A drop weight impact test device and method for detecting the impact performance of eroded rock and soil particles

Abstract

The present invention discloses a drop-hammer impact test device and method for detecting the impact performance of eroded rock and soil particles, the device comprises an in-situ seepage erosion device for rock and soil particles, an electric slide rail drop-hammer impact test device is arranged outside the in-situ seepage erosion device, and is used to provide dynamic loading test conditions; the in-situ seepage erosion device comprises a rock and soil sample container, a container cover is arranged on the upper part of the rock and soil sample container, and the two sides of the rock and soil sample container are respectively connected to the water inlet channel and the water outlet channel through a water permeable filter assembly. The test system of the present invention can complete the simulation of the seepage erosion process of rock and soil particles, and carry out drop-hammer impact mechanical tests at medium and low strain rates while keeping the rock and soil sample in the in-situ state after erosion.

Description

Technical Field

[0001] The invention relates to a drop hammer impact test device for detecting the impact performance of eroded rock and soil particles, belonging to the technical field of rock and soil environment simulation body devices. Background Art

[0002] The geological conditions of the deep overburden are characterized by complex genetic types and loose structure. Subsurface erosion is a typical manifestation that affects the stability of the deep overburden. The continuous loss of fine particles in the soil inside the deep overburden will aggravate the unevenness of local physical and mechanical properties, causing uneven settlement of the foundation. For high-frequency earthquake areas, the impact load generated by the rolling of soil and rocks in the upper foundation on the gravel and stone materials inside the deep overburden during an earthquake will cause the particles of the gravel and stone materials inside the deep overburden to break and rearrange, aggravating the cumulative damage of the gravel and stone materials at the dam foundation and further worsening the uneven settlement of the dam foundation. Therefore, studying the impact mechanics mechanism of rock and soil granular materials under the action of seepage erosion has important theoretical value and engineering significance.

[0003] The drop hammer impact test device is a commonly used test equipment for studying the dynamic characteristics of materials under low and medium strain rates. Current research mainly focuses on the impact resistance of solid materials such as concrete and masonry under dynamic effects such as earthquakes, and there is little research on the impact resistance of bulk materials. In addition, current research has not considered the actual occurrence environment of rock and soil particles in the seepage erosion zone in the deep overburden layer, mainly because the existing technology has not yet achieved the reproduction of the impact dynamic loading of rock and soil granular materials under the action of seepage erosion. Therefore, it is necessary to explore the impact dynamic characteristics of rock and soil particles under the action of seepage erosion from the perspective of in-situ tests.

[0004] The existing drop hammer impact tests only rarely consider the impact dynamic characteristics testing process of rock and soil granular materials, and have not yet considered the migration and loss process of fine particles that may be caused when rock and soil particles encounter seepage. Summary of the invention

[0005] The technical problem to be solved by the present invention is as follows: in the process of testing the impact dynamic properties of rock and soil particles under the action of seepage erosion, the environmental simulation body device of the drop hammer impact test device in the prior art cannot realize dynamic loading under in-situ seepage erosion conditions, and cannot simulate the actual existence environment of rock and soil particles acting in the seepage erosion zone in the deep covering layer.

[0006] In order to solve the above technical problems, the present invention provides a drop weight impact test device for detecting the impact performance of eroded rock and soil particles, including an in-situ seepage erosion device for rock and soil particles;

[0007] The electric slide-type drop-weight impact test device is arranged outside the in-situ seepage erosion device to provide dynamic loading test conditions;

[0008] The in-situ seepage erosion device comprises a rock and soil sample container, a container cover is arranged on the top of the rock and soil sample container, and two sides of the rock and soil sample container are respectively connected to a water inlet channel and a water outlet channel through a water permeable filter assembly.

[0009] The aforementioned drop hammer impact test device for detecting the impact performance of eroded rock and soil particles, the electric slide rail drop hammer impact test device includes an outer frame, the outer frame includes two outer vertical beams, the top ends of the two outer vertical beams are connected by a cross beam, two inner vertical beams are arranged on the inner sides of the two outer vertical beams, and the two side wings of the cross beam suspended drop hammer are respectively provided with through holes, the two inner vertical beams pass through the through holes, and the cross beam suspended drop hammer can slide freely along the inner vertical beams; an electric slide rail is fixed on the outer vertical beam, and an electric telescopic magnet device is fixed on the electric slide rail, the electric telescopic magnet device is attracted to the cross beam suspended drop hammer, and the electric slide rail is connected to the motor.

