A device and method for simulating karst collapse under conditions of rainfall and variable karst passage

Abstract

The application discloses a device for simulating karst collapse under conditions of simulated rainfall and variable karst passages, which comprises a cover soil layer simulation box, a water head control mechanism arranged on the outer side of the cover soil layer simulation box, a rainfall mechanism arranged above the cover soil layer simulation box, a test soil body contained in the cover soil layer simulation box, a karst hole simulation opening formed in the bottom of the cover soil layer simulation box, and a karst cave simulation box arranged below the cover soil layer simulation box. A simulation pipeline is connected between the karst hole simulation opening and the karst cave simulation box, and the simulation pipeline corresponds to the shape of the simulated karst passage. The simulation pipeline is a hose. A pipeline shaping assembly is further arranged between the karst hole simulation opening and the karst cave simulation box, and the pipeline shaping assembly can shape the simulation pipeline into a required shape. The application can simulate variable karst passages.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of karst collapse simulation, in particular to a device and method for simulating karst collapse under rainfall and variable karst passage conditions. BACKGROUND

[0002] The karst system in the deep karst area is relatively developed, and the karst system includes karst caves, karst fissures and karst passages, which can all provide space for water and soil migration. Under the action of rainfall, the action of underground water, karst water and surface water is intensified, the degree of water and soil loss in the deep karst area is deepened, and the physical properties of the soil in the covering layer change, thereby triggering disasters such as karst collapse. Therefore, it is necessary to develop a simulation test device for deep karst collapse under rainfall conditions to study the water and soil migration law in the deep karst area. The existing karst collapse test device can only simulate a karst passage with a fixed shape, but the shape of some karst passages may change in the process of karst collapse. At present, there is still a lack of a corresponding simulation test device for simulating karst collapse under variable karst passage conditions. SUMMARY

[0003] The present application provides a device and method for simulating karst collapse under rainfall and variable karst passage conditions, which can simulate variable karst passages.

[0004] Technical scheme: In order to achieve the above-mentioned purpose, the device for simulating karst collapse under rainfall and variable karst passage conditions comprises a covering soil layer simulation box, a water head control mechanism is arranged on the outer side of the covering soil layer simulation box, a rainfall mechanism is arranged above the covering soil layer simulation box, a test soil body is contained in the covering soil layer simulation box, a karst hole simulation opening is formed in the bottom of the covering soil layer simulation box, and a karst cave simulation box is arranged below the covering soil layer simulation box; a simulation pipeline is connected between the karst hole simulation opening and the karst cave simulation box, and the simulation pipeline corresponds to the shape of the karst passage; the simulation pipeline is a flexible pipe; a pipeline shaping assembly is further arranged between the karst hole simulation opening and the karst cave simulation box, and the pipeline shaping assembly can shape the simulation pipeline into a required shape.

[0005] Further, the simulation pipeline is detachably assembled between the karst hole simulation opening and the karst cave simulation box, so that the simulation pipeline can be replaced.

[0006] Further, assembly heads are installed at both ends of the simulation pipeline; a pipeline interface is formed in the top of the karst cave simulation box, and the pipeline interface is detachably connected with the assembly head at the lower end of the simulation pipeline; a plurality of karst hole simulation openings are formed in the bottom of the covering soil layer simulation box, each karst hole simulation opening can be independently opened and closed, and the assembly head at the upper end of the simulation pipeline can be selectively connected with one of the karst hole simulation openings.

[0007] Further, the opening size of the karst hole simulation mouth can be adjusted.

[0008] Further, the shape of the pipeline plasticizing assembly can be actively changed, so that the shape of the simulated pipeline can change during the simulation of karst collapse.

