Large-scale model test system for studying dynamic response of tunnel structures under train vibration

Abstract

The present invention relates to the field of tunnel and underground engineering test technology, and in particular to a large-scale model test system for studying the dynamic response of a tunnel structure under train vibration, comprising a test pit, a tunnel structure model is arranged at the lower part of the test pit, a large-scale excitation system is arranged between the test pit and the tunnel structure model, and the large-scale excitation system is electrically connected to an intelligent vibration control system; the test pit is filled with soil, a monitoring end of a monitoring system is arranged in the soil, and terminals of the intelligent vibration control system and the monitoring system are arranged outside the test pit; the large-scale excitation system comprises an adjustable base, the adjustable base is fixedly connected to the bottom of the test pit, one end of the adjustable base extending into the tunnel structure model is fixedly connected to an adjustable beam, a vibration part is arranged on the adjustable beam, and the vibration part abuts against the inner wall of the tunnel structure model. The present invention can accurately simulate the dynamic response law of a tunnel structure under the action of train vibration through a large-scale model test.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel and underground engineering tests, and in particular to a large-scale model test system for studying dynamic response of a tunnel structure under train vibration. Background Art

[0002] With the continuous development of underground space engineering in my country, the construction of railway, highway and subway tunnels is also in full swing. In recent years, the impact of train vibration on tunnel structure has become increasingly prominent. Long-term train vibration can lead to cracks in tunnel linings, hollowing of roadbeds and other defects. Once tunnel defects occur, they will seriously affect the operational safety of trains, and major accidents are very likely to occur, causing adverse social impacts. Therefore, this problem needs to be solved urgently.

[0003] Model tests can effectively simulate the dynamic response laws of tunnels. However, due to the limitations of test costs and large workload, existing model tests involving the study of the dynamic response of tunnel structures under train vibration mainly consider the situation with a similarity ratio of 1:20-1:40, and lack large-scale model test research. The smaller the scale of the model test, the greater the test error. Therefore, there is an urgent need for a large-scale model test system for the study of the dynamic response of tunnel structures under train vibration to meet the needs of scientific research and actual engineering, and to provide more accurate test data support for the dynamic response of tunnels. Summary of the invention

[0004] The purpose of the present invention is to provide a large-scale model test system for studying the dynamic response of tunnel structures under train vibration, so as to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above-mentioned object, the present invention provides the following scheme: a large-scale model test system for studying the dynamic response of a tunnel structure under train vibration, comprising a test pit, a tunnel structure model is arranged at the lower part of the test pit, a large-scale excitation system is arranged between the test pit and the tunnel structure model, and the large-scale excitation system is electrically connected to an intelligent vibration control system; the test pit is filled with soil, a monitoring end of a monitoring system is arranged in the soil, and the terminals of the intelligent vibration control system and the monitoring system are arranged outside the test pit;

[0006] The large-scale excitation system includes an adjustable base, which is fixedly connected to the bottom of the test pit. One end of the adjustable base extending into the tunnel structure model is fixedly connected to an adjustable beam, and a vibration part is provided on the adjustable beam, which abuts against the inner wall of the tunnel structure model.

[0007] Preferably, the test foundation pit includes three lateral concrete walls and one front concrete wall, two adjacent lateral concrete walls are fixedly connected, two ends of the front concrete wall are fixedly connected to the ends of two non-adjacent lateral concrete walls, and a tunnel structure placement area is arranged between the three lateral concrete walls and the front concrete wall.

[0008] Preferably, a concrete support central opening is opened on the front concrete wall, the concrete support central opening is fixedly connected to and communicated with the tunnel structure model, and a transport staircase is fixedly connected to the bottom of one end of the concrete support central opening away from the tunnel structure model.

