Seepage internal erosion evolution experimental equipment capable of controlling leakage outlet position height

Abstract

The utility model relates to the field of geotechnical engineering, in particular to seepage internal erosion evolution experimental equipment capable of controlling the height of a seepage outlet position, which comprises a box body, a water storage box, a partition plate, a seepage inlet, a soil box, a seepage outlet and a collection box, the seepage inlet is formed in the middle of the partition plate, the multiple seepage outlets are formed in the lower portion of the right side wall of the soil box in the vertical direction at intervals, and the collecting box is arranged below the seepage outlets. The water storage tank supplies water through an upstream water level control device, the water level in the water storage tank and the sandy soil height in the soil tank are larger than the height of the seepage inlet, and the height of the seepage inlet is larger than the height of the seepage outlet; and plugs are arranged on the seepage inlet and the seepage outlet. According to the utility model, the development process of sand seepage internal erosion and particle migration disasters under laboratory conditions is simulated by changing the height of the seepage outlet position.

Description

Technical Field

[0001] This utility model relates to the field of geotechnical engineering, and in particular to an experimental device for controlling the height of the seepage outlet to study the internal erosion evolution of seepage. Background Technology

[0002] In the design and operation of basic infrastructure, soil deformation leading to surface settlement and internal erosion from seepage in sandy soil are particularly prominent issues. Fine particles in the soil migrate and are lost through the pore channels between coarse particles under seepage. When the loss of fine particles is excessive, the soil structure becomes insufficient to resist external loads or its own weight, causing surface subsidence or collapse. This poses a significant threat to urban safety. Therefore, scholars in many related research fields have conducted extensive work. Numerous studies have shown that sandy soil, due to its high permeability, lack of cohesion, and poor self-stabilizing ability, is highly susceptible to seepage erosion, resulting in particle loss and surface settlement, ultimately leading to surface collapse. Once defects appear in road surface engineering, the previously balanced stress and seepage fields will change, resulting in extremely high water pressure. This will continuously erode particles near the defect, eventually forming seepage channels and gradually creating cavities within the strata. When external loads such as vehicles act on the surface, collapse is easily triggered, which is the root cause of a series of problems such as road surface settlement and ground subsidence.

[0003] Currently, research on surface subsidence, soil deformation, and internal erosion damage caused by seepage in sandy soils primarily relies on engineering case studies or indoor simulation experiments. Systematic laboratory experiments investigating the evolution of internal erosion damage caused by seepage under various conditions in road subsidence and ground collapse are not yet comprehensive. Research related to laboratory experiments on internal erosion damage caused by seepage due to surface collapse can be divided into three main types. The first type focuses on varying soil types and particle size distributions across different regions to study their impact on internal seepage erosion damage in ground engineering projects. For example, some regions have predominantly sandy soil layers, while others have widely distributed clay layers; some regions have continuous sand particle size distribution, while others have discontinuously graded sand. This type of research mainly explores the influence of the soil's inherent properties and does not consider other environmental factors, thus differing from actual conditions. The primary function of the experimental setup is soil sieving. The second category treats different fluid conditions as variables to study the impact of varying groundwater conditions on seepage erosion within surface engineering projects. Some scholars have investigated the effects of different water levels, water qualities, and water pressures. The focus of these studies is on the outflow or dewatering devices to control water flow conditions. The third category primarily studies the impact of different seepage inlets on seepage erosion damage within surface engineering projects, considering factors such as the shape, size, and height of the inlets. These experiments are mainly conducted by modifying models of seepage inlet conditions, resulting in a relatively narrow research scope. These studies repeatedly highlight that seepage erosion within surface engineering projects is a complex problem, requiring consideration of multiple factors such as soil properties, particle size distribution, water flow conditions, and seepage inlet conditions. They also suggest that after sand seeps in, the increased permeability coefficient accelerates liquid flow, leading to the removal of more soil particles—a deteriorating coupled process. To date, there is very little research on the impact of different seepage outlet heights on internal seepage erosion and damage in ground engineering projects. The internal seepage mechanism of sandy soil has not been effectively solved. Most researchers are still focused on the impact of soil properties, particle size distribution, water flow conditions, and seepage inlet conditions on internal seepage erosion and damage in ground engineering projects. Experiments and technical solutions on the impact of seepage outlet height on internal seepage erosion and damage are relatively simple and lack systematicity and comprehensiveness.