[0009] Further, the pipeline plasticizing assembly comprises an inner plasticizing unit and an outer plasticizing unit; the inner plasticizing unit comprises an inner support mold, which is made of hard material and is arranged in the simulated pipeline, and can support the simulated pipeline into a desired shape; a layer of soluble material is coated on the inner support mold, and the layer of soluble material can change the internal shape of the simulated pipeline when it dissolves; the outer plasticizing unit comprises an outer movable support, and the outer wall of the simulated pipeline is provided with a plurality of force receiving points, and the outer movable support is connected with the force receiving points; the outer movable support can actively deform to change the shape of the simulated pipeline.

[0010] Further, the inner support mold is arranged on the upper surface of the inner wall of the simulated pipeline to shape the upper profile surface of the simulated pipeline, and a layer of soluble material is coated on the side of the inner support mold facing the lower surface of the inner wall of the simulated pipeline; the outer movable support is connected with the force receiving points on the lower surface of the outer wall of the simulated pipeline to shape the lower profile surface of the simulated pipeline.

[0011] Further, the water head control mechanism comprises two water storage tanks, which are arranged on the two sides of the overburden simulation box, and each of the two water storage tanks is connected with the water delivery holes on the two sides of the overburden simulation box or the karst cave simulation box through a water delivery pipe; the two water storage tanks are respectively installed on vertical guide rails, so that the height of the two water storage tanks can be adjusted.

[0012] Further, the rainfall mechanism comprises a plurality of rows of rainfall pipes arranged above the overburden simulation box, and the rainfall pipes are provided with water outlet holes; a water tank supplies water to the plurality of rows of rainfall pipes through a water pump.

[0013] Further, a method for simulating karst collapse under variable karst passage conditions and rainfall, comprising the following steps: step S1: obtaining a shape structure of a karst passage required to be simulated, and predicting a shape change trend of the karst passage in a karst collapse process according to software; step S2: manufacturing an inner support mold according to the shape structure of the karst passage required to be simulated, coating a soluble material layer on the inner support mold, then inserting the inner support mold into a simulation pipeline, and making the soluble material layer face a lower surface of an inner wall of the simulation pipeline, so as to shape an upper profile surface of the simulation pipeline by the inner support mold; step S3: assembling the simulation pipeline between a karst hole simulation opening and a karst cave simulation box, then connecting an outer movable support to force end points on a lower surface of an outer wall of the simulation pipeline, and then actively deforming the outer movable support by a computer, so as to shape a lower profile surface of the simulation pipeline by the outer movable support; step S4: loading a test soil into the cover soil layer simulation box; step S5: a water head control mechanism supplies water to the cover soil layer simulation box and the karst cave simulation box to simulate underground water; step S6: a rainfall mechanism is started to simulate rainfall, and the rainfall makes water and soil in the cover soil layer simulation box flow to the karst cave simulation box through the simulation pipeline; in the process of rainfall, the soluble material layer is dissolved, and the computer controls deformation of the outer movable support according to a prediction of the software, to jointly simulate shape change of the karst passage in the karst collapse process.

[0014] Beneficial effects: The device and method for simulating karst collapse under variable karst passage conditions and rainfall have the following beneficial effects:

[0015] 1) The simulation pipeline is used to simulate the shape of the karst passage, the simulation pipeline is a hose, and the simulation pipeline can be shaped into a required shape by a pipeline shaping assembly, so that the simulation pipeline can simulate the karst passage with variable shape;

[0016] 2) The upper profile surface of the simulation pipeline is shaped by the inner support mold, the inner support mold is coated with a soluble material layer, the soluble material layer is gradually dissolved in the process of water and soil loss, so as to simulate the change of the karst passage under natural conditions; the lower profile surface of the simulation pipeline is shaped by the outer movable support, and the shape of the outer movable support is controlled by the simulation result of the computer, so as to change the shape of the lower profile surface of the simulation pipeline; thus, in the present application, the simulation result of the computer and the simulation result of the soluble material layer are combined, compared with a single simulation result, the two simulation results are combined to reduce errors and improve simulation effect. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a perspective view of the simulation device; Figure 1 Figure 2 is a front view of the simulation device;

[0018] Figure 3 is a perspective view of the simulation device; Figure 2 Figure 4 is a front view of the simulation device;

[0019] Figure 5 is a perspective view of the simulation device; Figure 3Figure 2 is a sectional view of the simulation device;

[0020] Figure 1 is a schematic view of the simulation device. Figure 4 Figure 3 is a schematic view of the inner support mold and the force end point. DETAILED DESCRIPTION

[0021] The application will be further described below with reference to the drawings.

