A confining pressure loading erosion-dynamic coupling separated Hopkinson bar test system

Abstract

The present invention discloses a confining pressure loading erosion-dynamic coupling separated Hopkinson bar test system and method, including a variable confining pressure rock and soil particle in-situ seepage erosion device, a separated Hopkinson bar connected to the variable confining pressure in-situ seepage erosion device, for providing dynamic loading test conditions, the variable confining pressure in-situ seepage erosion device includes a left pressure-bearing sleeve with openings at both ends, a confining pressure loading device, and a right pressure-bearing sleeve, the confining pressure loading device includes a middle pressure-bearing sleeve, a confining pressure chamber is arranged on the periphery of the middle pressure-bearing sleeve; a cavity is arranged between the confining pressure chamber and the middle pressure-bearing sleeve; the flange of the left pressure-bearing sleeve, the left water-stop rubber, the right water-stop rubber, and the flange of the right pressure-bearing sleeve are fitted and fixed by a spring pressing steel rod. The test system of the present invention can complete the simulation of the seepage erosion process under the condition of autonomously changing the confining pressure, and carry out impact mechanics tests while keeping the rock and soil sample in the in-situ state after erosion.

Description

Technical Field

[0001] The invention relates to a confining pressure loading type erosion-dynamic coupling separation type Hopkinson bar testing system, belonging to the technical field of rock and soil environment simulation body devices. Background Art

[0002] The geological complexity of deep overburden is a major problem that hydropower dam projects need to solve urgently. Considering that the phenomenon of subsidence is particularly significant in deep overburden, soil erosion caused by groundwater flow causes the stratum structure to change and evolve continuously. Subsidence not only weakens the stability of the stratum, but may also cause surface collapse and other secondary geological disasters. For earthquake-prone zones, frequent seismic activities bring greater uncertainty and destructive power to the already fragile geological environment. The combined effect of seismic loads and subsidence forms a complex and dangerous geological dynamic system, posing a serious threat to regional safety and stability.

[0003] The split Hopkinson bar is the most commonly used indoor test equipment for studying the dynamic properties of materials under medium and high strain rates. Current research has only preliminarily explored the mechanical properties of rock and soil particles under erosion-dynamic coupling. But in fact, rock and soil particles in deep overburden areas are usually under high confining stress conditions, and confining stress is a very important factor affecting the mechanical properties of rock and soil particles. Prior art has not yet achieved that rock and soil can autonomously change the confining stress while the Hopkinson operating platform is eroding in situ. Therefore, it is very meaningful to install a CNC confining pressure loading device on the outside of rock and soil particles. Summary of the invention

[0004] The technical problem to be solved by the present invention is as follows: the environmental simulation body device of the separated Hopkinson bar in the prior art cannot realize in-situ seepage-erosion coupled dynamic loading under variable confining pressure, and cannot simulate the actual storage environment of rock and soil particles in the seepage and erosion zone under the high confining pressure storage environment in the deep covering layer, so as to carry out the dynamic performance test of rock and soil particles under the seepage-erosion coupling effect.

[0005] In order to solve the above technical problems, the present invention provides a variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system, comprising:

[0006] Variable confining pressure rock and soil particle in-situ seepage erosion device;

[0007] The separated Hopkinson bar is connected to a variable confining pressure type in-situ seepage erosion device to provide dynamic loading test conditions. The variable confining pressure type in-situ seepage erosion device includes:

[0008] A left pressure-bearing sleeve with openings at both ends, a confining pressure loading device, and a right pressure-bearing sleeve, wherein the confining pressure loading device comprises a middle pressure-bearing sleeve, and a confining pressure chamber is arranged on the periphery of the middle pressure-bearing sleeve; a cavity is arranged between the confining pressure chamber and the middle pressure-bearing sleeve; a retractable left water-stop rubber is installed between the left pressure-bearing sleeve and the middle pressure-bearing sleeve;

[0009] Install the right water-stop rubber between the middle pressure sleeve and the right pressure sleeve;

[0010] The left pressure-bearing sleeve is provided with a flange on the side close to the left water-stop rubber, and the right pressure-bearing sleeve is provided with a flange on the side close to the right water-stop rubber; the flange of the left pressure-bearing sleeve, the left water-stop rubber, the right water-stop rubber and the flange of the right pressure-bearing sleeve are fitted and fixed by a spring-pressed steel rod.

[0011] The aforementioned variable confining pressure type rock and soil particle erosion-dynamic coupling separated Hopkinson bar test system, the confining pressure chamber includes two symmetrically arranged petals, a water-stop rubber is placed in the gap between the two petals for sealing and water-stopping, and the two petals are fixed by screws; the confining pressure chamber and the middle pressure sleeve are fixed by screws.

