Dynamic monitoring system for subway ballast bed stripping model test

Abstract

The utility model discloses a dynamic monitoring system for a subway ballast bed stripping model test. The dynamic monitoring system comprises an exciting force measuring device, a contact surface tension measuring device, a displacement measuring device and a strain measuring device, and the exciting force measuring device measures exciting force through a vibration exciter and a tension and pressure sensor. The contact surface tension measuring device realizes tension measurement of a track bed-segment contact surface position through a cross beam type mechanical force measuring device and a fixed steel wire. The displacement measurement device achieves displacement measurement of a duct piece structure, displacement measurement of a ballast bed structure and ballast bed stripping deformation measurement through a springback type differential variable pressure displacement sensor, a duct piece displacement measurement platform and a ballast bed displacement measurement platform. The strain measurement device achieves ballast bed-duct piece contact surface strain measurement through strain gauges arranged on the duct piece structure. According to the utility model, the dynamic monitoring of various data in the ballast bed stripping model test can be realized, and effective data support can be provided for the mechanism research of ballast bed stripping diseases.

Description

Technical Field

[0001] The utility model relates to a dynamic monitoring system for a subway roadbed stripping model test, which is mainly used for dynamic monitoring in a subway tunnel model test. Background Art

[0002] Under the long-term effects of train loads, the roadbed structure and shield segments of subway tunnels lose their tight connection, resulting in cracks. Over time, these cracks gradually expand, leading to debonding between the roadbed and segments, compromising train safety. To address this issue, research into the mechanisms of roadbed debonding is necessary. Currently, monitoring of roadbed debonding is performed by entering the tunnel during tunnel opening hours. Manual measurements, such as core sampling and crack width measurement with thickness gauges, are used to assess the debonding's development and distribution. However, personnel are prohibited from entering subway sections during operation, making real-time dynamic monitoring of the debonding impossible. Debonding typically develops under the repeated effects of train dynamic loads, so data collected during tunnel opening hours cannot reflect the most adverse conditions. Only data measured during train passages can best reflect the true debonding condition. Given the hidden location of roadbed debonding, on-site research is not possible to ensure safe subway operations. Therefore, model testing is needed to investigate the debonding mechanism. Model testing is an effective method for studying the mechanisms of engineering problems. By scaling the main features of real engineering problems to appropriate proportions and conducting research, the authenticity of the test results can be guaranteed.

[0003] Since subway roadbed stripping disease is a problem that has begun to appear in recent years, there is currently little research on model tests of stripping disease, and research on dynamic monitoring systems in model tests is even more insufficient, which cannot effectively provide data support for mechanism research. Utility Model Content

[0004] The purpose of the utility model is to provide a dynamic monitoring system for a subway roadbed stripping model test, by which dynamic monitoring of various data in the roadbed stripping model test can be achieved.

[0005] The utility model is realized through the following technical solutions: a dynamic monitoring system for subway track bed peeling model test, the test model includes a pipe segment structure and a track bed structure made according to a similarity ratio, and the track bed structure is fixed on the pipe segment structure, and its characteristics are: the dynamic monitoring system includes an exciting force measuring device, a contact surface tension measuring device, a displacement measuring device, and a strain measuring device, the exciting force measuring device includes an exciter, a first reaction force bracket, and a tension and pressure sensor, the first reaction force bracket is a door structure, the horizontal section of the first reaction force bracket is parallel to the axis of the pipe segment structure and passes through the pipe segment structure, and the two columns of the first reaction force bracket are parallel to the axis of the pipe segment structure and pass through the pipe segment structure. The vibrator is fixed on the outside of the test model, the vibrator is fixed on the lower part of the horizontal section of the first reaction support, the tension and pressure sensor is fixed on the lower end of the vibrator, and the tension and pressure sensor is in contact with the surface of the roadbed structure. The contact surface tension measuring device includes a crossbeam mechanical force measuring device, a pipe segment pre-embedded point, and a fixed steel wire. The crossbeam mechanical force measuring device includes a crossbeam, a pressure sensor connected to the lower part of both ends of the crossbeam, and an adjustable screw threaded on the crossbeam. The crossbeam mechanical force measuring device is fixed on the surface of the roadbed structure. The pipe segment pre-embedded point corresponds to the crossbeam mechanical force measuring device pre-embedded on the outer wall of the pipe segment structure. One end of the fixed steel wire is connected to the pipe segment pre-embedded point. The other end of the fixed steel wire passes through the ballast structure and is fixedly connected with the adjustable screw of the beam-type mechanical force measuring device. The displacement measuring device includes a rebound differential transformer displacement sensor, a segment displacement measuring platform, and a ballast displacement measuring platform. The segment displacement measuring platform and the ballast displacement measuring platform are respectively arranged on both sides of the ballast structure. A first fixing rod is fixed to the bottom of the ballast displacement measuring platform, and the lower end of the first fixing rod is fixed inside the ballast structure. The rebound differential transformer displacement sensor is correspondingly arranged on the upper part of the ballast displacement measuring platform, which is fixed on the second reaction bracket. The bottom of the segment displacement measuring platform is fixed. A second fixing rod is provided, the lower end of which is fixed inside the segment structure after passing through the through hole on the roadbed structure. The rebound differential transformer displacement sensor is also provided correspondingly on the upper part of the segment displacement measurement platform, which is fixed on the third reaction support. The second reaction support and the third reaction support are both door-type structures. The horizontal sections of the second reaction support and the third reaction support are parallel to the axis of the segment structure and pass through the segment structure. The columns of the second reaction support and the third reaction support are fixed on the outside of the test model. The strain measurement device includes a plurality of strain gauges, which are arranged on the inner wall of the segment structure along the circumferential direction of the segment structure.