[0022] Figure 1 is a schematic view of the simulation device. Figures 1 to 4 The device for simulating rainfall and karst collapse under variable karst passage conditions comprises a cover soil layer simulation box 1, a water head control mechanism 2 arranged on the outer side of the cover soil layer simulation box 1, a rainfall mechanism 3 arranged above the cover soil layer simulation box 1, a test soil body contained in the cover soil layer simulation box 1, a karst hole simulation opening 4 formed in the bottom of the cover soil layer simulation box 1, and a karst cave simulation box 5 arranged below the cover soil layer simulation box 1. The bottom of the karst cave simulation box 5 is provided with a water outlet hole for discharging substances in the karst cave simulation box 5. The karst cave simulation box 5 is installed on the device in a push-pull manner to control the air tightness of the simulation device.

[0023] The simulation pipeline 6 is connected between the karst hole simulation opening 4 and the karst cave simulation box 5 and corresponds to the shape of the simulated karst passage. The simulation pipeline 6 is a flexible pipe. The karst hole simulation opening 4 and the karst cave simulation box 5 are further provided with a pipeline shaping assembly which can shape the simulation pipeline 6 into a required shape. The pipeline shaping assembly shapes and changes the shape of the simulation pipeline 6, so that the simulation pipeline 6 can simulate a karst passage with variable deformation.

[0024] The simulation pipeline 6 is detachably assembled between the karst hole simulation opening 4 and the karst cave simulation box 5, so that the simulation pipeline 6 can be replaced. The simulation pipeline 6 can be replaced with a pipe body with different shapes, different materials and different sizes, so as to simulate different karst passages.

[0025] The two ends of the simulation pipeline 6 are respectively provided with assembly heads 7. The top of the karst cave simulation box 5 is provided with a pipeline interface 8 which is detachably connected with the assembly head 7 at the lower end of the simulation pipeline 6. The bottom of the cover soil layer simulation box 1 is provided with a plurality of karst hole simulation openings 4 which can be individually opened and closed. The assembly head 7 at the upper end of the simulation pipeline 6 can be selectively connected with one of the karst hole simulation openings 4. Although the simulation pipeline 6 is a flexible pipe with variable shape, the relative positions of the upper and lower ends of the simulation pipeline 6 are fixed after the simulation pipeline 6 is assembled and cannot be changed. Therefore, a plurality of karst hole simulation openings 4 are arranged at the bottom of the cover soil layer simulation box 1, and the relative positions of the upper and lower ends of the simulation pipeline 6 can be changed by selecting different karst hole simulation openings 4.

[0026] The opening size of the karst hole simulation port 4 is adjustable to simulate karst channels with different opening sizes.

[0027] The shape of the pipe shaping component can be actively changed, so that the shape of the simulated pipe 6 can change during the process of simulating karst collapse. Through the active change of the pipe shaping component, the simulated pipe 6 can simulate the karst channel with variable deformation.

[0028] Specifically, the pipe molding assembly includes an internal molding unit and an external molding unit. The internal molding unit shapes the simulated pipe 6 from the inside of the pipe, while the external molding unit shapes the simulated pipe 6 from the outside of the pipe.

[0029] As attached Figure 4 As shown, the in-pipe molding unit includes an inner support mold 9, which is made of a rigid material. Since the simulated pipe 6 is a flexible tube, the inner support mold 9 can be inserted into the simulated pipe 6 and can shape the simulated pipe 6 into the desired form. In addition, a soluble material layer 11 is deposited on the inner support mold 9. The soluble material layer 11 can dissolve in water. When water and soil flow through the simulated pipe 6, the soluble material layer 11 will dissolve and change the internal shape of the simulated pipe 6.

