Gravel soil slope hydraulic erosion test device and method

Abstract

The invention discloses a gravel soil side slope hydraulic erosion test device and method. The device comprises a model water tank, a side slope model arranged in the model water tank, a water supply assembly connected with the model water tank and a monitoring assembly arranged outside the model water tank. The device is reasonable in structural design and stable and reliable in operation, and through multi-scale tests and numerical simulation, a positive feedback mechanism that fine particle loss drives pore structure recombination, induces skeleton instability and accelerates fine particle loss due to skeleton damage in the seepage erosion process of the slope model is disclosed. The progressive degradation rule and the collapse instability mechanism of the gravelly soil side slope under the action of seepage erosion are further clarified, a new theoretical framework is provided for understanding the collapse instability of the side slope, and the cognitive direction of monitoring and early warning research on the instability of the gravelly soil side slope is expanded.

Description

Technical Field

[0001] This invention relates to the field of geological engineering technology, specifically to a test device and method for hydraulic erosion of gravelly soil slopes. Background Technology

[0002] Natural gravelly soil refers to soil in which particles with a diameter >2mm account for more than 50% of the total weight. Based on particle shape and size, from largest to smallest, it includes: boulders, boulders, cobbles, crushed stone, rounded gravel, and angular gravel. Correspondingly, artificial gravelly soil refers to natural soil mixed with boulders, boulders or cobbles, crushed stone or rounded gravel, or angular gravel, so that the content of particles with a diameter between 20 and 200mm is not less than 50%, and the content exceeding 50% is classified as boulders, boulders, cobbles, crushed stone, rounded gravel, or angular gravel. Gravelly soil is widely used in high embankment projects due to its high strength and low compressibility. However, due to its inconsistent particle size and gradation, under the influence of high groundwater permeability, the fine particles filling it are easily carried away by groundwater flow, leading to erosion and damage. Moreover, with climate change and increased rainfall frequency, the risk of slope instability is increasing. Therefore, studying the impact of hydraulic erosion on the stability of gravelly soil high embankment slopes is of great significance.

[0003] Current research on the collapse and instability of gravelly soil slopes mostly involves isolated analyses of macroscopic displacement or microscopic particle changes. It is difficult to clarify the intrinsic coupling relationship between fine particle migration, pore structure evolution, skeleton instability, and overall collapse, and there is a lack of quantitative criteria for each evolution stage. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a test device and method for hydraulic erosion of gravelly soil slopes.

[0005] The technical solution of the present invention is as follows: a hydraulic erosion test device for gravelly soil slope, comprising a model water tank, a slope model set inside the model water tank, a water supply component connected to the model water tank, and a monitoring component set outside the model water tank; the model water tank is open at both the tail end and the top end, and a tailwater collection pool is connected to the tail end of the model water tank, and a net box for collecting eroded particles is movably attached to the top of the tailwater collection pool; a porous permeable plate is set on the side of the model water tank near the front end; The slope model is set inside the model water tank, and the slope model is located between the porous permeable plate and the tailwater collection tank; The water supply components include a water supply pipe installed at the front end of the model water tank, an inlet solenoid valve and an electromagnetic flow meter installed at the connection between the water supply pipe and the model water tank, and a flow control pump installed at the end of the water supply pipe away from the model water tank. The monitoring components include a high-speed camera, a laser scanner, and a data logger, which are respectively installed on the side walls of the model's water tank. The high-speed camera and the laser scanner are electrically connected to the data logger. Several laser displacement sensors, each electrically connected to the data logger, are distributed at equal intervals on the slope surface of the slope model. Several pore water pressure sensors and soil pressure sensors, each electrically connected to the data logger, are distributed at equal intervals inside the slope model. Four high-speed cameras are installed, located at the top of the front edge, the top of the rear edge, and both sides of the slope model.

