A tunnel boring test device

Abstract

The present invention discloses a tunnel boring test device, which relates to the technical field of tunnel boring tests and includes a model box, a tunnel model, a scaling mechanism and a lifting mechanism; the tunnel model includes rigid arc-shaped plates and soft connectors that can be telescopically deformed, and multiple rigid arc-shaped plates and multiple soft connectors are alternately connected into a circular tube shape. The scaling mechanism is used to control the expansion and contraction of the tunnel model. Therefore, the problem of accurately simulating the outer shape of the tunnel lining with the soft-hard alternating structure is solved, so as to achieve the accurate simulation of ground loss; the lifting mechanism is used to control the lifting of the tunnel model and realize relevant pressure monitoring. Therefore, it can accurately simulate the situation of the excavation and unloading weight of different soils, so as to accurately reproduce the soil rebound phenomenon caused by excavation and unloading; therefore, after adopting this solution, the problems that the prior art cannot achieve ground loss and accurately simulate the soil rebound caused by excavation and unloading can be effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel boring tests, and particularly relates to a tunnel boring test device. Background Art

[0002] In recent years, shield tunnels have been widely used in the construction of subway tunnels. However, due to the huge volume of the shield machine, in order to study its actual working conditions, it can only be simulated in the laboratory using relevant experimental equipment. This experimental simulation is mainly used to study phenomena such as ground loss and soil rebound caused by excavation unloading. However, due to the imperfections of the existing experimental equipment, the experimental simulation effect has always been poor. The specific reasons are as follows:

[0003] First, the existing tunnel boring test device includes a tunnel model and a scaling mechanism. The scaling mechanism is used to adjust the radial dimension of the tunnel model to simulate ground loss by changing the radial dimension of the tunnel model. However, this tunnel model is integrally formed using iron sheets. Therefore, when the scaling mechanism controls the tunnel model to expand, it is actually forcibly stretching the iron sheets, so it is impossible to ensure that the tunnel model remains circular after expansion, which is different from the situation where the tunnel lining at the construction site is circular, resulting in an inability to achieve accurate experimental simulation at all.

[0004] Second, the prior art uses the method of arranging water bags inside the tunnel lining to simulate the excavation unloading phenomenon and the soil rebound phenomenon. For example, at the beginning, the water bags inside the tunnel are filled with water, which will exert pressure on the tunnel lining and the underlying soil. When it is necessary to simulate excavation unloading during tunnel boring, the water in the water bags is drained. At this time, the force on the tunnel lining and the underlying soil will disappear, thus simulating the excavation unloading phenomenon. However, if water bags are used for simulation, since the density of water is much smaller than that of soil, and the volume inside the tunnel is certain, the weight of the same volume of water is much smaller than the weight of soil. Therefore, it cannot accurately simulate the weight of excavation unloading.

[0005] Therefore, developing a device that can accurately simulate both the ground loss phenomenon and the soil rebound phenomenon caused by excavation unloading has become an urgent problem to be solved. Summary of the Invention

[0006] The purpose of the present invention is to provide a tunnel boring test device to solve the problem that the prior art cannot accurately simulate the ground loss phenomenon and the soil rebound phenomenon caused by excavation unloading.

[0007] To solve the above technical problems, the present invention provides a tunnel boring test device, comprising a model box, a tunnel model, a scaling mechanism and a lifting mechanism; two opposite box walls of the model box are respectively provided with a first transparent baffle and a second transparent baffle, a first through hole penetrating the first transparent baffle is provided on the first transparent baffle, and a second through hole penetrating the second transparent baffle is provided on the second transparent baffle; the tunnel model is arranged in the model box and is placed between the first transparent baffle and the second transparent baffle; the tunnel model includes a rigid arc-shaped plate and a soft connecting piece that can be telescopically deformed, and multiple rigid arc-shaped plates and multiple soft connecting pieces are alternately connected into a circular tube shape; the scaling mechanism is used to control the expansion and contraction of the tunnel model, and the scaling mechanism includes a power output unit, a lead screw, a movable nut, a transmission rod and a support plate; the power output unit is used to drive the lead screw to rotate; the lead screw is coaxially arranged with the axis of the tunnel model, and both ends of the lead screw respectively pass through the first through hole and the second through hole to be respectively connected with the lifting mechanism, and the diameters of the first through hole and the second through hole are both larger than the diameter of the lead screw; the movable nut is sleeved outside the lead screw, and the movable nut is threadedly connected with the lead screw; multiple transmission rods are arranged around the circumference of the movable nut, and multiple transmission rods are all movably connected with the movable nut; multiple support plates are respectively fixedly connected with the inner walls of multiple rigid arc-shaped plates, and multiple support plates are respectively movably connected with multiple transmission rods; the lifting mechanism is arranged outside the model box, and the lifting mechanism includes a connecting seat, a base, and a hydraulic cylinder and a pressure sensor arranged on the base; the connecting seat is arranged above the base, and the connecting seat is connected with the lead screw; the telescopic end of the hydraulic cylinder is connected with the connecting seat, and the hydraulic cylinder is used to drive the connecting seat to move up and down; the pressure sensor is arranged below the connecting seat, and the pressure sensor is used to abut against the bottom of the connecting seat for pressure monitoring.

[0008] In one embodiment, the tunnel wall of the tunnel model is provided with grouting holes penetrating it, and the two tunnel openings of the tunnel model are respectively covered with a first flexible sealing plate and a second flexible sealing plate that can be elastically deformed; the first flexible sealing plate is arranged opposite to the first transparent baffle, and a first sealing shaft sleeve is provided on the first flexible sealing plate; the second flexible sealing plate is arranged opposite to the second transparent baffle, and a second sealing shaft sleeve is provided on the second flexible sealing plate; a grouting joint is provided on the first transparent baffle, and the grouting joint passes through the first flexible sealing plate and is connected to the grouting hole, and the connection between the grouting joint and the first flexible sealing plate is a sealed connection; both ends of the screw rod are inserted into the first sealing shaft sleeve and the second sealing shaft sleeve respectively; and a third flexible sealing plate that can be elastically deformed is provided in the first through hole, a third sealing shaft sleeve is provided on the third flexible sealing plate, and the screw rod is sealingly sleeved in the third sealing shaft sleeve; a fourth flexible sealing plate that can be elastically deformed is provided in the second through hole, a fourth sealing shaft sleeve is provided on the fourth flexible sealing plate, and the screw rod is sealingly sleeved in the fourth sealing shaft sleeve.

[0009] In one embodiment, a first shaft hole is provided at the geometric center of the first flexible sealing plate, and a second shaft hole is provided at the geometric center of the second flexible sealing plate; the first sealing shaft sleeve includes a first inner plate with a hole, a first outer plate with a hole and a first sealing bearing. In the direction from the inside to the outside of the tunnel model, the first inner plate with a hole, the first shaft hole and the first outer plate with a hole are arranged in a state where the hole positions are coaxial, and the first inner plate with a hole, the first shaft hole and the first outer plate with a hole are fixedly connected by bolts; the first sealing bearing is sealingly installed in the hole positions of the first inner plate with a hole, the first shaft hole and the first outer plate with a hole, and the screw rod is sealingly sleeved in the first sealing bearing; the second sealing shaft sleeve includes a second inner plate with a hole, a second outer plate with a hole and a second sealing bearing. In the direction from the inside to the outside of the tunnel model, the second inner plate with a hole, the second shaft hole and the second outer plate with a hole are arranged in a state where the hole positions are coaxial, and the second inner plate with a hole, the second shaft hole and the second outer plate with a hole are fixedly connected by bolts; the second sealing bearing is sealingly installed in the hole positions of the second inner plate with a hole, the second shaft hole and the second outer plate with a hole, and the screw rod is sealingly sleeved in the second sealing bearing.

[0010] In one embodiment, a third shaft hole is provided at the geometric center of the third flexible sealing plate, and a fourth shaft hole is provided at the geometric center of the fourth flexible sealing plate; the third sealing shaft sleeve includes a third inner plate with a hole, a third outer plate with a hole, and a third sealing bearing. In the direction from the inside to the outside of the tunnel model, the third inner plate with a hole, the third shaft hole, and the third outer plate with a hole are arranged in a state where the hole positions are coaxial in sequence, and the third inner plate with a hole, the third shaft hole, and the third outer plate with a hole are fixedly connected by bolts; the third sealing bearing is hermetically installed in the hole positions of the third inner plate with a hole, the third shaft hole, and the third outer plate with a hole, and the screw rod is hermetically sleeved inside the third sealing bearing; the fourth sealing shaft sleeve includes a fourth inner plate with a hole, a fourth outer plate with a hole, and a fourth sealing bearing. In the direction from the inside to the outside of the tunnel model, the fourth inner plate with a hole, the fourth shaft hole, and the fourth outer plate with a hole are arranged in a state where the hole positions are coaxial in sequence, and the fourth inner plate with a hole, the fourth shaft hole, and the fourth outer plate with a hole are fixedly connected by bolts; the fourth sealing bearing is hermetically installed in the hole positions of the fourth inner plate with a hole, the fourth shaft hole, and the fourth outer plate with a hole, and the screw rod is hermetically sleeved inside the fourth sealing bearing.