[0004] This invention, unlike existing simulated internal erosion tests, designs a novel, visualized experimental device for the evolution of internal erosion at controllable seepage outlet heights. By blocking seepage outlets at different heights with three cork cylinders, and opening one outlet after sand saturation, the maximum settlement depth, settlement impact range, and water and sand leakage are monitored and recorded at the seepage outlet location. This allows for the simulation of internal erosion evolution at different outlet locations, monitoring the impact of different locations on the range and depth of erosion cavities around the seepage outlet, and further exploring the mechanisms and causes of changes in various parameters during the seepage process. Corresponding measures to prevent internal seepage erosion damage in ground engineering projects are proposed, providing experimental evidence for preventing road surface settlement and ground collapse in urban construction. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an experimental device for controlling the height of the seepage outlet to study the internal erosion evolution of sand under laboratory conditions. By changing the height of the seepage outlet, the device simulates the development process of internal erosion and particle migration hazards in sandy soil seepage. Once soil seepage begins, the entire device becomes transparent and visible, allowing for effective observation of erosion damage and changes in cavity morphology during the seepage process. It also facilitates recording changes in parameters such as the maximum settlement depth, settlement influence range, and cumulative sand leakage at the seepage outlet location. Based on these parameters, the causes of experimental phenomena and their correlations with various parameters can be analyzed. This lays a solid foundation for establishing appropriate models to predict the development process of internal erosion in seepage. It has positive guiding significance for research on soil erosion in geotechnical engineering, prevention of road surface settlement and ground subsidence hazards in engineering construction, and reduction of engineering and non-engineering accidents.

[0006] To achieve the objective of this utility model, the technical solution adopted by this utility model is as follows:

[0007] This utility model discloses an experimental device for controlling the height of seepage outlets in internal erosion evolution, comprising a box, a water tank, a partition, a seepage inlet, a soil tank, a seepage outlet, and a collection box. The box has a hollow square structure with an open top. The inner cavity of the box is divided into a water tank and a soil tank by the partition. The seepage inlet is located in the middle of the partition. Several seepage outlets are arranged vertically at intervals below the right side wall of the soil tank. The collection box is located below the seepage outlets. The water tank is supplied with water through an upstream water level control device. The water level in the water tank and the sand level in the soil tank are greater than the height of the seepage inlet, and the height of the seepage inlet is greater than the height of the seepage outlet. Both the seepage inlet and the seepage outlet are equipped with plugs.

[0008] The upstream water level control device includes a water supply tank, an inlet pipe, a valve, and a float flow meter. The height of the water supply tank is greater than the height of the water storage tank. The top end of the inlet pipe is connected to the bottom end of the water supply tank, and the bottom end of the inlet pipe is connected to the lower left side wall of the water storage tank. The inlet pipe is equipped with a valve and a float flow meter.

[0009] The front wall of the partition is equipped with a measuring device, which is a scale line set along the vertical direction. The zero mark of the scale line is flush with the bottom of the inner cavity of the soil box. The partition is an plexiglass plate.

[0010] The soil box is filled with four layers of sand, and each layer of sand is separated by colored sand.

[0011] The box is placed on top of a steel frame, which includes a top plate and support columns. The four bottom corners of the top plate are connected to the top of the support columns, the bottom of the support columns are placed on the ground, and the bottom of the box is placed on the top plate.

[0012] The collection box is placed on top of the electronic scale, which is placed on the ground to the right of the support column.

[0013] A drainage channel is fixed below the right side wall of the soil box. The drainage channel is U-shaped and located below the leakage outlet. The collection box can collect the seepage sand and water at the end of the drainage channel.

[0014] A high-definition camera is installed on the right side of the soil box.

[0015] The soil box has several rectangular overflow holes spaced at equal intervals along the horizontal direction on the upper rear side wall.

[0016] The beneficial effects of this utility model are as follows:

[0017] (1) This utility model simulates the development process of internal erosion and particle migration disasters in sand seepage under laboratory conditions by changing the height of the seepage outlet. After the soil begins to seep in the experiment, the entire device is transparent and visible, which can effectively observe the erosion damage and changes in the morphology of cavities during the seepage process. It is also beneficial to record the changes in parameters such as the maximum settlement depth, settlement influence range and cumulative sand leakage under the seepage outlet position conditions during the test. Based on the obtained parameters, the causes of the test phenomena and the correlation between them can be analyzed. This lays a solid foundation for establishing an appropriate model to predict the development process of internal erosion in seepage. It has positive guiding significance for the research on soil erosion in geotechnical engineering, the prevention of road surface settlement and ground collapse in engineering construction, and the reduction of engineering and non-engineering accidents.