[0010] The aforementioned drop hammer impact test device for detecting the impact performance of eroded rock and soil particles, the electric telescopic magnet device includes an outer frame, a small motor is arranged inside the outer frame, the small motor is connected to the magnet through a small slide rail, when the small motor in the electric telescopic magnet device is started, the magnet fixed on the small slide rail extends outward and engages with the crossbeam suspended drop hammer.

[0011] The aforementioned drop hammer impact test device for detecting the impact performance of eroded rock and soil particles has a small hole on the electric telescopic magnet device, so that the embedded small motor connection line extends through the small hole to fit the external vertical beam and connect to the control computer; the external motor connection line is connected to the control computer.

[0012] The aforementioned drop hammer impact test device for detecting the impact performance of eroded rock and soil particles, the water-permeable filter assembly includes a water-permeable filter, a part of the water-permeable filter is embedded in the rock and soil sample container, and a part of the water-permeable filter is connected to the water inlet channel and the water outlet channel; the water-permeable filter fixing screw fixes the water-permeable filter to the water-permeable filter fixing device, and the water inlet and outlet channel fixing bolts fix the water inlet channel, the water outlet channel, the water-permeable filter fixing device and the sample container.

[0013] In the aforementioned drop weight impact test device for testing the impact performance of eroded rock and soil particles, the rock and soil sample container 1 and the container cover are sealed with a waterproof rubber and fixed with screws.

[0014] A testing method for a rock and soil particle in-situ seepage erosion dynamic characteristics testing device comprises the following steps:

[0015] Step 1: When preparing the sample, replace some of the 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;

[0016] Step 2: Assemble the electric slide rail drop hammer impact test device and the rock and soil particle in-situ seepage erosion device;

[0017] Step 3: 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; in the process of injecting the seepage water into the rock and soil particles of the test sample, the soluble inorganic salts dissolve and flow out through the water outlet channel and into the downstream water-sand collection box along the direction of the seepage. 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;

[0018] Step 4: After the seepage erosion process is completed, close the water inlet valve; start the electric slide rail drop hammer impact test device, perform a drop hammer dynamic impact test on the rock and soil samples, and determine the dynamic parameters of the rock and soil particles eroded by seepage.

[0019] The aforementioned testing method for the in-situ seepage erosion dynamic characteristics testing device of rock and soil particles, in step 4, starts the small motor in the outer frame of the electric telescopic magnet device, extends the magnet fixed on the small slide rail outward and fixes it with the crossbeam suspended drop weight, starts the motor, causes the electric slide rail fixed on the outer vertical beam to start sliding and causes the electric telescopic magnet device to start sliding upward, and at the same time, the attached crossbeam suspended drop weight slides upward along the inner vertical beam at the same speed, and hovers when it slides to a preset value; controls the small motor in the electric telescopic magnet device to retract the magnet fixed on the small slide rail and separate it from the crossbeam suspended drop weight, at which time the crossbeam suspended drop weight slides freely along the inner vertical beam without resistance, and then performs a drop weight dynamic impact test on the rock and soil sample to determine the dynamic parameters of seepage erosion of rock and soil particles.

[0020] The above-mentioned testing method of the in-situ seepage erosion dynamic characteristics testing device of rock and soil particles, the dynamic parameters include strength parameters stress, strain, strain rate, seepage parameters erosion rate, flow rate

[0021] The test method of the aforementioned in-situ seepage erosion dynamic characteristics test device for rock and soil particles comprises the following steps for determining the dynamic parameters of seepage erosion rock and soil particles: a stress sensor is installed at the bottom of the rock and soil sample container; when a drop hammer dynamic impact test is performed, the impact force is transmitted through the rock and soil sample to the stress sensor, and then transmitted to a computer through a signal converter to obtain the dynamic parameter information.

[0022] Beneficial effects achieved by the present invention: The drop-hammer impact test device provided by the present invention for testing the impact performance of eroded rock and soil particles is equipped with an in-situ seepage erosion device for rock and soil particles on the basis of an electric slide-type drop-hammer impact test device, wherein the in-situ seepage erosion device for rock and soil particles includes a rock and soil sample container, a container cover, a waterproof rubber, a water-permeable gasket, a water inlet and outlet channel, an upstream water tank with an external numerically controlled air pressure pump, and a downstream water and sand collection device; the electric slide-type drop-hammer impact test device includes an inner vertical beam, an outer vertical beam, an electric telescopic magnet device, an electric slide rail, and a motor. During the seepage erosion process, the in-situ seepage erosion device for rock and soil particles uses the waterproof rubber to tightly fit the cover to the rock and soil sample container to perform a water-stop seal to ensure that the experimental effect will not be affected.

