 13 to rotate the threaded rod 15, so that the two groups of servo cylinders 7 move forward and backward until the subway loading model 9 contacts the rubber gasket 5;

[0058] IV. Input the subway moving speed, number of cycles, vertical load amplitude, load frequency, and cyclic load ratio into the operation console 21. The operation console 21 controls the rotation direction and rotation speed of the stepping motor 13, thereby controlling the two sets of subway loading models 9 to reciprocate left and right. The operation console 21 controls the servo cylinder 7 through the hydraulic servo system 18, and applies the corresponding vertical load amplitude, load frequency, and cyclic load ratio to the roadbed 3 through the subway loading model 9;

[0059] V. The deformation data of the roadbed 3 during the left-right cyclic reciprocating motion and vertical vibration of the subway loading model 9 are recorded by the laser ranging sensor 12, and the average value of the data measured by the laser ranging sensor 12 is used as the deformation of the roadbed 3.

[0060] Embodiment 2

[0061] The subgrade model test device simulating bidirectional subway reciprocating load can not only realize the simulation of subgrade 3 under bidirectional subway reciprocating load, but also carry out subgrade 3 model tests under different stress rotation fixed angles. The test steps are as follows:

[0062] I. Load the roadbed soil into the model box 2 and compact the soil to form a roadbed 3, level the surface of the paved roadbed 3, and place the track 2 6 on the leveled roadbed 3;

[0063] II. The operating console 21 controls the hydraulic servo system 18 to extend the oil cylinder in the servo oil cylinder 7 out of the servo oil cylinder 7 until the subway loading model 9 contacts the track II 6;

[0064] III. The operation console 21 controls the stepping motor 13 to rotate the threaded rod 15, and moves the two sets of servo cylinders 7 to fixed positions according to the required stress deflection angle;

[0065] IV. Inputting the vertical load amplitude, load frequency, and cyclic load ratio into the operation console 21, the operation console 21 controls the servo cylinder 7 through the hydraulic servo system 18, and applies the corresponding vertical load amplitude, load frequency, and cyclic load ratio to the roadbed 3 through the subway loading model 9;

[0066] V. The deformation data of the roadbed 3 during the vertical vibration of the subway loading model 9 is recorded by the laser ranging sensor 12, and the average value of the data measured by the laser ranging sensor 12 is used as the deformation of the roadbed 3.

[0067] The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A roadbed model test device simulating bidirectional subway reciprocating load, characterized in that: include: Reaction frame (1); A model system, used for simulating a subway track subgrade, wherein the model system is arranged at the bottom of the reaction frame (1); A loading component, mounted on the reaction frame (1), the loading component being used to apply a dynamic load to the model system; A moving assembly is mounted on a side of the reaction frame (1) close to the loading assembly, and the moving assembly is used to move the loading assembly; The control and acquisition system is used to control the loading component to load, control the moving component to move, and collect monitoring data.

2. The roadbed model test device for simulating bidirectional subway reciprocating load according to claim 1 is characterized in that: The model system comprises a model box (2), a roadbed (3) and a track 2 (6); the model box (2) is placed below a reaction frame (1), and two ends of the model box (2) are respectively fixedly connected to two ends of the reaction frame (1); the roadbed (3) is arranged in the model box (2), the track 2 (6) is placed on the surface of the roadbed (3), and one end of the loading component away from the reaction frame (1) is slidably matched with the track 2 (6).

3. The roadbed model test device for simulating bidirectional subway reciprocating load according to claim 2 is characterized in that: Both ends of the second track (6) are provided with rubber gaskets (5), and the rubber gaskets (5) are used to prevent the loading assembly from directly colliding with the model box (2).

4. The roadbed model test device for simulating bidirectional subway reciprocating load according to claim 2 is characterized in that: A track one (4) is provided on the reaction frame (1), and one end of the loading assembly close to the reaction frame (1) is slidably matched with the track one (4).

5. The roadbed model test device for simulating bidirectional subway reciprocating load according to claim 4 is characterized in that: The loading assembly is provided with two groups for simulating two trains passing back and forth; the loading assembly comprises a servo cylinder (7), a suspension column (8) and a subway loading model (9); both ends of the upper part of the suspension column (8) are provided with wing-shaped hangers (10); the servo cylinder (7) is hung on the track one (4) through the wing-shaped hangers (10) on the suspension column (8); the moving assembly is in transmission cooperation with the suspension column (8); the subway loading model (9) is arranged at the bottom of the servo cylinder (7), and the subway loading model (9) is in sliding cooperation with the track two (6).