[0018] (2) This utility model can control the water flow rate and water level by means of valves, float flow meters and rectangular overflow holes;

[0019] (3) By sealing the seepage inlet and leakage outlet of the seepage erosion generating device inside the seepage flow with a plug, this utility model can make the seepage test of saturated sand start after the sand is saturated, and can control the start time of the test.

[0020] (4) This utility model simulates the internal erosion process of sand seepage under laboratory conditions by changing the height of the seepage outlet, thereby deduce the development process of particle migration disasters that occur on the road surface;

[0021] (5) This utility model can obtain the amount of sand leakage after erosion occurs inside the seepage in a timely manner through the collection device, without having to wait until the end of the experiment to measure the amount of sand leakage, which is simple and easy to operate.

[0022] (6) This utility model has a camera installed on one side of the soil box, which can obtain the most clearly visible and appropriately sized test pictures and videos of the entire test process;

[0023] (7) The box of this utility model is made of organic glass plate, which can withstand a large force without losing stability. Furthermore, the outer surface of the erosion generating device of the test device is provided with scale lines along the vertical direction, which is beneficial for observing the water level in the erosion generating device and the height and settlement changes of the soil in the erosion generating device. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this utility model;

[0025] Figure 2 This is a schematic diagram showing the filling state of sand in the soil box of this utility model.

[0026] In the attached diagram, 1 is a water supply tank, 2 is an inlet pipe, 3 is a valve, 4 is a float flow meter, 5 is a water storage tank, 6 is a partition, 7 is a seepage inlet, 8 is a soil tank, 9 is a rectangular overflow hole, 10 is a measuring device, 11 is sand, 12 is colored sand, 13 is a leakage outlet, 14 is a plug, 15 is a diversion channel, 16 is a steel bracket, 18 is a collection box, 19 is an electronic scale, and 20 is a high-definition camera. Detailed Implementation

[0027] The present invention will be further described below:

[0028] Please see Figure 1-2 ,

[0029] This utility model discloses an experimental device for controlling the height of seepage outlets to study the evolution of internal erosion in seepage. The device includes a box, a water tank 5, a partition 6, a seepage inlet 7, a soil tank 8, seepage outlets 13, and a collection box 18. The box has a hollow square structure with an open top. The inner cavity of the box is divided into the water tank 5 and the soil tank 8 by the partition 6. The seepage inlet 7 is located in the middle of the partition 6. Several seepage outlets 13 are spaced vertically below the right side wall of the soil tank 8. The collection box 18 is located below each seepage outlet 13. The water tank 5 is supplied with water through an upstream water level control device. The water level in the water tank 5 and the height of the sand 11 in the soil tank 8 are greater than the height of the seepage inlet 7, which is greater than the height of the seepage outlet 13. Both the seepage inlet 7 and the seepage outlet 13 are equipped with plugs 14. By changing the height of the seepage outlet 13, the device simulates the development process of internal erosion and particle migration disasters in sand seepage under laboratory conditions. After the soil began to seep in the experiment, the entire device became transparent and visible, allowing for effective observation of erosion damage and changes in cavity morphology during the seepage process. It also facilitated recording changes in parameters such as the maximum settlement depth, settlement influence range, and cumulative sand leakage at seepage outlet location 13 during the experiment. This enabled analysis of the causes of the experimental phenomena and their correlation with various parameters, laying a solid foundation for establishing appropriate models to predict the internal erosion development process of seepage. This has positive guiding significance for research on soil erosion in geotechnical engineering, prevention of road surface settlement and ground subsidence hazards in engineering construction, and reduction of engineering and non-engineering accidents.

[0030] Furthermore, the upstream water level control device includes a water supply tank 1, an inlet pipe 2, a valve 3, and a float flow meter 4. The height of the water supply tank 1 is greater than the height of the water storage tank 5. The top end of the inlet pipe 2 is connected to the bottom end of the water supply tank 1, and the bottom end of the inlet pipe 2 is connected to the lower left side wall of the water storage tank 5. The inlet pipe 2 is equipped with a valve 3 and a float flow meter 4. Several rectangular overflow holes 9 are evenly spaced along the horizontal direction on the upper rear side wall of the earthen tank 8. The water flow rate and water level can be controlled by the valve 3, the float flow meter 4, and the rectangular overflow holes 9.

