CN210037399U - Consolidation-infiltration-shear wave velocity coupling experimental device - Google Patents

Abstract

The utility model discloses a consolidation-penetration-shear wave velocity coupling experiment device. It includes a top cover plate, a bottom cover plate, a sample cylinder and two pressurizing piston mechanisms. The sample cylinder is installed with a pair of radial bending elements. The upper and lower ends of the sample cylinder are connected with a top cover plate and a bottom cover plate. The press piston mechanism is installed in the sample cylinder and extends out of the sample cylinder; the pressurized piston mechanism includes a piston plate, a deflector, a permeable stone, a piston rod and a cap body, and the piston plate is placed in the sample cylinder and opened with a A circular groove, the guide plate is provided with a guide groove and a confluence hole of the guide plate, and the axial bending element is installed in the installation hole of the guide plate and the permeable stone, and is inserted into the soil sample to be tested in the soil sample cavity. The inner wall of the hydraulic chamber is arranged with a rubber membrane jack, and two through holes communicated with the hydraulic chamber are opened on the top cover plate and the bottom cover plate. The utility model can simultaneously measure the shear wave velocity, the permeability coefficient and the vertical deformation value in the radial direction and the axial direction in a soil body, and carry out the pollutant breakdown experiment.

Description

A Consolidation-Infiltration-Shear Wave Velocity Coupling Experimental Device

technical field

The utility model belongs to a test device for a unit body of geotechnical engineering, in particular to a consolidation-penetration-shear wave velocity coupling experimental device, which can simultaneously measure the shear wave velocity, permeability coefficient and consolidation compressibility coefficient of soil samples.

Background technique

Soil and groundwater pollution is a current global challenge. Globally, there are more than 5 million contaminated sites that need to be treated. In my country, it is estimated that 1.01 million square kilometers of soil pollution exceeds the standard, and the total treatment cost is 682.1 billion yuan. Informal municipal solid waste landfills are one of the main reasons for the above situation. There are currently 1,600 municipal solid waste landfills and 27,000 simple landfills in my country. There is a common risk of leachate leakage into the surrounding groundwater and soil. The estimated treatment cost is 21.6 billion yuan.

The soil-bentonite-organic bentonite vertical antifouling barrier has low permeability, high adsorption and good chemical compatibility, which can effectively reduce the risk of leachate leakage for a long time, and has the potential to be widely used in engineering sites. However, no scholars have comprehensively evaluated the changes of permeability coefficient, shear wave velocity and compressibility coefficient of the material under the condition of long-term permeation by leachate. Although the traditional geotechnical triaxial instrument can meet the above requirements, it can only measure the shear wave velocity in the upper and lower axial directions of the soil unit body.

How to simultaneously measure the shear wave velocity, permeability coefficient, and compressibility coefficient in the radial and axial directions in a soil mass is a technical problem lacking in the prior art, and a technical problem that needs to be solved.

Utility model content

In view of the key problems raised in the background technology, the utility model provides a test device for simultaneously measuring the shear wave velocity, permeability coefficient and compressibility coefficient of soil samples, and a test device for simultaneously infiltrating, consolidating and measuring the shear wave speed of soil samples , is a test device that can simultaneously test the radial and axial shear wave velocity, permeability coefficient, vertical deformation value and pollutant breakdown curve under the consolidation stress of the soil unit.

In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

The utility model comprises a top cover plate, a bottom cover plate, a sample cylinder and two pressurizing piston mechanisms with the same structure and symmetrically arranged up and down. The upper and lower ends of the cylinder are respectively connected with a top cover plate and a bottom cover plate. The upper and lower two pressurizing piston mechanism bodies are installed inside the sample cylinder. out of the sample cylinder; the inner cavity of the sample cylinder between the upper and lower pressurizing piston mechanisms constitutes a soil sample cavity, and the soil sample to be tested is placed in the soil sample cavity.

Each pressurized piston mechanism includes a piston plate, a deflector, a permeable stone, a piston rod and a cap body. The piston plate is placed in the sample cylinder, and the outer wall of the piston plate is connected with the inner wall of the sample cylinder through a second O-shaped sealing ring. The permeable stone is placed on the end face of the piston plate close to the center of the sample cylinder. The piston plate has a circular groove in the center of the end face in contact with the permeable stone. The bottom center of the circular groove has a sinking groove, and the circular groove is equipped with a diversion. The end face of the deflector near the center of the sample cylinder is provided with a diversion groove, and the eccentric side of the end face of the deflector close to the center of the sample cylinder is provided with a diversion plate confluence hole, a diversion groove and a deflector confluence hole Connected, the confluence hole of the deflector and the sink are connected; the center of the deflector and the permeable stone are provided with installation holes for installing the axial bending element, and the axial bending element is installed in the installation hole of the deflector and the permeable stone and penetrates After exiting the installation hole, insert it into the soil sample to be tested in the soil sample cavity; one end of the piston rod is connected to the center of the end face of the piston plate away from the center of the sample cylinder through threads, and the other end of the piston rod passes through the top cover plate/bottom cover plate and passes through the The cap body is threadedly connected, the inflow and outflow holes and the outlet of the bending element connecting line are respectively provided on both sides of the cap body, and the bending element wire plug is installed at the outlet of the bending element connecting line; an axial hollow channel is arranged inside the piston rod, and one end of the hollow channel is connected to the inflow and outflow. The hole and the outlet of the bending element connecting line, the other end of the hollow channel is connected to the sinking groove of the piston plate; the inner cavity space of the sample cylinder between the piston plate and the top cover plate/bottom cover plate forms a hydraulic chamber, and the inner wall of the hydraulic chamber is arranged with an annular Rubber film jack, rubber film jack is divided into four parts: outer edge sealing part, outer ring peripheral surface wrinkle part, bottom surface part and inner ring peripheral surface part, and the four parts are connected into one in turn; the outer edge sealing part is closely arranged on the Between the outer end face of the sample cylinder and the top cover plate/bottom cover plate, the wrinkled part of the outer ring peripheral surface is closely arranged on the inner wall of the sample cylinder, and the bottom part is closely arranged on the end face of the piston plate away from the center of the sample cylinder, and the inner ring The interference fit of the peripheral surface part is tightly fitted on the outside of the piston rod; the folded part of the peripheral surface of the outer ring has elastic elasticity, and the outer edge sealing part, the bottom surface part and the peripheral surface part of the inner ring do not have elastic elasticity, which makes the piston plate in the consolidation process. When the experiment and penetration experiment are carried out, the movement will drive the folded part of the peripheral surface of the outer ring to extend or shrink, and the sealing part of the outer edge, the bottom surface part and the peripheral surface part of the inner ring remain close to their respective surfaces; the top cover and bottom cover are open. There are two through holes communicating with the hydraulic chamber, one through hole is used as an overflow hole, the other through hole is installed with a hydraulic chamber valve, and the hydraulic chamber valve outlet is used as a hydraulic water inlet.

