A simplified device and experimental method for simulating the influence of supporting trolleys in overlapping tunnels

Abstract

The present invention discloses a simplified device and experimental method for simulating the influence of a support trolley in an overlapping tunnel, comprising: a model box; a newly built tunnel model, the newly built tunnel model is horizontally mounted in the model box; an existing tunnel model, the existing tunnel model is horizontally mounted in the model box and is located below the newly built tunnel model; a support trolley, the support trolley is slidably arranged in the existing tunnel model, the support trolley comprises a plurality of sub-trolleys connected in series, the sub-trolley comprises a plurality of trolley portals connected in series, the spacing between two connected trolley portals is the same as the width of the pipe segment of the existing tunnel model, a plurality of support wheel groups are fixed to the outer wall of the cross section of each trolley portal, and a weight adjustment device is fixed to the inner wall of the cross section of each trolley portal; a power device, the power device is connected to the support trolley; a detection device, the detection device is installed at the monitoring section of the existing tunnel model. It is suitable for simulating overlapping tunnels (a newly built tunnel is passed through above and an existing tunnel is passed through below).

Description

Technical Field

[0001] The present invention belongs to the technical field of shield tunnel model testing, and particularly relates to a simplified device and experimental method for simulating the influence of a support trolley in an overlapping tunnel. The device is suitable for simulating overlapping tunnels (a newly built tunnel above and an existing tunnel below), especially when the excavation of the upper tunnel of the overlapping section will cause the lower tunnel to bulge, and is particularly suitable for studying the anti-floating effect of the support trolley in the existing tunnel. Background Art

[0002] The excavation of the upper shield tunnel in the overlapping section will cause the lower tunnel to bulge and deform, resulting in ground settlement, which seriously affects the use function and safety of the operating tunnel. In order to control the floating deformation of the existing tunnel, a support trolley is often used to reinforce the tunnel in the existing tunnel.

[0003] The method of using a support trolley to control the floating deformation of the existing tunnel in the lower part of the overlapping section has been applied in many projects. Many scholars at home and abroad have also studied the control effect of using a support trolley as a reinforcement method in overlapping tunnels. The main research methods include numerical simulation, field measurement, theoretical analysis and indoor model test. Among them, the numerical simulation method depends to a large extent on the selection of simulation conditions, the accuracy is difficult to control, and the error is often large; the field measurement method directly measures the data in the actual project, and the measurement results are more intuitive and accurate, but there are also disadvantages such as complex stratum shape, complex construction conditions, and difficulty in burying test components. In order to simplify the calculation, the theoretical analysis method will simplify the working conditions in the actual case to a certain extent, which often causes a certain gap between the calculated data and the actual data; the indoor model test method, as an effective research method, can simulate the actual problems of the project indoors on the basis of ensuring a certain degree of accuracy and intuitiveness, saving a lot of manpower and material resources. However, the indoor model test research on the use of a support trolley as a reinforcement method in the existing tunnel under the condition of shield tunneling close-range crossing overlap has not been seen yet, and needs to be further developed.

[0004] At present, the research methods used at home and abroad generally have problems such as difficult to control accuracy, lack of intuitive measurement results, complex research conditions, high cost, time-consuming and labor-intensive. Therefore, it is necessary to develop a model test device for supporting trolleys in overlapping tunnels. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a simplified device and experimental method for simulating the influence of a support trolley in an overlapping tunnel.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a simplified device for simulating the influence of a support trolley in an overlapping tunnel, comprising:

[0008] Model box;

[0009] A new tunnel model is created, wherein the new tunnel model is horizontally mounted in the model box;

[0010] An existing tunnel model, the existing tunnel model being horizontally mounted in the model box and located below the newly-built tunnel model;

[0011] A supporting trolley, wherein the supporting trolley is slidably arranged in the existing tunnel model, the supporting trolley comprises a plurality of sub-trolleys connected in series, the sub-trolley comprises a plurality of trolley gantries connected in series, the spacing between two connected trolley gantries is the same as the width of the pipe segment of the existing tunnel model, a plurality of supporting wheel groups are fixed to the outer wall of the cross section of each trolley gantries, and a weight adjustment device is fixed to the inner wall of the cross section of each trolley gantries;

[0012] A power device, the power device is connected to the supporting trolley;

[0013] A detection device is installed at the monitoring section of the existing tunnel model.