[0006] In the present invention, the exciter in the exciting force measuring device can simulate the effect of the vibration load of the subway train by generating the exciting force, and the exciting force of the exciter can be monitored in real time by the tension and pressure sensor arranged at the lower end of the exciter; in the contact surface tension measuring device, one end of the fixed steel wire is connected to the pre-buried point of the pipe segment, and the other end is connected to the adjustable screw of the beam-type mechanical force measuring device fixed on the roadbed structure, that is, the roadbed structure and the pipe segment structure are connected by the steel wire, so the tensile stress can be transmitted through the steel wire, and the roadbed-pipe segment structure contact is realized by the pressure sensor of the beam-type mechanical force measuring device. Measurement of surface position tension; in the displacement measuring device, the segment displacement measuring platform and the roadbed displacement measuring platform are connected to the segment structure and the roadbed structure respectively through fixed rods, and the probes of the corresponding rebound differential transformer displacement sensor can be in contact with the segment displacement measuring platform and the roadbed displacement measuring platform respectively. The displacement of the segment structure and the roadbed structure can be measured respectively through the corresponding rebound differential transformer displacement sensor, and the roadbed peeling deformation can be obtained by calculating the displacement deformation difference between the roadbed structure and the segment structure; in the strain measuring device, the strain of the roadbed-segment contact surface is measured by a strain gauge.

[0007] Furthermore, three rows of the beam-type mechanical force measuring devices are arranged on the surface of the roadbed structure near the expansion joint, and each row is provided with 5 beam-type mechanical force measuring devices.

[0008] Furthermore, the first fixing rod is fixed at a position 10 mm inside the track bed structure; and the second fixing rod is fixed at a position 10 mm inside the segment structure.

[0009] Furthermore, three rows of the displacement measuring devices are arranged on the surface of the track bed structure near the expansion joint.

[0010] The beneficial effects of the present invention are as follows: at present, there are few studies on the model test of roadbed stripping disease, among which there is no monitoring system for the model test of roadbed stripping. The present invention proposes a dynamic monitoring system for subway roadbed stripping model test for the first time, which can realize the dynamic monitoring of various data in the roadbed stripping model test, and provide effective data support for the study of the mechanism of roadbed stripping disease; since the location of roadbed stripping is hidden, the stripping is located at the contact surface between the roadbed and the pipe segment structure, and conventional methods cannot be directly measured, the stripping location of the model test is more hidden, and the measurement is more difficult. To address the problem, the utility model utilizes a specially designed segment displacement measuring platform and a roadbed displacement measuring platform and a rebound differential transformer displacement sensor to realize dynamic measurement of roadbed displacement and segment displacement, based on which the stripping amount can be calculated, thus solving the problem that the roadbed stripping amount is difficult to measure in the prior art; the utility model adopts a beam-type force measuring device and uses a fixed steel wire to connect the segment structure and the adjustable screw of the beam-type force measuring device to realize dynamic measurement of the tension at the contact surface of the roadbed-segment structure in the model test, which facilitates comprehensive analysis of the stress conditions and provides data support for the analysis of the disease mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the three-dimensional structure of the monitoring system used for the subway roadbed stripping model test in the present utility model;