[0012] The aforementioned variable confining pressure rock and soil particle erosion-dynamic coupling separate Hopkinson bar test system has multiple sliding holes arranged along the circumferential direction at the corresponding positions of the flange of the left pressure sleeve, the left water-stop rubber, the right water-stop rubber, and the flange of the right pressure sleeve, and a spring-pressed steel rod is installed in the sliding hole.

[0013] In the aforementioned variable confining pressure rock and soil particle erosion-dynamic coupling separated Hopkinson bar test system, the sliding holes on the flange of the left pressure sleeve and the flange of the right pressure sleeve include an outer hole and an inner hole arranged in a radial direction, and the outer hole and the inner hole are connected;

[0014] The spring-pressed steel rod includes a rod portion, which is a porous hollow steel rod. A spring assembly and an end are respectively connected to both sides of the rod portion. An active buckle is provided at the end of the spring assembly close to one side of the rod portion. When the active buckle is popped up, it can extend into an opening of the rod portion. When the active buckle is retracted, the active buckle enters the interior of the rod portion and moves under the action of the spring assembly.

[0015] In the aforementioned variable confining pressure rock and soil particle erosion-dynamic coupling separated Hopkinson bar test system, the left water-stop rubber and the right water-stop rubber both include four or six fan-shaped pieces, which gradually fit together into a circle during the process of moving toward the axis.

[0016] The aforementioned variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system is provided with a left metal gasket inside the left pressure sleeve and close to the left water stop rubber, and the left metal gasket 1 is fixed to the middle pressure sleeve by bolts; one end of the left metal gasket extends into the left pressure sleeve, and the other end extends into the middle pressure sleeve;

[0017] A metal gasket is arranged inside the right pressure-bearing sleeve and near the right water-stop rubber, and the right metal gasket is fixed to the middle pressure-bearing sleeve by bolts. One end of the left metal gasket extends into the right pressure-bearing sleeve, and the other end extends into the middle pressure-bearing sleeve.

[0018] The aforementioned variable confining pressure rock and soil particle erosion-dynamic coupling separated Hopkinson bar test system, the separated Hopkinson bar adopts a one-dimensional Hopkinson bar, including an incident rod and a transmission rod, the incident rod and the transmission rod are respectively inserted into the outside of the left pressure sleeve and the right pressure sleeve, the incident rod is fitted with the left metal gasket, and the transmission rod is fitted with the right metal gasket.

[0019] A variable confining pressure rock and soil particle in-situ seepage erosion test method comprises the following steps:

[0020] Step 1: When preparing the sample, replace the part of the rock and soil fine particles that are expected to be eroded with soluble inorganic salts of the same particle size, mix the rock and soil particles with the inorganic salts, and prepare a sample with the same initial physical properties as the sample of the original mixture of coarse and fine rock and soil particles;

[0021] Step 2: Assemble the split Hopkinson bar and the rock and soil particle in-situ seepage erosion device:

[0022] Place water-stop rubber at the gap of the two-flap combined confining pressure chamber to seal and stop water, and fix it with screws; fix the two-flap combined confining pressure chamber and the middle pressure sleeve with screws; connect the left pressure sleeve, the middle pressure sleeve, the right pressure sleeve, the left water-stop rubber and the right water-stop rubber through the outer hole of the sliding hole with a spring-pressed steel rod, first fix the left metal gasket to the middle pressure sleeve with bolts, fill the test rock and soil particles, and then fix the right metal gasket to the middle pressure sleeve with bolts;

[0023] The incident rod is passed through the circular channel inside the left pressure-bearing sleeve to fit with the left metal gasket, and the transmission rod is passed through the circular channel inside the right pressure-bearing sleeve to fit with the right metal gasket;

[0024] The flange of the left pressure-bearing sleeve, the left water-stop rubber, the right water-stop rubber, and the flange of the right pressure-bearing sleeve are fitted and fixed by a spring-pressed steel rod;

[0025] Step 3: Use a water-permeable filter fixing device to connect and fix the middle pressure sleeve with the water inlet channel and the water outlet channel, wherein the water-permeable filter fixing bolt fixes the water-permeable filter, and the water inlet and outlet channel fixing bolts fix the water inlet channel and the water outlet channel. Use a numerically controlled air pump pressurizing device to introduce the water in the upstream water tank into the in-situ seepage erosion device through the water inlet channel; at the same time, use a numerically controlled hydraulic loading system to start and push the hydraulic motor, inject the liquid in the hydraulic cabin into the two-flap combined confining pressure chamber through the channel, and feed back to the connected computer through the pressure sensor. When the confining pressure value reaches the preset value, close the valve to keep the confining pressure value constant during the entire test process;

