CN108680430B - A kind of tailings material centrifugal model consolidation seepage control system and test method - Google Patents

Abstract

The invention discloses a tailings material centrifugal model consolidation seepage control system and a test method. Including sample device, water head control device, water inlet device and power device. The present invention also provides a method for using the system of the present invention to carry out the consolidation seepage test of the tailings material centrifugal model, using the system to prepare the tailings material sample according to the test method provided by the present invention; start the geotechnical centrifuge to reach a given centrifugal acceleration Then, the self-weight stress consolidation of the sample under the condition of stable seepage is realized; by monitoring the consolidation deformation and pore pressure of the sample, it is judged that the seepage and consolidation process of the sample have reached a stable state, and then the sample is fixed on the top cover of the model cylinder. The mechanical parameters of the test specimens were tested by the pocket penetrometer. The system and method of the present invention can be used for soil mechanical parameter testing of various tailings ponds, dam anti-seepage bodies, and embankment soil bodies under the coupling condition of consolidation and seepage.

Description

A kind of tailings material centrifugal model consolidation seepage control system and test method

technical field

The invention relates to a tailings material centrifugal model consolidation seepage control system and a test method, which are especially suitable for soil mechanics parameter testing of various tailings ponds, dam anti-seepage bodies, embankments, etc. under the coupling condition of consolidation and seepage.

Background technique

With the development of beneficiation technology and the restriction of land use, my country's tailings ponds will inevitably develop towards the direction of fine-grained dams and high-stack tailings dams, and the hidden dangers of disasters will become more prominent. Fine-grained tailings have low permeability, and the seepage and consolidation processes are coupled, so it is difficult to measure their mechanical parameters by conventional test methods.

Using the hypergravity field provided by the centrifuge, the synchronous coupling of seepage and consolidation processes can be better achieved, but at present, there is no relevant equipment and test methods for centrifugal model consolidation seepage at home and abroad.

SUMMARY OF THE INVENTION

The purpose of this invention is to provide a kind of tailings material centrifugal model consolidation seepage control system and test method.

For realizing the above-mentioned technical purpose, the present invention adopts following technical scheme:

A tailings material centrifugal model consolidation seepage control system, characterized in that it includes a sample device, a water head control device, a water inlet device and a power device; the sample device includes a sample tube, and the sample tube is provided with It is placed in the water tank of the lower water head control device; the inner wall of the sample cylinder is provided with an upper permeable plate and a lower permeable plate, and a tailings material sample is placed between the upper permeable plate and the lower permeable plate; a displacement meter is connected above the upper permeable plate to measure The upper permeable plate is displaced; the upper permeable plate is also provided with a through center hole, and the pocket penetrator penetrates the center hole of the upper permeable plate and penetrates into the tailings material sample; the pore water pressure sensor is embedded in the tailings material sample; the upper permeable plate A first overflow hole is provided on the wall of the sample cylinder at the upper water head above, and the first overflow hole is connected with an overflow pipe for water outlet; the lower water head control device includes a water tank; the water bucket is arranged on the sample Below the cylinder; a second overflow hole is opened on the wall of the sample cylinder under the lower permeable plate, and the water seeping down from the lower permeable plate is introduced into the water bucket; The water inlet device includes a water pump; one end of the water pump is connected to a water source, and the other end pumps the water into the sample device through a first water pipe; the power device is connected to a pocket penetrometer for providing power. According to the test needs, the power device can be turned on to realize the downward penetration of the pocket penetrator in the tailings material sample, and the mechanical parameters of the tailings material sample can be obtained.

As a further improvement of the present invention, it also includes a circulating water storage device; the circulating water storage device includes a circulating water storage tank, the water bucket is arranged in the circulating water storage tank, and the water level in the circulating water storage tank must be lower than the water level in the water tank. a water head; the first overflow hole is connected to an overflow pipe to introduce water into the circulating water storage device; the third overflow hole introduces the water in the tub into the circulating water storage device; the water inlet device includes a second water pipe; the The water pump draws out the water in the circulating water storage cylinder through the second water pipe, and pumps the water into the sample device through the first water pipe. Using the circulating water storage device, the water seeping out during the test can be recovered and put into the next round of tests, saving water sources, and the water flowing through the tailings sand will not flow out and cause no environmental pollution.

As a further improvement of the present invention, it also includes a top cover, which is arranged on the top of the circulating water storage cylinder; the water pump, the first water pipe and the power device are fixed on the top cover; one end of the displacement gauge is connected to a water permeable plate, The other end is connected to the lower part of the top cover; the top cover is provided with a through center hole, one end of the pocket penetrator extends out of the center hole of the top cover and is connected to the power unit, and the other end penetrates the center hole of the upper permeable plate and penetrates into the tailings material sample .