[0012] Figure 2 It is a cross-sectional schematic diagram of the monitoring system used for subway roadbed stripping model test in the present utility model;

[0013] Figure 3 It is a cross-sectional schematic diagram of the monitoring system used for subway roadbed stripping model test in the present utility model;

[0014] Figure 4 yes Figure 3 An enlarged schematic diagram of the lower middle part;

[0015] Figure 5 This is a schematic diagram of the main view of the beam-type mechanical force measuring device in the present invention;

[0016] Figure 6 1 is a top view of the beam-type mechanical force measuring device in the present invention (the adjustable screw is not shown);

[0017] Figure 7 This is a schematic diagram of the connection between the contact surface tension measuring device and the segment structure in the present invention;

[0018] Figure 8 It is a schematic diagram of the arrangement of the contact surface tension measuring device and the displacement measuring device in a specific embodiment of the present utility model;

[0019] 1, segment structure, 2, first counterforce support, 3, second counterforce support, 4, third counterforce support, 5, track bed structure, 6, exciter, 7, tension and compression force sensor, 8, contact surface tension measuring device, 9, expansion joint, 10, displacement measuring device, 11, strain gauge;

[0020] 8.1, beam type mechanical force measuring device, 8.2, segment pre-buried point, 8.3, fixed steel wire;

[0021] 8.1.1, beam, 8.1.2, adjustable screw rod, 8.1.3, pressure sensor;

[0022] 10.1, first rebound type differential variable displacement sensor, 10.2, track bed displacement measuring platform, 10.3, first fixed rod, 10.4, second rebound type differential variable displacement sensor, 10.5, segment displacement measuring platform, 10.6, second fixed rod. DETAILED DESCRIPTION

[0023] The utility model will be further explained by non-restrictive examples and in combination with the drawings:

