Experimental device for simulating train to pass through tunnel under action of ground stress

Abstract

The invention discloses an experimental device for simulating a train to pass through a tunnel under the action of ground stress, which comprises a model box, a base fixedly arranged at the bottom of the model box, a simulation tunnel communicated with the front and rear side surfaces in the model box, a rail road surface arranged on the bottom surface of the simulation tunnel, a bottom pressurizing device arranged at the bottom of the model box, and a top pressurizing device arranged in the model box, the model box is filled with rock-soil bodies, a buffer assembly is fixedly arranged on the upper end face of the track pavement, a supporting frame penetrating through the simulation tunnel is fixedly arranged on the upper end face of the base, a conveying belt device is fixedly arranged on the supporting frame, and a vibration simulation mechanism is fixedly arranged on the side face of the conveying belt device. The stress, displacement and vibration response characteristics of tunnel surrounding rock and soil above the tunnel in the process that a train passes through the tunnel are simulated through the conveying belt device and the vibration exciter, the bottom pressurizing device and the top pressurizing device are arranged, and more accurate ground stress is kept by applying force in multiple directions through a hydraulic and air pressure combined method.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel mechanics experimental devices, and in particular to an experimental device for simulating a train passing through a tunnel under ground stress. Background Art

[0002] During the operation of the railway, train vibration may cause slight deformation of the soil layer and lining structure around the tunnel. This deformation is irreversible and may gradually accumulate and eventually lead to overall deformation or instability of the tunnel structure. Affected by its vibration effect, tunnel collapse disasters occur from time to time. Therefore, the prediction and analysis of the tunnel instability process cannot be ignored. However, it is difficult to monitor the surrounding rock of the tunnel on site, and the stress and displacement conditions of the upper rock and soil are not available for observation. The use of numerical simulation methods also requires experimental verification. Therefore, building a similar experimental device is a feasible research method. The existing experiments mostly use a model box tunnel and rock and soil, a vibration system, and a ground stress maintenance system. The change pattern during the test is obtained through various sensors, and its evolution law is analyzed with the recorded data. Therefore, by building a simulated train passing through the tunnel experimental device under the action of ground stress, the deformation characteristics of the surrounding rock and the upper rock and soil when the train passes through the tunnel are studied, which is of great significance for the protection of the tunnel-ecological environment and sustainable development. At present, similar model devices still have the following defects when simulating vibration:

[0003] First, most of the current methods for simulating vibration using similar model devices do not consider that the train is in a moving state, and cannot simulate the deformation characteristics of the tunnel surrounding rock and the rock and soil above it when the train passes through the tunnel. Secondly, in the ground stress maintaining device, most of them only apply pressure in the vertical direction. However, the shape of the mountain is often narrow at the top and wide at the bottom. The existing experimental equipment cannot apply force in multiple directions to maintain more accurate ground stress. Summary of the invention

[0004] 1. Technical issues

[0005] The present invention provides an experimental device for simulating a train passing through a tunnel under the action of ground stress, aiming to solve the problem that the traditional similarity model does not consider the movement effect of the train and the ground stress maintaining device does not consider the application direction.

[0006] (II) Technical content

[0007] In order to solve the above technical problems, the technical solution of the present invention is: an experimental device for simulating a train passing through a tunnel under the action of ground stress, comprising a model box, the model box is assembled and fixed by acrylic plates, a base is fixedly arranged at the bottom of the model box, a simulated tunnel connecting the front and rear sides is arranged inside the model box, a track pavement is arranged at the bottom of the model box, a bottom pressurizing device for applying pressure to the simulated tunnel from bottom to top is arranged at the bottom of the model box, a top pressurizing device for applying pressure to the simulated tunnel from top to bottom is arranged inside the model box, a rock and soil body is filled inside the model box, a buffer assembly is fixedly arranged on the upper end face of the track pavement, a support frame penetrating the simulated tunnel is fixedly arranged on the upper end face of the base, a conveyor belt device is fixedly arranged on the support frame, a vibration simulation mechanism is fixedly arranged on the side of the conveyor belt device, and also includes a data monitoring system, the data monitoring system includes a plurality of vibrating wire earth pressure gauges buried inside the rock and soil body, a plurality of strain gauges fixedly arranged on the outer side of the simulated tunnel, a laser rangefinder distributed on the outer side of the model box, and a strain measuring instrument electrically connected to the strain gauge, and the vibrating wire earth pressure gauge, the laser rangefinder and the strain measuring instrument all transmit data to an external data display through a wire.