[0026] Step 4: The simulation method of seepage erosion is as follows: when the seepage water is injected into the rock and soil particles of the test sample, the soluble inorganic salts dissolve and flow out through the outlet channel along the direction of the seepage and enter the downstream water-sand collection box. After the inorganic salts dissolve, the internal structure of the rock and soil particles of the test sample changes, and the simulation process of in-situ seepage erosion is completed;

[0027] Step 5: After the seepage erosion process is completed, close the water inlet valve, remove the spring-pressed steel rod, and drive the left and right water-stop rubbers to peel off the left and right metal gaskets, so that the left and right metal gaskets can slide without resistance in the middle pressure sleeve, and then carry out a dynamic impact test to determine the dynamic parameters of rock and soil particles eroded by seepage.

[0028] The aforementioned variable confining pressure type rock and soil particle in-situ seepage erosion test method, in step 2, first slide the spring pressing steel rod from the outer hole to the inner hole of the sliding hole, during this process, the pressure sleeve devices do not move, and the left water-stop rubber and the right water-stop rubber move radially with the spring pressing steel rod until they are tightly fitted with the left metal gasket and the right metal gasket, so that the left water-stop rubber and the right water-stop rubber slide radially with the spring pressing steel rod and tightly fit the surfaces of the left metal gasket and the right metal gasket, thereby playing a water-stopping role, and by pressing the spring assembly inside the spring pressing steel rod to reduce the length of the rod and control the end to be stuck in the inner hole of the sliding hole, the left pressure sleeve, the right pressure sleeve, the left water-stop rubber, the right water-stop rubber and the left metal gasket and the right metal gasket are fixed.

[0029] In the aforementioned variable confining pressure type rock and soil particle in-situ seepage erosion test method, in step 5, the process of removing the spring pressed steel rod is: by pressing the spring assembly in the spring pressed steel rod to pop the end of the pressed steel rod open, and sliding the spring pressed steel rod from the inner hole of the sliding hole to the outer hole, and pressing the spring assembly again to clamp the end of the pressed steel rod into the outer hole.

[0030] The present invention takes into account the phenomenon of fine particle loss during seepage erosion, and adds a variable confining pressure seepage erosion device to the separated Hopkinson bar device. This test system adopts a specific method of simulating the loss of fine particles, and selects soluble inorganic salts with a similar particle size to the fine particles to replace the fine particles that can be lost. Under the action of seepage water, the salt particles dissolve and are carried out of the sample with the water flow, ensuring that the internal structure of the sample changes after in-situ seepage erosion, completing the simulation of the seepage erosion process, and further carrying out impact mechanics tests while keeping the rock and soil sample in the in-situ state after erosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a front view of the variable confining pressure type rock and soil particle erosion-dynamic coupling separation type Hopkinson bar test system device of the present invention;

[0032] Figure 2 It is a schematic structural diagram of a variable confining pressure type seepage erosion combination device of the present invention;

[0033] Figure 3a It is a structural schematic diagram of the confining pressure loading device of the present invention;

[0034] Figure 3b It is a structural cross-sectional view of the confining pressure loading device of the present invention;

[0035] Figure 4a It is a schematic diagram of the structure of the spring pressing steel rod of the present invention when it is extended;

[0036] Figure 4b It is a schematic diagram of the structure of the spring-pressed steel rod of the present invention when it is contracted;

[0037] Figure 5 It is a schematic diagram of the sliding hole structure of the present invention;

[0038] Figure 6 It is a schematic structural diagram of the water permeable filter fixing device of the present invention;

[0039] Figure 7 It is a schematic diagram of the structure of the numerically controlled hydraulic motor of the present invention.

[0040] Figure numerals: 1. left metal gasket, 2. right metal gasket, 3. left pressure-bearing sleeve, 4. confining pressure loading device, 401. bolt, 402. bolt, 403. water-stop rubber, 404. gap, 405. middle pressure-bearing sleeve, 406. bolt, 407. confining pressure chamber, 408. cavity, 5. right pressure-bearing sleeve, 6. left water-stop rubber, 7. right water-stop rubber, 8. spring-pressed steel rod, 801. spring, 802. end, 803. rod, 804. movable buckle, 805. opening, 9. incident rod, 10. transmission rod, 11. water inlet channel , 12. Water outlet channel, 13. Test sample rock and soil particles, 14. Upstream water tank, 15. CNC air pressure pump, 16. Water sand collection box, 17. Confining pressure chamber connecting channel, 1701. Valve, 18. CNC hydraulic loading system, 1801. Hydraulic motor, 1802. Hydraulic cabin, 1803. Pressure sensor, 19. Computer, 20. Permeable filter fixing device, 2001. Permeable filter, 2002. Permeable filter fixing bolts, 2003. Inlet and outlet channel fixing bolts, 2101. Outer hole, 2102. Inner hole, 22. Water inlet valve. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0042] Example 1

[0043] This embodiment provides a variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system, including:

[0044] Installation platform;

[0045] A variable confining pressure type rock and soil particle in-situ seepage erosion device is installed on the installation platform;

[0046] The separated Hopkinson bar is connected to the variable confining pressure in-situ seepage erosion device to provide dynamic loading test conditions.