[0014] Furthermore, the newly built tunnel model includes a first inner tube and an annular airbag adhered to the first inner tube, both ends of the first inner tube are close to the side walls of the model box, and the annular airbag is inflated and exhausted through a connected rubber hose.

[0015] Furthermore, the existing tunnel model includes a second inner tube and second port covers installed at both ends of the second inner tube, a roadbed plate is arranged inside the second inner tube, and the supporting trolley is slidably arranged on the roadbed plate.

[0016] Furthermore, the second port cover is provided with a lead-in hole, a receiving hole horizontal to the lead-in hole is provided on the model box, a rubber ring is provided circumferentially inside the receiving hole, the traction end of the power device is connected to one end of the supporting trolley after passing through the receiving hole, the other end of the supporting trolley is connected to a heavy object after passing through the receiving hole on the other side of the model box with a thin wire, and the lead-in hole and the receiving hole are connected by a plastic hose.

[0017] Furthermore, a pull ring is provided on the supporting trolley, and the pull ring is connected to the power device through a connecting piece.

[0018] Furthermore, the power device includes a steel support, a steel strand and a winch, wherein the winch is fixed on the steel support, the steel strand is wound around the winch, and the steel strand is connected to the supporting trolley.

[0019] Furthermore, a tape measure is bonded to the steel strand, and a positioning steel plate is provided on the steel bracket, and the reading of the tape measure is read through the positioning steel plate.

[0020] Furthermore, there are two grooves on the roadbed plate for the support wheel group at the bottom of the support trolley to pass through.

[0021] Furthermore, the detection device includes a displacement meter, an earth pressure box and a strain gauge. The displacement meter is arranged at the bottom of the existing tunnel model, and the displacement meter is fixed inside the displacement meter fixing device. The earth pressure boxes and strain gauges are arranged on the arch top, arch bottom, arch waist and 1 / 4 arch waist outside the tunnel.

[0022] Furthermore, the displacement meter fixing device comprises a retractable steel tube, fixing screws and a base, the retractable steel tube is fixed on the base, and after the displacement meter is placed in the retractable steel tube, it is fixed using the fixing screws.

[0023] In a second aspect, an embodiment of the present invention provides an experimental method of the simplified device for simulating the influence of a support trolley in an overlapping tunnel, comprising the following steps:

[0024] (1) Single group test: Before the test, gas is added to the annular airbag through a rubber hose; during the test, the gas in the annular airbag is discharged through the rubber hose in sequence to simulate the shield tunneling process. The support trolley is pulled to the right by the power device, and the speed and position of the support trolley are controlled by a thin wire to keep the support trolley consistent with the excavation position and speed of the newly built tunnel model above. The exhaust speed of the annular airbag is determined according to the test plan, and the detection device monitors the settlement, deformation and soil pressure data around the existing tunnel model in real time;

[0025] (2) Readjust the weight of the supporting trolley using the weight adjustment device and conduct the next set of tests.

[0026] According to the above technical solution, the beneficial effects of the present invention are:

[0027] 1) It is convenient to simulate the control effect of the supporting trolley on the tunnel floating

[0028] The support trolley is placed on the roadbed plate inside the existing tunnel segment. The two grooves on the roadbed plate allow the two pulleys at the bottom of the support trolley to pass through. The other three pulleys of the support trolley are tightly attached to the inner wall of the existing tunnel segment, supporting the existing tunnel. The support trolley inside the existing tunnel model drives the steel strands through the winch to move along with the excavation of the new tunnel model above, which can simulate the control effect of the support trolley on the floating of the existing tunnel below when the upper tunnel of the overlapping section is excavated.