[0024] As shown in the accompanying drawings, a dynamic monitoring system for subway trackbed stripping model tests is described. The test model comprises a segment structure 1 and a trackbed structure 5, fabricated to a similar ratio. The trackbed structure 5 is fixed to the segment structure 1. The dynamic monitoring system includes an excitation force measurement device, a contact surface tension measurement device 8, a displacement measurement device 10, and a strain measurement device. The excitation force measurement device comprises an exciter 6, a first reaction support 2, and a tension and pressure sensor 7. The first reaction support 2 is a portal structure, with its horizontal section parallel to the axis of the segment structure and extending through it. The two uprights of the first reaction support 2 are fixed to the outside of the test model. The exciter 6 is fixed to the lower portion of the horizontal section of the first reaction support 2, and the tension and pressure sensor 7 is fixed to the lower end of the exciter 6. In the unloaded state, the tension and pressure sensor 7 must be in direct contact with the trackbed surface. Both the exciter 6 and the tension and pressure sensor 7 are conventional. The exciter 6 is selected based on its structural dimensions and the range of the excitation force. The contact surface tension measuring device 8 comprises a crossbeam-type mechanical force measuring device 8.1, pre-embedded segments 8.2, and a fixed steel wire 8.3. The crossbeam-type mechanical force measuring device 8.1 comprises a crossbeam 8.1.1, pressure sensors 8.1.3 connected to the lower ends of the crossbeam 8.1.1, and an adjustable screw 8.1.2 threadedly connected to the middle of the crossbeam. The crossbeam-type mechanical force measuring device 8.1 is fixed to the surface of the ballast structure 5, with the pre-embedded segments 8.2 corresponding to the crossbeam-type mechanical force measuring device 8.1 pre-embedded on the outer wall of the segment structure 1. One end of the fixed steel wire 8.3 is fixedly connected to the pre-embedded segments 8.2, while the other end of the fixed steel wire 8.3 passes through the ballast structure and is fixedly connected to the adjustable screw 8.1.2 of the crossbeam-type mechanical force measuring device. Thus, the ballast structure 5 and the segment structure 1 are connected via the fixed steel wire 8.3, allowing tensile stress to be transmitted through the fixed steel wire 8.3, thereby enabling measurement of tension at the ballast-segment structure contact surface. Pressure sensors 8.1.3 are conventional. Segment embedded points 8.2 are embedded according to test requirements. Preferably, three rows of beam-type mechanical force measuring devices 8.1 are arranged on the surface of the track structure near the expansion joint, with each row containing five beam-type mechanical force measuring devices. Segment embedded points 8.2 are correspondingly located on the segment structure 1.The displacement measuring device 10 includes a track bed displacement measuring device and a segment displacement measuring device. The track bed displacement measuring device includes a first rebound differential transformer displacement sensor 10.1 and a track bed displacement measuring platform 10.2. The segment displacement measuring device includes a second rebound differential transformer displacement sensor 10.4 and a segment displacement measuring platform 10.5. The segment displacement measuring platform 10.5 and the track bed displacement measuring platform 10.2 are respectively arranged on both sides of the track bed structure 5. A first fixing rod 10.3 is fixed to the bottom of the track bed displacement measuring platform 10.2. The lower end of fixed rod 10.3 is fixed within the trackbed structure 5. A first rebound-type differential transformer displacement sensor 10.1 is mounted on the upper portion of trackbed displacement measurement platform 10.2 and fixed to the second reaction support 3. A second fixed rod 10.6 is fixed to the bottom of segment displacement measurement platform 10.5. The lower end of second fixed rod 10.6 passes through a through-hole in trackbed structure 5 and is fixed within the segment structure 5. A second rebound-type differential transformer displacement sensor 10.4 is mounted on the upper portion of segment displacement measurement platform 10.5 and fixed to the third reaction support 4. Both second and third reaction supports 3 and 4 are portal structures. The horizontal sections of both are parallel to the axis of the segment structure and extend through it. The columns of both second and third reaction supports 3 and 4 are fixed to the outside of the test model. The trackbed displacement measurement platform 10.2 and the segment displacement measurement platform 10.5 are used to contact the probes of the first rebound differential transformer displacement sensor 10.1 and the second rebound differential transformer displacement sensor 10.4, respectively. The model of the rebound differential transformer displacement sensor is determined based on the specific dimensions of the model test, and the measuring range and measurement accuracy can be selected based on the structural dimensions. Rebound differential transformer displacement sensors are conventional technology. The first rebound differential transformer displacement sensor 10.1 and the second rebound differential transformer displacement sensor 10.4 can respectively measure the displacement of the segment structure and the trackbed structure. Trackbed debonding deformation is measured by calculating the difference in displacement between the trackbed and segment. To ensure the reliability of the test data, it is preferred that the first fixing rod 10.3 be fixed 10 mm inside the trackbed structure, and the second fixing rod 10.6 be fixed 10 mm inside the segment structure. The layout of the displacement measuring device 10 is determined according to the test requirements. Preferably, three rows of displacement measuring devices are deployed on the surface of the trackbed structure near the expansion joint. The strain measuring device includes multiple strain gauges 11, arranged circumferentially along the inner wall of the segment structure. These strain gauges 11 are conventional technology. After each measuring device is deployed, data cables are connected to the corresponding sensors, which are then connected to a data acquisition device. Finally, an external computer is connected to synchronize data from multiple sensor groups using dedicated software.

[0025] In the present invention, the exciter 6 in the excitation force measuring device can simulate the effect of the vibration load of the subway train by generating the excitation force, and the excitation force of the exciter can be measured by the tension and pressure sensor 7 arranged at the lower end of the exciter 6; in the contact surface tension measuring device, one end of the fixed steel wire 8.3 is connected to the pre-buried point 8.2 of the pipe segment, and the other end is connected to the adjustable screw of the beam-type mechanical force measuring device fixed on the roadbed structure, so that the tensile stress can be transmitted through the steel wire, and the measurement of the tension at the contact surface of the roadbed-pipe segment structure is realized by the pressure sensor of the beam-type mechanical force measuring device; In the displacement measurement device, the segment displacement measurement platform 10.5 and the track bed displacement measurement platform 10.2 are connected to the segment structure and the track bed structure respectively through fixed rods. The probes of the corresponding rebound differential transformer displacement sensors can contact the segment displacement measurement platform and the track bed displacement measurement platform respectively. The displacement of the segment structure and the track bed structure can be measured respectively through the corresponding rebound differential transformer displacement sensors. Based on this, the track bed peeling deformation can be obtained by calculating the difference in displacement deformation between the track bed structure and the segment structure. In the strain measurement device, the strain of the track bed-segment contact surface can be measured by strain gauges.