[0009] Preferably, the tunnel structure model includes a plurality of concrete pipe segments arranged in the tunnel structure placement area, a rubber waterproof strip is arranged between two adjacent concrete pipe segments, a plurality of circular observation windows are embedded in the concrete pipe segments, and the concrete pipe segments at both ends are respectively fixedly connected and communicated with the lateral concrete wall and the central opening of the concrete support.

[0010] Preferably, the vibration part includes a plurality of large-scale exciters, which are detachably connected to the adjustable cross beam via an exciter clamp, and one end of the large-scale exciter away from the adjustable cross beam is fixedly connected to a force sensor, and the force sensor abuts against the inner wall of the concrete pipe section.

[0011] Preferably, the intelligent vibration control system includes a control terminal, the control terminal is electrically connected to an intelligent signal generator, the intelligent signal generator is electrically connected to a plurality of signal amplifiers, and the signal amplifiers are arranged in a one-to-one correspondence with the large-scale exciter and are electrically connected.

[0012] Preferably, the terminal of the monitoring system includes a monitoring platform, and the monitoring end of the monitoring system includes a plurality of motion cameras, displacement monitoring equipment, mechanical monitoring equipment, and acceleration monitoring equipment.

[0013] Preferably, the motion camera, the displacement monitoring device, the mechanical monitoring device, and the acceleration monitoring device are electrically connected to the monitoring platform.

[0014] Preferably, the motion camera is disposed in the concrete pipe section, and the motion camera is disposed in a one-to-one correspondence with the circular observation window.

[0015] The present invention discloses the following technical effects:

[0016] The present invention sets a tunnel structure model in a test pit and fills the test pit with soil, so that the tunnel structure model is in the soil, and a large-scale excitation system can more accurately reflect the dynamic response law of the tunnel structure under the vibration of the train; at the same time, the intelligent vibration control system can accurately simulate the train speed, vibration waveform and train running interval, so as to realize related tests that are closer to the actual situation and have higher accuracy requirements, and the experimental data can be collected in real time through the monitoring system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the overhead structure of the test foundation pit of the present invention;

[0020] Figure 3 This is a schematic diagram of the front structure of the front concrete wall of the present invention;

[0021] Figure 4 It is a schematic diagram of the side view structure of the test foundation pit of the present invention;

[0022] Figure 5 It is a schematic diagram of the structure of the tunnel structure model of the present invention;

[0023] Figure 6 It is a schematic diagram of the structure of a large-scale excitation system of the present invention;

[0024] Figure 7 This is a schematic diagram of the intelligent vibration control system of the present invention;

[0025] Figure 8 It is a schematic diagram of the monitoring system of the present invention;

[0026] Among them, 1. Test pit; 2. Tunnel structure model; 3. Large-scale excitation system; 4. Intelligent vibration control system; 5. Monitoring system; 6. Lateral concrete wall; 7. Concrete support center opening; 8. Front concrete wall; 9. Transport stairs; 10. Tunnel structure placement area; 11. Large-scale exciter; 12. Exciter fixture; 13. Force sensor; 14. Adjustable base; 15. Adjustable beam; 16. Concrete pipe section; 17. Rubber waterproof strip; 18. Circular observation window; 19. Control terminal; 20. Intelligent signal generator; 21. Signal amplifier; 22. Monitoring platform; 23. Motion camera; 24. Displacement monitoring equipment; 25. Mechanical monitoring equipment; 26. Acceleration monitoring equipment. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Embodiment 1

[0030] Reference Figure 1-Figure 8 The present invention provides a large-scale model test system for studying the dynamic response of a tunnel structure under train vibration, comprising a test pit 1, a tunnel structure model 2 is arranged at the lower part of the test pit 1, a large-scale excitation system 3 is arranged between the test pit 1 and the tunnel structure model 2, and the large-scale excitation system 3 is electrically connected to an intelligent vibration control system 4; the test pit 1 is filled with soil, a monitoring end of a monitoring system 5 is arranged in the soil, and terminals of the intelligent vibration control system 4 and the monitoring system 5 are arranged outside the test pit 1;

[0031] The large-scale excitation system 3 includes an adjustable base 14, which is fixedly connected to the bottom of the test pit 1. One end of the adjustable base 14 extending into the tunnel structure model 2 is fixedly connected to an adjustable beam 15, and a vibration part is provided on the adjustable beam 15, which abuts against the inner wall of the tunnel structure model 2.