[0029] 2) It is convenient to simulate the excavation of a new shield tunnel

[0030] The newly built tunnel model consists of a first inner tube and multiple annular airbags pasted on the first inner tube. The two ends of the first inner tube are close to the side walls of the model box. The annular airbags are only in the middle part of the first inner tube, and there are no airbags within a certain distance from the two ends. The width of each annular airbag on the first inner tube is the same as the width of the shield tunnel segment converted by a similarity ratio. The excavation of the shield tunnel is simulated by exhausting the airbags.

[0031] 3) It is convenient to simulate the control effect of supporting trolleys of different weights on tunnel floating

[0032] The support trolley is provided with a hook, on which weights of different weights can be hung, which matches the conversion values ​​of different support trolley weights in actual projects, and is used to simulate the control effect of support trolleys of different weights on tunnel buoyancy.

[0033] 4) Arrange measuring instruments to accurately reflect test results

[0034] A displacement meter is set at the bottom of the existing tunnel model to measure the overall settlement of the tunnel; the soil pressure boxes set in eight directions outside the tunnel can measure the soil pressure distribution in various parts of the tunnel; strain gauges are installed in eight directions on the outer wall of the tunnel to monitor the changes in the bending moment of the existing tunnel model under the influence of the overlapping new tunnel. The three together monitor and measure the deformation of the existing tunnel model, fully reflecting the internal force and deformation of the existing tunnel model during the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 It is a schematic diagram of the overall structure of a simplified device for simulating the influence of a supporting trolley in an overlapping tunnel provided by an embodiment of the present invention;

[0037] Figure 2 is a layout plan of a newly built tunnel model in an embodiment of the present invention;

[0038] Figure 3 It is a schematic diagram of the overall structure of a newly built tunnel model in an embodiment of the present invention;

[0039] Figure 4 is a schematic cross-sectional view of the internal structure of an existing tunnel model according to an embodiment of the present invention;

[0040] Figure 5 2 is a schematic diagram of the overall structure of the supporting trolley device in an embodiment of the present invention;

[0041] Figure 6 is a side schematic diagram of a support trolley in an embodiment of the present invention;

[0042] Figure 7 is a schematic diagram of the longitudinal section of the internal structure of an existing tunnel model in an embodiment of the present invention;

[0043] Figure 8 is a schematic diagram of a displacement meter fixing device in an embodiment of the present invention;

[0044] Explanation of the reference numerals: model box 1; new tunnel model 2; existing tunnel model 3; receiving hole 4; steel strand 5; steel bracket 6; tape measure 7; positioning steel plate 8; fixing device 9; winch 10; first port cover 11; second port cover 11-1; air bag 12; first inner tube 13; second inner tube 13-1; earth pressure box 14; strain gauge 15; hook 16; pulley 17; trolley gantry 18; pull ring 19; displacement meter 20; roadbed plate 21; groove 22; retractable steel pipe 23; fixing screw 24; base 25; lead hole 26; plastic hose 27; supporting trolley 28; rubber hose 29; thin wire 30. DETAILED DESCRIPTION

[0045] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0046] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0047] like Figure 1As shown, an embodiment of the present invention provides a simplified device for simulating the influence of a support trolley in an overlapping tunnel, comprising: a model box 1, a newly built tunnel model 2, an existing tunnel model 3, a support trolley 28, a power device and a detection device, wherein the newly built tunnel model 2 is horizontally mounted in the model box 1; the existing tunnel model 3 is horizontally mounted in the model box 1 and is located below the newly built tunnel model 2; the support trolley 28 is slidably arranged in the existing tunnel model 3, and the support trolley 28 is composed of a plurality of sub-trolleys connected in series, and the sub-trolleys include a plurality of series The trolley gantries 18 are connected, and the spacing between the two connected trolley gantries 18 is the same as the width of the pipe segment of the existing tunnel model 3. A plurality of supporting wheel groups are fixed to the outer wall of the section of each trolley gantry 18, and a weight adjustment device is fixed to the inner wall of the section of each trolley gantry 18, so that the weight of the supporting trolley 28 can be matched with the conversion value of different supporting trolley weights in actual engineering, so as to simulate the control effect of supporting trolleys of different weights on tunnel buoyancy; the power device is connected to the supporting trolley 28; and the detection device is installed at the monitoring section of the existing tunnel model 3.