[0008] Furthermore, the bottom pressurizing device comprises a hydraulic cylinder fixedly arranged at the upper end of the base, and a pressure-bearing bottom plate is fixedly arranged at one end of the piston end of the hydraulic cylinder extending into the interior of the model box.

[0009] Furthermore, the top pressurizing device includes a pressure-bearing top plate movably arranged inside the model box, the pressure-bearing top plate is in an inverted V shape, and a pressurizing airbag is fixedly provided on the upper surface of the pressure-bearing top plate.

[0010] Furthermore, the buffer assembly includes a plurality of springs fixedly arranged on the track surface, and a buffer plate is fixedly arranged on the upper end of the spring.

[0011] Furthermore, a sliding rod is fixed on the support frame, and the vibration simulation mechanism includes an exciter, which is slidably arranged on the support frame through the sliding rod. The side of the exciter is fixedly connected to the conveyor belt device through an auxiliary fixing rod. The conveyor belt device drives the exciter to move along the simulated tunnel. Two excitation heads are fixed on the lower driving end of the exciter, and the excitation heads are in contact with the buffer plate.

[0012] Furthermore, the pressurized airbag is connected to an air compressor via a pipeline, and a pressure regulating valve is provided on the pipeline.

[0013] (III) Technical Effect

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] The present invention utilizes a conveyor belt device and a vibrator to simulate the stress, displacement and vibration response characteristics of the tunnel surrounding rock and the soil above it during the process of a train passing through a tunnel, which is more in line with actual working conditions, solves the problem that the vibration excitation method of the existing experimental device is not perfect, and realizes the dynamic load process of the train. The present invention is provided with a bottom pressurizing device and a top pressurizing device, and utilizes a combined method of hydraulic and pneumatic pressure to apply forces in multiple directions to maintain more accurate ground stress. The present invention utilizes sensors to monitor the deformation data of the tunnel, analyzes its deformation characteristics, and then compares them with the numerical simulation results, providing a theoretical basis for tunnel support and collapse prevention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front structural schematic diagram of the present invention.

[0017] Figure 2 It is a side structural schematic diagram of the present invention.

[0018] Figure 3 It is a schematic diagram of the assembly structure of the support frame, the conveyor belt device and the vibrator of the present invention.

[0019] Figure 4 It is a schematic diagram of the monitoring points and track pavement structure of the present invention.

[0020] As shown in the figure, 1-air compressor; 2-pipeline; 3-pressure regulating valve; 4-top plate of model box; 5-rock and soil; 6-tunnel; 7-conveyor device; 8-track pavement; 9-hydraulic cylinder; 10-base; 11-bottom plate of model box; 12-pressure bottom plate; 13-vibrator; 14-pressure top plate; 15-pressurized air bag; 16-acrylic plate; 17-support frame; 18-conveyor controller; 19-vibration regulator; 20-slide rod; 21-auxiliary fixing rod; 22-vibrator head; 23-vibrating wire soil pressure gauge; 24-laser rangefinder; 25-strain gauge; 26-spring; 27-buffer plate. DETAILED DESCRIPTION

[0021] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", "center", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation structure and operation, and therefore cannot be understood as a limitation on the present invention.

