Hydraulic coupling model test device for karst tunnel excavation and use method

Abstract

The invention provides a hydraulic coupling model test device for karst tunnel excavation and a use method, and relates to the technical field of tunnel models.The device comprises a box body, and at least one set of door openings directly facing each other are formed in the first side wall and the second side wall of the box body; the partition plate assembly is detachably connected with the box body and divides the interior of the box body into at least two containing grooves, and the at least two containing grooves are suitable for being filled with simulation materials. The water supply assembly comprises a first water tank moving in the height direction of the box body, and the first water tank selectively communicates with the bottom of the box body; the pressure assembly comprises a pressing plate located on the top of the box body, and the pressing plate selectively moves towards or away from the interior of the box body. According to the method, the geological environment of the lava-non-lava contact zone can be truly simulated, meanwhile, excavation is conducted by selecting the door opening, the tunnel excavation process of the lava-non-lava contact zone in a real scene can be simulated, and therefore the risk point in the tunnel excavation project can be predicted.

Description

Technical Field

[0001] This invention relates to the field of tunnel model technology, and more specifically, to a hydraulic coupling model test device and its usage method for karst tunnel excavation. Background Technology

[0002] In tunnel construction, sections traversing the contact zone between soluble and insoluble rocks face an extremely high risk of sudden water inrush. This type of stratum not only exhibits significant differences in rock strength and uneven rock mass integrity, but also suffers from hydraulic coupling effects under high-pressure, water-rich conditions, further exacerbating the risk of instability after tunnel excavation. Existing tunnel geomechanical model testing devices primarily focus on simulating single rock strata or general aquifers, exhibiting significant limitations in simulating the unique geological structure of the "soluble-insoluble rock contact zone," which possesses substantial permeability differences and interface effects. Summary of the Invention

[0003] The purpose of this invention is to provide a hydraulic coupling model test device and its usage method for karst tunnel excavation, in order to improve the aforementioned problems. To achieve the above objective, the technical solution adopted by this invention is as follows:

[0004] In a first aspect, this application provides a hydraulic coupling model test device for karst tunnel excavation, comprising: a box body with an open top, the box body including a first sidewall and a second sidewall facing each other, the first sidewall and the second sidewall being provided with at least one set of doorways facing each other; a partition assembly detachably connected to the box body, the partition assembly being adapted to divide the interior of the box body into at least two receiving slots, the at least two receiving slots being adapted to be filled with simulation materials; a water supply assembly including a first water tank adapted to move along the height direction of the box body, the first water tank being selectively connected to the bottom of the box body; and a pressure assembly including a pressure plate located at the top of the box body, the pressure plate being selectively movable toward or away from the interior of the box body.

[0005] In a second aspect, this application provides a method for using a hydraulic coupling model test device for karst tunnel excavation. The method is applicable to the hydraulic coupling model test device for karst tunnel excavation described in the first aspect, comprising: filling at least two receiving slots within a box with different simulated materials; vertically lifting the partition assembly; controlling the pressure plate of the pressure assembly to move towards the box and apply a vertical load to the simulated materials within the box; connecting a first water tank to the bottom of the box and raising the first water tank to a preset height; manually drilling through corresponding openings to excavate the simulated materials within the box to excavate a tunnel model; wherein, during tunnel model excavation, excavation is carried out segment by segment according to a preset advance, and after each advance, the process is paused and data from sensors within the box is collected; after the sensor data stabilizes, initial support is simulated using shotcrete until a sudden water inrush disaster is induced.

[0006] The beneficial effects of this invention are as follows:

[0007] The hydraulic coupling model test device for karst tunnel excavation of the present invention features a detachable partition assembly that can accurately and conveniently construct the complex geological structure of the soluble-insoluble rock contact zone, achieving physical simulation of multi-lithological strata conditions. Furthermore, through water supply and pressure components, it enables independent and precise control of the stress and seepage fields of the simulated materials within the chamber, achieving flexible and stable simulation of high ground stress, high-pressure water-rich conditions, and various working conditions. Simultaneously, by selecting different portals for excavation, it can simulate single-tunnel, double-tunnel tunnels at the same height, and double-tunnel tunnels at different heights. Therefore, this application, through the above-mentioned setup, can more realistically simulate the geological environment of the soluble-insoluble rock contact zone. Moreover, by selecting different portals for excavation, it can simulate the process of excavating a tunnel in the soluble-insoluble rock contact zone under real-world conditions, thereby simulating the tunnel excavation process before actual tunnel construction and predicting potential risks during tunnel excavation.