During the consolidation experiment, the liquid in the soil sample cavity enters each diversion groove of the deflector through the permeable stone, and then converges to the confluence hole of the deflector, and then flows to the hollow channel inside the piston rod through the sink, and finally flows from the inlet and outlet. orifice outflow.

The sample cylinder, pressurizing piston, deflector, top cover, bottom cover and bolts are all made of stainless steel. The permeable stone is made of titanium alloy.

The top cover plate/bottom cover plate is provided with a central through hole, a cock is installed in the central through hole, the cock is sleeved on the piston rod, and the piston rod between the cock and the top cover plate/bottom cover plate is also sleeved with a first O-shaped sealing ring, the first O-shaped sealing ring is pressed against the gap between the piston rod and the central through hole after the cock is screwed into the central through hole.

In the upper and lower pressurizing piston mechanisms, the cap body is provided with a dial indicator on the side away from the center of the sample cylinder. The dial indicator is fixed on the top cover plate/bottom cover plate through a bracket. With the end facing the cap body, the dial indicator measures the distance between the probe tip and the cap body.

The upper and lower ends of the sample tube are provided with flange flanges, and the top cover plate and the bottom cover plate are respectively installed on the flange flanges provided on the upper and lower end faces of the sample tube by fastening short bolts, and at the same time, the long bolts of the bracket make the The sample tube is fixed.

There is an annular groove between the flange flange of the sample tube and the end face of the top cover plate/bottom cover plate, a rubber sealing gasket is installed in the annular groove, and the outer edge sealing part extends through the annular groove, and the rubber seal The gasket is located between the top/bottom cover plate ends of the rim seal section.

The axial bending element includes a bending element probe, a hollow bolt and a connecting wire, the installation hole of the deflector is a threaded hole, the installation hole of the permeable stone is a through hole, the bending element probe is fixed in the hollow bolt, and the hollow bolt passes through the thread. It is installed in the threaded hole of the deflector, and the detection end of the bending element probe passes through the through hole of the permeable stone and is inserted into the soil sample to be tested in the soil sample cavity. The input/output end of the bending element probe is connected to the outside through connecting wires. The receiving circuit of the connecting wire passes through the hollow bolt, the sink groove and the hollow channel of the piston rod in sequence, and then penetrates into the bending element wire plug at the outlet of the bending element connecting line, and connects to the external receiving circuit after passing through the bending element wire plug.

Also includes leachate storage tank, air pressure regulating valve, pressure water tank, peristaltic pump, inflow pressure chamber, outflow pressure chamber, waste liquid collection container, outflow flow meter and outflow sampling port; the outlet of the leachate storage tank is connected to the pressure water tank The inlet, the outlet of the pressure water tank is connected to the inlet of the inflow pressure chamber through the peristaltic pump, the outlet of the inflow pressure chamber is connected to the inflow hole of the sample cylinder, the outflow hole of the sample cylinder is connected to the inlet of the outflow pressure chamber, and the outlet of the outflow pressure chamber Connect to the waste liquid collection container; the air source is connected to the top of the pressure water tank, the inflow pressure chamber and the outflow pressure chamber through the air pressure regulating valve.

The utility model can realize the coupling experiment of consolidation-penetration-shear wave velocity through the design and installation of the pressurizing piston mechanism structure and the sample cylinder structure, that is, the test of consolidation-penetration-shear wave velocity can be simultaneously realized on the same device.

The utility model further cooperates with the flow meter, the porosimeter, the pollutant concentration test system and the back pressure saturated normal head system to realize the coupling experiment of consolidation-penetration-shear wave velocity.

The utility model realizes the consolidation function through the rubber membrane jack pushing the pressurizing piston to pressurize, and the hollow channel drains the water. The axial and radial shear wave velocities of soil samples are measured by the axial bending element pair embedded in the center of the baffle plate and the radial bending element pair in the side wall of the sample cylinder. The seepage liquid flows into the soil sample through the lower hollow channel, and finally flows out from the upper hollow channel to the inflow and outflow holes to realize the seepage function.

Compared with the background technology, the utility model has the following beneficial effects:

(1) The utility model creatively couples the radial and axial shear wave velocity measurement tests, penetration/pollutant breakdown tests, and consolidation tests in soil samples, which solves the problem that the traditional geotechnical triaxial test cannot test the soil Sample Radial Shear Wave Velocity Defects.

(2) The utility model adopts the upper and lower pressurizing pistons to apply the same load to the soil sample at the same time, so that the upper and lower surfaces of the soil body push the same displacement to the middle at the same time, so that the bending element at the half-height position of the soil body will not be deformed due to the soil body. subject to shearing.

(3) By correlating the outflow concentration curve of pollutants with the radial and axial shear wave velocity change curves, it is proposed to use the shear wave velocity value as a means of measuring and monitoring the pollution degree of the anti-fouling barrier.