[0032] The intelligent control system 4 is used to control the large-scale excitation system to simulate the magnitude, frequency and interval of the train vibration load.

[0033] The present invention sets a tunnel structure model 2 in a test pit 1 and fills the test pit 1 with soil so that the tunnel structure model 2 is in the soil. A large-scale excitation system 3 can be used to more accurately simulate the dynamic response law of the tunnel structure under the vibration of the train. At the same time, the intelligent vibration control system 4 can accurately simulate the train speed, vibration waveform and train running interval, so as to realize related tests that are closer to the actual situation and have higher accuracy requirements, and the monitoring system 5 can collect the experimental data in real time.

[0034] According to a further optimization scheme, the test foundation pit 1 includes three lateral concrete walls 6 and one front concrete wall 8, two adjacent lateral concrete walls 6 are fixedly connected, two ends of the front concrete wall 8 are fixedly connected to the ends of two non-adjacent lateral concrete walls 6, and a tunnel structure placement area 10 is provided between the three lateral concrete walls 6 and the front concrete wall 8.

[0035] The supporting structure of the test foundation pit 1 is formed by three lateral concrete walls 6 and a front concrete wall 8. The lateral concrete walls 6 and the front concrete wall 8 are cast in situ using C30 impermeable concrete and HRB400 steel bars.

[0036] To further optimize the solution, a concrete support center opening 7 is opened on the front concrete wall 8, the concrete support center opening 7 is fixedly connected and communicated with the tunnel structure model 2, and a transport staircase 9 is fixedly connected to the bottom of the end of the concrete support center opening 7 away from the tunnel structure model 2.

[0037] Reinforcement ribs are arranged around the central opening 7 of the concrete support to ensure the safety of the structure at the position of the central opening 7 of the concrete support; the transport stairs 9 facilitate the transportation of the structure and monitoring equipment.

[0038] According to a further optimization scheme, the tunnel structure model 2 includes a plurality of concrete pipe segments 16 arranged in the tunnel structure placement area 10, a rubber waterproof strip 17 is arranged between two adjacent concrete pipe segments 16, a plurality of circular observation windows 18 are embedded in the concrete pipe segments 16, and the concrete pipe segments 16 at both ends are fixedly connected and communicated with the lateral concrete wall 6 and the concrete support center opening 7 respectively.

[0039] The rubber waterproof strip 17 is arranged at the connection of two adjacent concrete pipe sections 16, and the two adjacent concrete pipe sections 16 are spliced ​​by embedded method. After the splicing is completed, the waterproof coating is applied on the surface of the connection to ensure the sealing of the joint.

[0040] According to a further optimized solution, the vibration part includes several large vibrators 11, which are detachably connected to an adjustable cross beam 15 via a vibrator clamp 12, and one end of the large vibrator 11 away from the adjustable cross beam 15 is fixedly connected to a force sensor 13, which abuts against the inner wall of the concrete pipe section 16.

[0041] According to a further optimization scheme, the intelligent vibration control system 4 includes a control terminal 19, the control terminal 19 is electrically connected to an intelligent signal generator 20, the intelligent signal generator 20 is electrically connected to a plurality of signal amplifiers 21, and the signal amplifiers 21 are arranged one-to-one with the large-scale exciter 11 and are electrically connected.

[0042] According to a further optimization scheme, the terminal of the monitoring system 5 includes a monitoring platform 22 , and the monitoring end of the monitoring system 5 includes a plurality of motion cameras 23 , a displacement monitoring device 24 , a mechanical monitoring device 25 , and an acceleration monitoring device 26 .