[0006] Furthermore, a model placement box is movably connected inside the model water tank. The top of the model placement box is open, and handles are provided on both sides of the upper surface of the model placement box. The front and rear ends of the model placement box are provided with through slots. The slope model is placed inside the model placement box. Note: By setting up a model placement box inside the model tank, it is convenient to install and move the slope model, and also convenient to collect the slope model after instability.

[0007] Furthermore, a water-blocking plate is slidably engaged inside the model water tank and at the front end of the porous permeable plate; a sealing strip is provided on the inner wall of the model water tank that is movably engaged with the water-blocking plate; and a water level scale is provided on the outer wall of the model water tank. Note: By setting up a water-blocking plate, it is easy to control the water level at the front end of the model water tank at the beginning of the experiment, thus facilitating the study of the impact of different water levels on the stability of the gravel soil slope.

[0008] Furthermore, a base is provided below the model water tank, the tailwater collection tank is fixedly connected to the base, and the rear end of the bottom surface of the model water tank is movably hinged to the upper end surface of the base; an electric push rod is movably hinged to the front end of the bottom surface of the model water tank, and the electric push rod is movably hinged to the upper end surface of the base. Note: By using an electric actuator to push the model water tank to deflect along the base, the slope of the model water tank can be adjusted, which facilitates the study of the instability conditions of gravelly soil slopes under different slopes.

[0009] Furthermore, a positioning component is provided on the bottom surface of the model water tank and at the rear end of the electric push rod; the positioning component includes two positioning frames that are movably hinged to the bottom surface of the model water tank, a guide plate that is set on the upper surface of the base and slidably engaged with the two positioning frames respectively, and a locking rod that is movably connected to the bottom end of the two positioning frames; a connecting seat is rotatably engaged at the bottom end of each of the two positioning frames, a locking block is slidably engaged inside the connecting seat, and a first compression spring that is sleeved on the outside of the locking block is provided inside the connecting seat; both ends of the locking rod pass through the two connecting seats respectively, and a locking groove that can engage with the locking block is provided on the outer wall of the locking rod; a second compression spring that abuts against the outer wall of the connecting seat at the corresponding position is sleeved on both ends of the locking rod. Note: During the adjustment of the model water tank, the bottom ends of the two positioning frames slide on the guide plate and move closer to each other. Under the action of the second compression spring, the connecting seat on the locking rod is always in close contact with the positioning frame at the corresponding position. The locking block inside the connecting seat is engaged with the locking groove on the locking rod under the action of the first compression spring. This helps to improve the support stability of the positioning frame for the model water tank and creates stable conditions for the hydraulic erosion test of the gravel soil slope.

[0010] Furthermore, the tail end of the model water tank is connected to an elastic guide plate located above the tailwater collection tank; Note: By setting up elastic guide plates, the collection effect of the erosion particle collection cage on erosion particles generated during the test can be improved.

[0011] Furthermore, the model water tank is equipped with an outer protective box, and a cover plate is movably hinged to the outer side wall of the outer protective box; universal wheels are movably hinged to the bottom surface of the outer protective box; a slide rail is provided at the bottom of the outer protective box, and a sliding sleeve is provided on the bottom surface of the base to slide and engage with the slide rail. Note: During the experiment, the model water tank and base were removed from the outer protective box. After the experiment, the outer protective box was used to store and transfer the device, which improved the integration of the device and thus improved its ease of use.

[0012] Furthermore, a purification box connected to the tailwater collection tank is provided on the upper surface of the base. Inside the purification box, a filter screen, a clean water tank, and an adsorption box are arranged in sequence. The clean water tank is filled with clean water packing material. The adsorption box is filled with activated carbon adsorbent. Note: Wastewater generated during the experiment enters the purification tank through the tailwater collection tank. The wastewater is then filtered through a filter screen, treated biochemically by water purification media, and purified by activated carbon adsorption. The purified wastewater can be recycled, saving water resources.