[0031] Furthermore, a measuring device 10 is provided on the front wall of the partition 6. The measuring device is a scale line set along the vertical direction, and the zero mark of the scale line is flush with the bottom of the inner cavity of the soil box 8. The partition 6 is an organic glass plate, which facilitates accurate control of the water level in the water supply tank 1 and the height of the sand 11 in the soil box 8, and observation of the water level and the settlement and height change of the soil in the seepage erosion device.

[0032] Furthermore, the soil box 8 is lined with four layers of the aforementioned sand 11, with each layer of sand 11 separated by colored sand 12.

[0033] Furthermore, the box is placed on top of the steel support 16, which includes a top plate 161 and a support column 162. The four bottom corners of the top plate 161 are connected to the top of the support column 162, and the bottom of the support column 162 is placed on the ground. The bottom of the box is placed on the top plate 161 to ensure that the leakage outlet 13 can better leak and facilitate collection.

[0034] Furthermore, the collection box 18 is placed on top of the electronic scale 19, which is placed on the ground to the right of the support column 162, so as to obtain the weight of the sand and water leaking from the leakage outlet 13 in a timely manner.

[0035] Furthermore, a drainage channel 15 is fixed below the right side wall of the soil box 8. The drainage channel 15 is arranged in a "U" shape below the leakage outlet 13. The collection box 18 can collect the leakage sand and water at the tail end of the drainage channel 15, which can play a role in drainage and ensure that all the leakage sand and water leaking from the leakage outlet 13 can be collected through the drainage channel 15.

[0036] Furthermore, a high-definition camera 20 is installed on the right side of the soil box 8 to record the changes in the side of the leakage generating device from the beginning to the end of the test.

[0037] Example:

[0038] The water storage tank 5 is 100mm long, 200mm wide, and 300mm high. The soil tank 8 is 400mm long, 200mm wide, and 300mm high. The partition 6 between the water storage tank 5 and the soil tank 8 is 200mm long, 300mm wide, and 8mm thick. The water level in the water storage tank 5 is kept constant at 200mm to ensure sufficient water pressure. A 10mm diameter seepage inlet 7 is located at the center of the left side partition 6 of the soil tank 8. The seepage inlet 7 is located 40mm above the water level in the water tank 5. When there is no leakage, the seepage inlet 7 is blocked with a cork plug 14. Three 10mm radius seepage outlets 13 are located at the center of the right side seepage outlet plate of the soil tank 8. The centers of the seepage outlets 13 are 20mm, 40mm, and 60mm away from the bottom of the soil tank 8, respectively. When there is no leakage, they are blocked with three plugs 14. The plugs 14 are made of cork cylinders and are used to block two seepage outlets 13 and control the leakage of one seepage outlet 13, so as to study the influence of the different positions of the seepage outlets 13 on the range and depth of the erosion cavities around the seepage outlets 13.

[0039] Four rectangular overflow holes 9 are opened on the upper back of the soil box 8 to ensure a stable water head height; an 800W high-definition camera 20 is installed on the right side of the soil box 8 to record the changes in the side of the leakage device from the beginning to the end of the test.

[0040] The specific experimental methods are as follows:

[0041] Step 1: Close valve 3 on inlet pipe 2, and plug seepage inlet 7 and leakage outlet 13 with plug 14. First, thoroughly mix the sand 11 used in the test, then soak it in water to ensure the sand particles are fully in contact with the water, saturating the sand 11 and removing air bubbles. Then, use the sand rain method to evenly drop the sand sample into the test soil box 8. Mark the vertical surface of the front outer surface of the leakage generating device with graduations to observe the filling height of the sand 11. After each layer of sand 11 is filled, vibrate it with an iron rod to level the surface and ensure a smooth interface between the two layers. Then, spread a thin layer of colored sand 12 on each layer of sand until the sand 11 is filled to the designated height, and proceed to the next step.

[0042] Step 2: Place the steel support 16 on the ground, place the seepage internal erosion generator on the steel support 16, and place the collection box 18 directly below the drainage channel 15. The sand and water will flow from the drainage channel 15 to the collection box 18. Place the collection box 18 on the electronic scale 19 and record the mass of particles lost at all times. Position an 800W high-definition camera 20 at an appropriate location on one side, adjusting its height to perfectly record the experimental phenomena.