[0047] like Figure 1 The variable confining pressure in-situ seepage erosion device comprises:

[0048] A left pressure-bearing sleeve 3 with openings at both ends, a confining pressure loading device 4, and a right pressure-bearing sleeve 5, wherein the confining pressure loading device comprises a middle pressure-bearing sleeve 405, wherein the middle pressure-bearing sleeve 405 is made of silicone, and a confining pressure chamber 407 is arranged on the periphery of the middle pressure-bearing sleeve 405; a cavity is arranged between the confining pressure chamber 407 and the middle pressure-bearing sleeve 405; the confining pressure chamber 407 comprises two symmetrically arranged petals, and a water-stopping rubber 403 is placed in the gap 404 between the two petals for sealing and water-stopping, and the two petals are fixed by screws 401; the confining pressure chamber 407 and the middle pressure-bearing sleeve 405 are fixed by screws 402; a retractable left water-stopping rubber 6 is installed between the left pressure-bearing sleeve 3 and the middle pressure-bearing sleeve 405;

[0049] Install the right water-stop rubber 7 between the middle pressure-bearing sleeve 405 and the right pressure-bearing sleeve 5;

[0050] The left pressure-bearing sleeve 3 is provided with a flange on the side close to the left water-stop rubber 6, and the right pressure-bearing sleeve 5 is provided with a flange on the side close to the right water-stop rubber 7; the flange of the left pressure-bearing sleeve 3, the left water-stop rubber 6, the right water-stop rubber 7, and the flange of the right pressure-bearing sleeve 5 are fitted and fixed by a spring-pressed steel rod 8.

[0051] A plurality of sliding holes are provided along the circumferential direction at corresponding positions of the flange of the left pressure-bearing sleeve 3, the left water-stop rubber 6, the right water-stop rubber 7, and the flange of the right pressure-bearing sleeve 5. In this embodiment, there are four sliding holes, and a spring-pressed steel rod 8 is installed in the sliding hole.

[0052] The sliding holes on the flange of the left pressure-bearing sleeve 3 and the flange of the right pressure-bearing sleeve 5 include an outer hole 2101 and an inner hole 2102 arranged in the radial direction, and the outer hole 2101 and the inner hole 2102 are connected.

[0053] like Figure 4a and Figure 4b As shown, the spring pressing steel rod 8 includes a rod portion 803, and the rod portion 803 is a porous hollow steel rod. A spring component 801 and an end 802 are respectively connected to both sides of the rod portion 803. An active buckle 804 is provided at the end of the spring component 801 close to the rod portion 803. When the active buckle 804 pops up, it can extend into an opening of the rod portion 803. When the active buckle 804 retracts, the active buckle 804 enters the interior of the rod portion 803 and moves under the action of the spring component 801.

[0054] The two ends of the rod 803 are against the spring assembly 801, and there are multiple opening positions 805 on the rod 803. When pressing the active buckle 804, it can be pressed into the rod 803. At this time, the rod 803 can compress the spring assembly 801 to shorten the length of the entire steel rod 8, and when the rod 803 is compressed to the point where the hole position 805 coincides with the active buckle 804, the active buckle automatically pops up to fix it again. If you need to restore the length of the entire steel rod 8, just repeat the same operation steps.

[0055] like Figure 2 As shown, the left water-stop rubber 6 and the right water-stop rubber 7 each include four sector-shaped pieces, which gradually adhere to form a circle during the process of moving toward the axis.

[0056] A left metal gasket 1 is arranged inside the left pressure-bearing sleeve 3 and near the left water-stop rubber 6, and the left metal gasket 1 is fixed to the middle pressure-bearing sleeve 405 by bolts 406; one end of the left metal gasket 1 extends into the left pressure-bearing sleeve 3, and the other end extends into the middle pressure-bearing sleeve 405;

[0057] A metal gasket 2 is arranged inside the right pressure-bearing sleeve 5, near the right water-stop rubber 7, and the right metal gasket 2 is fixed to the middle pressure-bearing sleeve 405 by bolts 406. One end of the left metal gasket 2 extends into the right pressure-bearing sleeve 7, and the other end extends into the middle pressure-bearing sleeve 405.