[0013] This invention also provides a method for testing the hydraulic erosion of gravelly soil slopes, based on the aforementioned test apparatus for testing the hydraulic erosion of gravelly soil slopes, comprising the following steps: S1. Set up a slope model inside the model water tank; during the slope model setup process, evenly set up several laser displacement sensors along the slope surface of the slope model, and evenly set up several pore water pressure sensors and several soil pressure sensors inside the slope model. S2. High-speed cameras are installed outside the model water tank, at the top of the front edge, the top of the rear edge, and both sides of the slope model. A laser scanner is installed outside the model water tank. The laser displacement sensor, pore water pressure sensor, soil pressure sensor, high-speed camera, and laser scanner are electrically connected to the data logger. S3. Use a flow-controlled electric pump to introduce external clean water into the model water tank through a water supply pipe, so that the water flows through the permeable plate and then enters the slope model. S4. During the experiment, a laser displacement sensor was used to acquire the surface deformation of the slope model; a pore water pressure sensor was used to acquire the changes in pore water pressure inside the slope model; an earth pressure sensor was used to acquire the changes in earth pressure inside the slope model; a high-speed camera was used to capture the deformation of the slope model during the experiment; a laser scanner was used to measure the settlement deformation of the slope surface and top of the slope model; and a data logger was used to record the observation data; a seepage and erosion fine particles in the slope model were collected using a burrowing particle collection cage; and the test tailwater was collected using a tailwater collection pond. S5. Based on the monitoring data from laser displacement sensors, pore water pressure sensors, soil pressure sensors, high-speed cameras, and laser scanners, compare and analyze the basic characteristics of landslide deformation, study the evolution process of gravelly soil slopes from local erosion and gradual failure to overall collapse and instability, reveal the basic characteristics of collapse and instability evolution and the variation laws of seepage erosion rate, settlement deformation, slope displacement, pore water pressure, and soil pressure.

[0014] Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects: First, the device of this invention has a reasonable structural design and stable and reliable operation. Through multi-scale tests and numerical simulations, it reveals the positive feedback mechanism in which fine particle loss drives pore structure reorganization, induces skeleton instability, and accelerates fine particle loss during the seepage erosion process of the slope model. It further clarifies the progressive deterioration law and collapse instability mechanism of gravelly soil slopes under seepage erosion, provides a new theoretical framework for understanding slope collapse instability, and expands the cognitive direction of research on monitoring and early warning of gravelly soil slope instability. Secondly, the device of the present invention pushes the model water tank to deflect along the base by an electric push rod, which can adjust the slope of the model water tank, thereby enabling the study of the instability conditions of gravelly soil slopes under different slopes; moreover, the positioning component locks the deflection position of the model water tank, creating stable conditions for the conduct of hydraulic erosion tests on gravelly soil slopes. Third, the present invention improves the integration and ease of use of the device by storing and transferring it in an outer protective box. The wastewater generated during the test is purified by the filter screen, clean water tank and adsorption box inside the purification box. The purified wastewater can be recycled, saving water resources. Attached Figure Description

[0015] Figure 1 This is a longitudinal sectional view of the device of the present invention; Figure 2 This is a front view of the device of the present invention; Figure 3This is a schematic diagram of the internal structure of the outer protective box of the present invention; Figure 4 This is a schematic diagram of the model placement box of the present invention; Figure 5 This is a schematic diagram showing the connection between the positioning component and the base of the present invention; Figure 6 This is a schematic diagram of the connection between the locking rod and the connecting seat of the present invention; Among them, 1-model water tank, 10-tailwater collection tank, 11-penetrating particle collection cage, 12-perforated permeable plate, 13-water-blocking plate, 14-base, 15-elastic guide plate, 16-sliding sleeve, 2-slope model, 20-model placement box, 200-handle, 201-through groove, 3-water supply component, 30-water supply pipe, 31-inlet solenoid valve, 32-electromagnetic flow meter, 33-flow electric control pump, 4-monitoring component, 40-high-speed phase 41-Laser scanner, 42-Data recorder, 5-Electric push rod, 6-Positioning component, 60-Positioning frame, 61-Guide plate, 62-Locking rod, 620-Locking groove, 621-Second compression spring, 63-Connecting seat, 630-Locking block, 631-First compression spring, 7-Outer protective box, 70-Cover plate, 71-Universal wheel, 72-Slide rail, 8-Purification box, 80-Filter screen, 81-Clean water tank, 82-Adsorption box. Detailed Implementation