(4) The utility model adopts the rubber membrane jack to pressurize, and the friction force between it and the sample cylinder is small, which greatly reduces the loss of the axial load. Good airtightness and high reliability.

Description of drawings

FIG. 1 is a schematic top view of the device of the present invention.

FIG. 2 is a schematic sectional view of 1-1 of the device of the present invention.

3 is a partial cross-sectional schematic diagram of the installation of the axial bending element of the device of the present invention.

4 is a partial cross-sectional schematic diagram of the rubber membrane jack of the device of the present invention.

FIG. 5 is a schematic diagram of the surface arrangement of the deflector.

Figure 6 is a schematic diagram of an embodiment of the present invention.

In the picture: 1. Top cover plate, 2. Sample cylinder, 3. Piston rod, 4. Cap body, 5. Long bracket bolt, 6. Fastening short bolt, 7. Overflow hole, 8. Dial indicator, 9. Hydraulic water inlet, 10. Inflow and outflow hole, 11. Bending element connecting line outlet, 12. Radial bending element pair, 13. Bottom cover plate, 14. First O-shaped sealing ring, 15. Plug, 16. Piston plate, 17, rubber membrane jack, 18, hydraulic chamber, 19, deflector, 20, deflector groove, 21, deflector confluence hole, 22, permeable stone, 23, pair of axial bending elements, 24, second O-type sealing ring, 25, rubber sealing gasket, 26, hydraulic chamber valve, 27, hollow channel, 28, soil sample chamber, 29, leachate storage tank, 30, air pressure regulating valve, 31, pressure water tank, 32, peristalsis Pump, 33, Inflow pressure chamber, 34, Inflow flowmeter, 35, Pore pressure gauge, 36, Outflow pressure chamber, 37, Waste liquid collection container, 38, Pressure/volume change controller, 39, Bending element test system, 40. Outflow flowmeter, 41, Outflow sampling port, 42, Valve; 17-1, Wrinkled part of outer ring peripheral surface, 17-2, Inner ring peripheral surface part, 17-3, Outer edge sealing part, 23- 1. Bending element probe, 23-2, hollow bolt, 23-3, connecting wire.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and embodiments.

The technical terms used in the present invention, unless otherwise specified, can generally be understood by those of ordinary skill in the art.

As shown in Figures 1 and 2, the specific implementation of the present invention includes a top cover plate 1, a bottom cover plate 13, a sample cylinder 2 and two pressure piston mechanisms with the same structure and symmetrically arranged up and down. A pair of radial bending elements 12 are symmetrically installed on the side walls on both sides. The upper and lower ends of the sample cylinder 2 are respectively connected with a top cover plate 1 and a bottom cover plate 13. The upper and lower two pressurizing piston mechanism bodies are installed inside the sample cylinder 2. , the upper and lower two pressurizing piston mechanisms respectively penetrate through the top cover plate 1 and the bottom cover plate 13 and protrude out of the sample cylinder 2; the inner cavity of the sample cylinder 2 between the upper and lower pressurizing piston mechanisms constitutes the soil sample. In the cavity 28, the soil sample to be tested is placed in the soil sample cavity 28.

The upper and lower ends of the sample cylinder 2 are provided with flange flanges, and the top cover plate 1 and the bottom cover plate 13 are respectively installed on the flange flanges provided on the upper and lower end surfaces of the sample cylinder 2 by tightening short bolts 6. Bolt 5 secures the entire device.

As shown in Figure 2, the top cover plate 1 and the bottom cover plate 13 are both provided with two through holes communicating with the hydraulic chamber 18, one through hole is used as an overflow hole, and the other through hole is installed with a hydraulic chamber valve 26. The cavity valve 26 outlet serves as the hydraulic water inlet 9 .

As shown in Figures 2-3, each pressurizing piston mechanism includes a piston plate 16, a deflector 19, a permeable stone, 22, a piston rod 3 and a cap 4, the piston plate 16 is placed in the sample cylinder 2, the piston The outer wall of the plate 16 and the inner wall of the sample cylinder 2 are gap-fitted through the second O-shaped sealing ring 24. The permeable stone 22 is placed on the end face of the piston plate 16 near the center of the sample cylinder 2. The piston plate 16 is in contact with the permeable stone 19. A circular groove is opened in the center of the end face, and a sinking groove is opened in the center of the bottom of the circular groove. The sinking groove is communicated with the hollow channel 27 to the inside of the piston rod 3. One end face of the center of the sample tube 2 is opened with multiple concentrically arranged annular guide grooves 20, and the multiple guide grooves 20 are connected through a radial guide channel, and the guide plate 19 is close to the center of the sample tube 2. The eccentric side of the end face is provided with a guide plate confluence hole 21, the guide groove 20 communicates with the guide plate confluence hole 21, and the guide plate confluence hole 21 communicates with the sink groove, as shown in FIG. 5 .

As shown in FIG. 2 , the center of the deflector 19 and the permeable stone 22 are provided with installation holes for installing the axial bending element 23, and the axial bending element 23 is installed in the installation holes of the deflector 19 and the permeable stone 22 and passes through it. After exiting the installation hole, insert it into the soil sample to be tested in the soil sample chamber 28; one end of the piston rod 3 is connected to the center of the end face of the piston plate 16 away from the center of the sample cylinder 2 through a threaded seal, and the other end of the piston rod 3 passes through the top cover plate 1/ After the bottom cover plate 13 is connected to the cap body 4 through the screw seal, the cap body 4 of the upper pressurizing piston mechanism is the top cap, the cap body 4 of the lower pressurizing piston mechanism is the bottom cap, and the upper sides of the cap body 4 are respectively provided with access The flow hole 10 and the bending element connecting line outlet 11, the bending element line plug is installed at the bending element connecting line outlet 11; the piston rod 3 is provided with an axial hollow channel 27, and one end of the hollow channel 27 is connected to the inflow and outflow hole 10 and the bending element connecting line At the outlet 11 , the other end of the hollow passage 27 communicates with the sink groove of the piston plate 16 .