[0058] The middle pressure sleeve 405 is connected and fixed to the water inlet channel 11 and the water outlet channel 12 by using the water permeable filter fixing device 20 .

[0059] The separated Hopkinson rod adopts a one-dimensional Hopkinson rod, including an incident rod 9 and a transmission rod 10, which are respectively inserted into the outside of the left pressure-bearing sleeve 3 and the right pressure-bearing sleeve 5, the incident rod 9 is fitted with the left metal gasket 1, and the transmission rod 10 is fitted with the right metal gasket 2.

[0060] The spring-pressed steel rod 8 is fixed to the left water-stop rubber 6 and the right water-stop rubber 7 through the rod portion 803. The ends 802 of the four spring-pressed steel rods 8 are first passed through the outer hole 2101 of the sliding hole, and then the rod portion 803 of the spring-pressed steel rod 8 is moved so that the spring-pressed steel rod 8, together with the left water-stop rubber 6 and the right water-stop rubber 7, moves in the axial direction. When the spring-pressed steel rod 8 moves to the position of the inner hole 2102, the steel rod spring assembly 801 in the spring-pressed steel rod 8 is pressed, and the movable buckle is used. 804 is fixed, the rod part 803 is shortened as a whole, and the end 802 is just stuck into the inner hole 2102 of the sliding hole, and the left water-stop rubber 6 and the right water-stop rubber 7 are fitted and fixed to the left pressure-bearing sleeve 3, the middle pressure-bearing sleeve 405, and the right pressure-bearing sleeve 5 by using the spring-pressed steel rod 8. At the same time, the left water-stop rubber 6 and the right water-stop rubber 7 that were originally peeled off the metal gasket are gradually fitted with the left metal gasket 1 and the right metal gasket 2 during the radial movement of the spring-pressed steel rod 8 to achieve good sealing for water stopping.

[0061] In this embodiment, a variable confining pressure rock and soil particle in-situ seepage erosion test method is provided, comprising the following steps:

[0062] Step 1: When preparing the sample, replace the part of the rock and soil fine particles that are expected to be eroded with soluble inorganic salts of the same particle size, mix the rock and soil particles with the inorganic salts, and prepare a sample with the same initial physical properties as the sample of the original mixture of coarse and fine rock and soil particles;

[0063] Step 2: If Figure 1-Figure 7 As shown in the figure, the separated Hopkinson bar is assembled with the rock and soil particle in-situ seepage erosion device:

[0064] Place a water-stop rubber 403 at the gap 404 of the two-flap combined confining pressure chamber 407 to seal and stop water, and fix it with screws 401; fix the two-flap combined confining pressure chamber 407 and the middle pressure sleeve 405 with screws 402; pass the spring-pressed steel rod 8 through the outer hole 2101 of the sliding hole 21 to connect the left pressure sleeve 3, the middle pressure sleeve 405, the right pressure sleeve 5, the left water-stop rubber 6 and the right water-stop rubber 7, first fix the left metal gasket 1 with the middle pressure sleeve 405 with bolts 406, fill it with test rock and soil particles 13, and then fix the right metal gasket 2 with the middle pressure sleeve 405 with bolts 406;

[0065] The incident rod 9 passes through the circular channel inside the left pressure-bearing sleeve and fits with the left metal gasket 1, and the transmission rod 10 passes through the circular channel inside the right pressure-bearing sleeve and fits with the right metal gasket 2;

[0066] First, slide the spring pressing steel rod 8 from the outer hole 2101 of the sliding hole 21 to the inner hole 2102. During this process, the pressure sleeve devices do not move. The left water-stop rubber 6 and the right water-stop rubber 7 move radially with the spring pressing steel rod 8 until they are tightly fitted with the left metal gasket 1 and the right metal gasket 2, so that the left water-stop rubber 6 and the right water-stop rubber 7 slide radially with the spring pressing steel rod 8 and tightly fit the surfaces of the left metal gasket 1 and the right metal gasket 2, thereby playing a role in water stopping. By pressing the spring component 801 inside the spring pressing steel rod 8, the length of the rod part 803 is reduced and the end 802 is controlled to be stuck into the inner hole 2102 of the sliding hole 21, so that the left pressure sleeve 3, the right pressure sleeve 5, the left water-stop rubber 6, the right water-stop rubber 7 and the left metal gasket 1 and the right metal gasket 2 are fixed;