[0016] Example 1 like Figure 1 The device shown is a hydraulic erosion test device for gravelly soil slope, including a model water tank 1, a slope model 2 set inside the model water tank 1, a water supply component 3 connected to the model water tank 1, and a monitoring component 4 set outside the model water tank 1; the model water tank 1 is open at both the tail end and the top end, and the tail end of the model water tank 1 is connected to a tailwater collection tank 10, and a movably clamped mesh box 11 for collecting eroded particles is installed at the top of the tailwater collection tank 10; a porous permeable plate 12 is provided on the side of the model water tank 1 near the front end; like Figure 1 As shown, the slope model 2 is set inside the model water tank 1, and the slope model 2 is located between the porous permeable plate 12 and the tailwater collection tank 10; wherein, the slope model 2 is a product of the prior art, which is made on site according to the test requirements; like Figure 1 , 3 As shown, the water supply component 3 includes a water supply pipe 30 installed at the front end of the model water tank 1, an inlet solenoid valve 31 and an electromagnetic flow meter 32 installed at the connection between the water supply pipe 30 and the model water tank 1, and a flow control pump 33 installed at the end of the water supply pipe 30 away from the model water tank 1. like Figure 3As shown, the monitoring component 4 includes a high-speed camera 40, a laser scanner 41, and a data logger 42, which are respectively installed on the side walls of the model water tank 1. The high-speed camera 40 and the laser scanner 41 are both electrically connected to the data logger 42. Four laser displacement sensors, each electrically connected to the data logger 42, are equidistantly distributed on the slope surface of the slope model 2. Six pore water pressure sensors, each electrically connected to the data logger 42, and four earth pressure sensors, each electrically connected to the data logger 42, are equidistantly distributed inside the slope model 2. Four high-speed cameras 40 are provided, and the four high-speed cameras 40 are respectively located at the top of the front edge, the top of the rear edge, and both sides of the slope model 2.

[0017] Example 2 This embodiment describes a method for testing the hydraulic erosion of gravelly soil slopes, based on a test apparatus for testing the hydraulic erosion of gravelly soil slopes as described in Embodiment 1, including the following steps: S1. A slope model 2 will be set up inside the model water tank 1. During the setting up of the slope model 2, four laser displacement sensors will be evenly set up along the slope surface of the slope model 2, and six pore water pressure sensors and four soil pressure sensors will be evenly set up inside the slope model 2. S2. High-speed cameras 40 are installed outside the model water tank 1, and at the top of the front edge, the top of the rear edge, and both sides of the slope model 2. A laser scanner 41 is installed outside the model water tank 1. The laser displacement sensor, pore water pressure sensor, soil pressure sensor, high-speed camera 40, and laser scanner 41 are electrically connected to the data logger 42. S3. Using the flow-controlled electric pump 33, external clean water is introduced into the model water tank 1 through the water supply pipe 30, so that the water flows through the permeable plate 12 and then enters the slope model 2 to carry out the hydraulic erosion test of the gravel soil slope. S4. During the experiment, the surface deformation of slope model 2 was obtained using a laser displacement sensor; the changes in pore water pressure inside slope model 2 were obtained using a pore water pressure sensor; the changes in soil pressure inside slope model 2 were obtained using an earth pressure sensor; the deformation of slope model 2 during the experiment was captured using a high-speed camera 40; the settlement deformation of slope model 2 at the slope surface and top was measured using a laser scanner 41; the observation data were recorded using a data logger 42; the seepage and erosion fine particles in slope model 2 were collected using a burrowing particle collection cage 11; and the test tailwater was collected using a tailwater collection pond 10. S5. Based on the monitoring data from the laser displacement sensor, pore water pressure sensor, soil pressure sensor, high-speed camera 40 and laser scanner 41, compare and analyze the basic characteristics of landslide deformation, study the evolution process of gravelly soil slope from local erosion, gradual failure to overall collapse and instability, reveal the basic characteristics of collapse and instability evolution and the variation laws of seepage erosion rate, settlement deformation, slope displacement, pore water pressure and soil pressure.