[0008] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a front view of the hydraulic coupling model test setup;

[0011] Figure 2 This is a schematic diagram of the water supply components;

[0012] Figure 3 This is a schematic diagram of the partition assembly;

[0013] Figure 4 This is a schematic diagram of a flange.

[0014] Marked in the image:

[0015] 10. Housing; 11. Flange;

[0016] 20. Partition assembly; 21. Partition body; 22. Sealing strip; 23. Supporting component;

[0017] 30. Water supply components; 31. First water tank; 32. Support bracket; 33. Connecting rope; 34. Pulley; 35. Second water tank; 36. Overflow pipe;

[0018] 41. Pressure plate; 42. Base; 43. Support frame; 44. Hydraulic cylinder. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] Example 1:

[0022] like Figures 1-4As shown, this embodiment provides a hydraulic coupling model test device for karst tunnel excavation, including: a box body 10, a partition assembly 20, a water supply assembly 30, and a pressure assembly. The top of the box body 10 is open. The box body 10 includes a first side wall and a second side wall facing each other. The first side wall and the second side wall are provided with at least one set of door openings facing each other. The partition assembly 20 is detachably connected to the box body 10. The partition assembly 20 is adapted to divide the interior of the box body 10 into at least two receiving slots. The at least two receiving slots are respectively adapted to be filled with simulation materials. The water supply assembly 30 includes a first water tank 31 adapted to move along the height direction of the box body 10. The first water tank 31 is selectively connected to the bottom of the box body 10. The pressure assembly includes a pressure plate 41 located at the top of the box body 10. The pressure plate 41 is selectively movable toward or away from the interior of the box body 10.

[0023] In some embodiments, the top of the housing 10 is open, and the housing 10 has a first sidewall and a second sidewall facing each other. At least one set of doorways facing each other is provided on the first and second sidewalls, that is, doorways facing each other are provided on the first and second sidewalls respectively, and the doorways facing each other on the first and second sidewalls constitute a set of doorways. The partition assembly 20 is detachably connected to the housing 10. The partition assembly 20 can be installed or removed from the housing 10 through the open opening at the top of the housing 10. The partition assembly 20 can divide the internal space of the housing 10 into at least two receiving slots, and different receiving slots are used to fill different simulation materials to simulate the complex geological conditions around a karst tunnel.

[0024] The water supply assembly 30 includes a first water tank 31 that can move along the height of the housing 10. The first water tank 31 is selectively connected to the bottom of the housing 10. When it is necessary to simulate a groundwater environment, the first water tank 31 can be connected to the bottom of the housing 10, allowing water in the tank to flow into the housing 10 to simulate groundwater seepage. When water supply is not needed or other operations are required, the connection can be disconnected. It is worth mentioning that by moving the first water tank 31, the influence of different water levels (water heads at different heights) on karst tunnels can also be simulated. The pressure assembly includes a pressure plate 41 set on the top of the housing 10. The pressure plate 41 can be selectively moved toward or away from the interior of the housing 10. When the pressure plate 41 moves toward the interior of the housing 10, it can apply pressure to the simulated material inside the housing 10, simulating the pressure effect of the overlying rock strata on the tunnel. When the pressure plate 41 moves away from the interior of the housing 10, the pressure application is released.

[0025] Understandably, when using the hydraulic coupling model test device for karst tunnel excavation of this application, the partition assembly 20 is first placed inside the box 10 through the top of the box 10. At this time, the partition assembly 20 divides the box 10 into at least two receiving slots. Here, the number of receiving slots is three, and siltstone, quartz sandstone, and dolomite are placed in the three receiving slots in sequence. The siltstone is used to simulate insoluble rock, the quartz sandstone is used to simulate the contact zone rock mass (soluble rock-insoluble rock contact zone), and the dolomite is used to simulate the contact zone rock mass (soluble rock-insoluble rock contact zone). The simulated soluble rock, quartz sandstone, is located between siltstone and dolomite. The simulated material in the three containment tanks is then compacted. Next, the partition assembly 20 is vertically lifted out and the pressure plate 41 of the pressure assembly is moved toward the box 10 to apply a vertical load to the simulated material in the box 10. Then, the first water tank 31 is connected to the bottom of the box 10 so that the water in the first water tank 31 can enter the box 10. Finally, the simulated material in the box 10 is excavated through one or more sets of doorways to simulate the tunnel excavation process.