[0030] The external molding unit includes an external movable support. Several force-bearing endpoints 10 are provided on the outer wall of the simulated pipe 6. The external movable support is connected to the multiple force-bearing endpoints 10, and the shape of the simulated pipe 6 is shaped by the external movable support. The external movable support can actively deform to change the shape of the simulated pipe 6.

[0031] The inner support mold 9 is mounted on the upper surface of the inner wall of the simulated pipe 6 to shape the upper contour surface of the simulated pipe 6. A soluble material layer 11 is deposited on the side of the inner support mold 9 facing the lower surface of the inner wall of the simulated pipe 6. If the inner support mold 9 were located on the lower surface of the inner wall of the simulated pipe 6, the dissolution rate of the soluble material layer 11 would be too fast when water and soil flow through the simulated pipe 6, which would be detrimental to the simulation of a variable lava channel. Therefore, the inner support mold 9 is mounted on the upper surface of the inner wall of the simulated pipe 6, and correspondingly, the outer movable support is connected to the force-bearing end point 10 on the lower surface of the outer wall of the simulated pipe 6 to shape the lower contour surface of the simulated pipe 6.

[0032] The water head control mechanism 2 includes two water storage tanks 12, located on either side of the overlying soil simulation tank 1. Both the overlying soil simulation tank 1 and the karst cave simulation tank 5 have water inlets on both sides. The two water storage tanks 12 can be connected to the water inlets on both sides of the overlying soil simulation tank 1 via water pipes 13, ensuring a certain amount of groundwater in the test soil to simulate the groundwater level of the overlying soil layer. The two water storage tanks 12 can also be connected to the water inlets on both sides of the karst cave simulation tank 5 via water pipes 13, ensuring a certain amount of groundwater in the simulated karst cave to simulate the groundwater level of the karst cave. The water inlets are plugged when not in use. The two water storage tanks 12 are respectively installed on vertical guide rails 14, allowing the height of the two water storage tanks 12 to be adjusted. By adjusting the height of the water storage tanks 12, the water head in either the overlying soil simulation tank 1 or the karst cave simulation tank 5 can be controlled.

[0033] As attached Figure 1 and 2 As shown, a support is installed on the soil cover simulation box 1, and two pressure measuring tubes 18 are provided on the support. One of the side pressure tubes is connected to the pressure measuring port on the soil cover simulation box 1, and the other pressure measuring tube 18 is connected to the pressure measuring port on the assembly head 7 to detect the air pressure in the soil cover simulation box 1 and the simulation pipeline 6.

[0034] The rainfall mechanism 3 includes multiple rows of rainfall pipes 15 positioned directly above the overlying soil simulation box 1. Each rainfall pipe 15 has water outlet holes, and a water supply tank 16 supplies water to the multiple rows of rainfall pipes 15 via a water pump 17. Infrared displacement sensors 19 are installed on each rainfall pipe 15, and these sensors detect the displacement of the surface layer of the soil inside the overlying soil simulation box 1.

[0035] This invention also provides a method for simulating rainfall and karst collapse under variable karst channel conditions, comprising the following steps:

[0036] Step S1: Obtain the shape and structure of the karst channel to be simulated by means of detectors, input the obtained shape of the karst channel into the computer, and let the computer predict the shape change trend of the karst channel during the karst collapse process based on the software.

[0037] Step S2: Based on the shape and structure of the karst channel to be simulated, make an inner support mold 9, apply a soluble material layer 11 to the inner support mold 9, then insert the inner support mold 9 into the simulated pipe 6, and make the soluble material layer 11 face the lower surface of the inner wall of the simulated pipe 6, so that the inner support mold 9 shapes the shape of the upper contour surface of the simulated pipe 6.