[0048] In one embodiment of the present application, the model box 1 is reduced in size by a ratio of 15:1, and has a length, width and height of 2m×2m×1.8m respectively. A newly built tunnel simulation 2 and an existing tunnel model 3 are horizontally arranged inside. The newly built tunnel model 2 is in the upper space and is placed horizontally at a predetermined position in the model box 1; a steel bracket 6 is arranged on the right side of the model box 1 for carrying the power device.

[0049] In one embodiment of the present application, Figure 2 , 3 As shown, the newly built tunnel model includes a first inner tube 13 and an annular airbag 12 attached to the first inner tube 13. The two ends of the first inner tube 13 are close to the side wall of the model box 1. The annular airbag 12 is filled with gas and exhausted through the connected rubber hose 29. Before the test, the airbag 12 is filled with gas through the rubber hose 29; during the test, the gas in the airbag 12 is exhausted through the rubber hose 29 to reduce the volume of the airbag 12, thereby simulating the soil loss during the shield tunnel excavation process. Using this method to simulate the excavation of the tunnel is convenient for controlling the excavation speed and is simple to operate. The two ends of the newly built tunnel model 2 in the model box 1 are sealed by the first port cover 11.

[0050] In one embodiment of the present application, Figure 4 , 5As shown in Figure 6, the existing tunnel model 3 includes a second inner tube 13-1 and second port covers 11-1 installed at both ends of the second inner tube 13-1. A roadbed plate 21 is arranged inside the second inner tube 13-1, and the support trolley is slidably arranged on the roadbed plate 21. There is a groove 22 on the roadbed plate 21 inside the existing tunnel model 3, and the groove 22 can be used for the pulley 17 to pass through, so as to facilitate the passage of the support trolley 28 inside the existing tunnel model 3; the second port covers 11-1 are installed at both ends of the existing tunnel model 3. Figure 4 , 7 As shown, the existing tunnel model 3 is provided with monitoring sections at regular intervals on the outside.

[0051] In one embodiment of the present application, the supporting wheel group is composed of a plurality of pulleys 17. There are two grooves 22 on the roadbed plate 21 for the pulleys 17 at the bottom of the supporting trolley 28 to pass through.

[0052] In one embodiment of the present application, a lead hole 26 is provided on the second port cover 11-1, and a receiving hole 4 horizontal to the lead hole 26 is provided on the model box 1. A rubber ring is provided circumferentially inside the receiving hole 4. The traction end of the power device passes through the receiving hole 4 and is connected to one end of the support trolley 28. The other end of the support trolley 28 passes through the receiving hole 4 on the other side of the model box 1 through a thin wire 30 and is connected to a weight, which is used to control the position and speed of the support trolley 28, so as to ensure that the support trolley 28 passes through the existing tunnel model 3 at the speed required by the test; the lead hole 26 and the receiving hole 4 are connected by a plastic hose 27.

[0053] In one embodiment of the present application, the weight adjustment device includes a hook 16 and a weight mounted on the hook, and the control effect of supporting trolleys of different weights on tunnel buoyancy is simulated by replacing the weights of different weights.