[0026] It is worth mentioning that when excavating the simulated material, the excavation proceeded from the doorway on the first side wall to the corresponding doorway on the second side wall, and the direction of excavation for the simulated material was: insoluble rock - contact zone rock mass - soluble rock.

[0027] It should be noted that when excavating the simulated material, it is possible to excavate only one set of portals or to excavate multiple sets of portals simultaneously to simulate single-tube tunnels, double-tube tunnels at the same height, and double-tube tunnels at different heights.

[0028] It should also be noted that when filling the three containment tanks with simulated material, a layered filling method is adopted. That is, after filling the three containment tanks with the first layer of simulated material, the second layer of simulated material is then filled into the three containment tanks. When the simulated material is filled to the preset height, the sensors are placed. Preferably, five monitoring sections are preset along the longitudinal direction of the tunnel, each monitoring section being perpendicular to the tunnel axis. Each of the five monitoring sections is equipped with multiple sets of sensors. Each set of sensors includes a pore water pressure sensor, an earth pressure sensor, and a wire displacement sensor. The multiple sets of sensors are arranged sequentially along the circumference of the monitoring section. Within each set of sensors, each sensor is spaced apart on the horizontal plane to avoid mutual interference between the sensors.

[0029] Preferably, the hydraulic coupling model test device also includes a static strain gauge, a dynamic signal acquisition instrument, a high-definition camera, and a digital camera. The static strain gauge (TST3826F-H) is used to collect information on seepage pressure and surrounding rock pressure, the dynamic signal acquisition instrument (DHDAS) is used to collect information on surrounding rock deformation, and the high-definition camera and digital camera are used to record the tunnel excavation process and the evolution of water and mud inrush disasters in real time during the test.

[0030] According to the present invention, the hydraulic coupling model test device for karst tunnel excavation has a detachable partition assembly 20 that can accurately and conveniently construct the complex geological structure of the contact zone between soluble and insoluble rocks, realizing the physical simulation of multi-lithological strata conditions. Moreover, through the water supply assembly 30 and the pressure assembly, the stress field and seepage field of the simulated material inside the box 10 can be independently and accurately controlled, realizing flexible and stable simulation of high ground stress, high pressure and water-rich conditions and different working conditions. At the same time, by selecting different portals for excavation, it can simulate single-tube tunnels, double-tube tunnels at the same height, and double-tube tunnels at different heights.

[0031] Therefore, this application can more realistically simulate the geological environment of the soluble rock-insoluble rock contact zone through the above settings. At the same time, by selecting to excavate different portals, it can simulate the process of excavating a tunnel in the soluble rock-insoluble rock contact zone in a real scenario. In this way, the tunnel excavation project can be simulated before the actual tunnel construction begins, thereby predicting the risk points in the tunnel excavation project.

[0032] According to some embodiments of the present invention, the water supply assembly 30 further includes a support bracket 32 ​​and a connecting rope 33. A pulley 34 is provided on the top of the support bracket 32. One end of the connecting rope 33 is connected to a winding device, and the other end of the connecting rope 33 passes around the pulley 34 and is connected to the first water tank 31.

[0033] In some embodiments, a pulley 34 is provided on the top of the support bracket 32, and a connecting rope 33 is fitted onto the pulley 34. One end of the connecting rope 33 is connected to the first water tank 31, and the other end of the connecting rope 33 is connected to a winding device. The winding device can wind up the connecting rope 33, and the winding of the connecting rope 33 can raise and lower the first water tank 31. It is worth mentioning that the winding device can be a hand-operated hoist or a winding machine, etc., and is not limited here.

[0034] According to some embodiments of the present invention, the water supply assembly 30 further includes a second water tank 35, which is located at the bottom of the first water tank 31 and cooperates with the support bracket 32 ​​and / or the ground. A water pump is provided in the second water tank 35, with the water pump inlet communicating with the inside of the second water tank 35 and the water pump outlet communicating with the inside of the first water tank 31.

[0035] In some embodiments, the second water tank 35 may be connected and fixed to the support bracket 32; the second water tank 35 may be supported on the ground; or the second water tank 35 may be connected and fixed to the support bracket 32 ​​and supported on the ground, which is not limited here.

[0036] It is understandable that the water pump in the second water tank 35 can pump the water in the second water tank 35 into the first water tank 31 to replenish the water in the first water tank 31, so as to avoid insufficient water in the first water tank 31 and thus fail to ensure the water-rich state of the simulated material in the tank 10.