[0011] In one embodiment, the tunnel boring test device further includes a first arc-shaped positioning plate and a second arc-shaped positioning plate; a plurality of the first arc-shaped positioning plates are all attached to the outer surface of the first flexible sealing plate, and a plurality of the first arc-shaped positioning plates are respectively arranged in alignment with a plurality of the hard arc-shaped plates, and the first arc-shaped positioning plate, the first flexible sealing plate, and the hard arc-shaped plate are fixedly connected by bolts; a plurality of the second arc-shaped positioning plates are all attached to the outer surface of the second flexible sealing plate, and a plurality of the second arc-shaped positioning plates are respectively arranged in alignment with a plurality of the hard arc-shaped plates, and the second arc-shaped positioning plate, the second flexible sealing plate, and the hard arc-shaped plate are fixedly connected by bolts.

[0012] In one embodiment, the first through hole and the second through hole are stepped holes, and the tunnel boring test device further includes a first pressing ring and a second pressing ring; the periphery of the third flexible sealing plate is clamped between the stepped surface of the first through hole and the first pressing ring, and the first pressing ring and the stepped surface of the first through hole are fixedly connected by bolts; the periphery of the fourth flexible sealing plate is clamped between the stepped surface of the second through hole and the second pressing ring, and the second pressing ring and the stepped surface of the second through hole are fixedly connected by bolts.

[0013] In one embodiment, a limiting plate is supported on the lead screw. The limiting plate is arranged inside the tunnel model. Multiple limiting grooves are provided on the limiting plate, and the multiple limiting grooves all extend radially along the tunnel model; mounting plates are connected to the multiple support plates, limiting pins are provided on the multiple mounting plates, and the multiple limiting pins are respectively inserted into the multiple limiting grooves. The cooperation between the multiple limiting pins and the multiple limiting grooves is used to limit the expansion and contraction range of the tunnel model.

[0014] In one embodiment, the tunnel boring test device further includes a sand rain sand leakage mechanism. The sand rain sand leakage mechanism includes a support frame, a sand box, and a height adjustment unit; the height adjustment unit is provided on the support frame; the sand box includes a fixed box body and a detachable box body arranged side by side. The two fixed box bodies are respectively arranged on opposite sides of the detachable box body. The detachable box body is detachably connected to the sand box, and sand inlets are provided at the tops of both the fixed box body and the detachable box body. Discharge sand doors with controllable opening and closing are provided at the bottoms of both the fixed box body and the detachable box body; the height adjustment unit is connected to the sand box, and the height adjustment unit is used to adjust the suspension height of the sand box inside the support frame.

[0015] In one embodiment, one of the multiple detachable box bodies is a central detachable box body, and the rest are side detachable box bodies. Along the length direction of the sand box, the length dimension of the central detachable box body is greater than the length dimension of the side detachable box bodies, and the two side detachable box bodies are symmetrically arranged on opposite sides of the central detachable box body.

[0016] In one embodiment, the height adjustment unit includes a winch and a rope guiding unit. A rope is wound around the winch, and the rope hangs the sand box after passing around the rope guiding unit.

[0017] The beneficial effects of the present invention are as follows:

[0018] Since the tunnel model includes rigid arc-shaped plates and soft connectors that can be elastically deformed, the multiple rigid arc-shaped plates and the multiple soft connectors are alternately connected into a circular tube shape, and the expansion and contraction mechanism is used to control the expansion and contraction of the tunnel model. Therefore, the rigid arc-shaped plates provide guarantee for the mechanical strength of the tunnel model, while the soft connectors enable the elastic expansion and contraction regulation of the tunnel model. At this time, even if the expansion and contraction mechanism is used to control the expansion and contraction of the tunnel model, the deformation amount of the soft connectors has little impact on the overall shape of the tunnel model, ensuring that the tunnel model can always maintain a circular tube structure, that is, the shape of the tunnel model is consistent with the shape of the tunnel lining, thereby realizing the accurate simulation of the ground loss phenomenon.

[0019] The telescopic end of the hydraulic cylinder is connected to the connecting seat, and the hydraulic cylinder is used to drive the connecting seat to move up and down. Therefore, under the mutual transmission of each component, this solution can use the telescopic change of the hydraulic cylinder to realize the lifting control of the tunnel model. When controlling the tunnel model to descend, the tunnel has a large acting force on the underlying soil, which can simulate the state before the soil is excavated. Then, when controlling the tunnel model to rise, the force of the tunnel on the underlying soil gradually decreases, which can simulate the phenomenon of soil excavation and unloading. Moreover, since the pressure sensor is arranged below the connecting seat and is used to abut against the bottom of the connecting seat for pressure monitoring, only by adjusting the telescopic degree of the hydraulic cylinder can the situation of different soil excavation and unloading weights be accurately simulated, that is, the accurate simulation of the excavation and unloading phenomenon and the soil rebound phenomenon is realized.

[0020] Therefore, after adopting the solution developed by the present invention, the problems that the prior art cannot realize the phenomenon of ground loss and accurately simulate the phenomenon of soil rebound caused by excavation and unloading can be effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for implementation will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1-1 is a schematic structural diagram provided by the first embodiment of the present invention;

[0023] Figure 1-2 is Figure 1-1 the rear view structural diagram of

[0024] Figure 1-3 is Figure 1-1 the top view structural diagram of

[0025] Figure 1-4 is Figure 1-1 the assembly structural diagram of the tunnel model and the expansion and contraction mechanism of

[0026] Figure 1-5 is Figure 1-4 the rear view structural diagram of

[0027] Figure 1-6 is Figure 1-4 the structural diagram of the tunnel model of

[0028] Figure 1-7 is Figure 1-6 the structural diagram of the rigid arc-shaped plate of

[0029] Figure 1-8 is Figure 1-6Schematic diagram of the soft connection structure;

[0030] Figure 1-9 is Figure 1-1 Schematic diagram of the enlarged structure of part A of;

[0031] Figure 1-10 is Figure 1-2 Schematic diagram of the enlarged structure of part B of;

[0032] Figure 1-11 is Figure 1-1 Schematic diagram of the assembly structure of the tunnel model, expansion and contraction mechanism, and lifting mechanism of;

[0033] Figure 2-1 Schematic diagram provided by the second embodiment of the present invention;

[0034] Figure 2-2 is Figure 2-1 Schematic diagram of the rear view of;

[0035] Figure 2-3 is Figure 2-1 Schematic diagram of the sealed assembly structure of the tunnel model of;

[0036] Figure 2-4 is Figure 2-3 Schematic diagram of the rear view of;

[0037] Figure 2-5 is Figure 2-1 Schematic diagram of the sectional view of;

[0038] Figure 2-6 is Figure 2-5 Schematic diagram of the enlarged structure of part C of;

[0039] Figure 2-7 is Figure 2-5 Schematic diagram of the enlarged structure of part D of;

[0040] Figure 3-1 Schematic diagram provided by the third embodiment of the present invention;

[0041] Figure 3-2 is Figure 3-1 Schematic diagram of the sand rain sand leakage mechanism of;

[0042] Figure 3-3 is Figure 3-2 Schematic diagram of the front view of;

[0043] Figure 3-4 is Figure 3-3 Schematic diagram of the structure after removing the middle removable box body of;

[0044] Figure 3-5 is Figure 3-2 Schematic diagram of the top view of;

[0045] Figure 3-6 is Figure 3-5 a schematic structural diagram of the sand discharge door.

[0046] The attached drawing reference numerals are as follows:

[0047] 10. Model box; 11. First transparent baffle; 111. First through hole; 12. Second transparent baffle; 121. Second through hole; 13. Sand discharge door; 14. Sand collecting tray; 15. Grouting joint; 161. First compression ring; 162. Second compression ring;

[0048] 20. Tunnel model; 21. Hard arc-shaped plate; 211. Splicing groove; 212. Fixed through hole; 213. Grouting hole; 22. Soft connecting piece; 221. Connecting part; 222. Straight groove part; 223. Fixed screw hole; 23. Fixed bolt; 241. First arc-shaped positioning plate; 242. Second arc-shaped positioning plate;

[0049] 30. Expansion and contraction mechanism; 311. First support seat; 312. Second support seat; 313. First bearing seat; 314. Second bearing seat; 315. Power output motor; 316. Reducer; 317. Coupling; 32. Lead screw; 33. Movable nut; 34. Transmission rod; 35. Support plate; 351. Limit pin; 352. Mounting plate; 36. Limit plate; 361. Limit groove;

[0050] 40. Lifting mechanism; 41. Connecting seat; 42. Base; 43. Hydraulic cylinder; 44. Pressure sensor; 45. Guide flange; 46. Column; 47. Guide rod;

[0051] 51. First flexible sealing plate; 52. Second flexible sealing plate; 53. Third flexible sealing plate; 54. Fourth flexible sealing plate;