[0054] In one embodiment of the present application, the power device includes a steel support 6, a steel strand 5 and a winch 10, wherein the winch 10 is fixed on the steel support 6, the steel strand 5 is wound on the winch 10, and the steel strand 5 is connected to the support trolley. The power device is located on the same horizontal line as the existing tunnel in the shield excavation direction. Since the winch 10 has the advantages of simple and easy operation of mechanical equipment and a wide range of applications, the winch 10 is used in this embodiment, but it is certainly not limited to this.

[0055] In one embodiment of the present application, a pull ring 19 is provided on the support trolley, and the pull ring 19 is connected to the steel strand 5 of the power device through a connecting piece.

[0056] In one embodiment of the present application, a tape measure 7 is bonded to the steel strand 5, and a positioning steel plate 8 is provided on the steel bracket 6. The position of the support trolley 28 and the traction speed are determined by reading the tape measure 7 through the positioning steel plate 8. Since the tape measure 7 has the advantages of simple reading and economical and practical, the tape measure 7 is used in this embodiment.

[0057] In one embodiment of the present application, the detection device includes a displacement meter 20, an earth pressure box 14 and a strain gauge 15. The displacement meter 20 is arranged at the bottom of the existing tunnel model 3, and the displacement meter 20 is fixed inside the displacement meter fixing device. The arch crown, arch bottom, arch waist and 1 / 4 arch waist outside the tunnel are all provided with earth pressure boxes 14 and strain gauges 15, which are used to measure the changes in the annular earth pressure of the existing tunnel model 3 and the changes in the bending moment generated by the outside. The displacement meter 20 is arranged at the arch bottom position to measure the settlement changes of the existing tunnel model. Since the arch crown, arch bottom, arch waist and 1 / 4 arch waist are the inflection points of the internal force and deformation of the tunnel, arranging measuring instruments at these locations can accurately understand the changes of the tunnel during the test.

[0058] In one embodiment of the present application, Figure 8 As shown, the displacement meter fixing device includes a retractable steel tube 23, a fixing screw 24 and a base 25. The retractable steel tube 23 is fixed on the base 25. After the displacement meter 20 is placed in the retractable steel tube 23, it is fixed by the fixing screw 24. The displacement meter fixing device is used to allow the displacement meter 20 to measure the settlement of the tunnel at the bottom of the existing tunnel model 3, which can avoid the influence of the newly built tunnel model 2 on the measurement accuracy.

[0059] The following is a detailed explanation with reference to specific cases.

[0060] The model size involved in the present invention can be flexibly adjusted according to the selected reduction ratio and the actual engineering situation of the simulation. The present invention selects a ratio of 15:1, and the outer diameter of the new tunnel model 2 and the existing tunnel model 3 is 41.3cm (the actual diameter is selected as 6.2m). For the soil loss during the shield tunnel construction process, the volume reduction caused by the exhaust of the airbag 12 in the new tunnel model 2 is simulated, and the excavation process of the shield tunnel is simulated by sequentially exhausting the gas in the airbag 12. The position of the support trolley 28 is determined by the tape measure 7 and the positioning steel plate 8, so that in the simulated new tunnel excavation process, the support trolley moves synchronously with the upper shield machine to ensure the safety of the lower tunnel structure.

[0061] The test is conducted using the simplified device for simulating the influence of a support trolley in an overlapping tunnel, including the following steps:

[0062] 1) Model making: A new tunnel model 2 and an existing tunnel model 3 are made by using aluminum alloy hollow pipes and related materials in a ratio of 15:1, and a support trolley 28 and a roadbed plate 21 are made by using square steel and steel plates in a ratio of 15:1. A metal pull ring 19 is welded at both ends of the support trolley 28, and two grooves 22 matching the pulley 17 at the bottom of the support trolley 28 are opened on the roadbed plate 21;

[0063] 2) Instrument installation: The soil pressure box 14 and the strain gauge 15 are glued to the outside of the existing tunnel model 3, the displacement meter 20 is installed in the displacement meter fixture, and the base 25 of the displacement meter fixture is glued to the test position. All the measuring lines are numbered and arranged into bundles to avoid the problem of messy measuring lines and unrecognizable problems during the test;

