Tunnel structure and surrounding rock dynamic response testing system

Abstract

The application discloses a kind of tunnel structure and the dynamic response test system of surrounding rock, including model box, loading system and monitoring system, at least one group of tunnel model is provided in model box, loading system is provided with multiple electromagnetic exciters for loading tunnel model, multiple electromagnetic exciters realize the accurate simulation of train moving load, and the dynamic response of tunnel structure and surrounding soil around can be monitored in real time by monitoring system;By replacing installation plate, the dynamic response of tunnel structure and surrounding rock of various section types, multiple tunnels under the moving car load can be simulated conveniently and quickly, the propagation law of train moving load in single line or multiple tunnels can be studied.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering rock and soil testing, and in particular to a dynamic response testing system for tunnel structures and surrounding rocks. Background Art

[0002] During train operation, track irregularities and other factors generate random vibration loads at the wheel-rail interface. These loads are ultimately transmitted to the ground surface and surface structures via the track, roadbed structure, tunnel structure, and strata. With the opening of numerous high-speed rail and subway lines, the issue of tunnel structure vibration and environmental vibration induced by train operation has gradually become a focus of scholarly attention. Currently, environmental vibration induced by subway train operation is internationally recognized as one of the seven major urban public hazards. Long-term exposure to environmental vibration and noise poses serious risks to people's physical and mental health. Furthermore, long-term, repetitive train vibration loads can induce the accumulation of internal damage in tunnel structures, accelerate the development of cracks and deformation, and potentially lead to cracking, block loss, and misalignment of the tunnel lining.

[0003] Since model tests are complex and difficult to implement to study the dynamic response characteristics of tunnel structures and surrounding soil layers under the action of train moving loads, current model tests mostly use single-point excitation to simulate train loads, without considering the travel effect of the train and cannot truly reflect the impact of the train's moving load on the tunnel structure and surrounding soil layers. Summary of the Invention

[0004] In response to the above problems, the present invention provides a dynamic response test system for tunnel structures and surrounding rocks, which solves the problem that existing model tests use single-point excitation to simulate train loads, do not consider the running effects of the train, and cannot truly reflect the impact of the train's moving load on the tunnel structure and surrounding soil layers.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0006] A dynamic response testing system for tunnel structure and surrounding rock is provided, which includes a model box, a loading system and a monitoring system;

[0007] The model box is filled with test soil; at least one set of tunnel models is set in the model box, and both ends of the tunnel models pass through the side walls of the model box; a track bed is set along the length of the tunnel model, and two track models are set on the track bed at intervals along the length of the tunnel model;

[0008] A reaction frame is provided on the model box. The reaction frame includes mounting beams of the same number as the tunnel models. Each mounting beam matches a set of tunnel models. Each mounting beam passes through the tunnel model and is located above the two track models.

[0009] The loading system includes a plurality of electromagnetic exciters; the monitoring system includes a plurality of dynamic force sensors, and the electromagnetic exciters and the dynamic force sensors are in a one-to-one matching relationship;

[0010] The lower end face of the mounting beam is provided with a plurality of electromagnetic exciters along its length direction. The tail end of each electromagnetic exciter is fixedly connected to the lower end face of the mounting beam. A dynamic force sensor is provided on the top rod of the electromagnetic exciter. The lower end face of the dynamic force sensor is provided with a distribution beam in contact with the upper end faces of the two track models.

[0011] The basic principle of the dynamic response test system for tunnel structure and surrounding rock in the present invention is: multiple electromagnetic exciters are placed in the tunnel model through the mounting beam on the reaction frame, and the distribution beam fixed on the electromagnetic exciter top rod accurately applies the train load to the track. The excitation time difference Δt of each exciter is used to simulate the movement effect of the train, and the dynamic response of the tunnel model and the test soil is monitored in real time through the monitoring system to study the propagation and attenuation laws of the vibration waves generated by the train operation in different directions in the tunnel structure and the surrounding soil layer, the impact of the vibration load generated by trains of different models and speeds on the tunnel structure and the surrounding soil layer, and the propagation law of the train moving load in single-line or multiple tunnels.

