A hypergravity strong rainfall simulation device and a rainfall simulation method

Abstract

The present invention discloses a high-gravity strong rainfall simulation device and a rainfall simulation method. The liquid inlet module is connected to the rainfall model. The liquid inlet module is used to supply the sprayed liquid to the soil model in the rainfall model box and can control the speed of the sprayed liquid. A viscous fluid is stored in the water supply tank, and the viscous fluid is used to simulate rainfall liquid and pore fluid; the method includes conducting a normal gravity rainfall simulation test to obtain a hydraulic pressure-rainfall intensity relationship curve when the rainfall liquid is the viscous fluid, and according to the similarity scale of the viscous fluid to simulate the high-gravity rainfall test, conducting a centrifugal rainfall simulation test under a high-gravity environment to obtain the transfer law between the rainfall intensity and the failure performance of the prototype soil sample. When the present invention uses a liquid with a viscosity coefficient higher than that of water as the rainfall simulation liquid, the effect of enhancing the rainfall intensity can be achieved in a high-gravity centrifugal test.

Description

Technical Field

[0001] The present invention belongs to the technical field of geotechnical engineering, and particularly relates to a supergravity strong rainfall simulation device and a rainfall simulation method. Background Art

[0002] Rainfall is one of the most typical and important climatic conditions that induce geotechnical disasters, and is a very important boundary condition in problems such as slope stability, wet-dry cycles of expansive soils, shallow foundation failure, and embankment deformation. The spatial scale (regional scope) and time span (seasonal wet-dry cycles, etc.) of rainfall-induced geotechnical disasters are large, making it difficult to achieve complete on-site observations. Scale model tests have become an indispensable means of reproduction. The centrifuge has "scale reduction" and "time reduction" effects, and it can be used to simulate large-scale and long-term prototype rainfall problems and completely reproduce the process of slope instability. When the centrifuge gravitational acceleration multiple N is 100, the model scale is reduced to 1 / 100 of the actual prototype, and the simulation test time of the geotechnical slope model is shortened to 1 / 100 of the actual prototype. 2 An airborne device that can truly simulate rainfall under supergravity conditions is the key to realizing rainfall centrifuge simulation.

[0003] Currently, the main method for the centrifuge airborne rainfall simulation device is through a specific type of nozzle. From the test data provided by the manufacturer, the particle size of the droplets ejected by the nozzle under a certain water pressure can be known. Combining components such as a water pressure gauge and a flow meter, quantitative simulation of rainfall intensity and duration within a certain range can be achieved through calibration. In supergravity tests, in order to make the model rainfall intensity under supergravity conditions equivalent to the prototype rainfall intensity, it is necessary to amplify the test model rainfall intensity to N times the prototype rainfall intensity. However, limited by the characteristics of the supergravity centrifuge test equipment, the traditional method of using an external pressure pump to increase the water pressure to simulate rainfall is often restricted by many factors. These include problems such as the low water supply pressure of the pressure pump and the high requirements for nozzles, which prevent the simulation of strong rainfall at a relatively high centrifugal acceleration g value. Summary of the Invention

[0004] In order to solve the problems existing in the background art, the purpose of the present invention is to provide a supergravity strong rainfall simulation device and a rainfall simulation method to solve the problem that it is impossible to simulate strong rainfall at a relatively high centrifugal acceleration due to limitations such as the water supply pressure of the pressure pump.

[0005] The technical solution adopted by the present invention is as follows:

[0006] I. A supergravity strong rainfall simulation device:

[0007] It includes a liquid inlet module and a rainfall model box; a soil model is installed in the rainfall model box, and a viscous fluid for simulating rainfall liquid is stored in the liquid inlet module. The outlet of the liquid inlet module is communicated with the inlet of the rainfall model box. The liquid inlet module is used to spray a liquid with a controllable speed onto the soil model in the rainfall model box to simulate the deformation and failure process of the soil model under rainfall conditions in a hypergravity environment, so as to restore the failure performance of the prototype soil sample under real rainfall conditions.

