Permeation erosion deslagging real-time monitoring test device compatible with three-axis equipment

Abstract

The invention discloses a triaxial equipment compatible penetration erosion deslagging real-time monitoring test device, which comprises a seepage loading system and a weighing system, the seepage loading system comprises a hole channel for collecting seepage at the bottom of a soil sample, the hole channel is vertically arranged and comprises a stepped hole, the diameter of the stepped hole is gradually increased along the downward direction, and the weighing system is arranged in the hole channel. The weighing system comprises a sand containing barrel, and a water inlet of the sand containing barrel is right opposite to the stepped hole. According to the penetration erosion deslagging real-time monitoring test device compatible with the three-axis equipment, a stepped hole and a vertical flow channel are formed in the bottom of a soil sample, and a second confining pressure chamber is directly arranged below a first confining pressure chamber and is connected with the first confining pressure chamber through a short stand column, so that the length of the flow channel is shortened; deposition and attachment of seepage erosion particles at all positions of the pipeline are reduced, and the accuracy of measured data is improved.

Description

Technical Field

[0001] The invention relates to a real-time monitoring test device for penetration erosion and slag discharge compatible with triaxial equipment. Background Art

[0002] The seepage of groundwater in water-rich strata can easily cause the migration of soil particles, trigger internal erosion of the soil, and then change the internal structure and mechanical properties of the soil, and even cause seepage damage to the soil. Seepage damage can be divided into four categories: soil flow, piping, contact scouring, and interface erosion. Soil flow is the phenomenon that soil or particles in a certain range of the surface are suspended and moved at the same time under the action of upward seepage water flow; piping refers to the phenomenon that fine particles in the soil move and flow in the pore channels formed by coarse particles under the action of seepage water flow. Foundation pits and dams in coastal areas often suffer from seepage erosion damage. In the process of seepage erosion, fine particles will be carried away from the pores of coarse particles under the impact of water. The amount of slag discharged during the erosion process is of great significance to the study of seepage erosion. Existing test devices, such as the test device and method for determining the permeability coefficient and permeability path of the soil-structure interface disclosed in the Chinese patent with publication number CN114324113A, the test device and method for measuring the permeability coefficient and permeability path of the gravel soil disclosed in the Chinese patent with publication number CN116465971A, and the test device and method for observing the displacement of seepage erosion particles disclosed in the Chinese patent with publication number CN117848925A, apply the upper and lower water heads through the air pressure controller to generate the seepage force, connect the slag outlet and the collection device with a pipeline, and open the collection device for simple collection after the saturation, consolidation, permeation and shearing process are completed. The above permeation erosion test still has many shortcomings in the collection of fine particles: 1. There will be a lot of losses in the process of eroding fine particles from the sample to the collection device, resulting in the loss of accuracy of the weight of the fine particles collected in the end. 2. The collection and weighing are carried out only after all the experimental steps are completed, and it is impossible to accurately distinguish the weight of fine particles generated by the permeation process, and it is impossible to obtain a complete and real-time fine particle curve of the erosion process. Summary of the invention

[0003] In view of the above shortcomings, the object of the present invention is to provide a penetration erosion slag real-time monitoring test device compatible with a triaxial device with more accurate slag amount monitoring.

[0004] To this end, the present invention provides a real-time monitoring test device for seepage erosion and slag discharge compatible with triaxial equipment, including a seepage loading system and a weighing system, wherein the seepage loading system includes a channel for collecting seepage at the bottom of the soil sample, the channel is vertically arranged and includes stepped holes, and the stepped holes gradually increase in diameter in a downward direction, and the weighing system includes a sand bucket, and the water inlet of the sand bucket is opposite to the stepped hole.

[0005] Furthermore, multiple sections of cylindrical holes or frustum-shaped holes are connected end to end, and the diameters of the holes gradually increase downward.

[0006] Furthermore, a fine mesh is provided on the upper part of the sand bucket, and water flows through the fine mesh and overflows from the upper part of the sand bucket, and a seepage channel connected to the stepped hole extends into the interior of the sand bucket, and the fine mesh cooperates with the outer wall of the seepage channel.