[0012] Furthermore, as a specific embodiment of the model box, the model box has a cubic structure with a square opening on the top, and square openings are provided on the front and rear side walls or the left and right side walls of the model box. A mounting plate can be removably installed in each square opening, and the mounting plate is made of transparent material. The mounting plate is provided with mounting notches for installing the tunnel model. The number of the mounting notches is the same as the number of tunnel models, and the cross-section of the mounting notches matches the cross-sectional contour of the tunnel model.

[0013] The mounting plate is detachably connected to the mounting notch by bolts. According to experimental requirements, multiple mounting notches can be provided on the mounting plate, and the cross-sections of the mounting notches can be set to different shapes. This allows multiple sets of tunnel models with different cross-sections to be installed on the mounting plate. This allows simulation of the dynamic response of tunnel structures and surrounding rocks of various cross-section types and multiple tunnels under vehicle-induced loads.

[0014] Furthermore, as a specific embodiment of the reaction frame, the reaction frame also includes two slide rails, which are arranged on the front and rear side walls or the top of the left and right side walls of the model box; multiple groups of support arms are vertically arranged on the two slide rails, and the number of support arm groups is the same as the number of mounting beams, each group of support arms includes two support arms, and the top of each group of support arms is slidably connected to the slide rails; a mounting beam is arranged between the bottoms of each group of support arms.

[0015] The setting of multiple groups of support arms allows multiple mounting beams to be installed on a reaction frame. Multiple mounting beams can realize dynamic response testing of multiple groups of tunnel models at the same time, simulating the dynamic response test of multiple-line tunnels in reality and improving test efficiency.

[0016] Each set of support arms can move along the length of the two slide rails, thereby adjusting the position of the mounting beam at the bottom of each set of support arms to adjust the positions of multiple electromagnetic exciters and distribution beams on the mounting beams. During the dynamic response test, the position of each set of support arms can be adjusted so that multiple electromagnetic exciters and distribution beams on the mounting beams cover the upper end surfaces of the two track models, thereby improving test accuracy.

[0017] Furthermore, a slide groove for matching with the slide rail is provided on the top of each support arm, and a locking bolt is provided on the top of each support arm, which passes through the slide groove and is in tight contact with the slide rail.

[0018] After the support arm is adjusted to the preset position, multiple electromagnetic exciters and distribution beams on the mounting beam are covered on the upper end surfaces of the two track models. The locking bolts are tightened to lock the support arm in its current position. During the dynamic response test, the support arm and the mounting beam at the bottom of the support arm can be prevented from moving in the horizontal position.

[0019] Furthermore, each support arm includes a first support arm and a second support arm, with the first support arm positioned above the second support arm. The second support arm is a hollow columnar structure, with the bottom of the first support arm movably disposed within the interior of the second support arm, and a slide groove is provided at the top of the first support arm. A mounting beam is fixedly connected between the bottoms of the two second support arms. A fixing bolt is provided on the outer wall of each second support arm, which passes through the outer wall of the second support arm and is in close contact with the first support arm. By adjusting the relative position between the first and second arms, the height position of the mounting beam can be adjusted to accommodate tunnel models of different sizes and shapes. The fixing bolts are used to fix the relative position between the first and second arms, thereby preventing the vertical movement of the mounting beam at the bottom of the support arm during dynamic response testing.

[0020] Furthermore, as a specific configuration of the loading system and the monitoring system, the loading system further includes a computer, a signal generator, and a power amplifier electrically connected to the plurality of electromagnetic exciters, and the computer, the signal generator, and the power amplifier are arranged outside the model box;

[0021] The monitoring system also includes multiple acceleration sensors, multiple dynamic strain sensors, and a signal acquisition device electrically connected to the multiple dynamic force sensors. The signal acquisition device is electrically connected to a computer. Multiple acceleration sensors are installed in the test soil at different depths, and multiple dynamic strain sensors are installed on the tunnel model. A computer is used to load the train load time history curve required for the test into a signal generator and power amplifier. A distribution beam fixed to the electromagnetic exciter's top rod accurately applies the train load to the track, and the effect of train movement is simulated by the excitation time difference Δt between each exciter. The signal acquisition device collects test data from the dynamic force sensors, acceleration sensors, and dynamic strain sensors embedded in the tunnel structure and test soil and transmits it to the computer.