[0067] Step 3: If Figure 5 As shown, a water-permeable filter fixing device 20 is used to connect and fix the middle pressure sleeve 405 with the water inlet channel 11 and the water outlet channel 12, wherein the water-permeable filter fixing bolts fix the water-permeable filter 2001, and the water inlet and outlet channel fixing bolts 2003 fix the water inlet channel 11 and the water outlet channel 12, and a numerically controlled air pump pressurizing device 15 is used to introduce the water in the upstream water tank 14 into the in-situ seepage erosion device through the water inlet channel 11; at the same time, a numerically controlled hydraulic loading system 18 is used to start and propel the hydraulic motor 1801, so that the liquid in the hydraulic cabin 1802 is injected into the two-petal combined confining pressure chamber 407 through the channel 17, and the pressure is fed back to the connected computer 19 through the pressure sensor 1803, and when the confining pressure value reaches the preset value, the valve 1701 is closed to keep the confining pressure value constant during the entire test process;

[0068] Step 4: The seepage erosion simulation method is as follows: during the process of seepage water being injected into the test sample rock and soil particles 13, the soluble inorganic salts dissolve and flow out through the water outlet channel 12 along the direction of the seepage and enter the downstream water-sand collection box 16. After the inorganic salts dissolve, the internal structure of the test sample rock and soil particles changes, thus completing the simulation process of in-situ seepage erosion;

[0069] Step 5: After the seepage erosion process is completed, close the water inlet valve 22, and press the spring assembly 801 in the spring-pressed steel rod to bounce the end 802 of the press-type steel rod open, and slide the spring-pressed steel rod 8 from the inner hole 2102 of the sliding hole 21 to the outer hole 2101, and press the spring assembly 801 again to insert the end 802 of the press-type steel rod into the outer hole 2101, driving the left water-stop rubber 6 and the right water-stop rubber 7 to peel off the left metal gasket 1 and the right metal gasket 2, so that the left metal gasket 1 and the right metal gasket 2 can slide without resistance in the middle pressure sleeve 405, and then carry out a dynamic impact test to determine the dynamic parameters of seepage erosion of rock and soil particles. The dynamic parameters include strength parameters stress, strain, strain rate, seepage parameters erosion rate, and flow rate.

[0070] Example 2

[0071] A variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system, comprising:

[0072] Installation platform;

[0073] A variable confining pressure type rock and soil particle in-situ seepage erosion device is installed on the installation platform;

[0074] The separated Hopkinson bar is connected to the variable confining pressure in-situ seepage erosion device to provide dynamic loading test conditions.

[0075] like Figure 1 The variable confining pressure in-situ seepage erosion device comprises:

[0076] A left pressure-bearing sleeve 3, a confining pressure loading device 4, and a right pressure-bearing sleeve 5 with openings at both ends, wherein the confining pressure loading device comprises a middle pressure-bearing sleeve 405, wherein the middle pressure-bearing sleeve 405 is made of silicone, and a confining pressure chamber 407 is arranged on the periphery of the middle pressure-bearing sleeve 405; a cavity is arranged between the confining pressure chamber 407 and the middle pressure-bearing sleeve 405; the confining pressure chamber 407 comprises two symmetrically arranged petals, and a water-stopping rubber 403 is placed in the gap 404 between the two petals for sealing and water-stopping, and the two petals are fixed by screws 401; the confining pressure chamber 407 and the middle pressure-bearing sleeve 405 are fixed by screws 402;

[0077] Install a retractable left water-stop rubber 6 between the left pressure-bearing sleeve 3 and the middle pressure-bearing sleeve 405;

[0078] Install the right water-stop rubber 7 between the middle pressure-bearing sleeve 405 and the right pressure-bearing sleeve 5;

[0079] The left pressure-bearing sleeve 3 is provided with a flange on the side close to the left water-stop rubber 6, and the right pressure-bearing sleeve 5 is provided with a flange on the side close to the right water-stop rubber 7; the flange of the left pressure-bearing sleeve 3, the left water-stop rubber 6, the right water-stop rubber 7, and the flange of the right pressure-bearing sleeve 5 are fitted and fixed by a spring-pressed steel rod 8.

[0080] A plurality of sliding holes are provided along the circumferential direction at corresponding positions of the flange of the left pressure-bearing sleeve 3, the left water-stop rubber 6, the right water-stop rubber 7, and the flange of the right pressure-bearing sleeve 5. In this embodiment, there are 6 sliding holes, and a spring-pressed steel rod 8 is installed in the sliding hole.

[0081] The left water-stop rubber 6 and the right water-stop rubber 7 each include six sector-shaped pieces, which gradually adhere to form a circle during the process of moving toward the axis.

[0082] Other technical features are the same as those of Example 1.