[0008] The liquid inlet module includes a water supply tank, an external pressure pump, a water delivery pipe, a flow meter, a pressure regulating valve, a first water pressure sensor, and a second water pressure sensor; the outlet of the water supply tank is communicated with the liquid inlet of the rainfall model box through the water delivery pipe, and an external pressure pump, a flow meter, a first water pressure sensor, a pressure regulating valve, and a second water pressure sensor are sequentially arranged on the water delivery pipe from the water supply tank to the rainfall model box;

[0009] The water supply tank stores a viscous fluid, which is used to simulate rainfall liquid and pore fluid in the soil model. The external pressure pump is used to transport the viscous fluid stored in the water supply tank into the water delivery pipe. The flow meter is used to monitor the flow rate in the water delivery pipe in real time. The pressure regulating valve is used to adjust the liquid pressure in the water delivery pipe. Both the first water pressure sensor and the second water pressure sensor are used to monitor the liquid pressure in the water delivery pipe in real time.

[0010] The rainfall model box includes a box body, a liquid spraying assembly, and a soil model; the soil model is placed inside the box body, and the liquid spraying assembly is installed on the top of the box body. The liquid spraying assembly is used to spray liquid on the soil model. The liquid in the water supply tank enters the liquid spraying assembly through the water delivery pipe. The pressure regulating valve adjusts the liquid pressure in the water delivery pipe, and then adjusts the liquid spraying speed to simulate different rainfall intensities in a hypergravity environment.

[0011] The viscosity coefficient of the viscous fluid in the water supply tank is obtained by the following formula:

[0012] µ v =N·µ w

[0013] Among them, µ v represents the viscosity coefficient of the viscous fluid in the water supply tank; µ w represents the viscosity coefficient of water; N represents the ratio of the centrifugal acceleration to the gravitational acceleration in a hypergravity environment.

[0014] Second, a hypergravity heavy rainfall simulation test method includes the following steps:

[0015] Step S1: First, inject a viscous fluid into the water supply tank, start the water supply tank and the external pressure pump under normal gravity, so that the viscous fluid in the water supply tank flows into the rainfall model box through the water delivery pipe;

[0016] Step S2: Adjust the liquid pressure in the water delivery pipe using a pressure regulating valve, and simultaneously use the first water pressure sensor and the second water pressure sensor to monitor the liquid pressure in the water delivery pipe in real time. When the liquid pressure in the water delivery pipe reaches the set hydraulic target value and stabilizes, start the rainfall simulation test under normal gravity to obtain the rainfall intensity in the rainfall model box.

[0017] Step S3: Change the hydraulic target value and repeat Step S2 multiple times to obtain the rainfall intensity under different hydraulic target values. Use the set hydraulic target value as the abscissa and the rainfall intensity corresponding to the hydraulic target value as the ordinate to plot the hydraulic-rainfall intensity relationship curve of the viscous fluid.

[0018] Step S4: Lift the entire device into a geotechnical centrifuge to conduct a centrifugal rainfall simulation test under supergravity conditions.

[0019] Step S5: Conduct microscopic observations on the soil model in the rainfall model box during the centrifugal rainfall simulation test to obtain the microscopic characteristics of the soil model at different positions, thereby restoring the failure performance of the prototype soil sample under rainfall conditions in the actual working condition, and obtaining the transfer law between the rainfall intensity and the failure performance of the prototype soil sample.

[0020] The specific process of the rainfall simulation test is as follows: When the liquid in the water delivery pipe after pressure regulation by the pressure regulating valve reaches the set hydraulic target value and stabilizes, the liquid spraying component at the top of the rainfall model box starts to spray liquid steadily onto the soil model. Then, observe the microscopic characteristics of the soil model during the liquid spraying process, and simultaneously record the amount of liquid sprayed per unit time as the rainfall intensity of the rainfall model box.