[0022] Furthermore, the load excitation curve of each electromagnetic exciter is the same, and the excitation time interval between two adjacent electromagnetic exciters is Δt:

[0023]

[0024] Where v is the train speed, Δs is the sleeper spacing, and the number and placement of electromagnetic exciters can be adjusted according to experimental requirements. There is an interval between the start excitation time of each electromagnetic exciter along the direction of train travel. Each electromagnetic exciter is excited in sequence according to the excitation time interval, thereby simulating the load of a moving train.

[0025] The beneficial effects of the present invention are as follows: compared with the model test in the prior art, the present invention fully considers the moving effect of the moving train, and by inputting the train load time curve required for the test into the computer and combining the excitation time difference of each exciter, the accurate simulation of the train moving load can be achieved, and the dynamic response of the tunnel structure and the surrounding soil layer can be dynamically monitored in real time through the monitoring system; by removing and replacing the mounting plate, the dynamic response of the tunnel structure and surrounding rock of various cross-section types and multiple tunnels under the load caused by the moving vehicle can be simulated conveniently and quickly; the dynamic response test system of the tunnel structure and surrounding rock in the present invention is used to study the propagation and attenuation laws of the vibration waves generated by the train operation in the tunnel structure and the surrounding soil layer in different directions, study the influence of the vibration load generated by trains of different models and speeds on the tunnel structure and the surrounding soil layer, and study the propagation law of the train moving load in a single track or multiple tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the main structure of the dynamic response test system for tunnel structure and surrounding rock.

[0027] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure in the AA direction.

[0028] Figure 3This is a structural diagram of the mounting plate with different mounting notches.

[0029] Figure 4 This is a structural diagram of two groups of support arms provided on the reaction frame.

[0030] Figure 5 for Figure 1 Schematic diagram of the enlarged structure at point B in the middle.

[0031] Among them, 1. Model box; 2. Tunnel model; 3. Roadbed; 4. Track model; 5. Reaction frame; 501. Mounting beam; 502. Slide rail; 503. Support arm; 5031. First arm; 5032. Second arm; 6. Electromagnetic exciter; 7. Dynamic force sensor; 8. Distribution beam; 9. Square opening; 10. Mounting plate; 11. Mounting notch; 12. Slide groove; 13. Locking bolt; 14. Fixing bolt. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0033] Example 1

[0034] like Figure 1 、 Figure 2 and Figure 5 As shown, this embodiment provides a dynamic response test system for tunnel structures and surrounding rocks, which is used to study the propagation and attenuation laws of vibration waves generated by train operation in tunnel structures and surrounding soil layers in different directions, study the impact of vibration loads generated by trains of different types and speeds on tunnel structures and surrounding soil layers, and study the propagation laws of train moving loads in single-track or multiple tunnels.

[0035] The dynamic response test system includes a model box 1, a loading system, and a monitoring system. The model box 1 is a cubic structure with an open top. The length, width, and height of the interior space of the model box 1 are 3000mm, 2000mm, and 2500mm, respectively. The model box 1 is uncovered to facilitate filling with test soil. Square openings 9 are provided on the front and rear side walls or the left and right side walls of the model box 1. The length and width of the square openings 9 are 2000mm and 1500mm, respectively. A removable mounting plate 10 is installed in each square opening 9. The mounting plate 10 is made of a transparent material, such as a plexiglass plate. The length, width, and height of the mounting plate 10 are 2600mm × 2100mm × 30mm, respectively. The mounting plate 10 can be installed on the inner wall of the model box 1 with bolts.

[0036] The mounting plate 10 is pre-formed with mounting notches 11 for mounting the tunnel models 2. The number of mounting notches 11 is the same as the number of tunnel models 2, and the cross-section of the mounting notches 11 matches the cross-sectional profile of the tunnel models 2. At least one set of tunnel models 2 is mounted in the mounting notches 11.