[0037] According to some embodiments of the present invention, an overflow pipe 36 is connected to the side wall of the first water tank 31, one end of the overflow pipe 36 is connected to the inside of the first water tank 31, and the other end of the overflow pipe 36 is connected to the inside of the second water tank 35.

[0038] In some embodiments, the overflow pipe 36 may be connected to the side wall of the first water tank 31, or it may be connected to the bottom wall and side wall of the first water tank 31; no limitation is made here. The top end of the overflow pipe 36 extends into the first water tank 31 and is located at a preset height, while the bottom end of the overflow pipe 36 extends into the second water tank 35.

[0039] Therefore, the water pump in the second water tank 35 can pump water from the second water tank 35 into the first water tank 31 to replenish the water in the first water tank 31. When the water level in the first water tank 31 exceeds a preset value, the water in the first water tank 31 can flow into the second water tank 35 through the overflow pipe 36, thus completing the water circulation. Thus, through the above configuration, water waste is avoided while ensuring that the water level in the first water tank 31 remains at the preset level.

[0040] In some embodiments, a water inlet pipe is provided at the bottom of the housing 10, and a first valve is provided at the water inlet pipe. The water inlet pipe is connected to the first water tank 31. A first drain pipe is also provided at the bottom of the housing 10. One end of the first drain pipe is connected to the inside of the housing 10, and a second valve is provided at the other end of the first drain pipe. A second drain pipe is provided at the bottom of the second housing 10. One end of the second drain pipe is connected to the inside of the second housing 10, and a third valve is provided at the other end of the second drain pipe.

[0041] According to some embodiments of the present invention, the partition assembly 20 includes two partition bodies 21, which are detachably connected to the housing 10. The two partition bodies 21 are adapted to divide the interior of the housing 10 into a first space, a second space, and a third space, which are respectively adapted to be filled with simulated materials.

[0042] In some embodiments, a first space, a second space, and a third space are arranged sequentially. The first space contains siltstone, which is used to simulate insoluble rock. The second space contains quartz sandstone, which is used to simulate contact zone rock mass (soluble rock-insoluble rock contact zone). The third space contains dolomite, which is used to simulate soluble rock.

[0043] According to some embodiments of the present invention, the two ends of the partition body 21 are respectively stopped by the inner wall of the box 10 through sealing strips 22. It can be understood that the sealing strips 22 can ensure that the simulated materials in the first space, the second space and the third space do not mix with each other when filling the simulated material.

[0044] In some embodiments, the bottom of the partition body 21 is supported on the bottom of the box 10 by the support member 23 to ensure the verticality and stability of the partition body 21. The top of the partition body 21 is provided with two lifting holes to facilitate the lifting operation of the partition body 21. In addition, the surface of the partition body 21 is coated with a lubricating layer (petroleum jelly can be applied to the surface of the partition body 21 to form a lubricating layer) to reduce the frictional resistance when the partition body 21 is pulled out after the simulated material is compacted.

[0045] According to some embodiments of the present invention, the pressure assembly further includes a base 42 and a support frame 43, the base 42 being adapted to cooperate with the ground, the support frame 43 being connected to the base 42, and the pressure plate 41 being connected to the support frame 43 via a hydraulic cylinder 44.

[0046] In some embodiments, two bases 42 are configured to be disposed in the width direction of the housing 10, and the support frame 43 is configured in a "door" shape. The bottom of the support frame 43 is connected to the two bases 42 respectively. A plurality of hydraulic cylinders 44 are disposed on the support frame 43, and the piston rods of the plurality of hydraulic cylinders 44 are respectively connected to the pressure plate 41. The operation of the plurality of hydraulic cylinders 44 can jointly drive the pressure plate 41, thereby enabling the pressure plate 41 to move toward or away from the housing 10. Preferably, the bases 42 are connected to the housing 10 to ensure the stability of the bases 42, thereby ensuring the stability of the support frame 43.

[0047] According to some embodiments of the present invention, the bottom of the support frame 43 is rotatably connected to the base 42. The support frame 43 rotates and has a loading state and a clearance state. In the loading state, the projection of the pressure plate 41 in the height direction of the housing 10 is located inside the housing 10. In the clearance state, the projection of the pressure plate 41 in the height direction of the housing 10 is spaced apart from the housing 10. Preferably, the support frame 43 is connected to the base 42 via a rotating shaft. Further, a rotating motor is fixedly installed on the base 42, and the rotating shaft of the rotating motor is fixedly connected to the support frame 43.