As a further improvement of the present invention, the sample cylinder is provided with a plurality of first overflow holes, and the required first overflow holes are selected according to the elevation of the upper water head to be connected to the overflow pipe, and other overflow holes are closed. During the test, the overflow pipes can be fixed to the first overflow holes of different heights according to the requirements of the upper water head, and the other first overflow holes are sealed.

As a further improvement of the present invention, a plurality of third overflow holes are opened on the tub, and the required third overflow holes are selected according to the elevation of the lower water head, and other overflow holes are closed. During the test, the third overflow hole at a specific position can be opened and other third overflow holes can be sealed according to the requirements of the launching head. The overflowing water flow enters the circulating water storage section.

As a further improvement of the present invention, the penetrating rod of the pocket penetrator is covered with a sleeve. The casing can eliminate the friction between the penetration rod of the pocket penetrator and the tailings material sample, and reduce the influence of the device on the accuracy of the test results.

As a further improvement of the present invention, a lifting lug is provided on the top cover. Setting lifting lugs can be used to hoist the system in the laboratory.

Another object of the present invention is to provide a test method for the above-mentioned tailings pond centrifugal model consolidation seepage control system, the steps are as follows:

S1. Place the water tank in the circulating water storage tank;

S2. Close the overflow pipe and overflow hole of the sample tube, and place it in the water container;

S3. Place the permeable plate in the sample cylinder;

S4. Put the air-dried tailings material into the sample tube in layers, each layer is 2~3cm, control the thickness of the sample according to the required void ratio, and slowly fill the sample tube with water after each layer of samples is loaded To the top surface of the sample; during the loading period, bury the pore water pressure sensor and the pocket penetrator as required, and the position of the pocket penetrator is in the center of the sample;

S5. After the sample is loaded, put the upper permeable plate over the pocket penetrator and place it on the tailings material sample;

S6. Open the overflow pipe and slowly fill the sample cylinder with water to the upper head;

S7. Open the third overflow hole, and slowly fill the water tank to the water head;

S8. Preliminarily estimate the flow required for the seepage of the sample, slowly fill the circulating water storage tank with water according to the flow, and the water level in the circulating water storage tank must be lower than the water head; and open the second overflow hole;

S9. Fix the displacement gauge, water pipe, water pump and water pipe to the top cover;

S10. Fix the top cover on the top of the circulating water storage cylinder, and the penetration rod of the pocket penetrator passes through the center hole of the top cover; connect the power unit with the penetration rod of the pocket penetrator, and fix the power unit on the top cover; complete the system installation;

S11. Hoist the system to the centrifuge basket platform, connect the pore water pressure sensor, pocket penetrometer, and displacement gauge to the centrifuge data acquisition system; supply power to the water pump and power unit through the power slip ring equipped with the centrifuge; turn on the water pump , keep it open until the end of the test, and keep the upper and lower heads of the tailings material sample;

S12. Start the centrifuge to the design acceleration, apply a hypergravity field to the tailings material sample, make the head difference between the upper and lower water heads reach the actual working condition, and at the same time realize the self-weight consolidation of the tailings material sample, through the pore water pressure Collect data from sensors and displacement meters to monitor the state of seepage and consolidation;

S13. When both seepage and consolidation reach a stable state, start the power device, drive the pocket penetrator to perform static penetration test on the tailings material sample, and test the mechanical parameters of the tailings material sample; stop the power device after the test is completed ;

S14. Stop the centrifuge and stop the water pump;

S15. Convert the density of the tailings material sample after seepage consolidation and stabilization through the data of the displacement meter.

Using the system and method of the present invention, after starting the geotechnical centrifuge to reach a given centrifugal acceleration, the self-weight stress consolidation of the sample under the condition of stable seepage is realized; by monitoring the consolidation deformation and pore pressure of the sample, the seepage and After the consolidation process reached a stable state, the mechanical parameters of the samples were tested by a pocket penetrometer fixed on the top cover of the model cylinder. The system and method of the present invention can be used for soil mechanical parameter testing of various tailings ponds, dam anti-seepage bodies, and embankment soil bodies under the coupling condition of consolidation and seepage. By adopting the system and the test method provided by the present invention, the mechanical parameters of the soil body under the coupling condition of consolidation and seepage can be accurately determined. And the test water can be recycled, which is more economical and environmentally friendly.