[0083] The above is a detailed description of the implementation mode of the present invention in conjunction with the accompanying drawings, but the above is only a preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system, characterized in that: It includes a variable confining pressure type rock and soil particle in-situ seepage erosion device; The separated Hopkinson bar is connected to a variable confining pressure type in-situ seepage erosion device to provide dynamic loading test conditions. The variable confining pressure type in-situ seepage erosion device includes: A left pressure-bearing sleeve (3) with openings at both ends, a confining pressure loading device (4), and a right pressure-bearing sleeve (5), wherein the confining pressure loading device comprises a middle pressure-bearing sleeve (405), and a confining pressure chamber (407) is arranged on the periphery of the middle pressure-bearing sleeve (405); a cavity is arranged between the confining pressure chamber (407) and the middle pressure-bearing sleeve (405); A retractable left water-stop rubber (6) is installed between the left pressure-bearing sleeve (3) and the middle pressure-bearing sleeve (405); A right water-stop rubber (7) is installed between the middle pressure-bearing sleeve (405) and the right pressure-bearing sleeve (5); The left pressure-bearing sleeve (3) is provided with a flange on the side close to the left water-stop rubber (6), and the right pressure-bearing sleeve (5) is provided with a flange on the side close to the right water-stop rubber (7); the flange of the left pressure-bearing sleeve (3), the left water-stop rubber (6), the right water-stop rubber (7), and the flange of the right pressure-bearing sleeve (5) are fitted and fixed by a spring-pressing steel rod (8); a plurality of sliding holes are provided along the circumferential direction at corresponding positions of the flange of the left pressure-bearing sleeve (3), the left water-stop rubber (6), the right water-stop rubber (7), and the flange of the right pressure-bearing sleeve (5); the spring-pressing steel rod (8) is installed in the sliding hole; the sliding holes on the flange of the left pressure-bearing sleeve (3) and the flange of the right pressure-bearing sleeve (5) include an outer hole (2101) and an inner hole (2102) arranged in a radial direction, and the outer hole (2101) and the inner hole (2102) are connected; The left water-stop rubber (6) and the right water-stop rubber (7) both include four or six fan-shaped pieces, which gradually fit together to form a circle during the movement toward the axis. The spring-pressed steel rod is slid from the outer hole to the inner hole of the sliding hole, and the left water-stop rubber and the right water-stop rubber move radially together with the spring-pressed steel rod. The spring component inside the spring-pressed steel rod is pressed to reduce the length of the rod and control the end of the spring-pressed steel rod to be stuck into the inner hole of the sliding hole, thereby achieving fitting and fixing.

2. The variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system according to claim 1, characterized in that: The confining pressure chamber (407) includes two symmetrically arranged lobes, and a waterproof rubber (403) is placed in the gap (404) between the two lobes for sealing and waterproofing. The two lobes are fixed by screws (401); the confining pressure chamber (407) and the middle pressure sleeve (405) are fixed by screws (402).

3. The variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system according to claim 1, characterized in that: The spring pressing steel rod 8 comprises a rod portion (803), wherein the rod portion (803) is a porous hollow steel rod, and a spring assembly (801) and an end (802) are connected in sequence on both sides of the rod portion (803), and an active buckle (804) is arranged at an end of the spring assembly (801) close to one side of the rod portion (803). When the active buckle (804) is popped up, it can extend into a certain opening of the rod portion (803), and when the active buckle (804) is retracted, the active buckle (804) enters the interior of the rod portion (803) and moves under the action of the spring assembly (801).

4. The variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system according to claim 1, characterized in that: A left metal gasket (1) is arranged inside the left pressure-bearing sleeve (3) and near the left water-stop rubber (6), and the left metal gasket (1) is fixed to the middle pressure-bearing sleeve (405) by bolts (406); one end of the left metal gasket (1) extends into the left pressure-bearing sleeve (3), and the other end extends into the middle pressure-bearing sleeve (405); A right metal gasket (2) is arranged inside the right pressure-bearing sleeve (5) and near the right water-stop rubber (7), and the right metal gasket (2) is fixed to the middle pressure-bearing sleeve (405) by bolts (406); one end of the right metal gasket (2) extends into the right pressure-bearing sleeve (5), and the other end extends into the middle pressure-bearing sleeve (405).

5. The variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar test system according to claim 1, characterized in that: The split Hopkinson rod adopts a one-dimensional Hopkinson rod, comprising an incident rod (9) and a transmission rod (10). The incident rod (9) and the transmission rod (10) are respectively inserted into the interior of the outer sides of a left pressure-bearing sleeve (3) and a right pressure-bearing sleeve (5). The incident rod (9) is fitted with a left metal gasket (1), and the transmission rod (10) is fitted with a right metal gasket (2).