[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "provided with", "installed", "connected", "connected" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0024] Combined with Figure 1 To Attachment Figure 4 An experimental device for simulating a train passing through a tunnel under ground stress, comprising a model box, the model box is assembled and fixed by acrylic plates 16, a base 10 is fixedly arranged at the bottom of the model box, a simulated tunnel 6 connecting the front and rear sides is arranged inside the model box, a track pavement 8 is arranged on the bottom of the simulated tunnel 6, a bottom pressurizing device for applying pressure to the simulated tunnel 6 from bottom to top is arranged at the bottom of the model box, a top pressurizing device for applying pressure to the simulated tunnel 6 from top to bottom is arranged inside the model box, a rock and soil body 5 is filled inside the model box, a buffer assembly is fixedly arranged on the upper end surface of the track pavement 8, and a cushion assembly is fixedly arranged on the upper end surface of the base 10. A support frame 17 penetrating the simulated tunnel 6 is fixedly provided on the end face, a conveyor belt device 7 is fixedly provided on the support frame 17, a vibration simulation mechanism is fixedly provided on the side of the conveyor belt device 7, and also includes a data monitoring system, which includes a plurality of vibrating-wire earth pressure gauges 23 buried in the rock and soil body 5, a plurality of strain gauges 25 fixed on the outer side of the simulated tunnel 6, a laser rangefinder 24 distributed on the outer side of the model box, and a strain measuring instrument electrically connected to the strain gauge 25. The vibrating-wire earth pressure gauge 23, the laser rangefinder 24 and the strain measuring instrument all transmit data to an external data display through wires.

[0025] The model of the vibrating-wire earth pressure gauge is SN-TYLJ, the model of the strain gauge is DH3818Y, and the model of the laser ranging sensor is GFL-F.

[0026] In this embodiment, as a preferred technical solution, the bottom pressurizing device includes a hydraulic cylinder 9 fixedly arranged at the upper end of the base 10, and the piston end of the hydraulic cylinder 9 extends into the end of the model box and is fixedly provided with a pressure-bearing bottom plate 12. The top pressurizing device includes a pressure-bearing top plate 14 movably arranged inside the model box, the pressure-bearing top plate 14 is in an inverted V shape, and a pressurizing airbag 15 is fixedly arranged on the upper end surface of the pressure-bearing top plate 14, and the pressurizing airbag 15 is connected to an air compressor 1 through a pipeline 2, and a pressure regulating valve 3 is provided on the pipeline 2.

[0027] In this embodiment, as a preferred technical solution, the buffer assembly includes a plurality of springs 26 fixed on the track pavement 8, and a buffer plate 27 is fixed on the upper end of the spring 26. A slide bar 20 is fixed on the support frame 17, and the vibration simulation mechanism includes an exciter 13, which is slidably arranged on the support frame 17 through the slide bar 20, and the side of the exciter 13 is fixedly connected to the conveyor belt device 7 through an auxiliary fixing rod 21, and the conveyor belt device 7 drives the exciter 13 to move along the simulated tunnel 6, and two excitation heads 22 are fixed on the lower driving end of the exciter 13, and the excitation heads 22 are in contact with the buffer plate 27.

[0028] The spring 26 and the buffer plate 27 are mainly used to simulate the role of train rails. Since the exciter head 22 will fluctuate up and down during the use of the exciter 13, it will cause direct damage to the road surface and affect the monitoring results. The excitation point of the exciter is on the buffer plate 27, which can buffer this damage and reduce experimental errors.

[0029] Before using the present invention, first connect an external power supply. The specific experimental steps of the present invention are as follows:

[0030] 1. Turn on the bottom and top pressurizing devices and stabilize the pressure: turn on the air compressor 1, adjust the pressure of the pressurized airbag 15 through the pressure regulating valve 3, and turn on the hydraulic cylinder 9 at the same time. Set the pressure parameters according to the experimental requirements. Pressure sensors are provided on the pressure-bearing top plate 14 and the pressure-bearing bottom plate 12 to monitor the applied pressure in real time, observe the pressure data of the pressure-bearing bottom plate 12 and the pressure-bearing top plate 14, and wait for the pressure data to stabilize for more than 3 minutes.

[0031] 2. Turn on the data monitoring system and stabilize the data: turn on the vibrating wire earth pressure gauge 23, strain gauge and laser rangefinder 24, set the corresponding parameters, such as measurement frequency, range, etc., observe the data on the data display, and wait for the data to stabilize for more than 3 minutes.