[0021] The specific steps of Step S4 are as follows:

[0022] First, lift the entire device into the geotechnical centrifuge and fix it. Start the geotechnical centrifuge, gradually increase the centrifugal acceleration of the geotechnical centrifuge to the preset Ng and maintain it for a preset time. Then, start the water supply tank and the external pressure pump under the Ng supergravity condition, so that the viscous fluid in the water supply tank flows into the rainfall model box through the water delivery pipe. Next, use the pressure regulating valve to adjust the liquid pressure in the water delivery pipe, and simultaneously use the first water pressure sensor and the second water pressure sensor to monitor the liquid pressure in the water delivery pipe in real time. When the liquid pressure in the water delivery pipe reaches the set hydraulic target value and stabilizes, start the centrifugal rainfall simulation test under supergravity.

[0023] Under the Ng supergravity condition, the viscous fluid in the water supply tank uses a viscous fluid with an N-fold water viscosity coefficient.

[0024] In Step S4, the set hydraulic target value in the water delivery pipe after pressure regulation by the pressure regulating valve is obtained through the following method:

[0025] First, determine the rainfall intensity q of the prototype soil sample under the actual working condition to be simulated.p , according to the rainfall intensity q of the prototype soil sample p to determine the target rainfall intensity q of the soil model in the rainfall model box m , then use the hydraulic-rainfall intensity relationship curve of the viscous fluid to obtain the target rainfall intensity q m The corresponding hydraulic pressure is used as the set hydraulic pressure target value. Among them, the rainfall intensity q of the prototype soil sample p and the target rainfall intensity q of the soil model m The relationship expression is as follows:

[0026] q m / q p = k m / k p

[0027] k m = KρNg / µ v

[0028] k p = Kρg / µ w

[0029] Among them, k m is the soil permeability coefficient under Ng centrifugal acceleration; k p is the soil permeability coefficient under normal gravity; K represents the soil intrinsic permeability coefficient; ρ represents the fluid density; g represents the acceleration of gravity; µ v represents the viscosity coefficient of the viscous fluid in the water supply tank; µ w represents the viscosity coefficient of water.

[0030] The principle of the present invention is as follows:

[0031] Under the Ng hypergravity test, the hydraulic gradient remains unchanged. The ratio of the permeability coefficient of water between the soil model and the prototype under normal gravity is:

[0032] k m / k p =(KρNg / µ) / ( Kρg / µ)=N

[0033] Among them, k m is the soil permeability coefficient under centrifugal acceleration; k p is the soil permeability coefficient under normal gravity; K is the soil intrinsic permeability coefficient; ρ is the fluid density; g is the acceleration of gravity; µ is the hydrodynamic viscosity coefficient; Ng represents the centrifugal acceleration;

[0034] Under the condition of the same boundary conditions, the permeability coefficient of the soil in the centrifuge is N times that of the soil under normal gravity. Then the rainfall intensity is the same as the scale of the soil permeability coefficient, that is:

[0035] q m / q p = N

[0036] Among them, q m represents the rainfall intensity of the soil model; q p represents the rainfall intensity of the prototype soil sample;

[0037] If a liquid with a density similar to that of water but a viscosity coefficient N times that of water is used as the pore fluid, the ratio of the permeability coefficient of the soil model to that of the prototype soil sample is:

[0038] k m / k p =(KρNg / Nµ) / ( Kρg / µ)=N / N=1

[0039] Therefore, the ratio of the rainfall intensity of the soil model to that of the prototype soil sample q m / q p = 1, that is, by changing the liquid viscosity coefficient to reduce the soil permeability coefficient, under the limitation of test equipment, the rainfall intensity can also be equivalently increased to achieve the effect of simulating heavy rainfall.