[0018] Example 2 The difference between this embodiment and Embodiment 1 is that: like Figure 1 , 4 As shown, a model placement box 20 is movably connected inside the model water tank 1. The top of the model placement box 20 is open, and handles 200 are provided on both sides of the upper surface of the model placement box 20. The front and rear ends of the model placement box 20 are provided with through grooves 201. The slope model 2 is placed inside the model placement box 20.

[0019] Example 3 The difference between this embodiment and Embodiment 2 is that: like Figure 1 , 3 As shown, a water-blocking plate 13 is slidably engaged inside the model water tank 1 and at the front end of the porous permeable plate 12. A sealing strip is provided on the inner side wall of the model water tank 1, which is movably engaged with the water-blocking plate 13. A water level scale mark is provided on the outer side wall of the model water tank 1.

[0020] Example 4 The difference between this embodiment and embodiment 3 is that: like Figure 1 , 5 As shown in Figure 6, a base 14 is provided below the model water tank 1, and the tailwater collection tank 10 is fixedly connected to the base 14. The rear end of the bottom surface of the model water tank 1 is movably hinged to the upper end surface of the base 14. An electric push rod 5 is movably hinged to the front end of the bottom surface of the model water tank 1, and the electric push rod 5 is movably hinged to the upper end surface of the base 14. A positioning component 6 is provided on the bottom surface of the model water tank 1 and at the rear end of the electric push rod 5. The positioning component 6 includes two positioning frames 60 that are movably hinged to the bottom surface of the model water tank 1, and guides that are provided on the upper end surface of the base 14 and slidably engaged with the two positioning frames 60 respectively. Plate 61 and locking rod 62 are movably connected to the bottom of two positioning frames 60; each of the bottom of the two positioning frames 60 is rotatably engaged with a connecting seat 63, and a locking block 630 is slidably engaged inside the connecting seat 63. A first compression spring 631 is provided inside the connecting seat 63 and sleeved on the outside of the locking block 630; both ends of the locking rod 62 pass through the two connecting seats 63 respectively, and a locking groove 620 that can engage with the locking block 630 is provided on the outer wall of the locking rod 62. A second compression spring 621 that abuts against the outer wall of the connecting seat 63 at the corresponding position is sleeved on both ends of the locking rod 62.

[0021] Example 5 The difference between this embodiment and embodiment 4 is that: like Figure 1As shown, the tail end of the model water tank 1 is connected to an elastic guide plate 15 located above the tailwater collection tank 10; by setting the elastic guide plate 15, it is beneficial to improve the collection effect of the erosion particle collection net box 11 on the erosion particles generated during the test.

[0022] Example 6 The difference between this embodiment and embodiment 5 is that: like Figure 1 , 2 As shown, the model water tank 1 is provided with an outer protective box 7, and a cover plate 70 is movably hinged to the outer side wall of the outer protective box 7; a universal wheel 71 is movably hinged to the bottom surface of the outer protective box 7; a slide rail 72 is provided at the bottom inside the outer protective box 7, and a sliding sleeve 16 is provided on the bottom surface of the base 1 that slides and engages with the slide rail 72; during the test, the model water tank 1 and the base 1 are pulled out from inside the outer protective box 7, and after the test, the outer protective box 7 is used to store and transfer the device, which improves the integration of the device and thus improves the ease of use of the device.