[0023] Taking into account the phenomenon of fine particle loss during seepage erosion, the present invention adds an in-situ seepage erosion device for rock and soil particles to the independently invented electric slide rail drop hammer impact test device. This test system uses a specific method to simulate 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 a drop hammer impact mechanics test while keeping the rock and soil sample in its in-situ state after erosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the drop-hammer impact test device for eroded rock and soil particles of the present invention;

[0025] Figure 2 It is a structural schematic diagram of the electric slide rail drop weight impact test device of the present invention;

[0026] Figure 3 It is a schematic structural diagram of the rock and soil particle in-situ erosion device of the present invention;

[0027] Figure 4 It is a schematic diagram of the container cover structure of the present invention;

[0028] Figure 5 It is a schematic structural diagram of the electric telescopic magnet device of the present invention;

[0029] Figure numerals: 1. Geotechnical sample container, 2. Permeable filter fixing device, 201. Permeable filter, 202. Inlet and outlet water channel fixing bolts, 203. Permeable filter fixing bolts, 3. Test sample geotechnical particles, 4. Container cover, 402. Bolts, 403. Water-stop rubber, 5. Inlet channel, 6. Outlet channel, 7. Inlet valve, 8. Upstream water tank, 9. CNC air pump pressurizing device, 10. Downstream water-sand collecting box, 11. Beam hanging drop weight, 12. Inner vertical beam, 13. Electric slide rail, 14. Outer vertical beam, 15. Electric telescopic magnet device, 1501. Embedded small motor, 1502. Small hole, 1503. Connecting wire, 1504. Magnet, 1505. Small slide rail 16. Motor, 1603. Connecting wire, 17. Computer, 18. Stress sensor, 19. Signal converter. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Example

[0031] This embodiment provides a drop weight impact test device for detecting the impact performance of eroded rock and soil particles, which is characterized by comprising:

[0032] Installation platform;

[0033] An in-situ seepage erosion device for rock and soil particles is installed on the installation platform;

[0034] The electric slide-type drop-weight impact test device is arranged outside the in-situ seepage erosion device to provide dynamic loading test conditions;

[0035] like Figure 1 The in-situ seepage erosion device includes a rock and soil sample container 1, a container cover 4 is arranged on the top of the rock and soil sample container, and both sides of the rock and soil sample container 1 are connected to a water inlet channel 5 and a water outlet channel 6 through a water permeable filter assembly;

[0036] like Figure 2 As shown, the electric slide rail drop hammer impact test device includes an outer frame, which includes two outer vertical beams 14, the top ends of the two outer vertical beams 14 are connected by a cross beam, and two inner vertical beams 12 are arranged on the inner sides of the two outer vertical beams. The two side wings of the cross beam suspended drop hammer 11 are respectively provided with through holes, and the two inner vertical beams 12 pass through the through holes. The cross beam suspended drop hammer 11 can slide freely along the inner vertical beams 12; an electric slide rail 13 is fixed on the outer vertical beam 14, and an electric telescopic magnet device 15 is fixed on the electric slide rail 13, and the electric telescopic magnet device 15 is attracted to the cross beam suspended drop hammer 11, and the electric slide rail 13 is connected to the motor 16.

[0037] like Figure 5As shown, the electric telescopic magnet device 15 includes an outer frame, a small motor 1501 is arranged in the outer frame, and the small motor 1501 is connected to the magnet 1504 through a small slide rail 1505. When the small motor 1501 in the electric telescopic magnet device 15 is started, the magnet 1504 fixed on the small slide rail 1505 extends outward and attracts the crossbeam hanging type drop weight 11. The slide rail slide 13 is started by the motor 16 to slide together with the electric telescopic magnet device 15, and the crossbeam hanging type drop weight 11 slides together.

[0038] The electric telescopic magnet device 15 is provided with a small hole 1502, so that the connecting wire 1503 of the embedded small motor 1501 extends through the small hole to fit the external vertical beam 14 and connect to the control computer; the external connecting wire 1603 of the motor 16 is connected to the control computer.