[0037] According to experimental requirements, multiple mounting notches 11 can be provided on the mounting plate 10, and the cross-sections of the mounting notches 11 can be set to different shapes, that is, multiple sets of tunnel models 2 with different cross-sections can be installed on the mounting plate 10, which can simulate various cross-sectional types, the dynamic response of the tunnel structure and surrounding rock of multiple tunnels under the load caused by a moving vehicle.

[0038] exist Figure 3 In the figure, the mounting plate 10 can be provided with two left and right mounting notches 11, or two upper and lower mounting notches 11. The cross-section of the mounting notch 11 can be a rectangular structure or a tunnel arch structure. The mounting plate 10 and the mounting notch 11 can be flexibly manufactured according to experimental requirements.

[0039] exist Figure 4 In the figure, two left and right mounting notches 11 are provided on the mounting plate 10 , and correspondingly, two left and right parallel tunnel models 2 are mounted on the mounting plate 10 .

[0040] Currently, the model boxes 1 used in tunnel-related experimental research are mostly made of welded steel plates. According to the test requirements, openings are cut on the side of the box to accommodate the tunnel model 2. If the size and shape of the tunnel section need to be changed in later tests or the mutual influence between multiple tunnels is considered, the box needs to be modified, which is expensive and difficult to implement.

[0041] In this embodiment, a square opening 9 is provided on the model box 1 to facilitate installation of tunnel models 2 of different numbers and specifications through the mounting plate 10, so as to facilitate the study of the propagation law of train moving load in a single-track or multiple tunnels in subsequent tests.

[0042] The model box 1 is filled with test soil; both ends of the tunnel model 2 pass through the side walls of the model box 1; a track bed 3 is arranged in the tunnel model 2 along its length, and two track models 4 are arranged on the track bed 3 at intervals along its length.

[0043] A reaction frame 5 is provided on the model box 1, and the reaction frame 5 includes the same number of mounting beams 501 as the number of tunnel models 2. Each mounting beam 501 matches a group of tunnel models 2, and each mounting beam 501 passes through the tunnel model 2. The mounting beams 501 are located above the two track models 4.

[0044] The loading system includes a plurality of electromagnetic exciters 6 ; the monitoring system includes a plurality of dynamic force sensors 7 , and the electromagnetic exciters 6 and the dynamic force sensors 7 are in a one-to-one matching relationship.

[0045] The lower end face of the mounting beam 501 is provided with a plurality of electromagnetic exciters 6 along its length direction. The tail end of each electromagnetic exciter 6 is fixedly connected to the lower end face of the mounting beam 501. A dynamic force sensor 7 is provided on the top rod of the electromagnetic exciter 6. The lower end face of the dynamic force sensor 7 is provided with a distribution beam 8 that contacts the upper end faces of the two track models 4.

[0046] The load excitation curve of each electromagnetic exciter 6 is the same, and the excitation time interval between two adjacent electromagnetic exciters 6 is Δt:

[0047]

[0048] Among them, v is the train speed, Δs is the spacing between sleepers, the number and placement of electromagnetic exciters 6 can be adjusted according to experimental requirements, and there is an interval between the start excitation time of each electromagnetic exciter 6 along the direction of train travel. Each electromagnetic exciter 6 is excited in turn according to the excitation time interval, which can realize the simulation of the moving train load.

[0049] Multiple electromagnetic exciters 6 are placed in the tunnel model 2 through the mounting beam 501 on the reaction frame 5. The distribution beam 8 fixed on the top rod of the electromagnetic exciter 6 accurately applies the train load to the track. The excitation time difference Δt of each exciter is used to simulate the movement effect of the train. The dynamic response of the tunnel model 2 and the test soil is monitored in real time through the monitoring system to study the propagation and attenuation laws of the vibration waves generated by the train operation in different directions in the tunnel structure and the surrounding soil layer, the impact of the vibration load generated by trains of different models and speeds on the tunnel structure and the surrounding soil layer, and the propagation law of the train moving load in a single track or multiple tunnels.