[0038] Step S3: selecting a proper karst hole simulation port 4, assembling a simulation pipeline 6 between the karst hole simulation port 4 and the karst cave simulation box 5, closing the karst hole simulation ports 4 not connected with the simulation pipeline 6, and adjusting the karst hole simulation ports 4 connected with the simulation pipeline 6 to proper sizes; then, connecting the outer movable support to the stress end points 10 on the lower surface of the outer wall of the simulation pipeline 6, and then actively deforming the outer movable support by the computer, so as to shape the lower profile surface of the simulation pipeline 6 by the outer movable support;

[0039] Step S4: loading the test soil into the overburden simulation box 1;

[0040] Step S5: the water head control mechanism 2 supplies water to the overburden simulation box 1 and the karst cave simulation box 5 to simulate the underground water;

[0041] Step S6: the rainfall mechanism 3 is started to simulate the rainfall, and the rainfall makes the water and soil in the overburden simulation box 1 flow to the karst cave simulation box 5 through the simulation pipeline 6; during the rainfall, the soluble material layer 11 is dissolved, and the computer controls the deformation of the outer movable support according to the software prediction to jointly simulate the shape change of the karst passage during the karst collapse.

[0042] In the present application, the upper profile surface of the simulation pipeline 6 is shaped by the inner support mold 9, the inner support mold 9 is coated with the soluble material layer 11, and the soluble material layer 11 is gradually dissolved during the water and soil loss, so as to simulate the change of the karst passage under natural conditions; the lower profile surface of the simulation pipeline 6 is shaped by the outer movable support, and the shape of the outer movable support is controlled by the simulation result of the computer, so as to change the shape of the lower profile surface of the simulation pipeline 6; thus, in the present application, the simulation result of the computer and the simulation result of the soluble material layer 11 are combined.

[0043] Since the actual shape change of the karst passage during the karst collapse is extremely complex, if a single simulation method is used, the error of the simulation result is large. In the present application, two simulation methods are used to simulate the shape change of the karst passage, which can reduce the error, more approach the change trend of the actual karst passage, and thus improve the reliability of the karst collapse simulation test under the condition of the variable karst passage.

[0044] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A device for simulating karst collapse under conditions of rainfall and variable karst passage, characterized in that it comprises: The utility model provides a karst cave simulation device, including the simulation box of covering soil layer (1), the outside of simulation box of covering soil layer (1) is provided with water head control mechanism (2), the top of simulation box of covering soil layer (1) is provided with rainfall mechanism (3), simulation box of covering soil layer (1) is filled with test soil body, the bottom of simulation box of covering soil layer (1) is provided with karst hole simulation mouth (4), the bottom of simulation box of covering soil layer (1) is provided with karst cave simulation box (5);Karst hole simulation mouth (4) is connected with karst cave simulation box (5) between simulation pipeline (6), simulation pipeline (6) corresponds the shape of simulation karst passage; The simulation pipeline (6) is a hose; Karst hole simulation mouth (4) and karst cave simulation box (5) between still be provided with pipeline plastic component, and the pipeline plastic component can be molded into the shape of simulation pipeline (6) as required; The shape of the pipeline plastic component can be actively changed, so that the shape of the simulation pipeline (6) can change during the simulation of karst collapse; The pipeline plastic component includes an inner plastic unit and an outer plastic unit; The inner plastic unit includes an inner support mold (9) made of hard material and placed inside the simulation pipeline (6); The inner support mold (9) can support the simulation pipeline (6) into the required shape; A soluble material layer (11) is coated on the inner support mold (9); The soluble material layer (11) changes the internal shape of the simulation pipeline (6) when dissolved; The outer plastic unit includes an outer movable support; The outer tube wall of the simulation pipeline (6) is provided with a plurality of stress end points (10); The outer movable support is connected with the plurality of stress end points (10); The outer movable support can actively deform to change the shape of the simulation pipeline (6).

2. The device for simulating rainfall and karst collapse under variable karst passage conditions according to claim 1, characterized in that: The simulation pipeline (6) can be detachably assembled between the karst hole simulation mouth (4) and the karst cave simulation box (5), so that the simulation pipeline (6) can be replaced.