[0052] 61. First sealing shaft sleeve; 611. First perforated inner plate; 612. First perforated outer plate; 613. First sealing bearing; 62. Second sealing shaft sleeve; 621. Second perforated inner plate; 622. Second perforated outer plate; 623. Second sealing bearing; 63. Third sealing shaft sleeve; 631. Third perforated inner plate; 632. Third perforated outer plate; 633. Third sealing bearing; 64. Fourth sealing shaft sleeve; 641. Fourth perforated inner plate; 642. Fourth perforated outer plate; 643. Fourth sealing bearing;

[0053] 70. Sand rain sand leakage mechanism; 71. Support frame; 711. Top frame; 712. Support feet; 713. Universal wheels; 714. Positioning feet; 715. Cross bar; 72. Sand box; 721. Fixed box body; 722. Sand inlet; 723. Sand discharge door; 723-1. Door body; 724. Middle detachable box body; 725. Side detachable box body; 726. Door lock; 726-1. Electromagnet; 726-2. Outer cover; 727. Anti-sway wheel; 728. Anti-collision strip; 731. First guide wheel; 732. Second guide wheel; 733. Third guide wheel; 734. Fourth guide wheel; 735. Winch; 736. Rope; 736-1. Main rope segment; 736-2. Branch rope segment. Detailed implementation mode

[0054] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0055] Embodiment 1

[0056] The present invention provides a tunnel boring test device, and its first embodiment is as Figures 1-1 to 1-11 shown, including a model box 10, a tunnel model 20, a scaling mechanism 30 and a lifting mechanism 40. The model box 10 is used to load soil, the tunnel model 20 is used to simulate tunnel lining, the scaling mechanism 30 is used to control the scaling of the tunnel model 20, and the lifting mechanism 40 is used to control the lifting of the tunnel model 20.

[0057] Regarding the model box 10, as Figures 1-1 to 1-3 shown, first transparent baffles 11 and second transparent baffles 12 are respectively provided on two opposite box walls of the model box 10. A first through hole 111 penetrating it is provided on the first transparent baffle 11, and a second through hole 121 penetrating it is provided on the second transparent baffle 12.

[0058] It should be noted that the model box 10 has an upper opening and a hollow interior structure to facilitate the placement of equipment from top to bottom or sand leakage operations; and a detachable sand discharge door 13 is provided at the bottom of the model box 10, and a sand collecting tray 14 is provided below the sand discharge door 13, so that after the experiment is completed, the sand discharge door 13 can be opened to empty the sand and soil in the model box 10 onto the sand collecting tray 14.

[0059] Regarding the tunnel model 20, as Figures 1-1 to 1-8As shown in the figure, the tunnel model 20 is arranged inside the model box 10 and is placed between the first transparent baffle 11 and the second transparent baffle 12. The tunnel model 20 includes a rigid arc-shaped plate 21 and a soft connector 22 that can be elastically deformed. Splicing grooves 211 are provided on both opposite side walls of the rigid arc-shaped plate 21, and the splicing grooves 211 extend along the axial direction of the rigid arc-shaped plate 21. Connecting portions 221 are provided on both opposite sides of the soft connector 22. Therefore, after installing the connecting portions 221 into the splicing grooves 211, the four rigid arc-shaped plates 21 and the four soft connectors 22 can be alternately connected into a circular tube shape.

[0060] Among them, the above-mentioned tunnel model 20 can be made by using 3D printing technology, so as to be flexibly produced according to different experimental needs. For example, the rigid arc-shaped plate 21 can be made of high-toughness photosensitive resin to ensure that the rigid arc-shaped plate 21 has sufficient mechanical strength, while the soft connector 22 can be made of soft materials such as silica gel to ensure that the tunnel model 20 can achieve elastic expansion and contraction.

[0061] In addition, as Figures 1-6 to 1-8 shown, the soft connector 22 of this embodiment further includes a straight groove portion 222. The straight groove portion 222 is a linear groove structure. Connecting portions 221 are provided on both outer side walls of the straight groove portion 222, and the connecting portions 221 are installed in the splicing grooves 211. Therefore, after adding the straight groove portion 222, the two groove walls of the straight groove portion 222 can be more easily bent inward, so that the deformation effect of the soft connector 22 is better and is more similar to the actual on-site construction environment.

[0062] Moreover, in this embodiment, the cross-sections of the splicing grooves 211 and the connecting portions 221 are both in a convex shape with matching dimensions. Therefore, after the connecting portions 221 are fitted into the splicing grooves 211, the splicing grooves 211 and the soft connector 22 assemble the tunnel model 20 into a radially anti-disconnection structure, thereby further strengthening the connection stability between the rigid arc-shaped plate 21 and the soft connector 22.

[0063] Furthermore, to strengthen the connection strength between the rigid arc-shaped plate 21 and the soft connector 22, in this embodiment, a plurality of fixing through holes 212 are provided on the groove walls of the splicing grooves 211. The plurality of fixing through holes 212 all penetrate the inner surface of the rigid arc-shaped plate 21, and fixing bolts 23 are installed in the plurality of fixing through holes 212. The fixing bolts 23 are threadedly connected to the fixing screw holes 223 of the soft connector 22. Therefore, the fixing bolts 23 can press the soft connector 22 inside the splicing grooves 211, thereby preventing the phenomenon of loosening and separation between the rigid arc-shaped plate 21 and the soft connector 22.

[0064] Regarding the expansion and contraction mechanism 30, as Figure 1-1 、 Figure 1-2 、 Figure 1-4 and Figure 1-5As shown, the expansion and contraction mechanism 30 includes a power output unit, a lead screw 32, a movable nut 33, a transmission rod 34, and a support plate 35. By connecting and transmitting each component, the effect of applying radial pushing and pulling forces to the tunnel model 20 can be achieved.

[0065] As Figure 1-4 and Figure 1-5 shown, in this embodiment, the above-mentioned power output unit is used to drive the lead screw 32 to rotate self - rotatably. Therefore, this purpose can be achieved by using the motor drive method. In this embodiment, it is preferably set that the power output unit includes a first support seat 311, a second support seat 312, a first bearing seat 313, a second bearing seat 314, a power output motor 315, a reducer 316, and a coupling 317; the first support seat 311 and the second support seat 312 are respectively arranged outside the two tunnel openings of the tunnel model 20 for supporting and holding the remaining components; the first bearing seat 313 is arranged on the first support seat 311, the second bearing seat 314 is arranged on the second support seat 312, and the first bearing seat 313, the second bearing seat 314, and the tunnel model 20 are arranged in a state where the hole axes coincide to support and fix the lead screw 32; the output shaft of the power output motor 315 is connected to the power input end of the reducer 316, the power output end of the reducer 316 is fixedly connected to one access end of the coupling 317, and the other access end of the coupling 317 is fixedly connected to one end of the lead screw 32 to achieve the low - speed rotation control of the lead screw 32.

[0066] As Figure 1-4 and Figure 1-5 shown, in this embodiment, the above - mentioned lead screw 32 is arranged coaxially with the axis of the tunnel model 20. The circumferential wall of the middle part of the lead screw 32 is provided with an external thread, and both ends of the lead screw 32 are in a smooth rod structure; when installing the lead screw 32, the part with the external thread of the lead screw 32 is located inside the tunnel model 20, and both ends of the lead screw 32 extend outside the tunnel model 20 and are respectively rotatably installed in the first bearing seat 313 and the second bearing seat 314; among them, one end of the lead screw 32 passes through the first bearing seat 313 and is fixedly connected to the coupling 317, thereby realizing the transmission connection between the lead screw 32 and the power output unit.

[0067] Moreover, in this embodiment, both ends of the lead screw 32 respectively pass through the first through - hole 111 and the second through - hole 121 and are respectively connected with a lifting mechanism 40. The diameters of the first through - hole 111 and the second through - hole 121 are both larger than the diameter of the lead screw 32, so as to realize the up - and - down lifting movement of the tunnel model 20.

[0068] Furthermore, a limit plate 36 is supported on the lead screw 32 in this embodiment. The limit plate 36 is arranged inside the tunnel model 20, and a limit pin 351 is arranged on the support plate 35. By the mutual cooperation of the limit plate 36 and the limit pin 351, the expansion and contraction range of the tunnel model 20 is limited.

[0069] As Figure 1-5 shown, in this embodiment, the above-mentioned limit plate 36 is in the shape of a circular plate with a perforation in the middle, so that the lead screw 32 can pass through the perforation in the middle of the limit plate 36 to achieve the through connection and installation between the two. At this time, the relationship between the two is only a socketing relationship, that is, the rotation of the lead screw 32 will not drive the limit plate 36 to rotate; moreover, four straight-slot-shaped limit grooves 361 are provided on the limit plate 36, and the four limit grooves 361 are respectively arranged at the upper, lower, left, and right positions of the limit plate 36. Each limit groove 361 extends along the radial direction of the tunnel model 20 to facilitate the limitation of the expansion and contraction trajectory of the tunnel model 20.

[0070] As Figure 1-5 shown, in this embodiment, to realize the installation of the above-mentioned limit pin 351, mounting plates 352 are connected to all four support plates 35. The mounting plates 352 and the support plates 35 are connected in a perpendicular state so that the mounting plates 352 can extend towards the center of the tunnel model 20; moreover, limit pins 351 are provided on all four mounting plates 352, and the four limit pins 351 are respectively inserted into the four limit grooves 361. The cooperation between the four limit pins 351 and the four limit grooves 361 is used to limit the expansion and contraction range of the tunnel model 20.