[0023] Example 7 The difference between this embodiment and embodiment 6 is that: like Figure 3 As shown, a purification box 8 connected to the tailwater collection tank 10 is provided on the upper surface of the base 1. Inside the purification box 8, a filter screen 80, a clean water tank 81, and an adsorption box 82 are arranged in sequence. The clean water tank 81 is filled with clean water filler, which is gravel particles with a particle size of 2~3mm. The adsorption box 82 is filled with activated carbon adsorbent, which has a particle size of 0.8~1.2mm.

[0024] Example 8 This embodiment describes a method for testing the hydraulic erosion of gravelly soil slopes, based on a test apparatus for testing the hydraulic erosion of gravelly soil slopes as described in Embodiment 7, and includes the following steps: S1. Attach the model placement box 20 to the inside of the model water tank 1, and then lay out the slope model 2 inside the model placement box 20. During the laying out of the slope model 2, evenly lay out 4 laser displacement sensors along the slope surface of the slope model 2, and evenly lay out 6 pore water pressure sensors and 4 soil pressure sensors inside the slope model 2. S2. High-speed cameras 40 are installed outside the model water tank 1, and at the top of the front edge, the top of the rear edge, and both sides of the slope model 2. A laser scanner 41 is installed outside the model water tank 1. The laser displacement sensor, pore water pressure sensor, soil pressure sensor, high-speed camera 40, and laser scanner 41 are electrically connected to the data logger 42. S3. Use the flow control pump 33 to introduce external clean water into the model water tank 1 through the water supply pipe 30. Observe the water level height inside the model water tank 1 through the water level scale mark on the outer wall of the model water tank 1. When the water level height reaches the set value, pull the water blocking plate 13 upward so that the water flows through the permeable plate 12 and enters the slope model 2. S4. During the experiment, a laser displacement sensor was used to acquire the surface deformation of slope model 2; a pore water pressure sensor was used to acquire the changes in pore water pressure inside slope model 2; an earth pressure sensor was used to acquire the changes in earth pressure inside slope model 2; a high-speed camera 40 was used to capture the deformation of slope model 2 during the experiment; a laser scanner 41 was used to measure the settlement deformation of slope model 2 at the slope surface and top; and a data logger 42 was used to record the observation data; a seepage erosion fine particles in slope model 2 were collected using a erosion particle collection box 11; and the test tailwater was collected using a tailwater collection tank 10. The test tailwater entered the purification tank 8 and was successively filtered by a filter screen 80, biochemically treated by water purification packing, and adsorbed and purified by activated carbon adsorbent. The purified tailwater was then recycled. S5. During the experiment, the electric push rod 5 was used to push the model water tank 1 to deflect along the base 14 to adjust the slope of the model water tank 1 and study the instability conditions of the gravel soil slope under different slopes. During the adjustment of the model water tank 1, the bottom ends of the two positioning frames 60 slid on the guide plate 61 and approached each other. The connecting seat 63 on the locking rod 62 was always in close contact with the positioning frame 60 at the corresponding position under the action of the second compression spring 621. The locking block 630 inside the connecting seat 63 was engaged and locked with the locking groove 620 on the locking rod 62 under the action of the first compression spring 631. S6. Based on the monitoring data from the laser displacement sensor, pore water pressure sensor, soil pressure sensor, high-speed camera 40 and laser scanner 41, compare and analyze the basic characteristics of landslide deformation, study the evolution process of gravelly soil slope from local erosion and gradual failure to overall collapse and instability, reveal the basic characteristics of collapse and instability evolution and the variation laws of seepage erosion rate, settlement deformation, slope displacement, pore water pressure and soil pressure.

[0025] It should be noted that the displacement sensor, pore water pressure sensor, soil pressure sensor, inlet solenoid valve 32, electromagnetic flow meter 32, flow control pump 33, high-speed camera 40, laser scanner 41, data logger 42 and electric push rod 5 used in this invention all adopt existing technologies and are not specifically limited here. Those skilled in the art can select the corresponding products according to actual needs.