As shown in FIG. 4 , the inner cavity space of the sample cylinder 2 between the piston plate 16 and the top cover plate 1/bottom cover plate 13 forms a hydraulic chamber 18, and an annular rubber membrane jack 17 is arranged on the inner wall of the hydraulic chamber 18. The rubber membrane The jack 17 is divided into four parts: the outer edge sealing part 17-3, the outer ring peripheral surface fold part 17-1, the bottom surface part and the inner ring peripheral surface part 17-2, and the four parts are connected in turn in the radial direction into one; The edge sealing part 17-3 is closely arranged between the outer end surface of the sample cylinder 2 and the top cover plate 1/bottom cover plate 13, and the outer ring peripheral surface corrugated part 17-1 is closely arranged on the inner wall of the sample cylinder 2, and the bottom surface part Closely arranged on the end face of the piston plate 16 away from the center of the sample cylinder 2, the inner ring peripheral surface part 17-2 is tightly fitted outside the piston rod 3 with an interference fit, and the inner ring peripheral surface part 17-2 tightly wraps the piston rod 3. Outer peripheral surface, the inner cylindrical surface of the inner ring peripheral surface part 17-2 can be provided with annular protrusions to enhance the sealing performance in contact with the piston rod 3; The sealing part 17-3, the bottom surface part and the inner ring peripheral surface part 17-2 do not have elastic elasticity, so that the piston plate 16 moves during the consolidation test and the penetration test, driving the outer ring peripheral surface fold part 17-1 to stretch. Or shrink, the outer edge sealing part 17-3, the bottom surface part and the inner ring peripheral surface part 17-2 are kept close to their respective surfaces.

There is an annular groove between the flange flange of the sample tube 2 and the end face of the top cover plate 1/bottom cover plate 13, a rubber sealing gasket 25 is installed in the annular groove, and the outer edge sealing part 17-3 extends through the annular groove groove, the rubber sealing gasket 25 is located between the end faces of the top cover plate 1/bottom cover plate 13 of the outer edge sealing part 17-3.

The top cover plate 1/bottom cover plate 13 is provided with a central through hole, a cock 15 is installed in the central through hole, the cock 15 is sleeved on the piston rod 3, and the piston rod 3 between the cock 15 and the top cover plate 1/bottom cover plate 13 A first O-shaped sealing ring 14 is also set on the upper part. After the cock 15 is screwed into the central through hole, the first O-shaped sealing ring 14 is pressed against the gap between the piston rod 3 and the central through hole, so as to realize the piston rod 3 and top cover 1/bottom cover 13. Tightening the cock 15 can ensure the airtightness inside the hydraulic chamber 18, and at the same time try to keep the frictional force between the first O-shaped sealing ring 14 and the piston rod 3 within a small range.

There is usually no membrane structure like the rubber membrane jack 17 of the present invention in the prior art. When the liquid pressure applied to the hydraulic chamber 18 is pressed to the soil sample chamber 28 through the piston plate 16, the piston plate 16 and the sample cylinder 2 will be affected. Part of the friction is lost due to the excessive friction caused by the interference fit between them. After the rubber membrane jack 17 is adopted in the present invention, the interference fit between the piston plate 16 and the sample cylinder 2 can be replaced by a clearance fit, and the hydraulic pressure inside the hydraulic chamber 18 will cause the bottom surface of the rubber membrane jack 17 to squeeze the piston tightly. The space between the plate 16 and the sample cylinder 2 . The movement of the pressurizing piston mechanism toward the soil can be realized only by pulling the corrugated portion 17-1 of the outer ring peripheral surface of the rubber membrane jack 17. This design greatly reduces the frictional force generated during the movement of the pressurized piston mechanism to the soil, thereby keeping the liquid pressure applied to the hydraulic chamber 18 substantially the same as the pressure applied to the soil sample chamber 28 .

As shown in FIG. 2 , during the consolidation experiment, the liquid in the soil sample cavity 28 penetrates the permeable stone 19 and enters into each diversion groove 20 of the deflector 19, and then converges to the confluence hole 21 of the deflector, and then circulates through the sink. to the hollow passage 27 inside the piston rod 3 , and finally flows out from the inlet and outlet flow holes 10 .

In the upper and lower pressurizing piston mechanisms, the cap body 4 is provided with a dial indicator 8 on the side away from the center of the sample cylinder 2, and the dial indicator 8 is fixed on the top cover plate 1/bottom cover plate 13 through a bracket, The probe end of the dial indicator 8 faces the cap body 4 and is used to contact and connect to the outer end of the cap body 4. The dial indicator 8 measures the distance between the probe end and the cap body 4, and measures the axial deformation value of the soil sample to be tested.

As shown in FIG. 3 , the axial bending element 23 includes a bending element probe 23-1, a hollow bolt 23-2 and a connecting wire 23-3, the installation holes of the guide plate 19 are threaded holes, and the installation holes of the permeable stones 22 are through-holes. The bending element probe 23-1 is fixed in the hollow bolt 23-2, and the hollow bolt 23-2 is installed in the threaded hole of the deflector 19 through the thread, specifically by winding the raw material tape to the surface of the hollow bolt 23-2, and then Screw it into the threaded hole, the detection end of the bending element probe 23-1 passes through the through hole of the permeable stone 22 and then is inserted into the soil sample to be tested in the soil sample cavity 28. By changing the number of turns of the hollow bolt 23-2 , the depth to which the bending element probe 23-1 extends into the soil sample to be tested in the sample cylinder can be adjusted. The input/output end of the bending element probe 23-1 is connected to the external circuit system through the connecting wire 23-3, and the connecting wire 23-3 is routed through the hollow bolt 23-2, the sink groove and the hollow channel 27 in turn and then penetrates into the bending The bending element wire plug of the element connecting wire outlet 11 passes through the bending element wire plug and is connected to an external receiving circuit.