[0048] In some embodiments, the support frame 43 is rotatably connected to the base 42 and has a loaded state and a clearance state. In the loaded state, the support frame 43 rotates relative to the housing 10 so that the pressure plate 41 is located at the top of the housing 10. At this time, the projection of the pressure plate 41 in the height direction of the housing 10 is located inside the housing 10. In the clearance state, the support frame 43 rotates relative to the housing 10 and is located on one side of the housing 10. At this time, the projection of the pressure plate 41 in the height direction of the housing 10 is spaced apart from the housing 10.

[0049] According to some embodiments of the present invention, the hydraulic coupling model test device for karst tunnel excavation further includes flanges 11, which are configured to correspond one-to-one with multiple door openings. The multiple flanges 11 are respectively connected to the housing 10 by fasteners. The connection between the flanges 11 and the housing 10 is suitable for sealing the corresponding door openings.

[0050] In some embodiments, when filling the simulated material, multiple flanges 11 are connected to the housing 10 to close multiple openings. After the simulated material is filled and the pressure plate 41 has applied a load to the simulated material, the flanges 11 of the corresponding opening group are removed. At this time, the simulated material can be excavated through the opening by manual drilling.

[0051] Understandably, the flange 11 is designed to prevent leakage of the simulated material during filling, ensuring the filling efficiency of the simulated material and the effectiveness of the load application.

[0052] In some specific embodiments, the box 10 is a sealed pressure-bearing box 10 constructed by welding stiffening steel plates. The internal clear dimensions of the box 10 are 3.0m in length, 2.0m in width, and 3.0m in height. The thickness of the main steel plate is 10mm to ensure sufficient structural strength. To resist the high internal pressure and ensure the stability of the geometric boundaries, crisscrossing stiffening ribs are welded to the outer walls of each side of the box 10 to form a regular grid-like reinforcing structure. Specifically, the stiffening ribs are evenly arranged at a spacing of 0.5m, and their cross-section is rectangular, with a height of 0.2m protruding from the outer surface of the box 10. Three sets of doorways for simulating tunnel entrances are correspondingly opened on the two opposite side walls (the first side wall and the second side wall) of the housing 10. A detachable flange 11 is provided at each doorway. The flange 11 is detachably connected to the housing 10 by evenly distributed screws and nuts, with a sealing rubber ring embedded between the connection surfaces to ensure a seal. The diameter of the doorway is 0.3m, and the diameter of the flange 11 is 0.4m, ensuring that the diameter of the flange 11 is larger than the diameter of the doorway. By closing or opening different flanges 11, various tunnel layouts such as single-tunnel and double-tunnel configurations can be flexibly simulated. Double-tunnel configurations can simulate situations at the same elevation or at different elevations. A water inlet is located at the bottom of the right side wall of the housing 10 (the side wall between the first and second side walls), and a drain outlet is located at the bottom of the same side wall. The water inlet and drain outlet are used to connect to the water supply pipe and the drainage pipe, respectively. The free end of the water supply pipe is connected to and communicates with the first housing 10. Multiple sealed lead wire holes are provided on the upper side wall of the housing 10 for leading the wires of the internal monitoring sensors to the external data acquisition equipment.

[0053] The partition body 21 is made of steel plate with a thickness of 10mm. The planar dimensions of the partition body 21 are 3.0m long and 2.7m high to match the inner cavity of the box 10. A compressible elastic sealing strip 22 is provided between the side of the partition body 21 and the inner wall of the box 10.

[0054] The water supply system provides a stable and precisely controllable osmotic pressure for the simulated material inside the tank 10. The water supply system mainly includes water supply pipelines, a first water tank 31, a second water tank 35, and a height adjustment device. In a preferred embodiment, the second water tank 35 has a volume of 3m³. 3 The effective volume of the first water tank 31 is approximately 2m³. 3 To meet the water circulation and replenishment needs during the experiment, the first water tank 31 is connected to the inlet of the tank body 10 via a water supply pipeline. The height adjustment device includes a tripod (support bracket 32), a connecting rope 33, and a fixed pulley at the top of the tripod. One end of the connecting rope 33 is connected to the first water tank 31, and the other end of the connecting rope 33 passes around the fixed pulley and is connected to an external force application source (winding device). Different groundwater heads are simulated by raising and lowering the height of the first water tank 31. Preferably, by adjusting the height of the first water tank 31, different levels of groundwater head conditions such as 60m, 80m, and 100m can be stably simulated. The first water tank 31 is equipped with an overflow pipe 36. The inlet height of the overflow pipe 36 determines the water supply head. Excess water overflows through the overflow pipe 36 to the second water tank 35 to maintain a constant water level. The second water tank 35 is equipped with a submersible pump. The inlet of the submersible pump is connected to the second water tank 35, and the outlet of the submersible pump is connected to the first water tank 31, thus forming a complete water circulation.