[0032] 3. Turn on the conveyor belt device and the vibrator and collect data: the conveyor belt device 7 is connected to the conveyor belt controller 18, the conveyor belt device 7 is turned on, the conveyor belt speed is set, and the appropriate conveyor belt speed value is determined according to the experimentally simulated train speed. The vibrator 13 is connected to the vibration regulator 19, the vibrator 13 is turned on, and the excitation frequency is set to simulate the vibration generated during the operation of the train. The excitation frequency can be set according to the actual vibration characteristics of the train. As the conveyor belt device 7 drives the vibrator 13 to move along the simulated tunnel 6, the vibrating wire earth pressure gauge 23, the strain gauge 25 and the laser rangefinder 24 collect the pressure, strain and displacement data of the rock and soil around the tunnel in real time, and transmit the data to the external data display for real-time recording. When the vibrator 13 moves from one end of the simulated tunnel 6 to the other end, the conveyor belt device 7 and the vibrator 13 are stopped.

[0033] 4. Data analysis: Organize and analyze the data collected during the experiment, including time history analysis and spatial distribution analysis of pressure, strain and displacement data, and compare them with the numerical analysis results to draw conclusions.

[0034] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. An experimental device for simulating a train passing through a tunnel under the action of ground stress, comprising a model box, the model box being assembled and fixed by acrylic plates (16), a base (10) being fixed at the bottom of the model box, a simulated tunnel (6) connecting the front and rear sides being arranged inside the model box, and a track pavement (8) being arranged on the bottom of the simulated tunnel (6), characterized in that: A bottom pressure device for applying pressure to the simulated tunnel (6) from bottom to top is provided at the bottom of the model box, a top pressure device for applying pressure to the simulated tunnel (6) from top to bottom is provided inside the model box, a rock and soil body (5) is filled inside the model box, a buffer assembly is fixedly provided on the upper end face of the track pavement (8), a support frame (17) penetrating the simulated tunnel (6) is fixedly provided on the upper end face of the base (10), a conveyor belt device (7) is fixedly provided on the support frame (17), a vibration simulation mechanism is fixedly provided on the side of the conveyor belt device (7), and a data monitoring system is also included, the data monitoring system includes a plurality of vibrating wire earth pressure gauges (23) buried inside the rock and soil body (5), a plurality of strain gauges (25) fixedly provided on the outer side of the simulated tunnel (6), a laser rangefinder (24) distributed outside the model box, and a strain measuring instrument electrically connected to the strain gauge (25), the vibrating wire earth pressure gauge (23), the laser rangefinder (24) and the strain measuring instrument all transmit data to an external data display via a wire.

2. The experimental device for simulating a train passing through a tunnel under ground stress according to claim 1, characterized in that: The bottom pressure device comprises a hydraulic cylinder (9) fixedly arranged on the upper end of the base (10), and a pressure-bearing bottom plate (12) is fixedly arranged on one end of the piston end of the hydraulic cylinder (9) extending into the interior of the model box.

3. The experimental device for simulating a train passing through a tunnel under ground stress according to claim 1, characterized in that: The top pressurizing device comprises a pressure-bearing top plate (14) movably arranged inside the model box, the pressure-bearing top plate (14) is in an inverted V shape, and a pressurizing air bag (15) is fixedly arranged on the upper end surface of the pressure-bearing top plate (14).

4. The experimental device for simulating a train passing through a tunnel under ground stress according to claim 1, characterized in that: The buffer assembly comprises a plurality of springs (26) fixedly arranged on the track pavement (8), and a buffer plate (27) is fixedly arranged on the upper end of the spring (26).

5. The experimental device for simulating a train passing through a tunnel under ground stress according to claim 4, characterized in that: A slide bar (20) is fixedly provided on the support frame (17). The vibration simulation mechanism comprises a vibration exciter (13). The vibration exciter (13) is slidably provided on the support frame (17) via the slide bar (20). The side surface of the vibration exciter (13) is fixedly connected to a conveyor belt device (7) via an auxiliary fixing rod (21). The conveyor belt device (7) drives the vibration exciter (13) to move along the simulation tunnel (6). Two vibration exciter heads (22) are fixedly provided at the lower driving end of the vibration exciter (13). The vibration exciter heads (22) are in contact with a buffer plate (27).

6. The experimental device for simulating a train passing through a tunnel under ground stress according to claim 3, characterized in that: The pressurized air bag (15) is connected to an air compressor (1) via a pipeline (2), and a pressure regulating valve (3) is provided on the pipeline (2).

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