6. The roadbed model test device for simulating bidirectional subway reciprocating load according to claim 5 is characterized in that: A pressure sensor (11) is arranged in the servo oil cylinder (7), and the pressure sensor (11) is used to record the dynamic load applied to the roadbed (3) by the subway loading model (9); a laser distance sensor (12) is arranged on the reaction frame (1), and the laser distance sensor (12) is used to record the vertical deformation generated by the roadbed (3) as a whole; the pressure sensor (11) and the laser distance sensor (12) are both connected to the control and acquisition system.

7. The roadbed model test device for simulating bidirectional subway reciprocating load according to claim 6 is characterized in that: The moving assembly is arranged corresponding to the loading assembly, and the moving assembly comprises a stepping motor (13), a support seat (14) and a threaded rod (15); the stepping motor (13) and the support seat (14) are respectively fixed at two ends of the reaction frame (1), one end of the threaded rod (15) is connected to the stepping motor (13), and the other end of the threaded rod (15) has no thread at the end; an opening (16) is provided in the middle of the suspension column (8), and an opening (17) is provided on the support seat (14); the threaded rod (15) passes through the opening (16) in the middle of the suspension column (8), and the end of the threaded rod (15) without thread is inserted into the opening (17) on the support seat (14).

8. The roadbed model test device for simulating bidirectional subway reciprocating load according to claim 7 is characterized in that: The control and acquisition system comprises a hydraulic servo system (18), an inlet and outlet oil pipe (19), a wire (20) and an operation console (21); the hydraulic servo system (18) is connected to the servo oil cylinder (7) via the inlet and outlet oil pipe (19); the operation console (21) is connected to a pressure sensor (11) and a laser distance sensor (12) via the wire (20); the operation console (21) is connected to the hydraulic servo system (18) via the wire (20); and the operation console (21) is connected to the stepping motor (13) via the wire (20).

9. A method for testing a roadbed model under a simulated bidirectional subway reciprocating load, based on the roadbed model testing device for simulating a bidirectional subway reciprocating load according to any one of claims 1 to 8, characterized in that: The test steps are as follows: I. Loading roadbed soil into the model box (2) and compacting the soil to form a roadbed (3), leveling the surface of the paved roadbed (3), placing track 2 (6) on the leveled roadbed (3), placing rubber gaskets (5) on both sides of track 2 (6), and the rubber gaskets (5) can be glued to the side walls of the model box (2); II. The operating console (21) controls the hydraulic servo system (18) to extend the oil cylinder in the servo oil cylinder (7) out of the servo oil cylinder (7) until the subway loading model (9) contacts the track two (6); III. The operating console (21) controls the stepping motor (13) to rotate the threaded rod (15), so that the two sets of servo cylinders (7) move forward and backward until the subway loading model (9) contacts the rubber gasket (5); IV. Inputting the subway moving speed, the number of reciprocating cycles, the vertical load amplitude, the load frequency, and the cyclic load ratio into the operation console (21), the operation console (21) controls the rotation direction and the rotation speed of the stepping motor (13), thereby controlling the two sets of subway loading models (9) to reciprocate left and right, and the operation console (21) controls the servo cylinder (7) through the hydraulic servo system (18), and applies the corresponding vertical load amplitude, load frequency, and cyclic load ratio to the roadbed (3) through the subway loading model (9); V. Using a laser distance measuring sensor (12), the deformation data of the roadbed (3) during the left-right cyclic reciprocating motion and vertical vibration of the subway loading model (9) are recorded, and the average value of the data measured by the laser distance measuring sensor (12) is used as the deformation of the roadbed (3).

10. A roadbed model test method under different stress rotation fixed angles, based on the roadbed model test device under simulated bidirectional subway reciprocating load according to any one of claims 1 to 8, characterized in that: The test steps are as follows: I. Loading roadbed soil into the model box (2) and compacting the soil to form a roadbed (3), leveling the surface of the paved roadbed (3), and placing track 2 (6) on the leveled roadbed (3); II. The operating console (21) controls the hydraulic servo system (18) to extend the oil cylinder in the servo oil cylinder (7) out of the servo oil cylinder (7) until the subway loading model (9) contacts the track two (6); III. The operating console (21) controls the stepping motor (13) to rotate the threaded rod (15) to move the two sets of servo cylinders (7) to a fixed position according to the required stress deflection angle; IV. Inputting the vertical load amplitude, load frequency, and cyclic load ratio into the operation console (21), the operation console (21) controls the servo cylinder (7) through the hydraulic servo system (18), and applies the corresponding vertical load amplitude, load frequency, and cyclic load ratio to the roadbed (3) through the subway loading model (9); V. Recording the deformation data of the roadbed (3) during the vertical vibration of the subway loading model (9) by means of a laser distance measuring sensor (12), and taking the average value of the data measured by the laser distance measuring sensor (12) as the deformation of the roadbed (3).

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