[0007] Furthermore, an overflow sedimentation device is provided in the sand bucket, and the overflow sedimentation device includes a circular partition. The lower end of the seepage channel is arranged in the middle of the circular partition. Adjacent overflow sedimentation devices are arranged at intervals. The partition is provided with a water passage for water to flow from the inner and outer sides separated by the circular partition.

[0008] Furthermore, the seepage channel includes a pipe, the lower end of the pipe is higher than the overflow port or flush with the overflow port, the upper end of an innermost circular partition adjacent to the pipe is higher than the lower end of the pipe or is provided with a transverse baffle to cooperate with the lower end of the pipe, an overflow port is formed at the upper end of the outer wall of the sand bucket, and the upper end of the circular baffle is higher than or equal to the overflow port.

[0009] Furthermore, there are three layers of circular baffles, the lower part of the inner circular baffle is provided with holes, the middle circular baffle is not provided with holes, and the height of the middle circular baffle is lower than the adjacent circular baffles so that water flows overflow from the upper part of the middle circular baffle, and the middle part of the outer baffle is provided with holes.

[0010] Furthermore, the weighing system includes a second confining pressure chamber, in which a sand bucket, a weighing sensor arranged below the sand bucket, and a supporting platform supporting the weighing sensor are provided, and a column is arranged below the supporting platform. The second confining pressure chamber is provided with a drainage channel for draining water to the outside.

[0011] Furthermore, it also includes a pressure-controlled vacuum system and a data processing and analysis system; the seepage loading system includes a first confining pressure chamber, the first confining pressure chamber is provided with a top cap and a base plate, the top cap and the base plate are used to set the soil sample, and the base plate is provided with a conical hole and a stepped hole connected to the conical hole; the pressure-controlled vacuum system includes a water storage tank, an air pump, a volume pressure controller, and a confining pressure controller, the air pump is connected to the volume pressure controller, the volume pressure controller is respectively connected to the water storage tank and the second confining pressure chamber, the confining pressure controller is connected to the first confining pressure chamber, and the water storage tank is connected to the seepage loading system through a pipeline; the bottom of the water storage tank is connected to a flow meter, the flow meter is connected to a flow collection box, the flow collection box, the volume pressure controller and the confining pressure controller are connected to the data processing and analysis system through lines; the data processing and analysis system includes a computer and a data acquisition device, the flow collection box, the volume pressure controller, the sensor, the confining pressure controller are connected to the data acquisition device, and then the computer is connected to the data acquisition device.

[0012] Furthermore, the first confining pressure chamber is arranged above the second confining pressure chamber, and the first confining pressure chamber and the second confining pressure chamber are connected by columns to form a double-chamber structure, so that the channel and seepage channel between the bottom of the soil sample and the water inlet of the sand bucket form a vertical channel.

[0013] Furthermore, a porous plate is arranged below the top cap and above the base plate, the internal space of the top cap is arranged at a certain inclination angle, the side of the aluminum alloy top cap is connected to the customized joint on the base plate through a pipe, and then the pipe is connected to the sand bucket of the weighing system, and it is connected to the volume pressure control vacuum system through a control valve.

[0014] Beneficial technical effects of the present invention:

[0015] (1) The present invention is a real-time monitoring test device for seepage erosion and slag discharge compatible with a triaxial device. A stepped hole and a vertical flow channel are arranged at the bottom of the soil sample. The second confining pressure chamber is directly arranged below the first confining pressure chamber and connected through a short column. This shortens the length of the flow channel, reduces the deposition and adhesion of seepage erosion particles at various positions of the pipeline, and improves the accuracy of the measured data.

[0016] (2) In a specific embodiment of the present invention, by setting up a multi-layer overflow sedimentation device, the loss of fine particles during sand-water separation is reduced, thereby improving the measurement accuracy. By setting the position of the seepage channel, the influence of the seepage channel on the accuracy of the measurement data is reduced, thereby reducing the influence of each link on the fine particle measurement.