Description of drawings

FIG. 1 is a schematic structural diagram of a device of a centrifugal model consolidation seepage control system for tailings material according to the present invention.

Detailed ways

Example 1

The tailings centrifugal model consolidation seepage control system shown in FIG. 1 includes a sample device, a water head control device, a water inlet device and a power device 21 ; the power device 21 adopts a motor 21 .

The sample device includes a sample cylinder 1, which is arranged in the water tank 12 of the lower water head control device; the inner wall of the sample cylinder 1 is provided with an upper water permeable plate 7 and a lower water permeable plate 2, and the upper water permeable plate 7 and The tailings material sample 3 is loaded between the lower permeable plates 2; a displacement meter 8 is connected above the upper permeable plate 7 to measure the displacement of the upper permeable plate 7; 5. Go deep into the tailings material sample 3 through the central hole of the upper permeable plate 7, wherein the penetration rod of the pocket penetrometer 5 is covered with a casing 6; the pore water pressure sensor 4 is embedded in the tailings material sample 3; A plurality of first overflow holes are opened on the wall of the sample cylinder 1 at the upper water head 10 above the permeable plate 7, and the required first overflow holes are selected according to the elevation of the upper water head 10 to connect the overflow pipe, and other overflow holes are closed. , the first overflow hole is connected to the overflow pipe 9 for water outlet;

The lower water head control device includes a water tank 12; the water tank 12 is arranged below the sample cylinder 1; a second overflow hole 11 is provided on the wall of the sample cylinder 1 below the lower permeable plate, and the lower permeable plate 2 is seeped downward. The water is introduced into the water bucket 12; the water bucket 12 is provided with a plurality of third overflow holes 13, and the required third overflow holes 13 are selected according to the elevation of the lower water head 14, and other overflow holes are closed for water outlet;

The water inlet device includes a water pump 18; one end of the water pump 18 is connected to the water source, and the other end pumps the water into the sample device through the first water pipe 19;

The power device 21 is connected to the pocket penetrator 5 for providing power.

The system test mode of the present embodiment is as follows:

Collect the tailings material from the site and transport it back to the laboratory for air-drying and sieving;

According to the requirements of safety performance analysis of tailings dam, several kinds of upper water head elevation, lower water head elevation, sample density and sample height were selected, and the centrifugal model consolidation seepage test of tailings material was carried out, and different seepage heads and self-weight consolidation were tested respectively. Mechanical parameters of tailings material under conditions;

Using the mechanical parameters of the tailings material obtained under different consolidation seepage conditions, the safety performance analysis of the tailings dam is carried out to provide corresponding technical support for the filling and safe operation of the tailings pond. The specific steps will be further described in Example 4.

Example 2

The only difference between this embodiment and Embodiment 1 is that it also includes a circulating water storage device;

The circulating water storage device includes a circulating water storage barrel 15, the water bucket 12 is arranged in the circulating water storage barrel 15, and the water level 16 in the circulating water storage barrel 15 must be lower than the lower water level 14 in the water bucket 12; the first overflow The hole is connected to the overflow pipe 9 to introduce water into the circulating water storage device; the third overflow hole 13 introduces the water in the tub 12 into the circulating water storage device;

The water inlet device includes a second water pipe 17 ; the water pump 18 extracts the water in the circulating water storage cylinder 15 through the second water pipe 17 , and pumps the water into the sample device through the first water pipe 19 .

Example 3

The only difference between this embodiment and Embodiment 2 is that it also includes a top cover 20;

The top cover 20 is arranged on the top of the circulating water storage cylinder 15;

The water pump 18, the first water pipe 19 and the power unit 21 are fixed on the top cover;

One end of the displacement gauge 8 is connected to the permeable plate 7, and the other end is connected to the lower part of the top cover;

The top cover 20 is provided with a through center hole, one end of the pocket penetrometer 5 protrudes out of the center hole of the top cover 20 and is connected to the power unit 21, and the other end penetrates the center hole of the upper permeable plate 7 and penetrates into the tailings material sample 3;

The top cover 20 is provided with lifting lugs.