[0040] According to the definition formula of rainfall intensity as the ratio of rainfall amount to rainfall time, the rainfall duration t m of the prototype soil sample and the rainfall duration t p of the model soil sample are:

[0041] t m =R m / q m

[0042] t p =R p / q p

[0043] Among them, t m represents the rainfall duration of the soil model; t p represents the rainfall duration of the prototype soil sample; R m represents the rainfall amount of the soil model; R p represents the rainfall amount of the prototype soil sample and R p =N R m .

[0044] If a liquid with a density similar to that of water but a viscosity coefficient N times that of water is used as the pore fluid, the ratio of the rainfall duration of the soil model to that of the prototype soil sample is:

[0045] t m / t p =1 / N

[0046] Therefore, when using a liquid with a viscosity N times that of water as the pore fluid and the rainfall liquid, the simulated rainfall intensity can be effectively increased without changing the total rainfall amount of the soil model.

[0047] The present invention can effectively simulate different rainfall intensities under the hypergravity environment by changing the size of the pressure regulating valve to adjust the water outlet rate. However, the simulation of heavy rainfall in the natural environment is often limited by the maximum pressure of the air compressor of the rainfall device. In order to effectively improve the problem that heavy rainfall cannot be simulated due to the limitation of the hypergravity test equipment, the purpose of the present invention is to achieve the effect of simulating heavy rainfall by using a viscous fluid as the rainfall liquid and the pore fluid to change the scale of the hypergravity rainfall similarity law.

[0048] The beneficial effects of the present invention are as follows:

[0049] 1. Without changing the rainfall device, the present invention realizes the simulation of heavy rainfall by adopting the method of replacing the viscous liquid to adjust the similarity ratio of the rainfall intensity between the model and the prototype.

[0050] 2. The present invention uses a liquid with a viscosity higher than that of water as the rainfall simulation liquid, which can achieve the effect of enhancing the rainfall intensity in the hypergravity centrifugal test. The method of the present invention can solve the problem that it is difficult to simulate a higher rainfall intensity due to the limitation of the rainfall device in the centrifugal test.

[0051] 3. The present invention adopts a liquid with a larger viscosity coefficient to replace the water source of the rainfall water supply tank, and then changes the rainfall similarity law. Even when the pressure regulation of the simulation test device is limited, the experimental simulation of heavy rainfall can be maximally improved.

[0052] 4. Using the viscous fluid to simulate the rainfall hypergravity test can also effectively solve the contradiction that the similarity ratio of the pore water pressure dissipation time and the particle movement time of the soil model under the hypergravity environment is different, and achieve a more realistic simulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a schematic diagram of the hypergravity centrifugal heavy rainfall simulation test device of the present invention;

[0054] Figure 2 is a schematic diagram of the process of the hypergravity centrifugal heavy rainfall simulation test of the present invention;

[0055] Figure 3 is a schematic diagram of the simulation experiment process under the hypergravity environment;

[0056] Figure 4 is a schematic diagram of the placement position of the hypergravity centrifugal heavy rainfall simulation test device in the centrifuge;

[0057] Figure 5 is a schematic diagram of the hypergravity centrifuge of the present invention.

[0058] In the figure: 1, water supply tank; 2, external pressure pump; 3, water delivery pipe; 4, micro flowmeter; 5, pressure regulating valve; 6, first water pressure sensor; 7, second water pressure sensor; 8, rainfall model box. Specific implementation mode

[0059] The present invention will be described in detail below in combination with specific implementation cases. The following implementation cases will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form.

[0060] As Figure 1 shown, the device includes a liquid inlet module and a rainfall model box 8; a soil body model is installed in the rainfall model box 8, a viscous fluid for simulating rainfall liquid is stored in the liquid inlet module, the outlet of the liquid inlet module is communicated with the inlet of the rainfall model box 8, and the liquid inlet module is used to spray a liquid with controllable speed into the soil body model of the rainfall model box 8 to simulate the deformation and failure process of the soil body model under rainfall conditions in a hypergravity environment, so as to restore the failure performance of the prototype soil sample under real rainfall conditions.