[0017] (3) The specific embodiment of the present invention is composed of a closed double chamber, a water tank, an air pressure controller and other devices. By operating the air pressure controller, the device can be tested under high back pressure; it can also be used to measure a clear fine particle collection curve in the penetration erosion stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a specific embodiment of the present invention;

[0019] Figure 2 It is a cross-sectional schematic diagram of a sand bucket;

[0020] Figure 3 Schematic diagram of the top view of the sand bucket.

[0021] Explanation of the reference numerals in the accompanying drawings: 1. first confining pressure chamber; 2. base plate; 3. top cap; 4. porous plate; 5. stepped hole; 6. customized joint; 7. load sensor; 9. second confining pressure chamber; 10. sand bucket; 101. fine mesh; 102. circular partition; 103. hole; 11. weighing sensor; 13. column; 15. water tank; 16. volume pressure controller; 17. air pump; 18. flow meter; 19. flow collection box; 20. confining pressure controller; 21. computer; 22. data acquisition device; 23. seepage pipe; 24. conical hole; 25. guide plate. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0023] Reference Figures 1 to 3As shown, a real-time monitoring test device for seepage erosion and slag discharge compatible with a triaxial device of the present invention comprises a seepage loading system, a weighing system, a pressure control vacuum system and a data processing and analysis system, wherein the seepage loading system comprises a channel for seepage at the bottom of the soil sample, the channel is arranged vertically and the channel comprises a stepped hole 5, the diameter of the stepped hole 5 increases stepwise in the downward direction, and the weighing system comprises a sand bucket 10, the water inlet of the sand bucket 10 is directly opposite to the stepped hole 5. In this embodiment, the seepage loading system comprises a first confining pressure chamber 1, the first confining pressure chamber 1 can be made of acrylic material, a top cap 3 and a base plate 2 are arranged in the first confining pressure chamber 1, the top cap 3 and the base plate 2 are made of aluminum alloy, the upper end of the top cap 3 is loaded with a vertical loading mechanism of the triaxial device and a load sensor 7, and axial stress can be applied to the soil sample. The soil sample is arranged between the top cap 3 and the base plate 2, and the side of the soil sample is wrapped with a latex film. A porous plate 4 and a highly permeable geotextile are arranged below the top cap 3 and above the base plate 2. The side of the top cap 3 is connected to the custom joint 6 on the base plate 2 through the water inlet pipe, and then connected to the sand bucket 10 of the weighing system. The valve is controlled to connect it to the volume pressure control vacuum system. The control valve controls the water in the water storage tank 15 to flow into the top cap 3 or the sand bucket 10. The internal space of the top cap 3 is set at a certain inclination angle. A conical hole 24 and a stepped hole 5 connected to the conical hole are set in the middle of the base plate 2. The conical hole 24 is set at the bottom of the soil sample to accelerate the flow rate of the water flow. The side of the base plate 2 can be set with a channel for injecting water into the first confining pressure chamber 1 and a sensor for measuring back pressure and pore pressure; the pressure control vacuum system and the data processing system can adopt existing technologies. The weighing system includes a sand bucket 10 and a weighing sensor 11. The pressure control vacuum system forms a water head difference at the upper and lower ends of the soil sample of the seepage loading system. The seepage at the bottom of the soil sample flows into the sand bucket 10 through the vertically arranged channel. The weighing sensor 11 transmits the measured real-time data to the data processing and analysis system. Compared with the existing test device, the present invention adopts a vertical channel, and the water flows vertically downward. Under the action of gravity, the speed and kinetic energy are more advantageous than the connecting pipes in the prior art. The stepped hole 5 is gradually enlarged, and the inner wall of the channel adopts a vertical or lower end enlarged structure, which reduces the friction between the inner wall of the channel and the water flow, and reduces the adhesion of fine particles.