[0055] A pressure assembly is mounted on top of the housing 10 to apply a stable and controllable vertical load to simulate the pressure of the overlying rock and soil in a tunnel. The pressure assembly includes a support frame 43, a pressure plate 41, four vertically arranged loading cylinders (hydraulic cylinders 44), and a movable beam support structure (base 42). The support frame 43 is mounted on top of the housing 10 via the movable beam support structure. The cylinder body of each loading cylinder is fixed to the support frame 43, and its piston rod extends downward into the housing 10 and connects to the pressure plate 41. In a preferred embodiment, the pressure plate 41 is made of 15mm thick steel plate with a planar dimension of 3.0m long and 2.0m wide to match the inner cavity of the housing 10; each loading cylinder has a rated output of 50kN, and the total system loading capacity can reach 200kN, sufficient to simulate the stress of the overlying rock strata in a deeply buried tunnel. All loading cylinders are connected to a unified hydraulic source to achieve synchronous and stable pressurization. The movable beam support structure is designed to allow the entire support frame 43 to switch between a "loaded state" and a "avoidance state". In the loaded state, the support frame 43 is fixed and the projection of the pressure plate 41 in the height direction of the box 10 is located inside the box 10, providing a reaction force. When it is necessary to lift and remove the partition assembly 20 or perform other top operations, it can be switched to the avoidance state, and the support frame 43 can be moved away from the space above the top of the model box, which greatly facilitates the test operation.

[0056] It should be noted that when filling the simulation materials, three different strata structures were set up in the first, second, and third spaces: insoluble rock, soluble rock-insoluble rock contact zone, and soluble rock. The insoluble rock was set as siltstone, the contact zone rock mass as quartz sandstone, and the soluble rock as dolomite. The thickness of the insoluble rock was set to 40cm, the contact zone thickness to 40cm, and the soluble rock thickness to 120cm. The direction of the contact surface of each rock layer was perpendicular to the tunnel excavation direction. Initially, the tunnel was excavated in the insoluble rock layer, and the tunnel successively exposed the contact zone and the soluble rock. Three water head heights were set in the model test: 60m, 80m, and 100m, corresponding to the heights of the first water tank 31 of 1.5m, 2m, and 2.5m. During the test, the soluble rock layer was kept in a water-rich state.

[0057] Five monitoring sections were arranged along the tunnel excavation direction, perpendicular to the tunnel axis. Following the principle of prioritizing monitoring near karst caves, monitoring sections I, II, III, IV, and V were located 30cm, 48cm, 64cm, 76cm, and 84cm ahead of the tunnel face, respectively. Each monitoring section was equipped with monitoring devices, including pore water pressure sensors, earth pressure sensors, and wire-type displacement sensors. Monitoring points were mainly arranged at 8cm and 16cm outside the tunnel centerline at the arch crown and abutment, respectively. A total of 30 pore water pressure sensors, 30 earth pressure sensors, and 30 displacement sensors were installed. All three types of monitoring devices were arranged in the same location, and to avoid mutual interference, they were spaced a certain distance apart on the horizontal plane.

[0058] Example 2:

[0059] This embodiment provides a method for using a hydraulic coupling model test device for karst tunnel excavation. This method is applicable to the hydraulic coupling model test device for karst tunnel excavation in Embodiment 1, and includes:

[0060] Different simulated materials are filled into at least two receiving slots inside the box 10.

[0061] In some embodiments, the number of containment slots can be three, namely a first space, a second space, and a third space, with the second space located between the first space and the third space. The first space contains siltstone, which is used to simulate insoluble rock. The second space contains quartz sandstone, which is used to simulate the contact zone rock mass (soluble rock-insoluble rock contact zone). The third space contains dolomite, which is used to simulate soluble rock.

[0062] The partition assembly 20 is lifted vertically out.

[0063] In some embodiments, the surface of the partition assembly 20 is provided with a lubricating layer to reduce the friction between the partition assembly 20 and the simulated material, thereby facilitating the lifting of the partition assembly 20.

[0064] Understandably, vertically lifting the partition assembly 20 can prevent it from obstructing the subsequent excavation of the simulated material, ensuring that the excavation of the simulated material can proceed smoothly. In addition, it can also prevent the partition assembly 20 from affecting the operation of the pressure plate 41, thereby ensuring the stability and effectiveness of the vertical load applied by the pressure plate 41 to the simulated material.