[0071] Obviously, after adopting the above setting method, if the limit pin 351 abuts against the outer end of the limit groove 361, the maximum expansion size of the tunnel model 20 is restricted. If the limit pin 351 abuts against the inner end of the limit groove 361, the minimum contraction size of the tunnel model 20 is restricted, so that the expansion and contraction range of the tunnel model 20 is always kept within the preset range, avoiding damage to the tunnel model 20 due to excessive expansion and contraction.

[0072] As Figure 1-4 and Figure 1-5 shown, in this embodiment, the above-mentioned movable nut 33 is sleeved outside the lead screw 32. The movable nut 33 is engaged with the external thread in the middle of the lead screw 32 through the internal thread in itself, so that the movable nut 33 and the lead screw 32 are in a threaded connection to facilitate the movement control of the movable nut 33 by using the lead screw 32; moreover, the movable nut 33 is hinged to the transmission rods 34 at the upper, lower, left, and right positions at both ends.

[0073] As Figure 1-4 shown, in this embodiment, there are a total of eight above-mentioned transmission rods 34. One ends of the eight transmission rods 34 are respectively hinged to the movable nut 33, and the other ends of the eight transmission rods 34 are respectively hinged to the four support plates 35, so that the movable nut 33 is transmitted to a corresponding support plate 35 through two transmission rods 34 in the up, down, left, and right four directions.

[0074] As Figure 1-4As shown, in this embodiment, there are four of the above-mentioned support plates 35, and the four support plates 35 are respectively connected and fixed to the inner walls of the four rigid arc-shaped plates 21, and the inner surfaces of the four support plates 35 are all hinged to the transmission rod 34.

[0075] Regarding the lifting mechanism 40, its function is to realize the lifting control of the tunnel model 20. Generally speaking, most conventional lifting structures can also meet this requirement. However, considering that the experimental environment has a relatively high pressure and the monitoring of relevant pressures also needs to be realized, in this embodiment, the lifting mechanism 40 is preferably set as Figure 1-1 , Figure 1-2 , and Figures 1-9 to 1-11 As shown. At this time, the lifting mechanism 40 is placed outside the model box 10. The lifting mechanism 40 includes a connecting seat 41, a base 42, a hydraulic cylinder 43 and a pressure sensor 44 provided on the base 42; the connecting seat 41 is arranged above the base 42, and the connecting seat 41 is connected to the lead screw 32. Specifically, at this time, a first support seat 311 and a first bearing seat 313 are provided on one connecting seat 41, and a second support seat 312 and a second bearing seat 314 are provided on the other connecting seat 41. Therefore, the first bearing seat 313 and the second support seat 312 can be sleeved outside the lead screw 32 to realize the connection and fixation between the two; and the hydraulic cylinder 43 is fixed to the base 42 in a vertically arranged manner, and the upper part of the hydraulic cylinder 43 is its vertically telescopic telescopic end. Therefore, after connecting the telescopic end of the hydraulic cylinder 43 to the connecting seat 41, the hydraulic cylinder 43 can be used to drive the connecting seat 41 to move up and down; and the pressure sensor 44 is arranged below the connecting seat 41. Therefore, at this time, the pressure sensor 44 will be located within the lifting trajectory of the connecting seat 41. According to the up and down movement of the connecting seat 41, the separation, abutment, and adjustment of different degrees of abutment states between the connecting seat 41 and the pressure sensor 44 can be controlled, so that the pressure sensor 44 can be used to abut against the bottom of the connecting seat 41 for pressure monitoring.

[0076] Among them, in order to ensure smooth lifting control and accurate pressure monitoring, in this embodiment, the lifting mechanism 40 is preferably set as Figures 1-9 to 1-11 As shown. At this time, a guiding flange 45 and a vertically arranged column 46 are provided on the top of the base 42, a pressure sensor 44 is provided on the top of the column 46, a vertically arranged guiding rod 47 is inserted into the guiding flange 45, and the guiding rod 47 is connected and fixed to the bottom of the connecting seat 41.

[0077] Therefore, after adopting this setting method, the column 46 can make the pressure sensor 44 closer to the connecting seat 41, so that the pressure sensor 44 can more accurately monitor the pressure generated by the micro-movement of the tunnel model 20; and the coordinated setting of the guiding flange 45 and the guiding rod 47 limits the vertical movement trajectory of the connecting seat 41 to ensure that the lifting movement of the tunnel model 20 is more stable and smooth.

[0078] In addition, compared with the case where only one lifting mechanism 40 is provided, in this embodiment, two lifting mechanisms 40 are used to apply forces simultaneously on both sides of the tunnel model 20, so that the lifting driving force for the tunnel model 20 is more sufficient. Moreover, the two lifting mechanisms 40 can not only perform synchronous lifting control, but also perform asynchronous lifting control, which provides more choices for the experimental process.

[0079] For example, during the normal experimental simulation process, the two lifting mechanisms 40 should be used for synchronous lifting control to achieve an accurate simulation of general situations. In some special cases, due to construction errors, the shield device or the tunnel lining may be tilted or the force application may be uneven. At this time, the asynchronous lifting control of the two lifting mechanisms 40 can simulate such situations, thus providing the possibility for studying the rescue plan after construction errors.

[0080] When using this embodiment to simulate the phenomenon of ground loss, the operation method is roughly as follows:

[0081] Drive the lead screw 32 to rotate by itself using the power output unit, and the movable nut 33 will move forward and backward accordingly. For example, if the translation of the movable nut 33 drives multiple transmission rods 34 to extend, the tunnel model 20 can be driven to expand accordingly. If the translation of the movable nut 33 drives multiple transmission rods 34 to retract, the tunnel model 20 can be driven to contract.

[0082] Obviously, after using this method to simulate the phenomenon of ground loss, at least the following beneficial effects are achieved:

[0083] First, with the mutual cooperation between the expansion and contraction mechanism 30 and the tunnel model 20, the continuous change of the radial dimension of the tunnel model 20 can be achieved. Not only does it improve the experimental efficiency without any disassembly and replacement operations, but also the continuous simulation of ground loss can be realized.

[0084] Second, the rigid arc-shaped plate 21 provides guarantee for the mechanical strength of the tunnel model 20, and the soft connector 22 enables the elastic expansion and contraction regulation of the tunnel model 20. At this time, even if the expansion and contraction mechanism 30 is used to control the expansion and contraction of the tunnel model 20, the deformation of the soft connector 22 has little impact on the overall shape of the tunnel model 20, ensuring that the tunnel model 20 can always maintain a circular tubular structure, that is, the shape of the tunnel model 20 is consistent with the shape of the tunnel lining, thus effectively solving the problem that the existing tunnel boring test device cannot accurately simulate the actual construction environment.

[0085] When using this embodiment to simulate the excavation unloading phenomenon and the soil rebound phenomenon, the operation method is roughly as follows:

[0086] S1. First, fill the soil in the model box 10 until the soil reaches the lower part of the originally simulated tunnel. Then stop adding soil, place the tunnel model 20 on the added soil, and use the lifting mechanism 40 to control the descent of the tunnel model 20. After the connecting seat 41 abuts against the pressure sensor 44, monitor the corresponding pressure information and adjust the pressure on the tunnel model 20 to be consistent with the force exerted by the soil to be simulated. Then lead out the relevant lines from the model box 10 and continue filling the soil until the soil reaches the designed height in the experiment.

[0087] S2. Control the tunnel model 20 to rise gradually at the experimental set rate, so that the pressure on the tunnel model 20 is gradually unloaded until only the self - weight of the tunnel model 20 remains, thus accurately simulating the situation of soil excavation and unloading during tunnel excavation.

[0088] Therefore, at this time, only the telescopic degree of the hydraulic cylinder 43 needs to be adjusted to accurately simulate the situation of different soil excavation and unloading weights, that is, the problem that the existing experimental device cannot accurately simulate the soil excavation and unloading weight is effectively solved.

[0089] Embodiment 2

[0090] The second embodiment of the tunnel boring test device of the present invention is as Figures 2-1 to 2-7 shown. It is basically the same as the first embodiment, except that the tunnel wall of the tunnel model 20 is provided with grouting holes 213 penetrating it, and the two tunnel openings of the tunnel model 20 are respectively covered with a first flexible sealing plate 51 and a second flexible sealing plate 52 that can be telescopically deformed; the first flexible sealing plate 51 is arranged opposite to the first transparent baffle 11, and the first flexible sealing plate 51 is provided with a first sealing shaft sleeve 61; the second flexible sealing plate 52 is arranged opposite to the second transparent baffle 12, and the second flexible sealing plate 52 is provided with a second sealing shaft sleeve 62; the first transparent baffle 11 is provided with a grouting joint 15, the grouting joint 15 passes through the first flexible sealing plate 51 and is connected to the grouting hole 213, and the connection between the grouting joint 15 and the first flexible sealing plate 51 is a sealed connection; both ends of the lead screw 32 are inserted into the first sealing shaft sleeve 61 and the second sealing shaft sleeve 62 respectively; and a third flexible sealing plate 53 that can be telescopically deformed is arranged in the first through - hole 111, the third flexible sealing plate 53 is provided with a third sealing shaft sleeve 63, and the lead screw 32 is hermetically sleeved in the third sealing shaft sleeve 63; a fourth flexible sealing plate 54 that can be telescopically deformed is arranged in the second through - hole 121, the fourth flexible sealing plate 54 is provided with a fourth sealing shaft sleeve 64, and the lead screw 32 is hermetically sleeved in the fourth sealing shaft sleeve 64.