The hollow bolt 23-2 is made of nylon top wire, and the bending element in the bending element probe 23-1 is made of standard brass reinforced piezoelectric ceramic plate produced by American Pizeo system. The bending element and the hollow bolt The gaps between are filled by AB glue.

In the specific implementation, the connecting lines of the left and right bending element pairs on the two side walls of the sample cylinder 2 are directly drawn out. The connecting line of the upper and lower bending element pairs in the inner cavity of the sample cylinder 2 is led out to the connecting line outlet 11 of the bending element at the end of the piston rod after passing through the hollow channel.

As shown in FIG. 6 , the specific implementation further includes a leachate storage tank 29, an air pressure regulating valve 30, a pressure water tank 31, a peristaltic pump 32, an inflow pressure chamber 33, an outflow pressure chamber 36, a waste liquid collection container 37 and an outflow flow meter 40; The outlet of the leachate storage tank 29 is connected to the inlet of the pressure water tank 31, the outlet of the pressure water tank 31 is connected to the inlet of the inflow pressure chamber 33 through the peristaltic pump 32, and the outlet of the inflow pressure chamber 33 is connected to the inflow hole of the lower pressurizing piston mechanism, and the upper pressurized The outflow hole of the piston mechanism is connected to the inlet of the outflow pressure chamber 36, and the outlet of the outflow pressure chamber 36 is connected to the waste liquid collection container 37; flow to the top of the pressure chamber 36 .

The pressure/volume change controller 38 acts as a hydraulic source, which is connected and installed on the hydraulic chamber valve 26, and the bending element testing system 39 is used to collect the test data of two pairs of bending elements and perform analysis and processing to obtain the shear wave velocity in the test soil sample value.

In the specific implementation, the pipeline between the inflow pressure chamber 33 and the inflow hole of the lower pressurizing piston mechanism is provided with an inflow flowmeter 34 , and the pipeline between the outflow hole of the upper pressurizing piston mechanism and the outflow pressure chamber 36 is provided. Pore pressure gauge 35 , outflow flowmeter 40 and outflow sampling port 41 are provided, and the outlet of outflow pressure chamber 36 is connected to waste liquid collection container 37 through valve 42 . Pipes between the leachate storage tank 29 and the pressure water tank 31, between the pressure water tank 31 and the peristaltic pump 32, between the peristaltic pump 32 and the inflow pressure chamber 33, and between the inflow pressure chamber 33 and the sample cylinder 2 are all provided with pipes. valve 42.

The inflow pressure chamber 33 is internally connected with a guide pipe extending from the bottom inlet to the space above the inner cavity, a sleeve made of PVC is fixed and bonded on the base platform of the inflow pressure chamber 33, and the guide pipe outlet is located just above the upper surface of the sleeve, The outflow liquid from the guide tube drips into the sleeve until the sleeve is overflowed by the inflow liquid, and the upper surface of the sleeve is the inflow head. The outflow pressure chamber 36 is internally connected with a guide pipe extending from the bottom inlet to the space above the inner cavity, the guide pipe discharges the outflow liquid, and the outlet of the guide pipe is the outflow head. The height difference between the inflow head and the outflow head forms the constant head difference required for infiltration/contaminant breakdown experiments.

The specific implementation process of the present utility model is as follows:

A. Consolidation technical solution process:

1) Pressurization scheme

Load the soil to be tested into the soil sample chamber 28, generally first install the lower pressurized piston mechanism, permeable stone 22 and filter paper, and then install the permeable stone 22, filter paper and the upper pressurized piston mechanism after loading the soil to be tested .

The airless water is output from the pressure/body change controller 38 and enters the hydraulic chamber 18 after passing through the two hydraulic chamber valves 26 of the upper and lower pressurizing piston mechanisms. The excess liquid overflows through the overflow hole 7 to ensure that the hydraulic chamber 18 is filled with liquid. No gas.

Increase the hydraulic pressure of the input airless water to the required consolidation pressure, and simultaneously apply pressure to the upper and lower piston plates 16 through the upper and lower rubber membrane jacks 17 to make the wrinkled rubber membrane 17-1 attached to the inner wall of the sample cylinder 2 It is pulled to push the pressurizing piston, thereby applying axial pressure to the soil to be tested in the soil sample chamber 28 . In this way, the pressure loss in the pressurization process can be greatly reduced, and the technical problem of easy pressure loss in the pressurization process is solved.

There is a clearance fit between the piston plate 16 and the sample cylinder 2, and the close fit between the two is provided by the rubber film jack 17 - the hydraulic pressure inside the rubber film jack will cause the bottom surface of the rubber film jack 17 to squeeze the piston plate 16. The gap between the sample cylinder 2 and the sample cylinder 2 effectively prevents the soil sample from being squeezed and flooded above the piston plate 16 . When the piston plate 16 is pushed toward the soil sample, it only needs to pull the wrinkled part 17-1 of the outer ring peripheral surface of the rubber membrane jack 17, which effectively avoids the sliding friction between the piston plate 16 and the inner wall of the sample cylinder 2, and greatly reduces the The friction force generated during the movement of the pressurized piston mechanism to the soil sample.

2) Drainage scheme

The soil to be tested is drained under the consolidation pressure, and the water on the upper and lower surfaces passes through the permeable stones 22 successively, and then is diverted through the diversion grooves 20 on the surface of the deflector 19, collects and flows into the confluence hole 21 of the deflector, and then flows through The sink in the center of the circular groove bottom and the hollow channel 27 inside the piston rod 3 finally flow to the inflow and outflow holes 10 at the end of the piston rod 3, and flow out to the external piping system through the quick screw connection.

B. The process of penetration technology scheme:

1) Water guide scheme.