[0061] The liquid inlet module includes a water supply tank 1, an external pressure pump 2, a water delivery pipe 3, a flowmeter 4, a pressure regulating valve 5, a first water pressure sensor 6 and a second water pressure sensor 7; the outlet of the water supply tank 1 is communicated with the liquid inlet of the rainfall model box 8 through the water delivery pipe 3, and an external pressure pump 2, a flowmeter 4, a first water pressure sensor 6, a pressure regulating valve 5 and a second water pressure sensor 7 are sequentially arranged on the water delivery pipe 3 from the water supply tank 1 to the rainfall model box 8;

[0062] The water supply tank 1 stores a viscous fluid, the viscous fluid is used to simulate rainfall liquid and pore fluid in the soil body model, the external pressure pump 2 is used to transport the viscous fluid stored in the water supply tank 1 into the water delivery pipe 3, the flowmeter 4 is used to monitor the flow rate in the water delivery pipe 3 in real time, the pressure regulating valve 5 is used to adjust the liquid pressure in the water delivery pipe 3, and both the first water pressure sensor 6 and the second water pressure sensor 7 are used to monitor the liquid pressure in the water delivery pipe 3 in real time.

[0063] Specifically, both the water supply tank 1 and the external pressure pump 2 are placed on the rotating boom of the centrifuge, and the flowmeter 4, the pressure regulating valve 5, the first water pressure sensor 6, the second water pressure sensor 7 and the rainfall model box 8 are placed together in the centrifuge basket. The schematic diagram of the centrifuge in the specific implementation is as Figure 5 shown. The first water pressure sensor 6 and the second water pressure sensor 7 are respectively located on both sides of the pressure regulating valve 5. The first water pressure sensor 6 can monitor the change of the liquid pressure in the water delivery pipe 3 with the increase and stabilization of the centrifugal acceleration value in real time. The liquid pressure in the water delivery pipe 3 will increase sharply with the increase of the centrifugal acceleration value under the action of centrifugal force. The liquid pressure can be stabilized at the target value through the pressure reducing valve 5, and the second water pressure sensor 7 can monitor the stabilized liquid pressure value in real time.

[0064] The rainfall model box 8 includes a box body, a liquid spraying assembly and a soil body model; the soil body model is placed inside the box body, the liquid spraying assembly is installed on the top of the box body, the liquid spraying assembly is used for spraying liquid on the soil body model, and the liquid in the water supply tank 1 enters the liquid spraying assembly after passing through the water delivery pipe 3. The pressure regulating valve 5 regulates the liquid pressure of the liquid passing through the water delivery pipe 3, and further regulates the liquid spraying speed to simulate different rainfall intensities under the hypergravity environment.

[0065] The viscosity coefficient of the viscous fluid in the water supply tank 1 is obtained by the following formula:

[0066] µ v =N·µ w

[0067] Wherein, µ v represents the viscosity coefficient of the viscous fluid in the water supply tank 1; µ w represents the viscosity coefficient of water; N represents the ratio of the centrifugal acceleration to the gravitational acceleration under the hypergravity environment, and the density of the viscous fluid is the same as that of water.

[0068] The embodiments of the present invention include the following steps, as Figure 2 shown:

[0069] Step S1: For the hypergravity test with a preset centrifugal acceleration of Ng, first inject the viscous fluid into the water supply tank 1, and start the water supply tank 1 and the external pressure pump 2 under normal gravity, so that the viscous fluid in the water supply tank 1 flows into the rainfall model box 8 through the water delivery pipe 6;

[0070] Step S2: Use the pressure regulating valve 5 to regulate the liquid pressure in the water delivery pipe 3, and at the same time use the first water pressure sensor 6 and the second water pressure sensor 7 to monitor the liquid pressure in the water delivery pipe 6 in real time. When the liquid pressure in the water delivery pipe 6 reaches the set hydraulic target value and stabilizes, start the rainfall simulation test under normal gravity to obtain the rainfall intensity in the rainfall model box 8;