[0091] As Figure 2-3As shown, in this embodiment, the above-mentioned first flexible sealing plate 51 can be made of a flexible material such as silica gel. The first flexible sealing plate 51 is in the shape of a circular plate to facilitate the full coverage of the tunnel opening of the tunnel model 20. There are two parts where the first flexible sealing plate 51 needs to be hermetically connected. One is the periphery of the first flexible sealing plate 51 and the periphery of the tunnel opening of the tunnel model 20, and the other is the connection part where the first flexible sealing plate 51 passes through the screw rod 32.

[0092] For the hermetic connection between the periphery of the first flexible sealing plate 51 and the periphery of the tunnel opening of the tunnel model 20, in this embodiment, a plurality of through holes are provided on the periphery of the first flexible sealing plate 51, a plurality of threaded holes are provided on the periphery of the tunnel opening of the tunnel model 20, and four first arc-shaped positioning plates 241 are provided. A plurality of through holes with matching positions are also provided on each first arc-shaped positioning plate 241.

[0093] Therefore, when the periphery of the first flexible sealing plate 51 is hermetically installed, it should be ensured that the four first arc-shaped positioning plates 241 are all attached to the outer surface of the first flexible sealing plate 51. Then, bolts are used to sequentially pass through the corresponding hole positions of the first arc-shaped positioning plates 241, the first flexible sealing plate 51, and are threadedly connected to the threaded holes of the tunnel model 20, so that the first arc-shaped positioning plates 241, the first flexible sealing plate 51, and the tunnel model 20 are fixedly connected by bolts, thereby realizing the hermetic connection between the periphery of the first flexible sealing plate 51 and the periphery of the tunnel opening of the tunnel model 20.

[0094] For the hermetic connection between the first flexible sealing plate 51 and the screw rod 32, it is mainly realized by the first sealing bushing 61; specifically as Figure 2-3 、 Figure 2-5 and Figure 2-6 shown, in this embodiment, a first shaft hole is provided at the geometric center of the first flexible sealing plate 51, and the first sealing bushing 61 is provided to include a first perforated inner plate 611, a first perforated outer plate 612, and a first sealing bearing 613. In the direction from the inside to the outside of the tunnel model 20, the first perforated inner plate 611, the first shaft hole, and the first perforated outer plate 612 are arranged in a state where the hole positions are coaxial. The first perforated inner plate 611, the first shaft hole, and the first perforated outer plate 612 are fixedly connected by bolts. The first sealing bearing 613 is hermetically installed in the hole positions of the first perforated inner plate 611, the first shaft hole, and the first perforated outer plate 612. The screw rod 32 is hermetically sleeved inside the first sealing bearing 613, thereby realizing the hermetic connection between the first flexible sealing plate 51 and the screw rod 32.

[0095] Similarly, as Figure 2-4As shown, in this embodiment, the second flexible sealing plate 52 can be made of a flexible material such as silica gel. The second flexible sealing plate 52 is in the shape of a circular plate to facilitate the full coverage of the other tunnel opening of the tunnel model 20. There are two parts where the second flexible sealing plate 52 needs to be hermetically connected. One is the periphery of the second flexible sealing plate 52 and the periphery of the tunnel opening of the tunnel model 20, and the other is the connection part where the second flexible sealing plate 52 passes through the lead screw 32.

[0096] For the hermetic connection between the periphery of the second flexible sealing plate 52 and the periphery of the tunnel opening of the tunnel model 20, in this embodiment, a plurality of through holes are provided on the periphery of the second flexible sealing plate 52, and a plurality of threaded holes are also provided on the periphery of the other tunnel opening of the tunnel model 20. Four second arc-shaped positioning plates 242 are provided, and a plurality of through holes with matching positions are also provided on each second arc-shaped positioning plate 242.

[0097] Therefore, when the periphery of the second flexible sealing plate 52 is hermetically installed, it should be ensured that the four second arc-shaped positioning plates 242 are all in contact with the outer surface of the second flexible sealing plate 52. Then, bolts are used to sequentially pass through the corresponding holes of the second arc-shaped positioning plates 242, the second flexible sealing plate 52, and are threadedly connected to the threaded holes of the tunnel model 20, so that the second arc-shaped positioning plates 242, the second flexible sealing plate 52, and the tunnel model 20 are fixedly connected by bolts, thus realizing the hermetic connection between the periphery of the second flexible sealing plate 52 and the periphery of the other tunnel opening of the tunnel model 20.

[0098] For the hermetic connection between the second flexible sealing plate 52 and the lead screw 32, it is mainly realized by the second sealing bushing 62; specifically as Figure 2-4 、 Figure 2-5 and Figure 2-7 , in this embodiment, a second shaft hole is provided at the geometric center of the second flexible sealing plate 52, and the second sealing bushing 62 is provided to include a second perforated inner plate 621, a second perforated outer plate 622, and a second sealing bearing 623. In the direction from the inside to the outside of the tunnel model 20, the second perforated inner plate 621, the second shaft hole, and the second perforated outer plate 622 are arranged in a state where the hole positions are coaxial, and the second perforated inner plate 621, the second shaft hole, and the second perforated outer plate 622 are fixedly connected by bolts; the second sealing bearing 623 is hermetically installed in the hole positions of the second perforated inner plate 621, the second shaft hole, and the second perforated outer plate 622, and the lead screw 32 is hermetically sleeved inside the second sealing bearing 623, thus realizing the hermetic connection between the second flexible sealing plate 52 and the lead screw 32.

[0099] Furthermore, as Figure 2-1 、 Figure 2-5 and Figure 2-6As shown, the third flexible sealing plate 53 of this embodiment can be made of a flexible material such as silica gel, and the third flexible sealing plate 53 is set as a circular plate to facilitate the full coverage of the first through hole 111. In addition, there are two parts where the third flexible sealing plate 53 needs to be hermetically connected. One is the periphery of the third flexible sealing plate 53 and the periphery of the first through hole 111, and the other is the connection part of the third flexible sealing plate 53 and the lead screw 32. The specific implementation method is as follows.

[0100] For the sealing connection between the periphery of the third flexible sealing plate 53 and the periphery of the first through hole 111, as Figure 2-6 shown, this embodiment sets the first through hole 111 as a stepped hole, and the tunnel boring test device further includes a first pressing ring 161. Therefore, the periphery of the third flexible sealing plate 53 can be clamped between the stepped surface of the first through hole 111 and the first pressing ring 161. Moreover, since the first pressing ring 161 and the stepped surface of the first through hole 111 are bolted and fixed, the sealing connection and fixation between the two are also realized.

[0101] For the sealing connection between the third flexible sealing plate 53 and the lead screw 32, as Figure 2-1 、 Figure 2-5 and Figure 2-6 shown, this embodiment is provided with a third shaft hole at the geometric center of the third flexible sealing plate 53, and the third sealing shaft sleeve 63 includes a third inner plate with holes 631, a third outer plate with holes 632 and a third sealing bearing 633. In the direction from the inside to the outside of the tunnel model 20, the third inner plate with holes 631, the third shaft hole and the third outer plate with holes 632 are arranged in a state where the hole positions are coaxial, and the third inner plate with holes 631, the third shaft hole and the third outer plate with holes 632 are bolted and fixed; the third sealing bearing 633 is hermetically installed in the hole positions of the third inner plate with holes 631, the third shaft hole and the third outer plate with holes 632, and the lead screw 32 is hermetically sleeved inside the third sealing bearing 633, so that the sealing connection between the third flexible sealing plate 53 and the lead screw 32 is realized.

[0102] Similarly, as Figure 2-2 、 Figure 2-5 and Figure 2-7 shown, the fourth flexible sealing plate 54 of this embodiment can be made of a flexible material such as silica gel, and the fourth flexible sealing plate 54 is set as a circular plate to facilitate the full coverage of the second through hole 121. In addition, there are two parts where the fourth flexible sealing plate 54 needs to be hermetically connected. One is the periphery of the fourth flexible sealing plate 54 and the periphery of the second through hole 121, and the other is the connection part of the fourth flexible sealing plate 54 and the lead screw 32. The specific implementation method is as follows.

[0103] For the sealing connection between the periphery of the fourth flexible sealing plate 54 and the periphery of the second through hole 121, as Figure 2-7As shown, in this embodiment, the second through hole 121 is provided as a stepped hole, and the tunnel boring test device is further provided with a second pressing ring 162. Therefore, the periphery of the fourth flexible sealing plate 54 can be clamped between the stepped surface of the second through hole 121 and the second pressing ring 162. Moreover, since the second pressing ring 162 and the stepped surface of the second through hole 121 are fixedly connected by bolts, the sealed connection and fixation between the two are also realized.