On the one hand, the airless water is output from the pressure/volume change controller 38, and simultaneously passes through the two hydraulic chamber valves 26 of the top cover 1 and the bottom cover 13 into the hydraulic chamber 18, and the excess liquid overflows through the overflow hole 7, The hydraulic chamber 18 is filled with a certain pressure.

The seepage liquid enters from the inflow hole, passes through the hollow channel 27 inside the piston rod 3 in the lower pressurized piston mechanism, the confluence hole 21 of the guide plate, the guide groove 20 on the surface of the guide plate 16, and the permeable stone 22, and then reaches the soil to be tested. In the sample, after passing through the permeable stone 22 in the upper pressurized piston mechanism, the diversion groove 20 on the surface of the deflector 16, the confluence hole 21 of the deflector, and the hollow channel 27 inside the piston rod 3, it finally flows out from the outflow hole.

2) Saturation scheme.

In order to ensure that the permeability coefficient of the saturated soil sample is measured, the inflow pressure chamber 33 and the outflow pressure chamber 36 respectively apply pressure (this part of the pressure is also called back pressure) to the inflow and outflow seepage liquid, so that the gas in the soil sample is Dissolved in water and discharged to achieve soil saturation.

3) Determination scheme of pollutant breakdown curve.

An outflow sampling port 41 is provided between the outflow hole of the upper pressurizing piston mechanism and the outflow pressure chamber 36, so that outflow samples of the polluted liquid can be obtained from the outflow pipeline at regular intervals after the pollutants begin to penetrate.

The contaminant concentration in the effluent sample is determined to obtain the breakdown curve of the contaminant under study.

C. The process of the shear wave velocity test technical scheme is as follows:

1) Screw the fabricated bending element pair directly into the two internally threaded holes on both sides of the outer wall of the sample cylinder at half height, and then test the shear wave velocity of the soil sample to be tested in the horizontal radial direction within its height range.

2) Screw the bending element pair into the inner threaded hole at the center of the upper and lower deflectors to test the shear wave velocity in the upper and lower axial directions of the soil to be tested.

Through these experimental results, we can obtain (1) the permeability coefficient and vertical deformation value changes of the soil unit body at a certain depth of the vertical anti-fouling barrier under its self-weight consolidation stress under the long-term infiltration of the leachate, as well as the changes in the corresponding pollutants. retardation factor, which comprehensively evaluates the long-term service performance of soil-organic bentonite in municipal solid waste landfills. (2) Correlating the shear wave velocity in the radial and axial directions and the pollution outflow concentration, it is proposed to use the shear wave velocity value as a measure and monitoring method for the pollution degree of the anti-fouling barrier.

Embodiments of the present utility model are as follows:

Soil-bentonite-organic bentonite is made by mixing a certain proportion of Gaomiaozi bentonite in Inner Mongolia, construction waste in Shenzhen Guangming New District, YS2001 organic bentonite produced by Tianjin Shuangrui Organic Bentonite Co., Ltd. and deionized water. The landfill leachate was obtained from the aged leachate of the Tianziling Landfill in Hangzhou (hereinafter referred to as leachate).

Axial pressure _Pe (the effective stress of the soil unit at a certain depth of the vertical antifouling barrier) is applied to the mixed soil-bentonite-organic bentonite in the rigid consolidation drainage cylinder and drained. Take out the soil sample after pre-consolidation, cut it into a soil column with a height of 10cm and a diameter of 10cm, and put it into the utility model.

Connect the components according to Figure 6. Pass the deionized water into the hydraulic chamber 18 until the water overflows the overflow hole 7, then change the pressure/volume change controller 38 and continue to pass the deionized water into the hydraulic chamber 18 until the water fills the pipeline and overflows again Flow hole 7, close the overflow hole 7, and reset the volume change value of the pressure/volume change controller 38 to zero. The retrieved leachate is put into the leachate storage tank 29, and 10 liters of the leachate therein is passed into the pressure water tank 31 by using a high water head.

Close the inflow valve of the pressure water tank 31 . The air pressure of the size P ₁ is applied to the pressure water tank 31 , the inflow pressure chamber 33 and the outflow pressure chamber 36 by the air pressure regulating valve 30 . Turn on the peristaltic pump 32, open the outflow valve of the pressure water tank and the inflow valve of the inflow pressure chamber, so that the leachate in the pressure water tank 31 flows into the guide pipe inside the pressure chamber 33, and flows into the inner sleeve until it overflows. Open the outflow valve of the inflow pressure chamber 33, so that the leachate with the hydraulic pressure of P ₁ enters the soil sample to be tested through the inflow hole, and at the same time, an axial pressure of P ₂ (P ₂ =P ₁ +P _e ) is applied to Soil sample 28. Close the outflow valve of the inflow pressure chamber 33 and the inflow valve of the outflow pressure chamber 36, increase the axial pressure by 20kpa, measure the change value of the porosimeter 35, and then measure the soil to be tested according to the increased axial pressure value and the change value of the pore water pressure. The same Skempton B value.

The axial pressure is then dropped back to P ₂ , and the outflow valve of the inflow pressure chamber 33 and the inflow valve of the outflow pressure chamber 36 are opened. If the Skempton B value does not reach 0.95. Then increase the back pressure P ₁ and the axial pressure P ₂ 50kpa at the same time, and continue to measure the Skempton B value of the soil sample to be tested after simultaneously increasing the back pressure P ₁ and the axial pressure P ₂ according to the above steps, and continue until the Skempton B value. ≥0.95. Then the soil sample can be considered saturated, and the leachate breakdown experiment under constant water head is being carried out.

(A) The breakdown curves of various pollutants obtained under the long-term permeation of leachate by soil-organic bentonite

After the soil is saturated at 0h, 2h, 4h, 8h, 16h, 24h, 2d, 3d, 4d,…10d, 12d, 14d,…30d, 35d, 40d,…60d, it is collected at the outflow sampling port 41. Flow the sample into a small reagent vial. And measure the concentration of various pollutants in the sample, draw the pollutant breakdown curve, and reverse the _{R d} value and DL value of various pollutants. To evaluate the blocking properties of clay-bentonite-organo-bentonite for various pollutants.