[0071] Step S3: Change the hydraulic target value, use the pressure regulating valve 5 to regulate the liquid pressure in the water delivery pipe 3, repeat step S2 multiple times, obtain the rainfall intensity under different hydraulic target values, use the set hydraulic target value as the abscissa, and use the rainfall intensity corresponding to the hydraulic target value as the ordinate to draw the hydraulic-rainfall intensity relationship curve of the viscous fluid with a viscosity coefficient of µ v ;

[0072] Step S4: As Figure 4 shown, lift the whole device into the geotechnical centrifuge to conduct the centrifugal rainfall simulation test under the hypergravity environment. The hydraulic target value in the centrifugal rainfall simulation test under the hypergravity environment is set according to the hydraulic-rainfall intensity relationship curve of the viscous fluid.

[0073] Step S5: Conduct microscopic observation on the soil model in the rainfall model box 8 during the centrifugal rainfall simulation test to obtain the microscopic characteristics and failure performance of the soil model at different positions, thereby restoring the failure performance of the prototype soil sample under the actual working conditions during rainfall, and obtaining the transfer law between the rainfall intensity and the failure performance of the prototype soil sample.

[0074] Specifically, the rainfall simulation test is as follows: When the liquid in the water delivery pipe 3 regulated by the pressure regulating valve 5 reaches the set hydraulic target value and stabilizes, the liquid spraying assembly at the top of the rainfall model box 8 starts to spray liquid steadily onto the soil model. Then, observe the microscopic characteristics of the soil model during the liquid spraying process to obtain the failure performance of the soil model, and at the same time record the amount of sprayed liquid per unit time as the rainfall intensity of the rainfall model box 8.

[0075] The rainfall simulation test includes the rainfall simulation test under normal gravity and the centrifugal rainfall simulation test under hypergravity environment.

[0076] Specifically, the specific steps of step S4 are as follows, as Figure 3 shown:

[0077] First, lift the entire device into the geotechnical centrifuge and fix it. Start the geotechnical centrifuge, gradually increase the centrifugal acceleration of the geotechnical centrifuge to the preset Ng and maintain it for a preset time. Then, start the water supply tank 1 and the external pressure pump 2 under the Ng hypergravity, so that the viscous fluid in the water supply tank 1 flows into the rainfall model box 8 through the water delivery pipe 6. Next, use the pressure regulating valve 5 to adjust the liquid pressure in the water delivery pipe 3, and at the same time use the first water pressure sensor 6 and the second water pressure sensor 7 to monitor the liquid pressure in the water delivery pipe 6 in real time. When the liquid pressure in the water delivery pipe 6 reaches the set hydraulic target value and stabilizes, start the centrifugal rainfall simulation test under hypergravity.

[0078] Under the Ng hypergravity, the viscous fluid in the water supply tank 1 uses a viscous fluid with an N-fold water viscosity coefficient, where g is the acceleration due to gravity.

[0079] That is, under the Ng hypergravity, the viscosity coefficient of the viscous fluid is obtained according to the following formula:

[0080] µ v =N·µ w

[0081] where, µ v represents the viscosity coefficient of the viscous fluid in the water supply tank 1; µ w represents the viscosity coefficient of water; N represents the ratio of the centrifugal acceleration to the acceleration due to gravity in the hypergravity environment.