[0024] Reference Figure 1As shown, the pressure control vacuum system includes a water tank 15, an air pump 17, a volume pressure controller 16, and a confining pressure controller 20. The air pump 17 is connected to the volume pressure controller 16, and the volume pressure controller 16 is respectively connected to the water tank 15 and the second confining pressure chamber 9. The confining pressure controller 20 is connected to the first confining pressure chamber 1. The water tank 15 is connected to the seepage loading system through a pipeline; the bottom of the water tank 15 is connected to a flow meter 18, and the flow meter 18 is connected to a flow collection box 19. The flow collection box 19, the volume pressure controller 16, and the confining pressure controller 20 are connected to a data processing and analysis system through lines; the pressure control vacuum system controls the pressure of the first confining pressure chamber 1 and the second confining pressure chamber 9, as well as the water head at the upper and lower ends of the soil sample.

[0025] Reference Figure 1 As shown, the data processing and analysis system includes a computer 21, a data acquisition device 22, a flow acquisition box 19, a volume pressure controller 16, a sensor, and a confining pressure controller 20 are connected to the data acquisition device 22, and then the computer 21 is connected to the data acquisition device 22. The sensors such as back pressure and pore pressure and the load sensor 7 convert the back pressure, pore pressure, displacement, axial force, flow, etc. into electrical signals and transmit them to the data acquisition device 22 of the data processing and analysis system.

[0026] In the above embodiment, referring to Figure 1 As shown, the stepped hole 5 includes a plurality of multi-section holes connected end to end, each section of the hole can be a frustum-shaped or cylindrical hole, and the radial size of the multi-section hole increases step by step, that is, the projection of any cross section of the hole on the horizontal plane covers the projection of the cross section above it on the horizontal plane. This embodiment can reduce the contact and friction between the water flow and the inner wall, increase the speed of the water flow, and reduce the adhesion of particles eroded by seepage.

[0027] In the above embodiment, referring to Figure 1 As shown, the first confining pressure chamber 1 is arranged above the second confining pressure chamber 9, and the first confining pressure chamber 1 and the second confining pressure chamber 9 are connected by a shorter column 13 to form a double-chamber structure, so that the channel and the seepage channel between the bottom of the soil sample and the water inlet of the sand bucket 10 form a vertical channel. In addition to realizing the vertical straight line setting, the double-chamber structure can also greatly shorten the length of the flow channel (the flow channel includes the channel and the seepage channel in the pipe connecting the sand bucket 10), reducing the adhesion of fine particles in the flow channel.

[0028] In the above embodiment, referring to Figure 1 and Figure 3As shown, a fine mesh 101 or a filter is provided on the upper part of the sand bucket. The mesh size of the filter or fine mesh 101 needs to be determined according to the soil sample. Different soil samples, such as sand or clay, have different permeabilities, and the particle sizes of eroded fine particles are also different. Usually, the pore size of the filter or fine mesh 101 is smaller than the particle size of the eroded fine particles. After passing through the fine mesh 101, water overflows from the upper part of the sand bucket, and the seepage channel connected to the stepped hole 5 extends into the interior of the sand bucket. The fine mesh 101 cooperates with the outer wall of the seepage channel, so that fine particles will not enter the top of the fine mesh 101 from the gap between the outer wall of the seepage channel and the fine mesh 101, thereby preventing fine particles from being brought out of the sand bucket 10 from the upper part of the fine mesh 101 and affecting the measurement accuracy. In this embodiment, the infiltrated water flows out of the seepage channel and enters the sand bucket 10, and overflows from the upper part of the sand bucket 10 after being filtered by the fine mesh 101, so as to separate the sand and water. The weighing sensor 11 measures the corresponding weight value and obtains the weight of the fine particles. This measurement method is a prior art. The sand bucket 10 actually contains a mixture of sand and water. Under the condition that the total volume of sand and water is constant and the density of sand and water is different, the weight of the sand can be calculated according to the measured total weight. Before the test starts, the sand bucket 10 is filled with water. After the test starts, the seepage water carries the fine particles into the sand bucket 10, and the fine particles replace part of the water in the sand bucket 10. The weighing system measures the corresponding value in real time and transmits it to the data processing and analysis system to form a weighing curve.