[0064] 3) Installing the existing tunnel model 3: Install the roadbed plate 21 into the existing tunnel model 3, then put the supporting trolley into the existing tunnel model, and place the two pulleys 17 at the bottom of the supporting trolley on the two grooves 22 of the roadbed plate 21, install the second port covers 11-1 at both ends of the existing tunnel model 3, then fill the model box 1 below the existing tunnel model 3 with fine sand, and compact the fine sand by standing, place the existing tunnel model 3 in the model box 1 according to the test position, and connect the lead hole 26 and the receiving hole 4 through the plastic hose 27;

[0065] 4) Installing the newly built tunnel model 2: Fill the model box 1 below the existing tunnel model 2 with fine sand, compact the fine sand by letting it stand, and place the existing tunnel model 2 in the model box 1 according to the test position;

[0066] 5) Filling with fine sand and installing instruments: Use the sand-sprinkling system to evenly fill the external fine sand into the model box 1, and let it stand for 24 hours every 100 mm. Repeat the operation until the fine sand is filled to the specified height, lead the measuring lines of the earth pressure cell 14 and the strain gauge 15 out of the model box 1, and connect the corresponding instruments;

[0067] 6) Conduct a single group test: Before the test, add gas to the airbag 12 through the rubber hose 29; during the test, the gas in the airbag 12 is discharged through the rubber hose 29 in sequence according to the excavation direction of the new tunnel, simulating the shield tunnel excavation process. Connect the pull ring 19 at one end of the support trolley 28 to the winch 10 through the steel strand 5, turn on the winch 10, use the steel strand 5 to pull the support trolley 28 to the right, and use the thin wire 30 to control the speed and position of the support trolley 28, so that the support trolley 28 keeps consistent with the excavation position and speed of the new tunnel 2 overlapping above; determine the exhaust speed of the airbag 12 according to the test plan, and the relevant measuring elements monitor the settlement, deformation and soil pressure data of the existing tunnel model 3 around the tunnel in real time;

[0068] 7) Subsequent more tests: After completing a single set of crossing tests, start to discharge the fine sand in the model box 1, remove the sand layer on the upper part of the newly built tunnel model 2, and then take out the tunnel model; continue to discharge the sand until the upper sand layer of the existing tunnel model 3 is removed, and then take out the tunnel model; continue to discharge the sand until the fine sand in the model box 1 is completely discharged; open the second port cover 11-1 of the existing tunnel model 3, pull out the roadbed plate 21 and the support trolley 28, then reassemble and readjust the weight of the support trolley 28 according to the test plan, clean the inner wall of the existing tunnel model 3, re-apply lubricant, and insert the roadbed plate 21 from one end of the existing tunnel model 3 again, then put the support trolley 28 into the existing tunnel model 3, apply lubricant, repeat the above sand filling process after the operation is completed, and conduct the next set of tests;

[0069] 8) Post-processing: Process the test data of soil pressure, bending moment and settlement of the existing tunnel model 3, draw relevant curves, and study the deformation and internal force of the existing tunnel model 3 under the combined action of the overlapping tunnel and the supporting trolley.