Claims

1. A test device for hydraulic erosion of gravelly soil slopes, characterized in that, The system includes a model water tank (1), a slope model (2) installed inside the model water tank (1), a water supply component (3) connected to the model water tank (1), and a monitoring component (4) installed outside the model water tank (1). The model water tank (1) is open at both the tail end and the top end. The tail end of the model water tank (1) is connected to a tailwater collection tank (10). A cavitation particle collection net box (11) is movably attached to the top of the tailwater collection tank (10). A porous permeable plate (12) is installed on one side of the model water tank (1) near the front end. The slope model (2) is set inside the model water tank (1), and the slope model (2) is located between the porous permeable plate (12) and the tailwater collection tank (10); The water supply assembly (3) includes a water supply pipe (30) installed at the front end of the model water tank (1), an inlet solenoid valve (31) and an electromagnetic flow meter (32) installed at the connection between the water supply pipe (30) and the model water tank (1), and a flow control pump (33) installed at the end of the water supply pipe (30) away from the model water tank (1). The monitoring component (4) includes a high-speed camera (40), a laser scanner (41), and a data logger (42) respectively installed on the side wall of the model water tank (1); the high-speed camera (40) and the laser scanner (41) are both electrically connected to the data logger (42); several laser displacement sensors are equidistantly distributed on the slope surface of the slope model (2) and are electrically connected to the data logger (42); several pore water pressure sensors and soil pressure sensors are equidistantly distributed inside the slope model (2) and are electrically connected to the data logger (42).

2. The hydraulic erosion test device for gravelly soil slopes according to claim 1, characterized in that, The model water tank (1) is connected to a model placement box (20) inside. The top of the model placement box (20) is open. Both sides of the upper surface of the model placement box (20) are provided with handles (200). The front and rear ends of the model placement box (20) are provided with through grooves (201). The slope model (2) is placed inside the model placement box (20).

3. The hydraulic erosion test device for gravelly soil slopes according to claim 1, characterized in that, A water-blocking plate (13) is slidably engaged inside the model water tank (1) and at the front end of the porous permeable plate (12). A sealing strip is provided on the inner side wall of the model water tank (1) and is movably engaged with the water-blocking plate (13). A water level scale mark is provided on the outer side wall of the model water tank (1).

4. The hydraulic erosion test device for gravelly soil slopes according to claim 1, characterized in that, A base (14) is provided below the model water tank (1), and the tailwater collection pool (10) is fixedly connected to the base (14). The rear end of the bottom surface of the model water tank (1) is movably hinged to the upper end surface of the base (14). An electric push rod (5) is movably hinged to the front end of the bottom surface of the model water tank (1), and the electric push rod (5) is movably hinged to the upper end surface of the base (14).

5. The hydraulic erosion test device for gravelly soil slopes according to claim 4, characterized in that, A positioning component (6) is provided on the bottom surface of the model water tank (1) and at the rear end of the electric push rod (5); the positioning component (6) includes two positioning frames (60) that are movably hinged to the bottom surface of the model water tank (1), a guide plate (61) that is provided on the upper surface of the base (14) and slidably engaged with the two positioning frames (60) respectively, and a locking rod (62) that is movably connected to the bottom end of the two positioning frames (60); a connecting seat (63) is rotatably engaged at the bottom end of each of the two positioning frames (60). The connecting seat (63) is slidably engaged with a locking block (630), and the connecting seat (63) is provided with a first compression spring (631) sleeved on the outside of the locking block (630); the two ends of the locking rod (62) pass through the two connecting seats (63) respectively, and the outer side wall of the locking rod (62) is provided with a locking groove (620) that can engage with the locking block (630), and the two ends of the locking rod (62) are respectively sleeved with a second compression spring (621) that abuts against the outer side wall of the connecting seat (63) at the corresponding position.