[0029] In the above embodiment, referring to Figure 1 and Figure 3 As shown, the sand bucket is provided with an overflow sedimentation device, which includes a circular partition 102. The lower end of the seepage channel is provided in the middle of the circular partition 102. Adjacent overflow sedimentation devices are provided at intervals. The partition is provided with a water passage for water to flow from the inner and outer sides separated by the circular partition 102. The water passage in this embodiment is a hole 103 provided on the circular partition 102. This embodiment can prevent the fine particle-containing water flow from the seepage channel from flowing directly to the overflow port, but flows to the overflow port after passing through the space separated by the multi-layer circular partition 102. In fact, the hydraulic retention time of the sand-containing water flow in the sand bucket 10 is increased, so that it flows out after sufficient sedimentation, which can further reduce the loss of fine particles and improve the measurement accuracy. In addition, a turbidity meter can be provided at the outlet of the seepage channel.

[0030] In the above embodiment, referring to Figure 2As shown, the seepage channel includes a seepage pipe 23 or a joint, the lower end of the seepage pipe 23 is located higher than the overflow or flush with the overflow, the upper end of the innermost circular partition 102 adjacent to the seepage pipe 23 is higher than the lower end of the seepage pipe 23 or is provided with a transverse baffle to cooperate with the lower end of the seepage pipe 23, the upper end of the outer wall of the sand bucket forms an overflow, and the upper end of the outermost circular partition is higher than or equal to the overflow. The lower end of the seepage pipe 23 of this embodiment no longer extends into the water, but is higher than or flush with the water surface. Since the seepage pipe 23 extends into the water to displace a certain volume of water, the interaction between the water and the outer wall of the pipe affects the accuracy of the weight measurement to a certain extent. This embodiment prevents it from displacing water, and uses the inner circular partition 102 to prevent the high-speed water flow from splashing out and affecting the measurement accuracy. Furthermore, the number of circular baffles 102 is three layers, the lower part of the inner circular baffle 102 is provided with holes 103, the middle circular baffle 102 is not provided with holes 103, and the height of the middle circular baffle 102 is lower than that of the adjacent circular baffle 102 so that the water flows overflow from the upper part of the middle circular baffle 102, and the middle part of the outer baffle is provided with holes 103. In this embodiment, the water flowing out of the seepage channel enters the inner circle through the lower holes 103 after the sedimentation of the central circle. Since the water inlet is arranged at the upper part of the central circle, the sand content of the upper water flow is high, so the hole 103 arranged at the lower part is used as a water passage, which increases the residence time of the incoming water in the central circle, which is conducive to sedimentation. After entering the middle circle, the fine particle density is greater than that of water, and has a tendency to settle downward. Therefore, after the water flow is settled, the sand content of the upper water flow is less, and the overflow enters the middle circle. After the water flow in the middle circle is settled, it enters the outer circle from the middle hole 103 and further settles, and then overflows and is discharged. The above structure is conducive to increasing the residence time of the incoming water in the sand bucket 10 and improving the sedimentation effect, thereby reducing the loss of fine particles. In this embodiment, in order to prevent water from adhering to the surface of the sand bucket 10 and increasing its weight, an inclined guide plate 25 can be provided outside the overflow port.

[0031] In the above embodiment, the weighing system includes a second confining pressure chamber 9, in which a sand bucket 10, a weighing sensor 11 arranged below the sand bucket 10, and a supporting platform for supporting the weighing sensor 11 are arranged, and a column 13 is arranged below the supporting platform. A drainage channel for draining water to the outside is provided in the second confining pressure chamber 9.

[0032] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A real-time monitoring test device for seepage erosion and slag discharge compatible with triaxial equipment, comprising a seepage loading system and a weighing system, characterized in that: The seepage loading system includes a channel for collecting seepage at the bottom of the soil sample, the channel is vertically arranged and includes stepped holes, the diameter of the stepped holes increases step by step in the downward direction, and the weighing system includes a sand bucket, the water inlet of the sand bucket is opposite to the stepped holes.