[0070] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A simplified device for simulating the influence of a support trolley in an overlapping tunnel, characterized in that: include: Model box (1); A new tunnel model (2) is constructed, wherein the new tunnel model (2) is horizontally mounted in the model box (1); An existing tunnel model (3), the existing tunnel model (3) being horizontally mounted in the model box (1) and located below the newly built tunnel model (2); A support trolley (28), the support trolley (28) being slidably disposed in the existing tunnel model (3), the support trolley (28) comprising a plurality of sub-trolleys connected in series, the sub-trolleys comprising a plurality of trolley portal frames (18) connected in series, the spacing between two connected trolley portal frames (18) being the same as the width of the pipe segment of the existing tunnel model (3), a plurality of support wheel groups being fixed to the outer wall of the cross section of each trolley portal frame (18), and a weight adjustment device being fixed to the inner wall of the cross section of each trolley portal frame (18); A power device, the power device being connected to the supporting trolley (28); A detection device, the detection device being installed at a monitoring section of the existing tunnel model (3); The newly built tunnel model comprises a first inner tube (13) and an annular airbag (12) attached to the first inner tube (13), the two ends of the first inner tube (13) are close to the side wall of the model box (1), and the annular airbag (12) is filled with air and exhausted through a connected rubber hose (29); The existing tunnel model (3) comprises a second inner tube (13-1) and second port covers (11-1) installed at both ends of the second inner tube (13-1); a track bed plate (21) is arranged inside the second inner tube (13-1), and the supporting trolley is slidably arranged on the track bed plate (21); The second port cover (11-1) is provided with a lead-in hole (26), a receiving hole (4) is provided on the model box (1) and is horizontal to the lead-in hole (26), a rubber ring is provided inside the receiving hole (4) along the circumferential direction, the traction end of the power device is connected to one end of the support trolley (28) after passing through the receiving hole (4), the other end of the support trolley (28) is connected to a weight after passing through the receiving hole (4) on the other side of the model box (1) via a thin wire (30), and the lead-in hole (26) and the receiving hole (4) are connected via a plastic hose (27).

2. A simplified device for simulating the influence of a support trolley in an overlapping tunnel according to claim 1, characterized in that: The power device comprises a steel support (6), a steel strand (5) and a winch (10); the winch (10) is fixed to the steel support (6); the steel strand (5) is wound around the winch (10); and the steel strand (5) is connected to a supporting trolley.

3. A simplified device for simulating the influence of a support trolley in an overlapping tunnel according to claim 2, characterized in that: A tape measure (7) is bonded to the steel strand (5), and a positioning steel plate (8) is provided on the steel bracket (6). The reading of the tape measure (7) is read through the positioning steel plate (8).

4. A simplified device for simulating the influence of a support trolley in an overlapping tunnel according to claim 1, characterized in that: The track bed plate (21) has two grooves (22) through which the supporting wheel set at the bottom of the supporting trolley (28) can pass.

5. A simplified device for simulating the influence of a support trolley in an overlapping tunnel according to claim 1, characterized in that: The detection device comprises a displacement meter (20), an earth pressure box (14) and a strain gauge (15); the displacement meter (20) is arranged at the bottom of the existing tunnel model (3); the displacement meter (20) is fixed inside the displacement meter fixing device; the earth pressure box (14) and the strain gauge (15) are arranged on the arch top, arch bottom, arch waist and 1 / 4 arch waist outside the tunnel.

6. A simplified device for simulating the influence of a support trolley in an overlapping tunnel according to claim 5, characterized in that: The displacement meter fixing device comprises a retractable steel tube (23), fixing screws (24) and a base (25); the retractable steel tube (23) is fixed on the base (25); after the displacement meter (20) is placed in the retractable steel tube (23), it is fixed using the fixing screws (24).

7. The experimental method of a simplified device for simulating the influence of a support trolley in an overlapping tunnel according to claim 1, characterized in that: The following steps are involved: (1) Single group test: Before the test, gas is first added to the annular airbag (12) through a rubber hose (29); during the test, the gas in the annular airbag (12) is discharged through the rubber hose (29) in sequence to simulate the shield tunnel excavation process, and the support trolley (28) is pulled to the right by a power device, and the speed and position of the support trolley (28) are controlled by a thin wire (30) so that the support trolley (28) and the excavation position and speed of the newly built tunnel model (2) overlapped above are consistent; the exhaust speed of the annular airbag (12) is determined according to the test plan, and the detection device monitors the settlement, deformation and soil pressure data around the existing tunnel model (3) in real time; (2) Re-adjust the weight of the supporting trolley (28) using the weight adjustment device and conduct the next set of tests.

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