6. The hydraulic erosion test device for gravelly soil slopes according to claim 4, characterized in that, The model water tank (1) is provided with an outer protective box (7), and a cover plate (70) is movably hinged to the outer side wall of the outer protective box (7); a universal wheel (71) is movably hinged to the bottom surface of the outer protective box (7); a slide rail (72) is provided at the bottom inside the outer protective box (7), and a sliding sleeve (16) is provided on the bottom surface of the base (1) that is slidably engaged with the slide rail (72).

7. The hydraulic erosion test device for gravelly soil slopes according to claim 4, characterized in that, The upper surface of the base (1) is provided with a purification box (8) connected to the tailwater collection tank (10). The purification box (8) is provided with a filter screen (80), a water purification tank (81) and an adsorption tank (82) in sequence. The water purification tank (81) is filled with water purification filler. The adsorption tank (82) is filled with activated carbon adsorbent.

8. A method for testing the hydraulic erosion of gravelly soil slopes, based on the hydraulic erosion testing apparatus for gravelly soil slopes as described in claim 5, characterized in that... Includes the following steps: S1. Attach the model placement box (20) to the inside of the model water tank (1), and then set up the slope model (2) inside the model placement box (20); During the setting up of the slope model (2), a number of laser displacement sensors are evenly set up along the slope surface of the slope model (2), and a number of pore water pressure sensors and soil pressure sensors are evenly set up inside the slope model (2). S2. High-speed cameras (40) are installed outside the model water tank (1) and on the top of the front edge, the top of the rear edge and both sides of the slope model (2). A laser scanner (41) is installed outside the model water tank (1). The laser displacement sensor, pore water pressure sensor, soil pressure sensor, high-speed camera (40) and laser scanner (41) are electrically connected to the data logger (42). S3. Use the flow electric control pump (33) to introduce external clean water into the model water tank (1) through the water supply pipe (30). Observe the water level height inside the model water tank (1) through the water level scale mark on the outer wall of the model water tank (1). When the water level height reaches the set value, pull the water blocking plate (13) upward so that the water flows through the permeable plate (12) and enters the slope model (2). S4. During the experiment, the surface deformation of the slope model (2) was obtained using a laser displacement sensor; the changes in pore water pressure inside the slope model (2) were obtained using a pore water pressure sensor; the changes in soil pressure inside the slope model (2) were obtained using an earth pressure sensor; the deformation of the slope model (2) during the experiment was captured using a high-speed camera (40); the settlement deformation of the slope surface and top of the slope model (2) was measured using a laser scanner (41); the observation data were recorded using a data logger (42); the seepage and erosion fine particles in the slope model (2) were collected using a erosion particle collection cage (11); and the test tailwater was collected using a tailwater collection pond (10). S5. During the experiment, the electric push rod (5) was used to push the model water tank (1) to deflect along the base (14) to adjust the slope of the model water tank (1) and study the instability conditions of the gravel soil slope under different slopes. During the adjustment of the model water tank (1), the bottom ends of the two positioning frames (60) slid on the guide plate (61) and approached each other. The connecting seat (63) on the locking rod (62) was always in close contact with the positioning frame (60) at the corresponding position under the action of the second compression spring (621), and the locking block (630) inside the connecting seat (63) was locked with the locking groove (620) on the locking rod (62) under the action of the first compression spring (631). S6. Based on the monitoring data of laser displacement sensor, pore water pressure sensor, soil pressure sensor, high-speed camera (40) and laser scanner (41), the basic characteristics of landslide deformation are compared and analyzed, and the evolution process of gravelly soil slope from local erosion, gradual destruction to overall collapse and instability is studied. The basic characteristics of collapse and instability evolution and the variation law of seepage erosion rate, settlement deformation, slope displacement, pore water pressure and soil pressure are revealed.

9. A method for testing the hydraulic erosion of gravelly soil slopes according to claim 8, characterized in that, The upper surface of the base (1) is provided with a purification box (8) connected to the tailwater collection tank (10). Inside the purification box (8) are arranged a filter screen (80), a clean water tank (81) and an adsorption box (82) in sequence.

Images