2. A real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 1, characterized in that: The stepped hole comprises a plurality of cylindrical holes or frustum-shaped holes which are connected end to end and whose diameters increase step by step downward.

3. A real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 1 or 2, characterized in that: A fine mesh is provided on the upper part of the sand bucket. After water flows through the fine mesh, it overflows from the upper part of the sand bucket. The seepage channel connected with the stepped hole extends into the interior of the sand bucket. The fine mesh cooperates with the outer wall of the seepage channel.

4. A real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 3, characterized in that: An overflow sedimentation device is provided in the sand bucket, and the overflow sedimentation device includes a circular partition. The lower end of the seepage channel is arranged in the middle of the circular partition. Adjacent overflow sedimentation devices are arranged at intervals. The partition is provided with a water passage for water to flow from the inner and outer sides separated by the circular partition.

5. A real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 4, characterized in that: The seepage channel includes a pipe, the lower end of the pipe is higher than the overflow port or flush with the overflow port, the upper end of an innermost circular partition adjacent to the pipe is higher than the lower end of the pipe or is provided with a transverse baffle to cooperate with the lower end of the pipe, an overflow port is formed at the upper end of the outer wall of the sand bucket, and the upper end of the circular baffle is higher than or equal to the overflow port.

6. A real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 5, characterized in that: There are three layers of circular baffles, the lower part of the inner circular baffle is provided with holes, the middle circular baffle is not provided with holes, and the height of the middle circular baffle is lower than the adjacent circular baffles so that water flows overflow from the upper part of the middle circular baffle, and the middle part of the outer baffle is provided with holes.

7. A real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 6, characterized in that: The weighing system includes a second confining pressure chamber, in which a sand bucket, a weighing sensor arranged below the sand bucket, and a supporting platform supporting the weighing sensor are arranged, a column is arranged below the supporting platform, and a drainage channel for draining water to the outside is arranged in the second confining pressure chamber.

8. The real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 7, characterized in that: It also includes a pressure control vacuum system and a data processing and analysis system; The seepage loading system comprises a first confining pressure chamber, the first confining pressure chamber is provided with a top cap and a base plate, a soil sample is arranged between the top cap and the base plate, and a conical hole and a stepped hole connected to the conical hole are arranged in the base plate; The pressure control vacuum system includes a water storage tank, an air pump, a volume pressure controller, and a confining pressure controller. The air pump is connected to the volume pressure controller, the volume pressure controller is respectively connected to the water storage tank and the second confining pressure chamber, the confining pressure controller is connected to the first confining pressure chamber, and the water storage tank is connected to the seepage loading system through a pipeline; the bottom of the water storage tank is connected to a flow meter, the flow meter is connected to a flow collection box, and the flow collection box, the volume pressure controller and the confining pressure controller are connected to a data processing and analysis system through lines; The data processing and analysis system comprises a computer and a data acquisition device. A flow acquisition box, a volume pressure controller, a sensor, and a confining pressure controller are connected to the data acquisition device, and then the computer is connected to the data acquisition device.

9. A real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 8, characterized in that: The first confining pressure chamber is arranged above the second confining pressure chamber, and the first confining pressure chamber and the second confining pressure chamber are connected by columns to form a double-chamber structure, so that the channel and seepage channel between the bottom of the soil sample and the water inlet of the sand bucket form a vertical channel.

10. The real-time monitoring test device for slag discharge from penetration erosion compatible with triaxial equipment according to claim 8, characterized in that: A porous plate is arranged below the top cap and above the base plate, and a certain inclination angle is arranged in the inner space of the top cap. The side of the aluminum alloy top cap is connected to the customized joint on the base plate through a pipeline, and then the pipeline is connected to the sand bucket of the weighing system, and it is connected to the volume pressure control vacuum system through a control valve.

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