6. The testing method of a variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar testing system according to claim 1, characterized in that: The following steps are involved: Step 1: When preparing the sample, replace the part of the rock and soil fine particles that are expected to be eroded with soluble inorganic salts of the same particle size, mix the rock and soil particles with the inorganic salts, and prepare a sample with the same initial physical properties as the sample of the original mixture of coarse and fine rock and soil particles; Step 2: Assemble the split Hopkinson bar and the rock and soil particle in-situ seepage erosion device: A waterproof rubber (403) is placed at the gap (404) of the two-flap combined confining pressure chamber (407) to seal and waterproof, and is fixed with screws (401); the two-flap combined confining pressure chamber (407) and the middle pressure sleeve (405) are fixed with screws (402); the left pressure sleeve (3), the middle pressure sleeve (405), the right pressure sleeve (5), the left waterproof rubber (6) and the right waterproof rubber (7) are connected by passing a spring-pressed steel rod (8) through the outer hole (2101) of the sliding hole (21); the left metal gasket (1) is first fixed to the middle pressure sleeve (405) with bolts (406), and the test rock and soil particles (13) are filled, and then the right metal gasket (2) is fixed to the middle pressure sleeve (405) with bolts (406); The incident rod (9) is passed through the circular channel inside the left pressure-bearing sleeve and is fitted with the left metal gasket (1), and the transmission rod (10) is passed through the circular channel inside the right pressure-bearing sleeve and is fitted with the right metal gasket (2); The flange of the left pressure-bearing sleeve (3), the left water-stopping rubber (6), the right water-stopping rubber (7), and the flange of the right pressure-bearing sleeve (5) are fitted and fixed by means of a spring-pressing steel rod (8); Step 3: Use a water-permeable filter fixing device (20) to connect and fix the middle pressure sleeve (405) with the water inlet channel (11) and the water outlet channel (12), wherein the water-permeable filter fixing bolts fix the water-permeable filter (2001), and the water inlet and outlet channel fixing bolts (2003) fix the water inlet channel (11) and the water outlet channel (12), and use a numerically controlled air pump pressurizing device (15) to introduce water in the upstream water tank (14) into the in-situ seepage erosion device through the water inlet channel (11); at the same time, use a numerically controlled hydraulic loading system (18) to start and propel the hydraulic motor (1801) to inject the liquid in the hydraulic cabin (1802) into the two-flap combined confining pressure chamber (407) through the confining pressure chamber connecting channel (17), and feed back to the connected computer (19) through the pressure sensor (1803), and when the confining pressure value reaches a preset value, close the valve (1701) of the confining pressure chamber connecting channel to keep the confining pressure value constant during the entire test process; Step 4: The seepage erosion simulation method is as follows: during the process of the seepage water being injected into the test sample rock and soil particles (13), the soluble inorganic salts are dissolved and flow out through the outlet channel (12) along the direction of the seepage flow and enter the downstream water-sand collection box (16). After the inorganic salts are dissolved, the internal structure of the test sample rock and soil particles changes, thus completing the simulation process of in-situ seepage erosion. Step 5: After the seepage erosion process is completed, close the water inlet valve (22), remove the spring-pressed steel rod (8), and drive the left water-stop rubber (6) and the right water-stop rubber (7) to peel off the left metal gasket (1) and the right metal gasket (2), so that the left metal gasket (1) and the right metal gasket (2) can slide without resistance in the middle pressure sleeve (405), and then carry out a dynamic impact test to determine the dynamic parameters of the rock and soil particles eroded by seepage.

7. The testing method of a variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar testing system according to claim 6, characterized in that: In step 2, the spring pressing steel rod (8) is first slid from the outer hole (2101) of the sliding hole (21) to the inner hole (2102). During this process, the pressure sleeve devices do not move. The left water-stop rubber (6) and the right water-stop rubber (7) move radially with the spring pressing steel rod (8) until they are tightly fitted with the left metal gasket (1) and the right metal gasket (2), so that the left water-stop rubber (6) and the right water-stop rubber (7) slide radially with the spring pressing steel rod (8). The spring assembly (801) inside the spring pressing steel rod (8) is pressed to reduce the length of the rod (803) and control the end (802) to fit into the inner hole (2102) of the sliding hole (21), thereby fixing the left pressure-bearing sleeve (3), the right pressure-bearing sleeve (5), the left water-stopping rubber (6), the right water-stopping rubber (7) and the left metal gasket (1) and the right metal gasket (2).

8. The testing method of a variable confining pressure rock and soil particle erosion-dynamic coupling separation Hopkinson bar testing system according to claim 7, characterized in that: In step 5, the process of removing the spring-pressed steel rod (8) is as follows: the end (802) is ejected by pressing the spring assembly (801) in the spring-pressed steel rod, and the spring-pressed steel rod (8) is slid from the inner hole (2102) of the sliding hole (21) to the outer hole (2101), and the spring assembly (801) is pressed again to insert the end (802) into the outer hole (2101).

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