(B) The change curve of the permeability coefficient of the obtained soil-organic bentonite under the long-term infiltration of the leachate

After the readings of the inflow flowmeter 34 and the outflow flowmeter 40 are stable, and the ratio of the inflow flow rate value to the outflow flow rate value is between 0.75 and 1.25, start to measure the permeability coefficient (K) value, K=Q/(A· i). The average flow value of the inflow and outflow is taken to calculate the permeability coefficient value regardless of the initial hydraulic gradient. The permeability coefficient values of 1d, 2d, 3d,…10d, 12d, 14d,…30d, 35d, 40d,…60d were measured. The curve of permeability coefficient with time can be used to analyze the long-term service performance of the new soil-bentonite-organic bentonite. If the K value decreases significantly with time, it indicates that the chemical compatibility of the new clay-bentonite-organic bentonite is poor.

(C) Variations of radial and axial shear wave velocities of soil-organic bentonite under long-term leachate infiltration

The connecting line of the radial bending element pair 12 and the axial bending element pair 23 is connected to the bending element testing system 39 . Read shear wave velocity values at 0h, 2h, 4h, 8h, 16h, 24h, 2d, 3d, 4d,…10d,12d,14d,…30d,35d,40d,…60d after soil saturation, and plot the axis Time-varying curves of shear wave velocity and radial shear wave velocity. Correlate the breakdown curve of pollutants with the change curves of axial shear wave velocity and radial shear wave velocity, and explore the values of axial shear wave velocity and radial shear wave velocity as monitoring methods for pollutant outflow concentration in the anti-seepage curtain possibility.

(D) Determination of soil deformation value

Take the initial position when the soil is just saturated, and reset the reading of the dial indicator to zero. After that, add the upper and lower dial indicator values to obtain the vertical deformation values corresponding to soil 5d, 10d, 20d, 30d, ... 60d respectively. The deformation value derived from the body deformation value displayed by the pressure/body deformation controller 38 is compared and checked. The obtained deformation values can evaluate the expansion and chemical compatibility of soil-bentonite-organobentonite.

The above is to further explain the present utility model in conjunction with the accompanying drawings and specific embodiments. However, it should be noted that this does not limit the present invention. Within the spirit of the present invention and the protection scope of the claims, any modifications and changes made to the present invention fall into the protection scope of the present invention.

Claims (8)

1. A consolidation-infiltration-shear wave velocity coupling experimental device is characterized in that: the device comprises a top cover plate (1), a bottom cover plate (13), a sample cylinder (2) and two pressurizing piston mechanisms which are identical in structure and are symmetrically arranged up and down, wherein radial bending element pairs (12) are symmetrically arranged on the side walls of the two sides of the middle of the sample cylinder (2), the upper end and the lower end of the sample cylinder (2) are respectively connected with the top cover plate (1) and the bottom cover plate (13), the upper pressurizing piston mechanism body and the lower pressurizing piston mechanism body are arranged inside the sample cylinder (2), and the upper pressurizing piston mechanism and the lower pressurizing piston mechanism respectively penetrate through the top cover plate (1) and the bottom cover plate (13) and extend out of the sample cylinder; an inner cavity of the sample cylinder (2) between the upper pressurizing piston mechanism and the lower pressurizing piston mechanism forms a soil sample containing cavity (28), and a soil sample to be tested is placed in the soil sample containing cavity (28);

each pressurizing piston mechanism comprises a piston plate (16), a guide plate (19), a permeable stone (22), a piston rod (3) and a cap body (4), the piston plate (16) is arranged in the sample cylinder (2), the outer wall of the piston plate (16) is matched and connected with the inner wall of the sample cylinder (2) through a second O-shaped sealed ring (24), the permeable stone (22) is arranged at the end face of the piston plate (16) close to the center of the sample cylinder (2), a circular groove is formed in the center of the end face of the piston plate (16) in contact with the permeable stone (22), a sink groove is formed in the center of the bottom of the circular groove, the guide plate (19) is arranged in the circular groove, a guide groove (20) is formed in one end face of the guide plate (19) close to the center of the sample cylinder (2), a guide plate collecting hole (21) is formed in one eccentric side of the end face of the guide plate (19) close to the center of the sample cylinder (, the guide plate converging hole (21) is communicated with the sink; mounting holes for mounting the axial bending elements (23) are formed in the centers of the guide plate (19) and the permeable stone (22), and the axial bending elements (23) are mounted in the mounting holes of the guide plate (19) and the permeable stone (22), penetrate through the mounting holes and then are inserted into a soil sample to be tested in the soil sample accommodating cavity (28); one end of a piston rod (3) is connected to the center of the end face of a piston plate (16) far away from the center of a sample cylinder (2) through threads, the other end of the piston rod (3) penetrates through a top cover plate (1)/a bottom cover plate (13) and then is connected with a cap body (4) through threads, an inflow and outflow hole (10) and a bent element connecting wire outlet (11) are respectively formed in two sides of the cap body (4), and a bent element wire plug is installed at the bent element connecting wire outlet (11); an axial hollow channel (27) is arranged in the piston rod (3), one end of the hollow channel (27) is communicated with the inlet and outlet hole (10) and the bent element connecting wire outlet (11), and the other end of the hollow channel (27) is communicated with a sinking groove of the piston plate (16); a hydraulic cavity (18) is formed in the inner cavity space of the sample cylinder (2) between the piston plate (16) and the top cover plate (1)/the bottom cover plate (13), an annular rubber film jack (17) is arranged on the inner wall of the hydraulic cavity (18), the rubber film jack (17) is divided into four parts, namely an outer edge sealing part (17-3), an outer ring circumferential surface folding part (17-1), a bottom surface part and an inner ring circumferential surface part (17-2), and the four parts are sequentially connected into a whole; the outer edge sealing part (17-3) is arranged between the outer end face of the sample cylinder (2) and the top cover plate (1)/the bottom cover plate (13) in a tightly attached mode, the outer ring circumferential surface fold part (17-1) is arranged on the inner wall of the sample cylinder (2) in a tightly attached mode, the bottom surface part is arranged on the end face, away from the center of the sample cylinder (2), of the piston plate (16) in a tightly attached mode, and the inner ring circumferential surface part (17-2) is sleeved outside the piston rod (3) in a tightly attached mode in an interference; the outer ring circumferential surface folded part (17-1) has elastic flexibility, the outer edge sealing part (17-3), the bottom surface part and the inner ring circumferential surface part (17-2) do not have elastic flexibility, so that the piston plate (16) moves when a consolidation experiment and a penetration experiment are carried out to drive the outer ring circumferential surface folded part (17-1) to stretch or contract, and the outer edge sealing part (17-3), the bottom surface part and the inner ring circumferential surface part (17-2) are kept to be tightly attached to respective surfaces; two through holes communicated with the hydraulic cavity (18) are formed in the top cover plate (1) and the bottom cover plate (13), one through hole is used as an overflow hole, a hydraulic cavity valve (26) is installed on the other through hole, and an outlet of the hydraulic cavity valve (26) is used as a hydraulic water inlet (9).