[0039] like Figure 3 As shown, the water-permeable filter assembly includes a water-permeable filter 201, a part of which is embedded in the geotechnical sample container 1, and a part of which is connected to the water inlet channel 5 and the water outlet channel 6; the water-permeable filter fixing screws 203 fix the water-permeable filter 201 to the water-permeable filter fixing device 2, and the inlet and outlet channel fixing bolts 202 fix the inlet channel 5, the water outlet channel 6 to the water-permeable filter fixing device 2 and the sample container 1; the geotechnical sample container 1 and the container cover 4 are water-stopped and sealed with a water-stop rubber 403, and are fitted and fixed with screws 402.

[0040] In this embodiment, a method for testing the in-situ seepage erosion dynamic characteristics of rock and soil particles is provided, comprising the following steps:

[0041] Step 1: When preparing the sample, replace some of the 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;

[0042] Step 2: If Figure 1-Figure 5 As shown in the figure, the electric slide rail drop hammer impact test device and the rock and soil particle in-situ seepage erosion device are assembled:

[0043] The sample is placed in a geotechnical sample container 1 with an opening, a container cover 4 is installed, a waterproof rubber 403 is installed between the container cover 4 and the sample container 1 for waterproof sealing, and the screws 402 are used to fit and fix them; the geotechnical sample container 1 is connected and fixed to the water inlet pipe 5 and the water outlet pipe 6 by using a water permeable filter assembly, the water permeable filter fixing bolt 203 fixes the water permeable filter 201, and the water inlet and outlet channel fixing bolts 202 fix the water inlet channel 5 and the water outlet channel 6;

[0044] Step 3: Use a numerically controlled air pump pressurizing device 9 to introduce the water in the upstream water tank 8 into the in-situ seepage erosion device through the water inlet channel 5; in the process of injecting the seepage water into the test sample rock and soil particles 3, the soluble inorganic salts dissolve and flow out through the water outlet channel 6 and into the downstream water-sand collection box 10 along the direction of the seepage flow. After the inorganic salts dissolve, the internal structure of the test sample rock and soil particles changes, and the simulation process of in-situ seepage erosion is completed;

[0045] Step 4: After the seepage erosion process is completed, the water inlet valve 7 is closed; the electric slide rail drop hammer impact test device is started to perform a drop hammer dynamic impact test on the rock and soil sample to determine the dynamic parameters of the seepage erosion rock and soil particles. The specific steps include:

[0046] Start the small motor 1501 in the outer frame of the electric telescopic magnet device 15, extend the magnet 1504 fixed on the small slide rail 1505 outward and fix it with the crossbeam hanging drop weight 11, start the motor 16, so that the electric slide rail 13 fixed on the outer vertical beam 14 starts to slide and the electric telescopic magnet device 15 starts to slide upward, and the crossbeam hanging drop weight 11 slides upward along the inner vertical beam 12 at the same speed, and hovers when it slides to a preset value; control the small motor 1501 in the electric telescopic magnet device 15 to retract the magnet 1504 fixed on the small slide rail 1505 and separate it from the crossbeam hanging drop weight 11, at this time the crossbeam hanging drop weight 11 slides freely along the inner vertical beam 12 without resistance, and then perform a drop weight dynamic impact test on the rock and soil sample to measure the dynamic parameters of seepage erosion of rock and soil particles, the dynamic parameters include strength parameters stress, strain, strain rate, seepage parameter erosion rate, flow rate.

[0047] The steps for determining the dynamic parameters of seepage erosion rock and soil particles are as follows: a stress sensor 18 is installed at the bottom of the rock and soil sample container 1. When a drop hammer dynamic impact test is performed, the impact force passes through the rock and soil sample and is transmitted to the stress sensor 18, and then transmitted to the computer 17 through the signal converter 19 to obtain the dynamic parameter information.

[0048] 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 drop weight impact test device for testing the impact performance of eroded rock and soil particles, characterized in that: It includes an in-situ seepage erosion device for rock and soil particles; The electric slide-type drop-weight impact test device is arranged outside the in-situ seepage erosion device to provide dynamic loading test conditions; The in-situ seepage erosion device comprises a rock and soil sample container (1), a container cover (4) is arranged on the top of the rock and soil sample container, and both sides of the rock and soil sample container (1) are connected to a water inlet channel (5) and a water outlet channel (6) respectively through a water permeable filter assembly; The electric slide rail type drop weight impact test device comprises an outer frame, the outer frame comprises two outer vertical beams (14), the top ends of the two outer vertical beams (14) are connected by a cross beam, two inner vertical beams (12) are arranged on the inner sides of the two outer vertical beams, two side wings of the cross beam suspension type drop weight (11) are respectively provided with through holes, the two inner vertical beams (12) pass through the through holes, and the cross beam suspension type drop weight (11) can slide freely along the inner vertical beams (12); an electric slide rail (13) is fixed on the outer vertical beam (14), an electric telescopic magnet device (15) is fixed on the electric slide rail (13), the electric telescopic magnet device (15) and the cross beam suspension type drop weight (11) are attracted to each other, and the electric slide rail (13) is connected to a motor (16); The electric telescopic magnet device (15) comprises an outer frame, a small motor (1501) is arranged inside the outer frame, and the small motor (1501) is connected to the magnet (1504) via a small slide rail (1505). When the small motor (1501) in the electric telescopic magnet device (15) is started, the magnet (1504) fixed on the small slide rail (1505) extends outward and is attracted to the crossbeam hanging type drop weight (11).