[0065] The pressure plate 41 of the control pressure assembly moves toward the box 10 and applies a vertical load to the simulated material inside the box 10.

[0066] Connect the first water tank 31 to the bottom of the tank body 10, and raise the first water tank 31 to the preset height.

[0067] In some embodiments, the pressure assembly includes a hydraulic cylinder 44 and a pressure plate 41. The pressure plate 41 is connected to the piston rod of the hydraulic cylinder 44. The hydraulic cylinder 44 drives the pressure plate 41 to apply a predetermined vertical load to the simulated material inside the box 10. Then, the first water tank 31 is connected to the bottom of the box 10 and the first water tank 31 is raised to a preset height. At this time, the water in the first water tank 31 can enter the box 10 from the bottom and saturate the soil from bottom to top.

[0068] The simulated material inside the box 10 is excavated through the corresponding doorway using manual drilling to create a tunnel model. The tunnel model is excavated segment by segment according to a preset advance, and the process is paused and data is collected from the sensors inside the box 10 after each advance.

[0069] Once the sensor data stabilizes, simulate shotcrete for initial support until a sudden water inrush disaster is induced.

[0070] Understandably, the simulated material is excavated through the corresponding portal. Manual drilling is used to simulate the tunnel excavation process, with the excavation direction being: insoluble rock - contact zone rock mass - soluble rock. During excavation, a preset advance is set. After each advance, excavation is paused, and data is collected from the sensors (pore water pressure sensor, soil pressure sensor, and wire-type displacement sensor) inside the housing 10. Once the sensor data stabilizes, initial spraying (simulating shotcrete for initial support) is applied to the excavated tunnel wall using plaster. If no abnormalities are found, the process of "excavation, sensor data collection, and simulated shotcrete" is repeated until a sudden water inrush disaster is induced.

[0071] According to the present invention, the method of using the hydraulic coupling model test device for karst tunnel excavation can more realistically simulate the geological environment of the contact zone between soluble and insoluble rocks. At the same time, by selecting to excavate different portals, the process of excavating a tunnel in the contact zone between soluble and insoluble rocks in a real scenario can be simulated. In this way, the tunnel excavation project can be simulated before the actual tunnel construction begins, thereby predicting the risk points in the tunnel excavation project.

[0072] According to some embodiments of the present invention, when filling the first, second, and third spaces with simulated material, a layered and partitioned filling method is adopted. Specifically, the first, second, and third spaces each include multiple layers of regions along the height direction of the housing 10. During filling, after the first layer of the first, second, and third spaces is filled with simulated material, the second layer of the first, second, and third spaces is filled with simulated material, followed by the third layer, the fourth layer, and so on, until the simulated material is completely filled. It is worth mentioning that a sensor group is arranged when the simulated material is filled to a preset position.

[0073] It should be noted that the ice ball is placed when the simulated material is filled to the preset position. The ice ball is located in the longitudinal direction of the simulated tunnel, that is, at least part of the projection of the ice ball onto the axial direction of the simulated tunnel overlaps with the simulated tunnel. Preferably, the diameter of the ice ball is 20 cm.

[0074] Then, the simulation material is filled again until the ice puck is covered. Next, a connecting pipe is installed, with one end of the connecting pipe connected to the first water tank 31 through the bottom of the box 10, and the other end of the connecting pipe located on top of the ice puck. Then, quick-drying cement is used to fix the connecting pipe to the simulation material. Finally, the simulation material is filled again until the simulation material is completely filled.

[0075] It is worth mentioning that a three-way pipe is provided at the bottom of the box 10. The three-way pipe has a first interface, a second interface and a third interface. The first interface is horizontally set and located outside the box 10, and the first interface is connected to the first water tank 31. The second interface is vertically set and located on the side of the first interface away from the ground, and the second interface is connected to the connecting pipe. The third interface is horizontally set and located inside the box 10, and the third interface is connected to the inside of the box 10.

[0076] It should be noted that the ice ball can form a cave after melting, and the cold air during the melting process can enter the three-way pipe through the connecting pipe and merge with the water. Since the water flow direction is from the first interface to the third interface and the water is flowing water, the cold air of the ice ball can be continuously and stably carried away by the water flow, thereby accelerating the melting rate of the ice ball and improving the experimental efficiency of the hydraulic coupling model test device of this application.