2. The consolidation-penetration-shear wave velocity coupling experimental device according to claim 1, wherein: during consolidation experiments, liquid in the soil sample accommodating cavity (28) penetrates through the permeable stone (22) to enter each flow guide groove (20) of the flow guide plate (19), then is converged into the flow guide plate convergence hole (21), then flows into the hollow channel (27) in the piston rod (3) through the sinking groove, and finally flows out from the flow inlet and outlet hole (10).

3. The consolidation-penetration-shear wave velocity coupling experimental device according to claim 1, wherein: the piston rod sealing structure is characterized in that a central through hole is formed in the top cover plate (1)/the bottom cover plate (13), a cock (15) is installed in the central through hole, the cock (15) is sleeved on the piston rod (3), a first O-shaped sealing ring (14) is further sleeved on the piston rod (3) between the cock (15) and the top cover plate (1)/the bottom cover plate (13), and the cock (15) is screwed into the central through hole and then compresses the first O-shaped sealing ring (14) at a gap between the piston rod (3) and the central through hole.

4. The consolidation-penetration-shear wave velocity coupling experimental device according to claim 1, wherein: in the upper and lower pressurizing piston mechanisms, a dial indicator (8) is arranged on one side of the cap body (4) far away from the center of the sample cylinder (2), the dial indicator (8) is fixed on the top cover plate (1)/the bottom cover plate (13) through a bracket, the probe end of the dial indicator (8) faces the cap body (4), and the dial indicator (8) measures the distance between the probe end and the cap body (4).

5. The consolidation-penetration-shear wave velocity coupling experimental device according to claim 1, wherein: the upper end and the lower end of the sample cylinder (2) are respectively provided with a flange, the top cover plate (1) and the bottom cover plate (13) are respectively arranged on the flange flanges arranged on the upper end surface and the lower end surface of the sample cylinder (2) through fastening short bolts (6), and the sample cylinder (2) is fixed through support long bolts (5).

6. The consolidation-penetration-shear wave velocity coupling experimental apparatus of claim 5, wherein: an annular groove is formed between the flange of the sample cylinder (2) and the end faces of the top cover plate (1)/the bottom cover plate (13), a rubber sealing gasket (25) is installed in the annular groove, the outer edge sealing part (17-3) extends through the annular groove, and the rubber sealing gasket (25) is located between the outer edge sealing part (17-3) and the end faces of the top cover plate (1)/the bottom cover plate (13).

7. The consolidation-penetration-shear wave velocity coupling experimental device according to claim 1, wherein: the axial bending element (23) comprises a bending element probe (23-1), a hollow bolt (23-2) and a connecting wire (23-3), a mounting hole of the guide plate (19) is a threaded hole, a mounting hole of the permeable stone (22) is a through hole, the bending element probe (23-1) is fixed in the hollow bolt (23-2), the hollow bolt (23-2) is mounted in the threaded hole of the guide plate (19) through threads, a detection end of the bending element probe (23-1) penetrates through the through hole of the permeable stone (22) and then is inserted into a soil sample to be detected in the soil sample accommodating cavity (28), an input/output end of the bending element probe (23-1) is connected to an external receiving circuit through the connecting wire (23-3), and the connecting wire (23-3) is wired to sequentially pass through the hollow bolt (23-2) and the sink groove, The hollow channel (27) of the piston rod (3) is inserted into the bent element plug of the bent element connecting wire outlet (11), and the bent element plug is connected to an external receiving circuit after penetrating out of the bent element plug.

8. The consolidation-penetration-shear wave velocity coupling experimental device according to claim 1, wherein: the device also comprises a percolate storage tank (29), an air pressure regulating valve (30), a pressure water tank (31), a peristaltic pump (32), an inflow pressure chamber (33), an outflow pressure chamber (36), a waste liquid collecting container (37), an outflow flow meter (40) and an outflow sampling port (41); an outlet of the percolate storage box (29) is connected to an inlet of a pressure water tank (31), an outlet of the pressure water tank (31) is connected to an inlet of an inflow pressure chamber (33) through a peristaltic pump (32), an outlet of the inflow pressure chamber (33) is connected to an inflow hole of the sample cylinder (2), an outflow hole of the sample cylinder (2) is connected to an inlet of an outflow pressure chamber (36), and an outlet of the outflow pressure chamber (36) is connected to a waste liquid collecting container (37); the gas source is connected to the top of the pressure water tank (31), the inflow pressure chamber (33) and the outflow pressure chamber (36) through a gas pressure regulating valve (30).

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