3. The device for simulating rainfall and karst collapse under variable karst passage conditions according to claim 2, characterized in that: The two ends of the simulation pipeline (6) are provided with assembly heads (7); The top of the karst cave simulation box (5) is provided with a pipeline interface (8); The pipeline interface (8) is detachably connected with the assembly head (7) at the lower end of the simulation pipeline (6); The bottom of the simulation box of covering soil layer (1) is provided with a plurality of karst hole simulation mouths (4); Each karst hole simulation mouth (4) can be independently opened or closed; The assembly head (7) at the upper end of the simulation pipeline (6) can be selectively connected with one of the karst hole simulation mouths (4).

4. The device for simulating rainfall and karst collapse under variable karst passage conditions according to claim 2, characterized in that: The size of the opening of the karst hole simulation mouth (4) can be adjusted.

5. The device for simulating rainfall and karst collapse under variable karst passage conditions according to claim 4, characterized in that: The inner support mold (9) is supported on the upper surface of the inner wall of the simulation pipeline (6) to shape the upper profile of the simulation pipeline (6); A soluble material layer (11) is coated on the side of the inner support mold (9) facing the lower surface of the inner wall of the simulation pipeline (6); The outer movable support is connected with the stress end points (10) on the lower surface of the outer wall of the simulation pipeline (6) to shape the lower profile of the simulation pipeline (6).

6. The device for simulating rainfall and karst collapse under variable karst passage conditions according to claim 5, characterized in that: The water head control mechanism (2) comprises two water storage tanks (12) arranged on the two sides of the overburden simulation box (1), and each of the two water storage tanks (12) is connected to the water delivery holes on the two sides of the overburden simulation box (1) or the karst cave simulation box (5) through a water delivery pipe (13); the two water storage tanks (12) are respectively arranged on vertical guide rails (14), so that the heights of the two water storage tanks (12) can be adjusted.

7. The device for simulating rainfall and karst collapse under variable karst passage conditions according to claim 6, characterized in that: The rainfall mechanism (3) comprises a plurality of rows of rainfall pipes (15) arranged above the overburden simulation box (1), wherein the rainfall pipes (15) are provided with water outlet holes, and a water tank (16) supplies water to the plurality of rows of rainfall pipes (15) through a water pump (17).

8. The use of a device for simulating rainfall and variable karst passage conditions for karst collapse according to claim 7, characterized in that: The method comprises the following steps: Step S1: obtaining the shape structure of the karst channel to be simulated, and predicting the shape change trend of the karst channel in the karst collapse process according to software; Step S2: according to the shape structure of the karst channel to be simulated, an inner support mold (9) is made, and a soluble material layer (11) is coated on the inner support mold (9), then the inner support mold (9) is inserted into the simulation pipeline (6), and the soluble material layer (11) faces the lower surface of the inner wall of the simulation pipeline (6), so that the shape of the upper profile surface of the simulation pipeline (6) is shaped by the inner support mold (9); Step S3: assembling the simulation pipeline (6) between the karst hole simulation opening (4) and the karst cave simulation box (5), then connecting the outer movable support to the stress end point (10) on the lower surface of the outer wall of the simulation pipeline (6), and then actively deforming the outer movable support controlled by the computer, so that the shape of the lower profile surface of the simulation pipeline (6) is shaped by the outer movable support; Step S4: loading the test soil into the overburden simulation box (1); Step S5: the water head control mechanism (2) delivers water to the overburden simulation box (1) and the karst cave simulation box (5) to simulate underground water; Step S6: the rainfall mechanism (3) is started and rainfall is simulated, and the water and soil in the overburden simulation box (1) flow to the karst cave simulation box (5) through the simulation pipeline (6) under the rainfall; during the rainfall process, the soluble material layer (11) is dissolved, and the computer controls the deformation of the outer movable support according to the software prediction to jointly simulate the shape change of the karst channel in the karst collapse process.

Images