[0104] For the sealed connection between the fourth flexible sealing plate 54 and the lead screw 32, as Figure 2-2 , Figure 2-5 and Figure 2-7 shown, in this embodiment, a fourth shaft hole is provided at the geometric center of the fourth flexible sealing plate 54, and the fourth sealing shaft sleeve 64 is provided to include a fourth perforated inner plate 641, a fourth perforated outer plate 642, and a fourth sealing bearing 643. In the direction from the inside to the outside of the tunnel model 20, the fourth perforated inner plate 641, the fourth shaft hole, and the fourth perforated outer plate 642 are arranged in a state where the hole positions are coaxial, and the fourth perforated inner plate 641, the fourth shaft hole, and the fourth perforated outer plate 642 are fixedly connected by bolts; the fourth sealing bearing 643 is hermetically installed in the hole positions of the fourth perforated inner plate 641, the fourth shaft hole, and the fourth perforated outer plate 642, and the lead screw 32 is hermetically sleeved inside the fourth sealing bearing 643, so that the sealed connection between the fourth flexible sealing plate 54 and the lead screw 32 is realized.

[0105] Therefore, after adopting the above setting method, the inside and outside of the tunnel model 20 can be isolated to meet the relevant requirements of the later grouting operation. The specific operation method is as follows:

[0106] S1, first fill the soil in the model box 10 until the soil reaches the lower part of the originally simulated tunnel, stop adding soil, place the tunnel model 20 on the added soil, use the lifting mechanism 40 to control the tunnel model 20 to descend. After the connecting seat 41 abuts against the pressure sensor 44, by monitoring the corresponding pressure information, adjust the pressure on the tunnel model 20 to be consistent with the soil force application situation to be simulated, and then lead out the relevant lines from the model box 10, and continue to fill the soil until the soil reaches the designed height in the experiment.

[0107] S2, control the tunnel model 20 to rise gradually at the experimental set rate, so that the pressure on the tunnel model 20 is gradually unloaded until only the self-weight of the tunnel model 20 remains, thereby accurately simulating the soil excavation and unloading situation during tunnel excavation; during this process, at the same time, connect the relevant grouting equipment through the grouting joint 15, so that the slurry is discharged through the grouting hole 213, and simulate the backfill grouting working condition according to the grouting pressure set in the experiment.

[0108] S3, change the grouting pressure, and repeat steps S1 and S2.

[0109] In S4, a displacement sensor and a slurry sensor can be arranged in the model box 10. By observing and recording the data of the displacement sensor and the slurry sensor, the situation of the floating of the tunnel model 20 and the pressure of the slurry on the tunnel model 20 under different grouting pressure conditions (such as the grouting pressure, the grouting volume, and the grouting speed can all be adjusted according to requirements) can be obtained, so as to provide guidance for the actual project.

[0110] For example, if the floating amount of the tunnel in the actual project is too large, phenomena such as the tunnel deviating from the expected construction track and the tunnel lining colliding with the soil body or the shield machine and causing damage will occur. Therefore, after using this embodiment to simulate the above situation, it will be convenient to ensure the grouting effect in the actual working conditions and control the grouting pressure as much as possible to reduce the floating amount of the tunnel.

[0111] Embodiment 3

[0112] The third embodiment of the tunnel boring test device of the present invention is as Figures 3-1 to 3-6 shown. It is basically the same as the second embodiment, except that this embodiment also has the function of sand rain experiment. Specifically, the tunnel boring test device of this embodiment further includes a sand rain sand leakage mechanism 70. The sand rain sand leakage mechanism 70 includes a support frame 71, a sand box 72 and a height adjustment unit. The support frame 71 is used to realize the suspension installation of the sand box 72. The sand box 72 is used to load the sand for the experiment. The height adjustment unit is used to adjust the height of the sand box 72.

[0113] Regarding the support frame 71, this embodiment is preferably set as Figure 3-2 shown. The height adjustment unit is provided on the support frame 71. The support frame 71 includes a top frame 711 and support feet 712. The top frame 711 is a rectangular frame. The sand box 72 is suspended in the space enclosed by the top frame 711. The tops of the four support feet 712 are respectively connected and fixed to the four end corners at the bottom of the top frame 711. Universal wheels 713 with self-locking functions are provided at the bottoms of the four support feet 712, so as to realize the support of the top frame 711 and the overall movement of the sand rain sand leakage mechanism 70. Moreover, at this time, the four support feet 712 are all arranged in an obliquely outward manner, so that a relatively large space is formed between the four support feet 712. This space can be used as an access channel for the model box 10 to enter below the sand box 72.

[0114] When in application, unlock the self-locking of the universal wheels 713, and then the sand rain sand leakage mechanism 70 can be pushed towards the model box 10. After the model box 10 enters the support frame 71 through the access channel and is placed below the sand box 72, the alignment preparation before the sand rain experiment is completed.

[0115] It should also be pointed out that after the sand box 72 and the model box 10 are aligned, it is necessary to ensure that their relative positions remain unchanged. Therefore, in addition to locking the universal wheels 713 to restrict their movement, such asFigure 3-2 As shown, this embodiment also adds a positioning foot 714 for positioning the sand rain sand leakage mechanism 70. Since the positioning foot 714 realizes the rotation and lifting function by means of threaded rotation installation, when the sand rain sand leakage mechanism 70 has moved in place, the positioning foot 714 can be rotated so that the positioning foot 714 moves downward until the positioning foot 714 is in close contact with the ground, and the positioning and fixing of the sand rain sand leakage mechanism 70 can be realized.

[0116] Regarding the sand box 72, its function is to adjust the sand leakage structure according to different experimental scenarios to meet the experimental requirements under different scenarios. Therefore, to achieve this purpose, this embodiment adopts Figures 3-2 to 3-6 the setting shown. The sand box 72 is an overall rectangular box. The sand box 72 includes a fixed box body 721 and a detachable box body arranged side by side. The two fixed box bodies 721 are respectively arranged on opposite sides of the detachable box body. The detachable box body is detachably connected to the sand box 72, and sand inlet ports 722 are provided at the tops of both the fixed box body 721 and the detachable box body. Sand discharge doors 723 with controllable opening and closing are provided at the bottoms of both the fixed box body 721 and the detachable box body.

[0117] Moreover, there are three detachable box bodies in this embodiment. One of the three detachable box bodies is a middle detachable box body 724, and the other two are side detachable box bodies 725. The three detachable box bodies are all arranged between the two fixed box bodies 721. Among them, the length dimension of the middle detachable box body 724 is greater than the length dimension of the side detachable box body 725, but the width and depth dimensions of the middle detachable box body 724 are the same as those of the two side detachable box bodies 725, and the two side detachable box bodies 725 are symmetrically arranged on opposite sides of the middle detachable box body 724.

[0118] After adopting this setting method, in addition to being able to achieve uniform sand leakage on both sides of the tunnel model 20, since the volume of the middle detachable box body 724 is relatively large, generally, only removing the middle detachable box body 724 can meet most experimental requirements, thus avoiding multiple removal operations. Only in some special cases is it necessary to remove the side detachable box body 725, which provides convenience for the experimental process of the experimenter.

[0119] In addition, the detachable connection method between the detachable box body and the sand box 72 is diverse. It can be a detachable connection with a sliding groove fit, or a detachable connection realized by a buckle. Considering that the detachable box body needs to load a large amount of experimental sand, it should be ensured that the installation of the detachable box body on the sand box 72 is stable. Therefore, this embodiment preferably sets that there are a plurality of threaded holes at the top of the detachable box body, and a plurality of through holes are provided at the top of the sand box 72. A plurality of positioning bolts are installed in the plurality of through holes, and the plurality of positioning bolts are respectively threadedly connected to the plurality of threaded holes.

[0120] When the detachable box body is not disassembled, only need to tighten the positioning bolts. A strong biting force will be formed between the positioning bolts and the threaded holes, thus ensuring the installation stability of the detachable box body on the sand box 72. When it is necessary to disassemble the detachable box body, only need to loosen the positioning bolts, and the disassembly operation is also extremely simple.

[0121] It should also be pointed out that the prior art uses the sand outlet for sand leakage operation. However, due to the small diameter of the sand outlet, the sand leakage process will be a single-point sand leakage state. If fixed-point sand leakage is carried out, a state where the sand layer in the middle is high and the sand layers on both sides are low will be formed. If controlled for moving sand leakage, the shaking generated during the moving process will also cause uneven sand leakage density at various places.

[0122] In this embodiment, a sand discharge door 723 is used to replace the sand outlet of the prior art. For example, the sand discharge door 723 of this embodiment is set as Figure 3-5 and Figure 3-6 As shown, the sand discharge door 723 is hinged to the outer wall bottom of the fixed box body 721 and the detachable box body by two door bodies 723-1, so as to set the sand discharge door 723 as a double-door opening structure; a door lock 726 for controlling the opening and closing of the sand discharge door 723 is provided at the double-door opening of the sand discharge door 723.