[0043] To further optimize the solution, the motion camera 23 , the displacement monitoring device 24 , the mechanical monitoring device 25 , and the acceleration monitoring device 26 are electrically connected to the monitoring platform 22 .

[0044] The intelligent signal generator 20 is used to output the vibration load of the train, and is connected to the signal amplifier 21 and the control terminal 19 through anti-interference wires; the custom vibration waveform is input into the monitoring platform 22, and the intelligent signal generator 20 generates corresponding instructions to control the signal amplifier 21 respectively, and then control the large-scale exciter 11 to output the vibration load and frequency; in addition, several large-scale exciters 11 can output different vibration loads, frequencies and vibration intervals, which can more realistically simulate the actual train vibration conditions.

[0045] The intelligent signal generator 20 is used to output the train vibration load, and is connected to the power amplifier 21 and the control terminal 19 through anti-interference wires; the custom vibration waveform is input into the control terminal, and the intelligent signal generator 20 generates corresponding instructions to control the power amplifier 21 respectively, and then control the large-scale exciter 11 to output the vibration load and frequency; in addition, several large-scale exciters 11 can output different vibration loads, frequencies and vibration intervals, which can more realistically simulate the actual train vibration conditions.

[0046] When the soil is filled, the displacement monitoring equipment 24, the mechanical monitoring equipment 25 and the acceleration monitoring equipment 26 are arranged according to the test requirements. The mechanical monitoring equipment 25 includes an earth pressure box and a pore water pressure gauge; the acceleration monitoring equipment 26 includes an acceleration sensor, and the displacement monitoring equipment 24 includes a displacement meter and a structural displacement measuring rod.

[0047] According to a further optimization scheme, the motion camera 23 is disposed in the concrete pipe section 16 , and the motion camera 23 and the circular observation window 18 are disposed in a one-to-one correspondence.

[0048] By aiming the motion camera 23 at the circular observation window 18 of the concrete pipe section, the changing characteristics of the soil layer can be observed in real time.

[0049] Working process: Set the train speed to 60km / h, full water level, and the train running interval to 90s;

[0050] Water level control: Use the layered filling method to fill the soil in the test pit 1 in layers, sprinkle water in layers and let it stand, add soil and water to the top of the pit, let the test model stand for 48 hours, and conduct dynamic response tests on the tunnel structure and surrounding strata.

[0051] Preparation of instruments and equipment: first fix the adjustable base 14 to the bottom of the test pit 1 to determine the position of the large vibrator 11 , and then adjust the height of the base 14 to ensure that the large vibrator 11 abuts against the inner wall of the concrete pipe section 16 .

[0052] Apply vibration load: connect the power cord of the instrument and turn on the instrument; apply a 60km / h train vibration load with a single pass cycle of 1.5s, and apply the train vibration load again after an interval of 90s; set the number of train vibrations as needed.

[0053] Test data analysis: The pore water pressure of the formation is analyzed by the pore water pressure gauge, and the effective stress is analyzed by the earth pressure cell. The two are compared to determine the liquefaction of the formation. The safety of the tunnel structure is monitored by the acceleration sensor and non-contact measurement device.

[0054] Embodiment 2

[0055] The difference between this embodiment and the first embodiment is that the test foundation pit 1 is 4.6m deep, 9m long and 6m wide, and is spliced ​​with three concrete pipe segments 16. Each concrete pipe segment 16 has a radius of 1.2m and a length of 1.5m. Two large vibrators 11 are provided, which are respectively located at 1 / 3 and 2 / 3 of the concrete pipe segment 16, and a circular observation window 18 is provided in the middle concrete pipe segment 16.