[0050] Example 2

[0051] like Figures 1 and 2 As shown, this embodiment makes further limitations on the basis of embodiment 1. The specific improvement lies in how to specifically set the reaction frame 5, the loading system and the monitoring system. For the remaining parts not mentioned, please refer to embodiment 1.

[0052] As a specific embodiment of the reaction frame 5, the reaction frame 5 also includes two slide rails 502, and the two slide rails 502 are arranged on the front and rear side walls or the top of the left and right side walls of the model box 1; multiple groups of support arms 503 are vertically arranged on the two slide rails 502, and the number of groups of support arms 503 is the same as the number of mounting beams 501, each group of support arms 503 includes two support arms 503, and the top of each group of support arms 503 is slidably connected to the slide rails 502; a mounting beam 501 is arranged between the bottoms of each group of support arms 503.

[0053] The setting of multiple groups of support arms 503 can install multiple mounting beams 501 on a reaction frame 5. Multiple mounting beams 501 can realize dynamic response testing of multiple groups of tunnel models 2 at the same time, simulate the dynamic response test of multiple-line tunnels in reality, and improve test efficiency.

[0054] Each set of support arms 503 can move along the length direction of the two slide rails 502, and then adjust the position of the mounting beam 501 at the bottom of each set of support arms 503 to adjust the positions of multiple electromagnetic exciters 6 and distribution beams 8 on the mounting beam 501. During the dynamic response test, the position of each set of support arms 503 can be adjusted so that the multiple electromagnetic exciters 6 and distribution beams 8 on the mounting beam 501 cover the upper end surfaces of the two track models 4, thereby improving the test accuracy.

[0055] A slide groove 12 for matching with the slide rail 502 is provided on the top of each support arm 503 , and a locking bolt 13 is provided on the top of each support arm 503 . The locking bolt 13 passes through the slide groove 12 and is in tight contact with the slide rail 502 .

[0056] After the support arm 503 is adjusted to the preset position, multiple electromagnetic exciters 6 and distribution beams 8 on the mounting beam 501 cover the upper end surfaces of the two track models 4, and the locking bolts 13 are tightened to lock and fix the current position of the support arm 503. During the dynamic response test, the support arm 503 and the mounting beam 501 at the bottom of the support arm 503 can be prevented from moving in the horizontal position.

[0057] Each support arm 503 includes a first support arm 5031 and a second support arm 5032, the first support arm 5031 is located above the second support arm 5032; the second support arm 5032 is a hollow columnar structure, the bottom of the first support arm 5031 is movably arranged inside the second support arm 5032, and a slide groove 12 is provided at the top of the first support arm 5031; a mounting beam 501 is fixedly connected between the bottoms of the two second support arms 5032; a fixing bolt 14 is provided on the outer wall of each second support arm 5032, and the fixing bolt 14 passes through the outer wall of the second support arm 5032 and is in tight contact with the first support arm 5031. By adjusting the relative position between the first support arm 5031 and the second support arm 5032, the height position of the mounting beam 501 can be adjusted to accommodate tunnel models 2 of different sizes and shapes. The relative position between the first support arm 5031 and the second support arm 5032 is fixed by fixing bolts 14. During dynamic response testing, the vertical movement of the mounting beam 501 at the bottom of the support arm 503 can be avoided.

[0058] As a specific setting mode of the loading system and the monitoring system, the loading system further includes a computer, a signal generator and a power amplifier electrically connected to the plurality of electromagnetic exciters 6, and the computer, the signal generator and the power amplifier are arranged outside the model box 1;

[0059] The monitoring system also includes multiple acceleration sensors, multiple dynamic strain sensors, and a signal acquisition device electrically connected to multiple dynamic force sensors 7. The signal acquisition device is electrically connected to a computer. Multiple acceleration sensors are installed at different depths in the test soil, and multiple dynamic strain sensors are installed on the tunnel model 2 to monitor the dynamic response of the tunnel model 2 and the test soil surrounding it. The computer loads the train load time history curve required for the test into a signal generator and power amplifier. A distribution beam 8 fixed to the top rod of the electromagnetic exciter 6 precisely applies the train load to the track. The excitation time difference Δt between the exciters is used to simulate the effect of train movement. The signal acquisition instrument collects the test data of the dynamic force sensor 7, acceleration sensor, and dynamic strain sensor buried in the tunnel structure and test soil and transmits them to the computer. Compared with the model test in the prior art, the present invention fully considers the movement effect of the moving train. By inputting the train load time curve required for the test into the computer and combining the excitation time difference of each exciter, the accurate simulation of the train moving load can be achieved, and the dynamic response of the tunnel structure and the surrounding soil layer can be dynamically monitored in real time through the monitoring system.