[0077] Therefore, the above-mentioned configuration enables the device of this application to simulate the phenomenon of encountering karst caves in tunnel excavation scenarios, so that the hydraulic coupling model test device of this application can simulate more scenarios, thereby improving the applicability of the hydraulic coupling model test device.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hydraulic coupling model test device for karst tunnel excavation, characterized in that, include: The box (10) has an open top and includes a first sidewall and a second sidewall facing each other, with at least one set of door openings facing each other. A partition assembly (20) is detachably connected to the housing (10). The partition assembly (20) is adapted to divide the interior of the housing (10) into at least two receiving slots, each of which is adapted to be filled with simulated material. Water supply assembly (30), the water supply assembly (30) includes a first water tank (31) adapted to move along the height direction of the tank body (10), the first water tank (31) being selectively connected to the bottom of the tank body (10); The pressure assembly includes a pressure plate (41) located on top of the housing (10), the pressure plate (41) being selectively movable toward or away from the interior of the housing (10).

2. The hydraulic coupling model test device for karst tunnel excavation according to claim 1, characterized in that, The water supply assembly (30) also includes a support bracket (32) and a connecting rope (33). The top of the support bracket (32) is provided with a pulley (34). One end of the connecting rope (33) is connected to a winding device, and the other end of the connecting rope (33) passes around the pulley (34) and is connected to the first water tank (31).

3. The hydraulic coupling model test device for karst tunnel excavation according to claim 2, characterized in that, The water supply assembly (30) also includes a second water tank (35), which is located at the bottom of the first water tank (31) and cooperates with the support bracket (32) and / or the ground. A water pump is installed in the second water tank (35), the inlet of the water pump is connected to the inside of the second water tank (35), and the outlet of the water pump is connected to the inside of the first water tank (31).

4. The hydraulic coupling model test device for karst tunnel excavation according to claim 3, characterized in that, The side wall of the first water tank (31) is connected to an overflow pipe (36), one end of which is connected to the inside of the first water tank (31), and the other end of which is connected to the inside of the second water tank (35).

5. The hydraulic coupling model test device for karst tunnel excavation according to claim 1, characterized in that, The partition assembly (20) includes two partition bodies (21), which are detachably connected to the box (10) respectively. The two partition bodies (21) are adapted to divide the box (10) into a first space, a second space and a third space, which are respectively adapted to be filled with simulated materials.

6. The hydraulic coupling model test device for karst tunnel excavation according to claim 5, characterized in that, The two ends of the partition body (21) are respectively sealed by sealing strips (22) and abut against the inner wall of the box (10).

7. The hydraulic coupling model test device for karst tunnel excavation according to claim 1, characterized in that, The pressure assembly also includes a base (42) and a support frame (43), the base (42) being adapted to fit with the ground, the support frame (43) being connected to the base (42), and the pressure plate (41) being connected to the support frame (43) via a hydraulic cylinder (44).

8. The hydraulic coupling model test device for karst tunnel excavation according to claim 7, characterized in that, The bottom of the support frame (43) is rotatably connected to the base (42). The support frame (43) rotates and has a loading state and a avoidance state. In the loading state, the projection of the pressure plate (41) in the height direction of the box (10) is located inside the box (10). In the avoidance state, the projection of the pressure plate (41) in the height direction of the box (10) is spaced apart from the box (10).

9. The hydraulic coupling model test device for karst tunnel excavation according to claim 1, characterized in that, It also includes flanges (11), which are configured to correspond one-to-one with multiple door openings. The multiple flanges (11) are respectively connected to the housing (10) by fasteners. The flanges (11) are connected to the housing (10) to be suitable for closing the corresponding door openings.

10. A method of using a hydraulic coupling model test device for karst tunnel excavation, the method of use being applicable to the hydraulic coupling model test device for karst tunnel excavation as described in any one of claims 1-9, characterized in that, include: Different simulated materials are filled into at least two receiving slots inside the box (10); The partition assembly (20) is lifted vertically out; The pressure plate (41) of the control pressure assembly moves toward the box (10) and applies a vertical load to the simulated material inside the box (10); Connect the bottom of the first water tank (31) to the bottom of the tank body (10), and raise the first water tank (31) to the preset height; The simulated material inside the box (10) is excavated by manual drilling through the corresponding doorway to excavate the tunnel model; when excavating the tunnel model, the excavation is carried out segment by segment according to the preset advance, and the data of the sensor inside the box (10) is collected after each advance. Once the sensor data stabilizes, simulate shotcrete for initial support until a sudden water inrush disaster is induced.

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