[0026] The present invention is described in detail below through specific embodiments:

[0027] Example:

[0028] The model test was conducted using a 10:1 similarity ratio. The test setup corresponded to a 30m long on-site tunnel, comprising 20 rings of segments, two 12m track beds, and two 3m track beds. The subway tunnel has an inner diameter of 5.4m and an outer diameter of 6.0m. The segments are 1.5m wide and 0.3m thick. A complete track bed section is 12m long and 2.8m wide. The excitation force applied by a conventional subway train is 105kN.

[0029] 1. Based on a geometric similarity ratio of 10:1, determine the dimensions of each model component. In the model, the segments have an inner diameter of 540mm, an outer diameter of 600mm, a thickness of 30mm, and a width of 150mm, for a total of 30 segments. The 1# and 4# trackbeds at the ends are 300mm long, while the 2# and 3# trackbeds in the middle are 1200mm long and 280mm wide, for a total of four trackbeds.

[0030] 2. Based on the similarity ratio, the excitation force in the model test was 105N, and the inner diameter of the subway tunnel segment was 540mm. Based on this, the specific parameters of the vibrator, including its dimensions and amplitude, were determined as follows: the vibrator model is SA-JZ020, providing a maximum excitation force of 200N, a maximum amplitude of 10mm, a loading frequency range of 0-4000Hz, a deadweight of 19kg, and a cylindrical shape measuring φ180mm x 245mm. The tension and compression sensors selected were: model SACL201LX, a piezoelectric sensor with a range of 0-200N and an error control range of less than 1%. The tension and compression sensors were installed at the bottom of the vibrator to transmit the vibrator load data in real time.

[0031] 3. Excitation force measurement: The vibrator 6 is positioned on the horizontal section of the first reaction support 2. The position of the vibrator 6 is adjusted to ensure that the center of the vibrator 6 coincides with the center of the first reaction support 2. The tension and pressure sensor 7 is fixed to the lower end of the vibrator 6. In the unloaded state, the tension and pressure sensor 7 should be ensured to be in direct contact with the surface of the track bed structure. The excitation force is measured by the tension and pressure sensor 7.

[0032] 4. Contact surface tension measurement: It is achieved through the contact surface tension measuring device, and the tension measurement is completed through the combination of pressure sensor and beam structure.

[0033] 4.1 The pressure sensor adopts a high-precision miniature resistance strain sensor with a measuring range of 0-5kg and an accuracy of 0.1%. It outputs the tension and pressure values ​​through the matching acquisition card and acquisition software.

[0034] 4.2 Pre-embedded points 8.2 are installed on the segment structure as required, and corresponding beam-type mechanical force measuring devices 8.1 are fixed on the surface of the track structure. The pre-embedded points 8.2 and the corresponding adjustable screws 8.1.2 of the beam-type mechanical force measuring devices 8.1 are connected by fixing wires 8.3. In this embodiment, three rows of beam-type mechanical force measuring devices 8.1 are arranged within 150mm of the 2# track bed near the expansion joint, with 5 measuring points in each row, as shown in the attached figure. Figure 8 As shown, the track bed structure and the segment structure are connected by the fixing wire 8.3, so the tensile stress can be transmitted through the fixing wire to achieve the measurement of the tensile force at the contact surface between the track bed and the segment structure.

[0035] 5. Displacement measurement:

[0036] 5.1 The Milong LVDT20-V1-5MM rebound differential transformer displacement sensor (LVDT) has a measurement range of 0-5mm and an accuracy of 1μm. The sensor is integrated into a 6005 data acquisition card via a transmission line and then connected to an external computer. Dedicated software then synchronously collects data from multiple sensors at a frequency of up to 10Hz.

[0037] 5.2 LVDT sensors are respectively arranged on both sides of the track bed structure and fixed on the corresponding reaction force brackets; a track bed displacement measurement platform is set up, the upper end of the first fixed rod is fixedly connected to the track bed displacement measurement platform, and the lower end of the first fixed rod is fixed at a position 10mm inside the track bed structure, forming an integral part with the track bed structure; a pipe segment displacement measurement platform is set up, the upper end of the second fixed rod is fixedly connected to the pipe segment displacement measurement platform, and the lower end of the second fixed rod is fixed at a position 10mm inside the pipe segment structure, forming an integral part with the pipe segment structure, and the second fixed rod passes through the through hole drilled on the track bed structure, and the diameter of the through hole drilled on the track bed structure should be larger than the diameter of the second fixed rod. The probe of the LVDT sensor should be in contact with the corresponding track bed displacement measurement platform and the pipe segment displacement measurement platform. In this embodiment, three rows of the displacement measuring devices are arranged on the surface of the track bed structure near the expansion joint, as shown in the attached figure. Figure 8 shown.