[0123] Since the closed sand discharge door 723 completely covers the bottom surfaces of the fixed box body 721 and the detachable box body, when the door lock 726 releases the closing lock of the sand discharge door 723, the sand discharge door 723 will open automatically due to gravity, so that the entire bottom of the fixed box body 721 and the detachable box body will perform all-round synchronous sand leakage. This process will not form a state where the sand layer in the middle is high and the sand layers on both sides are low, and no movement is required, so there will be no problem of uneven sand leakage density caused by shaking during the moving process.

[0124] It should be pointed out that in addition to the double-door opening structure, the sand discharge door 723 can also adopt a single-door opening structure. When adopting the single-door opening structure, only need to change the door lock 726 to be arranged on the side wall of the single door and the corresponding installation box body; and the setting method of the door lock 726 is also relatively diverse. For example, a mechanical linkage structure can be used to realize manual opening and closing control, or an electric control method can be used to realize opening and closing control. For example, the telescopic movement of an electric control bolt is one of the optional methods.

[0125] However, to avoid the sand discharge door 723 from being difficult to open and close under the heavy pressure of the experimental sand, such as Figure 3-5 and Figure 3-6As shown, in this embodiment, it is preferably set that the door lock 726 includes an electromagnet 726-1 and an outer cover 726-2 that can be magnetically attracted (such as an iron outer cover or a steel outer cover, etc.). The electromagnet 726-1 and the outer cover 726-2 are respectively arranged on the two door bodies 723-1 of the sand discharge door 723. When the sand discharge door 723 is closed, the electromagnet 726-1 is placed in the space surrounded by the outer cover 726-2, and the electromagnet 726-1 is magnetically attracted to the outer cover 726-2. Here, in addition to cooperating with the electromagnet 726-1 to realize the opening and closing control of the sand discharge door 723, the outer cover 726-2 also realizes the wrapping protection of the electromagnet 726-1.

[0126] When in application, as long as the electromagnet 726-1 is continuously powered, the electromagnet 726-1 will be in a continuously adsorbed state with the outer cover 726-2 to ensure the stable closing of the sand discharge door 723; and since the covered space of the sand discharge door 723 is relatively large, in order to strengthen the closing firmness of the sand discharge door 723, in this embodiment, the door lock 726 is also set to be multiple, and the multiple door locks 726 are arranged along the length direction of the sand discharge door 723 to simultaneously strengthen the closing tightness of the sand discharge door 723 at multiple places.

[0127] Finally, in order to prevent the sand box 72 from shaking and colliding during lifting and moving, this embodiment also adds corresponding guiding and anti-collision structures; for example, as Figure 3-2 shown, anti-sway wheels 727 that can roll are provided on the outer surfaces on both sides of the sand box 72 in its length direction. The anti-sway wheels 727 are rotatably connected to the ends of a support rod, and the support rod extends obliquely outward from the outer surface of the sand box 72. Therefore, when the sand box 72 is lifted and lowered in the model box 10, the anti-sway wheels 727 can abut against the inner wall of the model box 10, thereby realizing the lifting guidance of the sand box 72 and avoiding the shaking phenomenon of the sand box 72 during the lifting process; and at this time, a plurality of anti-collision strips 728 are provided on the outer wall of the sand box 72. The anti-collision strips 728 can be made of a material with relatively strong elasticity, such as rubber, silica gel, etc. Therefore, when the rest of the sand box 72 collides with the inner wall of the model box 10, the anti-collision strips 728 can also play a buffering role to ensure the smooth movement of the sand box 72.

[0128] Regarding the height adjustment unit, its function is to realize the smooth lifting and lowering of the sand box 72. Commonly used electric guide rails, telescopic rods, transmission lead screws 32, etc. can all achieve this purpose. However, in order to make the height control more convenient and flexible, this embodiment preferably adopts the method of adjusting the height of the sand box 72 by hanging a rope.

[0129] As Figure 3-2As shown, the height adjustment unit at this time includes a winch 735 and a rope guiding unit. A rope 736 is wound around the winch 735, and the rope 736 bypasses the rope guiding unit and suspends the sand box 72; wherein, the winch 735 is arranged on a cross bar 715, and both ends of the cross bar 715 are respectively connected to the lower parts of two adjacent support feet 712, so that the winch 735 is placed at a reasonable height, facilitating the experimenter to control the winch 735; while the rope guiding unit is arranged on the top frame 711 to realize the guiding of the rope 736; therefore, when the winch 735 is rotated to tighten the rope 736, the upward control of the sand box 72 can be realized, and when the winch 735 is rotated to loosen the rope 736, the downward control of the sand box 72 can be realized.

[0130] It should be noted that the above winch 735 can be an electric winch or a manual winch. However, for the convenience of the experimenter to operate flexibly, a hand-remote-controlled winch 735 is adopted in this embodiment. Therefore, the experimenter can flexibly adjust the tightening and loosening degree of the rope 736 by means of hand-crank control.

[0131] In addition, the function of the above rope guiding unit is to realize the guiding of the rope 736. The common method is a set of guide wheels, and the specific structure of the rope guiding unit in this embodiment is Figure 3-2 As shown, the above rope guiding unit includes a first guide wheel 731, a second guide wheel 732, a third guide wheel 733 and a fourth guide wheel 734. The first guide wheel 731 is arranged on the outer side of a long side of the top frame 711, and the rotation axis of the first guide wheel 731 is consistent with the length direction of this long side of the top frame 711; two sets of second guide wheels 732 are arranged on the top surface of this long side of the top frame 711, and both sets of second guide wheels 732 are arranged adjacent to the first guide wheel 731, and the rotation axes of both sets of second guide wheels 732 are arranged vertically; two sets of third guide wheels 733 are arranged on the top surface of the top frame 711, and the two sets of third guide wheels 733 are respectively arranged at the ends of this long side of the top frame 711, and the rotation axes of both sets of third guide wheels 733 are arranged vertically; two sets of fourth guide wheels 734 are arranged on the inner surfaces of the two short sides of the top frame 711, and the rotation axes of the two sets of fourth guide wheels 734 are consistent with the length direction of this long side of the top frame 711; and the above rope 736 includes a main rope segment 736-1 and branch rope segments 736-2. The main rope segment 736-1 is wound around the winch 735, and the end of the main rope segment 736-1 is connected to the two branch rope segments 736-2. Both branch rope segments 736-2 bypass the first guide wheel 731 and respectively bypass the two sets of second guide wheels 732, the two sets of third guide wheels 733 and the two sets of fourth guide wheels 734 and then are connected to both sides of the sand box 72; therefore, when the winch 735 is rotated, the tightening and loosening degrees of the two branch rope segments 736-2 can be controlled simultaneously by using the main rope segment 736-1 to realize the stable lifting control of the sand box 72.

[0132] As described above, the working principles and effects of the various structures of the sand-rain sand leakage mechanism 70 are already known. However, to more clearly reflect the application method of the sand-rain sand leakage mechanism 70, specific application scenarios will be combined here for explanation, and the specific operations are as follows:

[0133] S1. Move the sand-rain sand leakage mechanism 70 to achieve the alignment and installation of the sand box 72 and the model box 10. After the sand box 72 and the model box 10 are aligned, fix the installation position of the sand-rain sand leakage mechanism 70;

[0134] S2. Regulate the sand box 72 to the required sand leakage height, and then control the fixed box body 721 and the detachable box body to leak sand synchronously until the sand surface in the model box 10 reaches the specified position. Assume that the distance between the sand box 72 and the sand surface at this time is H;

[0135] S3. Load the tunnel model 20 into the model box 10;

[0136] S4. Remove the detachable box body, and regulate the tunnel model 20 to be placed between the two fixed box bodies 721, and then control the two fixed box bodies 721 to perform sand leakage operations. Under the unique design of this embodiment, the distance between the sand box 72 and the sand surface can still be maintained at H at this time.

[0137] After adopting this embodiment, the following multiple beneficial effects can be achieved:

[0138] First, after removing the detachable box body, this embodiment does not require a translation operation similar to the prior art. The two fixed box bodies 721 can directly perform synchronous sand leakage on both sides of the tunnel model 20, ensuring that uniform sand leakage can be achieved on both sides of the tunnel model 20, that is, effectively solving the problem that the sand-rain experimental device cannot achieve uniform sand leakage on both sides of the tunnel model 20.

[0139] Second, the overall shape of the sand box 72 is a rectangular parallelepiped. Therefore, when its width is adjusted to match the width of the small experimental device, due to its sufficient length, even if the loading capacity of the experimental sand is reduced, it can still meet the needs of small-scale experiments, thus enabling the sand-rain sand leakage mechanism 70 to be adapted for use with small experimental devices.

[0140] Third, after removing the detachable box body, the height regulation of the sand box 72 will no longer be affected by the tunnel model 20, thus ensuring that the sand box 72 has a sufficient range for regulating the sand leakage height and also meeting the requirement of maintaining a consistent sand leakage height in various situations.