Example 4

This embodiment takes the system described in Embodiment 3 as an example, and provides a specific test method, which includes the following steps:

S1. Place the water container 12 in the circulating water storage container 15;

S2. Close the overflow pipe 9 and the overflow hole 11 of the sample cylinder 1, and place it in the water container 12;

S3. Place the permeable plate 2 in the sample cylinder 1;

S4. Put the air-dried tailings material sample 3 into the sample cylinder 1 in layers, each layer is 2~3cm, and control the thickness of the sample according to the required void ratio. Slowly fill with water to the top surface of the sample; during the loading period, bury the pore water pressure sensor 4 and the pocket penetrator 5 as required, and the position of the pocket penetrator 5 is in the center of the sample;

S5. After the sample is loaded, put the upper permeable plate 7 through the pocket penetrator 5 and place it on the tailings material sample 3;

S6. Open the overflow pipe 9, and slowly fill the sample cylinder 1 with water to the upper head 10;

S7. Open the third overflow hole 13, and slowly fill the water tank 12 to the water head 14;

S8. Preliminarily estimate the flow required for the seepage of the sample, slowly fill the circulating water storage cylinder 15 with water according to the flow, and the water level 16 must be lower than the lower water head 14 in the tub 12; and open the second overflow hole 11;

S9. Fix the displacement gauge 8, the water pipe 17, the water pump 18, and the water pipe 19 to the top cover 20;

S10. Fix the top cover 20 on the top of the circulating water storage cylinder 15, and the penetration rod of the pocket penetrator 5 passes through the central hole of the top cover 20; connect the power device 21 to the penetration rod of the pocket penetrator 5, and Fix the power unit 21 on the top cover 20; complete the system installation;

S11. Hoist the system to the centrifuge basket platform, and connect the pore water pressure sensor 4, the pocket penetrometer 5, and the displacement meter 8 to the centrifuge data acquisition system; 21 Power supply; turn on the water pump 18, keep it on until the end of the test, and keep the upper head 10 and the lower head 14 of the tailings material sample 3;

S12. Start the centrifuge to the design acceleration, apply a hypergravity field to the tailings material sample 3, make the head difference between the upper water head 10 and the lower water head 14 reach the actual working condition, and at the same time realize the self-weight consolidation of the tailings material sample 3, The state of seepage and consolidation is monitored through the data collected by the pore water pressure sensor 4 and the displacement meter 8;

S13. When both seepage and consolidation reach a stable state, start the power device 21 and drive the pocket penetrator 5 to perform a static penetration test on the tailings material sample 3, and test the mechanical parameters of the tailings material sample 3; the test is completed Rear stop power unit 21;

S14. Stop the centrifuge and stop the water pump 18;

S15. According to the data of displacement meter 8, convert the density of tailings material sample 3 after seepage consolidation and stabilization.

Claims (6)