[0038] 6. Strain measurement:

[0039] Strain gauges are laid out along the circumference of the segment structure, mainly at the first ring of the 2# track bed. The strain gauges are distributed as shown in the attached figure. Figure 2 Medium 1-1 to 1-10.

[0040] 7. After the exciting force measuring device, contact surface tension measuring device, displacement measuring device, and strain measuring device are laid out, each device is connected to a data cable, which is then connected to the corresponding acquisition device and an external computer. By collecting data through the corresponding measurement software, the exciting force, trackbed-segment contact surface tension, displacement (trackbed displacement, segment displacement, peeling deformation), and trackbed-segment contact surface strain can be dynamically measured.

[0041] The other parts of this embodiment are all existing technologies and will not be described in detail here.

Claims

1. A dynamic monitoring system for a subway trackbed stripping model test, wherein the test model comprises a segment structure and a trackbed structure manufactured in a similar ratio, wherein the trackbed structure is fixed to the segment structure, and wherein: The dynamic monitoring system includes an exciting force measuring device, a contact surface tension measuring device, a displacement measuring device, and a strain measuring device. The exciting force measuring device includes a vibrator, a first reaction force bracket, and a tension and pressure sensor. The first reaction force bracket is a door-type structure. The horizontal section of the first reaction force bracket is parallel to the axis of the segment structure and passes through the segment structure. The two columns of the first reaction force bracket are fixed to the outside of the test model. The vibrator is fixed to the lower part of the horizontal section of the first reaction force bracket. The tension and pressure sensor is fixed to the lower end of the vibrator. The tension and pressure sensor is in contact with the surface of the track bed structure. The contact surface tension measuring device includes a crossbeam mechanical force measuring device, a pipe segment pre-embedded point, and a fixed steel wire. The crossbeam mechanical force measuring device includes a crossbeam, a pressure sensor connected to the lower part of both ends of the crossbeam, and an adjustable screw threaded on the crossbeam. The crossbeam mechanical force measuring device is fixed on the surface of the roadbed structure. The pipe segment pre-embedded point corresponds to the crossbeam mechanical force measuring device pre-embedded on the outer wall of the pipe segment structure. One end of the fixed steel wire is fixedly connected to the pipe segment pre-embedded point, and the other end of the fixed steel wire passes through the roadbed structure and is fixedly connected to the adjustable screw of the crossbeam mechanical force measuring device. The displacement measuring device includes a rebound differential transformer displacement sensor, a segment displacement measuring platform, and a track bed displacement measuring platform. The segment displacement measuring platform and the track bed displacement measuring platform are respectively arranged on both sides of the track bed structure. A first fixing rod is fixed to the bottom of the track bed displacement measuring platform, and the lower end of the first fixing rod is fixed inside the track bed structure. The upper part of the track bed displacement measuring platform is correspondingly provided with the rebound differential transformer displacement sensor, which is fixed on the second reaction force bracket. The bottom of the segment displacement measuring platform is fixed with a second fixing rod, and the lower end of the second fixing rod passes through the through hole on the track bed structure and is fixed inside the segment structure. The upper part of the segment displacement measuring platform is also correspondingly provided with the rebound differential transformer displacement sensor, which is fixed on the third reaction force bracket. The second reaction force bracket and the third reaction force bracket are both gate structures. The horizontal sections of the second reaction force bracket and the third reaction force bracket are both parallel to the axis of the segment structure and pass through the segment structure. The columns of the second reaction force bracket and the third reaction force bracket are both fixed on the outside of the test model. The strain measuring device includes a plurality of strain gauges, which are arranged on the inner wall of the segment structure along the circumferential direction of the segment structure.

2. The dynamic monitoring system for subway roadbed stripping model test according to claim 1 is characterized by: Three rows of the beam-type mechanical force measuring devices are arranged on the surface of the roadbed structure near the expansion joint, and each row is provided with 5 beam-type mechanical force measuring devices.

3. The dynamic monitoring system for subway roadbed stripping model test according to claim 2 is characterized by: The first fixing rod is fixed at a position 10 mm inside the trackbed structure; the second fixing rod is fixed at a position 10 mm inside the segment structure.

4. The dynamic monitoring system for subway roadbed stripping model test according to claim 3 is characterized by: Three rows of displacement measuring devices are arranged on the surface of the track bed structure near the expansion joint.

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