[0082] In step S4, the set hydraulic target value in the water delivery pipe 3 regulated by the pressure regulating valve 5 is obtained according to the following method:

[0083] First, determine the rainfall intensity q of the prototype soil sample under the real working conditions to be simulated p , and determine the target rainfall intensity q of the soil body model in the rainfall model box 8 according to the rainfall intensity q of the prototype soil sample p . Then, obtain the hydraulic pressure corresponding to the target rainfall intensity q by using the hydraulic pressure - rainfall intensity relationship curve of the viscous fluid as the set hydraulic pressure target value. Among them, the relationship expression between the rainfall intensity q of the prototype soil sample m and the target rainfall intensity q of the soil body model m is as follows: p

[0084] q m / q m = k p / k m

[0085] k p = KρNg / µ m

[0086] k v = Kρg / µ p w

[0087] Among them, k m is the soil permeability coefficient under the Ng centrifugal acceleration; k p is the soil permeability coefficient under normal gravity; K represents the inherent soil permeability coefficient; ρ represents the fluid density; g represents the acceleration due to gravity; µ v represents the viscosity coefficient of the viscous fluid in the water supply tank 1; µ w represents the viscosity coefficient of water.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.​​

Claims

1. A method for simulating a high gravity heavy rainfall test, characterized in that: The method adopts a hypergravity heavy rainfall simulation device, the device comprising a liquid inlet module and a rainfall model box (8); a soil model is installed in the rainfall model box (8), a viscous fluid for simulating rainfall liquid is stored in the liquid inlet module, an outlet of the liquid inlet module is connected to an inlet of the rainfall model box (8), and the liquid inlet module is used to spray liquid with a controllable speed into the soil model of the rainfall model box (8), so as to simulate the deformation and failure process of the soil model under rainfall conditions in a hypergravity environment, thereby restoring the failure performance of the prototype soil sample under real rainfall conditions; The method comprises the following steps: Step S1, first injecting a viscous fluid into the water supply tank (1), and starting the water supply tank (1) and the external pressure pump (2) under normal gravity, so that the viscous fluid in the water supply tank (1) flows into the rainfall model box (8) through the water pipe (3); Step S2, using the pressure regulating valve (5) to adjust the liquid pressure in the water pipe (3), and using the first water pressure sensor (6) and the second water pressure sensor (7) to monitor the liquid pressure in the water pipe (3) in real time, when the liquid pressure in the water pipe (3) reaches the set hydraulic target value and stabilizes, starting a rainfall simulation test under normal gravity to obtain the rainfall intensity in the rainfall model box (8); Step S3, changing the hydraulic target value, repeating step S2 multiple times, obtaining rainfall intensity under different hydraulic target values, and drawing a hydraulic pressure-rainfall intensity relationship curve of the viscous fluid with the set hydraulic target value as the abscissa and the rainfall intensity corresponding to the hydraulic target value as the ordinate; Step S4, hoisting the entire device into a geotechnical centrifuge to perform a centrifugal rainfall simulation test under a hypergravity environment; The specific steps of step S4 are as follows: First, the device is hoisted into a geotechnical centrifuge as a whole and fixed, the geotechnical centrifuge is started, the centrifugal acceleration of the geotechnical centrifuge is gradually increased to a preset value Ng and maintained for a preset time, and the water supply tank (1) and the external pressure pump (2) are started under Ng supergravity, so that the viscous fluid in the water supply tank (1) flows into the rainfall model box (8) through the water pipe (3), then, the liquid pressure in the water pipe (3) is adjusted by the pressure regulating valve (5), and the liquid pressure in the water pipe (3) is monitored in real time by the first water pressure sensor (6) and the second water pressure sensor (7), and when the liquid pressure in the water pipe (3) reaches the set hydraulic target value and stabilizes, the centrifugal rainfall simulation test under supergravity is started; In step S4, the hydraulic target value set in the water delivery pipe (3) after pressure regulation by the pressure regulating valve (5) is obtained by processing in the following manner: First, determine the rainfall intensity q of the prototype soil sample under the actual working conditions to be simulated p , according to the rainfall intensity q of the prototype soil sample p Determine the target rainfall intensity q of the soil model in the rainfall model box (8) m Then, the target rainfall intensity q is obtained by using the hydraulic pressure-rainfall intensity relationship curve of the viscous fluid m The corresponding hydraulic pressure is used as the set hydraulic target value, where the rainfall intensity q of the prototype soil sample is p and the target rainfall intensity q of the soil model m The relational expression is as follows: q m / q p = k m / k p k m = KρNg / µ v k p = Kρg / µ w Among them, k m is the soil permeability coefficient under the centrifugal acceleration of Ng; k p is the soil permeability coefficient under constant gravity; K is the soil inherent permeability coefficient; ρ is the fluid density; g is the gravitational acceleration; µ v represents the viscosity coefficient of the viscous fluid in the water supply tank (1); µ w It represents the viscosity coefficient of water; Step S5, in the centrifugal rainfall simulation test, microscopic observation is performed on the soil model in the rainfall model box (8) to obtain the microscopic characteristics of the soil model at different positions, thereby restoring the destructive performance of the prototype soil sample under the actual working condition under the rainfall working condition, and obtaining the transmission law between the rainfall intensity and the destructive performance of the prototype soil sample.