[0043] Step 3: Open valve 3 of water supply tank 1 to fill water into water storage tank 5. After reaching the corresponding water head height, let it stand for a period of time until the air in water storage tank 5 is expelled. Then, turn on the 800W high-definition camera to film. Remove one of the plugs 14 of seepage inlet 7 and seepage outlet 13 to start the test.

[0044] Step 4: The sand and water flow out through the leakage outlet 13. Adjust the upstream valve 3 to keep the water level in the storage tank 5 constant. Place the collection box 18 on the electronic scale 19 to record the sand and water loss rate at all times. Replace the collection box 18 at fixed intervals to obtain the mass of particles lost within the same time interval.

[0045] Step 5: When the seepage erosion reaches the point where a stable soil arch appears, the erosion cavity no longer extends or expands to the model boundary and sand collapse occurs, close the upstream valve 3 and simultaneously block the seepage inlet 7 and the leakage outlet 13. The test ends.

[0046] Step 6: Observe and photograph the particle erosion morphology at the seepage inlet and the sidewall and top morphology of the seepage cavity. Remove the remaining sand 11 from the test area, dry it, and weigh it. Let the collection box 18 settle, weigh the total mass of sand and water loss in the collection box, and dry and sieve the sand particles that leaked during the test.

[0047] Step 7: The shooting time and placement of the high-definition camera will be adjusted according to the specific test plan.

[0048] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. An experimental device for controlling the height of the seepage outlet to study the internal erosion evolution of seepage, characterized in that: The box, water storage tank (5), partition (6), seepage inlet (7), soil tank (8), leakage outlet (13) and collection box (18), The box is a hollow square structure with an open top, the inner cavity of the box is divided into a water storage tank (5) and a soil tank (8) by the partition (6), the middle part of the partition (6) is provided with the seepage inlet (7), the lower part of the right side wall of the soil tank (8) is provided with a plurality of seepage outlets (13) along the vertical direction, and the lower part of the seepage outlet (13) is provided with the collection box (18). The water storage tank (5) is supplied with water by an upstream water level control device, the water level in the water storage tank (5) and the height of the sand (11) in the soil tank (8) are greater than the height of the seepage inlet (7), and the height of the seepage inlet (7) is greater than the height of the seepage outlet (13); the seepage inlet (7) and the seepage outlet (13) are both provided with plugs (14).

2. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 1, characterized in that: The upstream water level control device comprises a water supply tank (1), a water inlet pipe (2), a valve (3) and a float flowmeter (4), the height of the water supply tank (1) is greater than the height of the water storage tank (5), the top end of the water inlet pipe (2) is connected with the bottom end of the water supply tank (1), the bottom end of the water inlet pipe (2) is communicated with the lower part of the left side wall of the water storage tank (5), and the water inlet pipe (2) is provided with the valve (3) and the float flowmeter (4).

3. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 2, characterized in that: The front wall of the partition (6) is provided with a measuring device (10), the measuring device is a scale line arranged along the vertical direction, and the zero scale of the scale line is flush with the inner cavity bottom of the soil tank (8); the partition (6) is a plexiglass plate.

4. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 3, characterized in that: Four layers of sand (11) are laid in the soil tank (8), and each layer of sand (11) is separated by colored sand (12).

5. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 1, characterized in that: The box is placed on the top of a profile steel support (16), the profile steel support (16) comprises a top plate and a support column, the bottom four corners of the top plate are respectively connected with the top ends of the support columns, the bottom ends of the support columns are placed on the ground, and the bottom of the box is placed on the top plate.

6. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 5, characterized in that: The collection box (18) is placed on the top of an electronic scale (19), and the electronic scale (19) is placed on the ground on the right side of the support column.

7. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 6, characterized in that: A drainage groove (15) is fixed to the lower part of the right side wall of the soil tank (8), the drainage groove (15) is arranged in the form of a "U" shape below the seepage outlet (13), and the collection box (18) can collect the seepage sand water at the tail end of the drainage groove (15).

8. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 7, characterized in that: A high-definition camera (20) is arranged on the right side of the soil tank (8).

9. The seepage internal erosion evolution experiment device of controllable seepage outlet position height according to claim 1, characterized in that: A plurality of rectangular overflow holes (9) are arranged on the upper part of the back wall of the soil tank (8) along the horizontal direction at equal intervals.

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