1. A tailings material centrifugal model consolidation seepage control system, characterized in that it comprises a sample device, a water head control device, a water inlet device, a circulating water storage device and a power device (21); The sample device comprises a sample cylinder (1), the sample cylinder (1) is arranged in the water bucket (12) of the lower water head control device; the inner wall of the sample cylinder (1) is provided with an upper water permeable plate (7) and The lower permeable plate (2), the tailings material sample (3) is loaded between the upper permeable plate (7) and the lower permeable plate (2); a displacement gauge (8) is connected above the upper permeable plate (7) to measure the upper The permeable plate (7) is displaced; the upper permeable plate (7) is also provided with a through center hole, and the pocket penetrator (5) penetrates the center hole of the upper permeable plate (7) and penetrates into the tailings material sample (3); A pore water pressure sensor (4) is embedded in the mineral material sample (3); a first overflow hole is provided on the wall of the sample cylinder (1) at the upper water head (10) above the upper permeable plate (7), and the first overflow hole is The flow hole is connected to the overflow pipe (9) for water outlet; The lower water head control device comprises a water bucket (12); the water bucket (12) is arranged below the sample cylinder (1); a second overflow hole ( 11), the water seeping down from the lower permeable plate (2) is introduced into the water bucket (12); the barrel wall of the water bucket (12) is provided with a third overflow hole (13) at the lower water head (14) for water outlet ; The water inlet device includes a water pump (18); one end of the water pump (18) is connected to a water source, and the other end pumps the water into the sample device through a first water pipe (19); The power device (21) is connected to the pocket penetrator (5) for providing power; The circulating water storage device comprises a circulating water storage cylinder (15), the water bucket (12) is arranged in the circulating water storage cylinder (15), and the water level (16) in the circulating water storage cylinder (15) is lower than the water bucket (12) ); the first overflow hole is connected to the overflow pipe (9) to introduce the water into the circulating water storage device; the third overflow hole (13) introduces the water in the tub (12) into the circulating water storage device; The water inlet device comprises a second water pipe (17); the water pump (18) draws out the water in the circulating water storage cylinder (15) through the second water pipe (17), and pumps the water through the first water pipe (19) into the sample device; A top cover (20) is provided on the top of the circulating water storage cylinder (15); the water pump (18), the first water pipe (19) and the power device (21) are fixed on the top cover; One end of the displacement meter (8) is connected to the upper water permeable plate (7), and the other end is connected to the lower part of the top cover; The top cover (20) is provided with a through central hole, one end of the pocket penetrator (5) protrudes out of the central hole of the top cover (20) and is connected with the power device (21), and the other end passes through the upper permeable plate (7) The central hole is deep into the tailings material sample (3); The test method of the system includes the following steps: S1. Put the water bucket (12) in the circulating water storage cylinder (15); S2. Close the overflow pipe (9) and the second overflow hole (11) of the sample cylinder (1), and place it in the water bucket (12); S3. Place the lower permeable plate (2) in the sample tube (1); S4. Load the air-dried tailings material sample (3) into the sample cylinder (1) in layers, each layer is 2~3cm, and control the thickness of the sample according to the required void ratio. The sample tube (1) is slowly filled with water to the top surface of the sample; during sample loading, the pore water pressure sensor (4) and the pocket penetrator (5) are embedded as required, and the position of the pocket penetrator (5) is at the test position. sample center; S5. After the sample is loaded, put the upper permeable plate (7) over the pocket penetrator (5) and place it on the tailings material sample (3); S6. Open the overflow pipe (9), and slowly fill the sample cylinder (1) with water to the upper head (10); S7. Open the third overflow hole (13), and slowly fill the water bucket (12) with water to the lower head (14); S8. Preliminarily estimate the flow rate required for the seepage of the sample, and slowly fill the circulating water storage tank (15) with water according to the flow rate. The water level (16) is lower than the lower water head (14) in the bucket (12); and open the second overflow hole (11); S9. Fix the displacement meter (8), the second water pipe (17), the water pump (18), and the first water pipe (19) to the top cover (20); S10. Fix the top cover (20) on the top of the circulating water storage cylinder (15), and pass the penetration rod of the pocket penetrator (5) through the center hole of the top cover (20); connect the power unit (21) to the pocket penetrator. Connect the penetration rods of the instrument (5), and fix the power unit (21) on the top cover (20); complete the system installation; S11. Hoist the system to the centrifuge basket platform, and connect the pore water pressure sensor (4), pocket penetrometer (5), and displacement meter (8) to the centrifuge data acquisition system; use the power slip ring equipped with the centrifuge Supply power to the water pump (18) and the power unit (21); turn on the water pump (18), keep it on until the end of the test, and keep the upper head (10) and lower head (14) of the tailings material sample (3); S12. Start the centrifuge to the design acceleration, apply a hypergravity field to the tailings material sample (3), make the head difference between the upper water head (10) and the lower water head (14) reach the actual working condition, and at the same time realize the tailings material sample (3) self-weight consolidation, the seepage and consolidation states are monitored through the data collected by the pore water pressure sensor (4) and the displacement meter (8); S13. When both seepage and consolidation reach a stable state, start the power device (21), drive the pocket penetrator (5) to perform static penetration test on the tailings material sample (3), and test the tailings material sample (21). 3) mechanical parameters; stop the power unit (21) after the test is completed; S14. Stop the centrifuge and stop the water pump (18); S15. Convert the density of the tailings material sample (3) after seepage consolidation and stabilization through the data of the displacement meter (8). 2. The tailings material centrifugal model consolidation seepage control system according to claim 1, characterized in that, a plurality of first overflow holes are opened on the sample cylinder (1), and the selected one is selected according to the elevation of the upper water head 10. The first overflow hole needs to be connected to the overflow pipe, and other overflow holes should be closed. 3. The tailings material centrifugal model consolidation seepage control system according to claim 1, wherein a plurality of third overflow holes (13) are opened on the water tub (12), according to the water head (14) ), select the third overflow hole (13) required, and close the other overflow holes. 4. The tailings material centrifugal model consolidation seepage control system according to claim 1, characterized in that, a casing (6) is sleeved on the penetration rod of the pocket penetration instrument (5). 5. The tailings material centrifugal model consolidation seepage control system according to claim 3, characterized in that, a lifting lug is provided on the top cover (20). 6 . The tailings material centrifugal model consolidation seepage control system according to claim 4 , wherein, in the S4 , the positions of the pocket penetrator ( 5 ) and the casing ( 6 ) are in the center of the sample; 6 . In the S5, after the sample is loaded, the upper permeable plate (7) is put over the pocket penetrometer (5) and the casing (6), and placed on the tailings material sample (3).

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