2. A method for simulating heavy rainfall under high gravity according to claim 1, characterized in that: The rainfall simulation test is specifically as follows: when the liquid in the water pipe (3) reaches the set hydraulic target value and stabilizes after being pressure-regulated by the pressure regulating valve (5), the liquid spraying assembly on the top of the rainfall model box (8) begins to stably spray liquid toward the soil model, then observes the microscopic characteristics of the soil model during the liquid spraying process, and simultaneously records the amount of liquid sprayed per unit time as the rainfall intensity of the rainfall model box (8).

3. The method for simulating a high gravity heavy rainfall test according to claim 1, characterized in that: Under the Ng supergravity, the viscous fluid in the water supply tank (1) uses a viscous fluid with a viscosity coefficient N times that of water.

4. The method for simulating a high gravity heavy rainfall test according to claim 1, characterized in that: The liquid inlet module comprises a water supply tank (1), an external pressure pump (2), a water pipe (3), a flow meter (4), a pressure regulating valve (5), a first water pressure sensor (6) and a second water pressure sensor (7); the outlet of the water supply tank (1) is connected to the liquid inlet of the rainfall model box (8) through the water pipe (3), and the external pressure pump (2), the flow meter (4), the first water pressure sensor (6), the pressure regulating valve (5) and the second water pressure sensor (7) are sequentially arranged on the water pipe (3) from the water supply tank (1) to the rainfall model box (8); The water supply tank (1) stores a viscous fluid, which is used to simulate rainfall liquid and pore fluid in a soil model. The external pressure pump (2) is used to transport the viscous fluid stored in the water supply tank (1) to the water pipe (3). The flow meter (4) is used to monitor the flow in the water pipe (3) in real time. The pressure regulating valve (5) is used to adjust the liquid pressure in the water pipe (3). The first water pressure sensor (6) and the second water pressure sensor (7) are both used to monitor the liquid pressure in the water pipe (3) in real time.

5. A method for simulating a high gravity heavy rainfall test according to claim 4, characterized in that: The rainfall model box (8) comprises a box body, a liquid spraying assembly and a soil model; the soil model is placed inside the box body, the liquid spraying assembly is installed on the top of the box body, the liquid spraying assembly is used to spray liquid on the soil model, the liquid in the water supply box (1) enters the liquid spraying assembly after passing through the water pipe (3), the pressure regulating valve (5) adjusts the pressure of the liquid passing through the water pipe (3), and then adjusts the spraying speed of the liquid to simulate different rainfall intensities in a hypergravity environment.

6. A method for simulating a high gravity heavy rainfall test according to claim 4, characterized in that: The viscosity coefficient of the viscous fluid in the water supply tank (1) is obtained by processing according to the following formula: µ v =N·µ w Among them, µ v represents the viscosity coefficient of the viscous fluid in the water supply tank (1); µ w represents the viscosity coefficient of water; N represents the ratio of centrifugal acceleration to gravitational acceleration in a hypergravity environment.

Images