2. A drop weight impact test device for detecting the impact performance of eroded rock and soil particles according to claim 1, characterized in that: The electric telescopic magnet device (15) is provided with a small hole (1502), so that the connecting wire (1503) of the embedded small motor (1501) can pass through the small hole and extend out to fit the external vertical beam (14) to be connected to the control computer; the external connecting wire (1603) of the motor (16) is connected to the control computer.

3. A drop weight impact test device for detecting the impact performance of eroded rock and soil particles according to claim 1, characterized in that: The water permeable filter assembly comprises a water permeable filter (201), a portion of which is embedded in a rock and soil sample container (1), and a portion of which is connected to an inlet channel (5) and an outlet channel (6); a water permeable filter fixing screw (203) fixes the water permeable filter (201) to a water permeable filter fixing device (2), and an inlet and outlet channel fixing bolt (202) fixes the inlet channel (5), the outlet channel (6), the water permeable filter fixing device (2) and the sample container (1).

4. A drop weight impact test device for detecting the impact performance of eroded rock and soil particles according to claim 1, characterized in that: The rock and soil sample container (1) and the container cover (4) are sealed with a waterproof rubber (403) and fixed with screws (402).

5. The testing method of a rock and soil particle in-situ seepage erosion dynamic characteristics testing device according to claim 1, characterized in that: The following steps are involved: Step 1: When preparing the sample, replace some of the 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 electric slide rail drop hammer impact test device and the rock and soil particle in-situ seepage erosion device; Step 3: Using a numerically controlled air pump pressurizing device (9), water in the upstream water tank (8) is introduced into the in-situ seepage erosion device through the water inlet channel (5); during the process of injecting the seepage water into the test sample rock and soil particles (3), the soluble inorganic salts are dissolved and flow out through the water outlet channel (6) and into the downstream water-sand collection box (10) along the direction of the seepage flow. 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 4: After the seepage erosion process is completed, the water inlet valve (7) is closed; the electric slide rail drop hammer impact test device is started to perform a drop hammer dynamic impact test on the rock and soil sample to determine the dynamic parameters of the seepage erosion rock and soil particles; In step 4, the small motor (1501) in the outer frame of the electric telescopic magnet device (15) is started, the magnet (1504) fixed on the small slide rail (1505) is extended outward and fixed with the crossbeam hanging type drop weight (11), the motor (16) is started, the electric slide rail (13) fixed on the outer vertical beam (14) starts to slide and the electric telescopic magnet device (15) starts to slide upward, and at the same time the crossbeam hanging type drop weight (11) moves along the same speed. The inner vertical beam (12) slides upward and stops when it slides to a preset value; the small motor (1501) in the electric telescopic magnet device (15) is controlled to retract the magnet (1504) fixed on the small slide rail (1505) and separate it from the crossbeam hanging drop weight (11). At this time, the crossbeam hanging drop weight (11) slides freely without resistance along the inner vertical beam (12), and then a drop weight dynamic impact test is carried out on the rock and soil sample to measure the dynamic parameters of the seepage erosion of rock and soil particles.

6. The testing method of a rock and soil particle in-situ seepage erosion dynamic characteristics testing device according to claim 5 is characterized in that: The dynamic parameters include strength parameters such as stress, strain, and strain rate, and seepage parameters such as erosion rate and flow velocity.

7. The testing method of a rock and soil particle in-situ seepage erosion dynamic characteristics testing device according to claim 5, characterized in that: The steps for determining the dynamic parameters of seepage erosion rock and soil particles are as follows: a stress sensor (18) is installed at the bottom of a rock and soil sample container (1); when a drop hammer dynamic impact test is performed, the impact force passes through the rock and soil sample and is transmitted to the stress sensor (18), and then transmitted to a computer (17) through a signal converter (19) to obtain dynamic parameter information.

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