[0141] The above is the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A tunnel boring test device, characterized in that it includes a model box, a tunnel model, a scaling mechanism and a lifting mechanism; On the two opposite box walls of the model box, a first transparent baffle and a second transparent baffle are respectively provided. A first through hole penetrating through it is provided on the first transparent baffle, and a second through hole penetrating through it is provided on the second transparent baffle; The tunnel model is arranged inside the model box, and the tunnel model is placed between the first transparent baffle and the second transparent baffle; the tunnel model includes a hard arc-shaped plate and a soft connecting piece that can be elastically deformed. Multiple hard arc-shaped plates and multiple soft connecting pieces are alternately connected into a circular tube shape; The scaling mechanism is used to control the expansion and contraction of the tunnel model. The scaling mechanism includes a power output unit, a lead screw, a movable nut, a transmission rod and a support plate; the power output unit is used to drive the lead screw to rotate; the lead screw is coaxially arranged with the axis of the tunnel model, and both ends of the lead screw respectively pass through the first through hole and the second through hole to be respectively connected with the lifting mechanism. The diameters of the first through hole and the second through hole are both larger than the diameter of the lead screw; the movable nut is sleeved outside the lead screw, and the movable nut is threadedly connected with the lead screw; multiple transmission rods are arranged around the circumferential side of the movable nut, and multiple transmission rods are all movably connected with the movable nut; multiple support plates are respectively fixedly connected with the inner walls of multiple hard arc-shaped plates, and multiple support plates are respectively movably connected with multiple transmission rods; The lifting mechanism is arranged outside the model box. The lifting mechanism includes a connecting seat, a base, and a hydraulic cylinder and a pressure sensor arranged on the base; the connecting seat is arranged above the base, and the connecting seat is connected with the lead screw; the telescopic end of the hydraulic cylinder is connected with the connecting seat, and the hydraulic cylinder is used to drive the connecting seat to move up and down; the pressure sensor is arranged below the connecting seat, and the pressure sensor is used to abut against the bottom of the connecting seat for pressure monitoring; The tunnel wall of the tunnel model is provided with a grouting hole penetrating through it. The two tunnel openings of the tunnel model are respectively covered with a first flexible sealing plate and a second flexible sealing plate that can be elastically deformed; the first flexible sealing plate is arranged opposite to the first transparent baffle, and a first sealing shaft sleeve is provided on the first flexible sealing plate; the second flexible sealing plate is arranged opposite to the second transparent baffle, and a second sealing shaft sleeve is provided on the second flexible sealing plate; A grouting joint is provided on the first transparent baffle. The grouting joint passes through the first flexible sealing plate and is connected to the grouting hole, and the grouting joint is hermetically connected with the first flexible sealing plate; Both ends of the lead screw are respectively inserted into the first sealing shaft sleeve and the second sealing shaft sleeve; And a third flexible sealing plate that can be elastically deformed is arranged in the first through hole. A third sealing shaft sleeve is provided on the third flexible sealing plate, and the lead screw is hermetically sleeved in the third sealing shaft sleeve; A fourth flexible sealing plate capable of telescopic deformation is arranged in the second through hole. A fourth sealing shaft sleeve is arranged on the fourth flexible sealing plate, and the lead screw is sealingly sleeved in the fourth sealing shaft sleeve.

2. The tunnel boring test device according to claim 1, wherein a first shaft hole is arranged at the geometric center of the first flexible sealing plate, and a second shaft hole is arranged at the geometric center of the second flexible sealing plate; The first sealing shaft sleeve includes a first inner plate with holes, a first outer plate with holes and a first sealing bearing. In the direction from the inside to the outside of the tunnel model, the first inner plate with holes, the first shaft hole and the first outer plate with holes are arranged in a state where the hole positions are coaxial in sequence, and the first inner plate with holes, the first shaft hole and the first outer plate with holes are fixedly connected by bolts; the first sealing bearing is sealingly installed in the hole positions of the first inner plate with holes, the first shaft hole and the first outer plate with holes, and the lead screw is sealingly sleeved in the first sealing bearing; The second sealing shaft sleeve includes a second inner plate with holes, a second outer plate with holes and a second sealing bearing. In the direction from the inside to the outside of the tunnel model, the second inner plate with holes, the second shaft hole and the second outer plate with holes are arranged in a state where the hole positions are coaxial in sequence, and the second inner plate with holes, the second shaft hole and the second outer plate with holes are fixedly connected by bolts; the second sealing bearing is sealingly installed in the hole positions of the second inner plate with holes, the second shaft hole and the second outer plate with holes, and the lead screw is sealingly sleeved in the second sealing bearing.

3. The tunnel boring test device according to claim 1, wherein a third shaft hole is arranged at the geometric center of the third flexible sealing plate, and a fourth shaft hole is arranged at the geometric center of the fourth flexible sealing plate; The third sealing shaft sleeve includes a third inner plate with holes, a third outer plate with holes and a third sealing bearing. In the direction from the inside to the outside of the tunnel model, the third inner plate with holes, the third shaft hole and the third outer plate with holes are arranged in a state where the hole positions are coaxial in sequence, and the third inner plate with holes, the third shaft hole and the third outer plate with holes are fixedly connected by bolts; the third sealing bearing is sealingly installed in the hole positions of the third inner plate with holes, the third shaft hole and the third outer plate with holes, and the lead screw is sealingly sleeved in the third sealing bearing; The fourth sealing shaft sleeve includes a fourth inner plate with holes, a fourth outer plate with holes and a fourth sealing bearing. In the direction from the inside to the outside of the tunnel model, the fourth inner plate with holes, the fourth shaft hole and the fourth outer plate with holes are arranged in a state where the hole positions are coaxial in sequence, and the fourth inner plate with holes, the fourth shaft hole and the fourth outer plate with holes are fixedly connected by bolts; the fourth sealing bearing is sealingly installed in the hole positions of the fourth inner plate with holes, the fourth shaft hole and the fourth outer plate with holes, and the lead screw is sealingly sleeved in the fourth sealing bearing.

4. The tunnel boring test device according to claim 1, wherein the tunnel boring test device further includes a first arc-shaped positioning plate and a second arc-shaped positioning plate; Multiple pieces of the first arc-shaped positioning plates are all attached to the outer surface of the first flexible sealing plate. Multiple pieces of the first arc-shaped positioning plates are respectively arranged in alignment with multiple pieces of the rigid arc-shaped plates, and the first arc-shaped positioning plates, the first flexible sealing plate and the rigid arc-shaped plates are fixedly connected by bolts; Multiple pieces of the second arc-shaped positioning plates are all attached to the outer surface of the second flexible sealing plate. Multiple pieces of the second arc-shaped positioning plates are respectively arranged in alignment with multiple pieces of the rigid arc-shaped plates, and the second arc-shaped positioning plates, the second flexible sealing plate and the rigid arc-shaped plates are fixedly connected by bolts.

5. The tunnel boring test device according to claim 1, wherein The first through hole and the second through hole are stepped holes, and the tunnel boring test device further includes a first pressure ring and a second pressure ring; The periphery of the third flexible sealing plate is clamped between the stepped surface of the first through hole and the first pressure ring, and the first pressure ring and the stepped surface of the first through hole are fixedly connected by bolts; The periphery of the fourth flexible sealing plate is clamped between the stepped surface of the second through hole and the second pressure ring, and the second pressure ring and the stepped surface of the second through hole are fixedly connected by bolts.

6. The tunnel boring test device according to claim 1, wherein A limiting plate is supported on the lead screw. The limiting plate is arranged inside the tunnel model. Multiple limiting grooves are provided on the limiting plate, and multiple limiting grooves all extend along the radial direction of the tunnel model; Multiple mounting plates are connected to multiple pieces of the support plates. Multiple limiting pins are provided on multiple mounting plates. Multiple limiting pins are respectively inserted into multiple limiting grooves, and the cooperation between multiple limiting pins and multiple limiting grooves is used to limit the expansion and contraction range of the tunnel model.

7. The tunnel boring test device according to claim 1, wherein The tunnel boring test device further includes a sand rain sand leakage mechanism. The sand rain sand leakage mechanism includes a support frame, a sand box and a height adjustment unit; The height adjustment unit is provided on the support frame; The sand box includes a fixed box body and a detachable box body arranged side by side. Two fixed box bodies are respectively arranged on opposite sides of the detachable box body. The detachable box body is detachably connected to the sand box. Inlets for sand are provided at the tops of the fixed box body and the detachable box body, and sand discharge doors with controllable opening and closing are provided at the bottoms of the fixed box body and the detachable box body; The height adjustment unit is connected to the sand box, and the height adjustment unit is used to adjust the hanging height of the sand box inside the support frame.

8. The tunnel boring test device according to claim 7, wherein, One of the multiple detachable box bodies is a middle detachable box body, and the rest are side detachable box bodies. Along the length direction of the sand box, the length dimension of the middle detachable box body is greater than the length dimension of the side detachable box bodies, and two side detachable box bodies are symmetrically arranged on opposite sides of the middle detachable box body.

9. The tunneling test device according to claim 7, characterized in that, The height adjustment unit includes a winch and a rope guiding unit. A rope is wound around the winch, and the rope hangs the sand box after passing around the rope guiding unit.

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