[0056] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0057] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A large-scale model test system for studying the dynamic response of tunnel structures under train vibration, characterized by: The invention comprises a test pit (1), a tunnel structure model (2) is arranged at the lower part of the test pit (1), a large-scale excitation system (3) is arranged between the test pit (1) and the tunnel structure model (2), and the large-scale excitation system (3) is electrically connected to an intelligent vibration control system (4); the test pit (1) is filled with soil, a monitoring end of a monitoring system (5) is arranged in the soil, and terminals of the intelligent vibration control system (4) and the monitoring system (5) are arranged outside the test pit (1); The large-scale excitation system (3) comprises an adjustable base (14), the adjustable base (14) being fixedly connected to the bottom of the test pit (1), one end of the adjustable base (14) extending into the tunnel structure model (2) being fixedly connected to an adjustable crossbeam (15), the adjustable crossbeam (15) being provided with a vibration part, the vibration part being in contact with the inner wall of the tunnel structure model (2); The tunnel structure model (2) comprises a plurality of concrete pipe sections (16) arranged in a tunnel structure placement area (10), a rubber waterproof strip (17) being arranged between two adjacent concrete pipe sections (16), and a plurality of circular observation windows (18) being embedded in the concrete pipe sections (16); The monitoring end of the monitoring system (5) includes a plurality of motion cameras (23), a displacement monitoring device (24), a mechanical monitoring device (25) and an acceleration monitoring device (26); The motion camera (23) is arranged in the concrete pipe section (16), and the motion camera (23) and the circular observation window (18) are arranged in a one-to-one correspondence.

2. The large-scale model test system for studying the dynamic response of tunnel structures under train vibration according to claim 1 is characterized by: The test foundation pit (1) comprises three lateral concrete walls (6) and a front concrete wall (8), two adjacent lateral concrete walls (6) are fixedly connected to each other, two ends of the front concrete wall (8) are fixedly connected to the ends of two non-adjacent lateral concrete walls (6), and a tunnel structure placement area (10) is provided between the three lateral concrete walls (6) and the front concrete wall (8).

3. The large-scale model test system for studying the dynamic response of tunnel structures under train vibration according to claim 2 is characterized by: A concrete support central opening (7) is provided on the front concrete wall (8), the concrete support central opening (7) is fixedly connected to and communicates with the tunnel structure model (2), and a transport staircase (9) is fixedly connected to the bottom of one end of the concrete support central opening (7) facing away from the tunnel structure model (2).

4. The large-scale model test system for studying the dynamic response of tunnel structures under train vibration according to claim 3 is characterized by: The concrete pipe sections (16) at both ends are respectively fixedly connected to and communicated with the lateral concrete wall (6) and the concrete support central opening (7).

5. The large-scale model test system for studying the dynamic response of tunnel structures under train vibration according to claim 4 is characterized by: The vibration part comprises a plurality of large-scale exciters (11), wherein the large-scale exciters (11) are detachably connected to the adjustable cross beam (15) via a vibrator clamp (12), and a force sensor (13) is fixedly connected to one end of the large-scale exciter (11) away from the adjustable cross beam (15), and the force sensor (13) abuts against the inner wall of the concrete pipe section (16).

6. The large-scale model test system for studying the dynamic response of tunnel structures under train vibration according to claim 5 is characterized by: The intelligent vibration control system (4) comprises a control terminal (19), the control terminal (19) being electrically connected to an intelligent signal generator (20), the intelligent signal generator (20) being electrically connected to a plurality of signal amplifiers (21), the signal amplifiers (21) being arranged in a one-to-one correspondence with the large-scale exciter (11) and being electrically connected.

7. The large-scale model test system for studying the dynamic response of tunnel structures under train vibration according to claim 4 is characterized by: The terminal of the monitoring system (5) comprises a monitoring platform (22).

8. The large-scale model test system for studying the dynamic response of tunnel structures under train vibration according to claim 7 is characterized by: The motion camera (23), the displacement monitoring device (24), the mechanics monitoring device (25), and the acceleration monitoring device (26) are electrically connected to the monitoring platform (22).

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