Claims

1. A dynamic response testing system for tunnel structure and surrounding rock, characterized in that: Including model box, loading system and monitoring system; The model box is filled with test soil; at least one set of tunnel models is arranged in the model box, and both ends of the tunnel models pass through the side wall of the model box; a roadbed is arranged in the tunnel model along its length, and two track models are arranged on the roadbed along its length at intervals; A reaction frame is provided on the model box, and the reaction frame includes mounting beams having the same number as the number of tunnel models, each mounting beam matches a set of tunnel models, each mounting beam passes through the tunnel model, and the mounting beam is located above the two track models; The loading system includes a plurality of electromagnetic exciters; the monitoring system includes a plurality of dynamic force sensors, and the electromagnetic exciters and the dynamic force sensors are in a one-to-one matching relationship; The lower end surface of the mounting beam is provided with a plurality of the electromagnetic exciters along its length direction, the tail end of each electromagnetic exciter is fixedly connected to the lower end surface of the mounting beam, the top rod of each electromagnetic exciter is provided with a dynamic force sensor, and the lower end surface of the dynamic force sensor is provided with a distribution beam in contact with the upper end surfaces of the two track models; The reaction frame also includes two slide rails, and the two slide rails are arranged on the front and rear side walls or the top of the left and right side walls of the model box; multiple groups of support arms are vertically arranged on the two slide rails, and the number of groups of support arms is the same as the number of mounting beams, each group of support arms includes two support arms, and the top of each group of support arms is slidably connected to the slide rails; a mounting beam is provided between the bottoms of each group of support arms; The top of each support arm is provided with a slide groove for matching with the slide rail, and the top of each support arm is provided with a locking bolt, and the locking bolt passes through the slide groove and is in tight contact with the slide rail; Each of the support arms includes a first support arm and a second support arm, the first support arm is located above the second support arm; the second support arm is a hollow columnar structure, the bottom of the first support arm is movably arranged inside the second support arm, and the top of the first support arm is provided with the slide groove; the bottoms of the two second support arms are fixedly connected with a mounting beam; the outer wall of each second support arm is provided with a fixing bolt, and the fixing bolt passes through the outer wall of the second support arm and is in tight contact with the first arm.

2. The tunnel structure and surrounding rock dynamic response testing system according to claim 1, characterized in that: The model box has a cubic structure with an open top, and square openings are provided on the front and rear side walls or the left and right side walls of the model box. A mounting plate can be removably installed in each of the square openings. The mounting plate is made of a transparent material, and mounting notches are provided on the mounting plate for installing the tunnel model. The number of the mounting notches is the same as the number of tunnel models, and the cross-section of the mounting notches matches the cross-sectional profile of the tunnel model.

3. The dynamic response testing system for tunnel structure and surrounding rock according to claim 1, characterized in that: The loading system further comprises a computer, a signal generator and a power amplifier electrically connected to the plurality of electromagnetic vibrators, wherein the computer, the signal generator and the power amplifier are arranged outside the model box; The monitoring system also includes multiple acceleration sensors, multiple dynamic strain sensors and a signal acquisition device electrically connected to the multiple dynamic force sensors, and the signal acquisition device is electrically connected to the computer; the multiple acceleration sensors are set in the test soil at different depths, and the multiple dynamic strain sensors are set on the tunnel model.

4. The tunnel structure and surrounding rock dynamic response testing system according to claim 3, characterized in that: The load excitation curve of each electromagnetic exciter is the same, and the excitation time interval between two adjacent electromagnetic exciters is Δ t : in, v is the train speed, Δ s is the spacing between sleepers.

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