Test device for measuring shear viscosity of sand under conventional triaxial stress state

Abstract

The invention discloses a test device for measuring the shear viscosity of sand under a conventional triaxial stress state, comprising a frame, a vertical pressure / displacement control system, a torsional deformation / torque control system and a test component. The frame is provided with a positioning platform, the test component is placed on the positioning platform, the test component comprises a confining pressure chamber, an annular soil sample to be tested is placed in the confining pressure chamber, a central hole of the annular soil sample is provided with a rotating central axis, an upper cover plate is provided on the upper end surface of the annular soil sample, a lower cap support plate is provided on the lower end surface, a movable rotating plate is provided around the central hole of the annular soil sample on the contact surface of the upper cover plate and the lower cap support plate with the annular soil sample, the movable rotating plate is composed of a plurality of circular ring sleeves of different diameters arranged in contact with each other from the inside to the outside, a raised ridge is provided on the contact surface of the circular ring sleeve and the sample to be tested, an annular arc groove is provided on the other end surface opposite to the contact surface of the circular ring sleeve and the annular soil sample, a ball is laid in the annular arc groove, and the circular ring sleeve slides and rotates on the upper cover plate and the lower cap support plate through the ball.

Description

Technical Field

[0001] The invention relates to a test device for measuring the shear viscosity of sand under a conventional triaxial stress state, and is used for testing foundation sand and filling sand. Background Art

[0002] With the construction of a modern infrastructure system, the number of backfill projects using sand as a building material is increasing day by day, and roads, bridges, earth-rock dams, offshore oil and gas projects built on sand foundations are widely appearing. The mechanical properties of foundation sand directly affect the safety and stability of the superstructure, and the rheological properties of foundation sand significantly affect the later safety of the building structure, especially for deep sand foundations. Even if the sand undergoes small stress-strain changes, the cumulative effect may still cause a large deformation of the foundation surface, increasing the risk of engineering failure. On the contrary, good plastic flow characteristics are more desired in the excavation of sand. However, no matter what the application scenario, it is extremely important to accurately grasp the rheological properties of sand.

[0003] Sand is a typical material with density and stress state correlation. The shear viscosity (ratio of shear stress to shear strain rate) changes with the change of dry density and the change of stress state. In actual engineering, sand materials are mostly in a conventional triaxial stress state. In order to ensure the long-term safety of sand foundation engineering, it is necessary to measure the shear viscosity of sand while controlling the density and conventional triaxial stress state.

[0004] Rotational shear rheometer is an important tool for testing shear viscosity, but existing rotational rheometers are only suitable for thin-layer fluids or pastes. When rotating sand and soil, the pressure state and density cannot be kept constant, and there is a problem that it is difficult to distinguish between equipment friction and material friction. Taking the cross-plate blade rotational shear rheometer as an example, a small number of devices have achieved isotropic pressure (vertical pressure σ z = Radial Pressure σ r = Circumferential pressure σ θ ) conditions, but vertical pressure cannot be achieved. σ z Greater than confining pressure σ r (= σ θ ) under the condition of shear viscosity, and the confining pressure is less than 1 MPa. During the rotational shear, the confining pressure state and the density of the soil sample change seriously. Due to the friction between the upper and lower edges of the cross-plate blades and the upper and lower restraining parts of the soil sample, the rotation of the soil sample is unclear, that is, the interference of the upper and lower control ends on the radial shear causes the shear state to be complex and uncontrollable. Summary of the invention

[0005] The present invention provides a test device for measuring the shear viscosity of sand under a conventional triaxial stress state. In order to realize the measurement of the shear viscosity of sand under a controllable conventional triaxial stress state and density conditions, a large-scale shear viscosity measuring device that can overcome the interference of upper and lower control ends on radial shear is provided. On the basis of a conventional triaxial instrument for soil, a rotating central axis connected to a torsional deformation / torque control system is adopted to realize radial rotational shearing of annular soil samples, and an upper cover plate and a lower cap support plate structure with a movable rotating plate are adopted to overcome the interference problem of the upper and lower control ends on radial shear.

[0006] In order to achieve the above object, the scheme of the present invention is:

[0007] The test device for measuring the shear viscosity of sand under conventional triaxial stress state comprises a frame, a vertical pressure / displacement control system, a torsional deformation / torque control system and a test assembly, wherein the frame is provided with a positioning platform, a through hole is provided in the center of the positioning platform, and the test assembly is placed on the positioning platform, wherein: the test assembly comprises a closed confining pressure chamber, the confining pressure chamber buckles the platform through hole and is sealed and fixed to the positioning platform, an annular soil sample to be tested is placed in the confining pressure chamber, a rotating central axis is provided in the center hole of the annular soil sample, an upper cover plate is provided around the center hole on the upper end surface of the annular soil sample, a lower cap support plate is provided around the center hole on the lower end surface of the annular soil sample, the lower cap support plate is positioned on the positioning platform, a pressure-bearing piston column is provided on the upper end surface of the upper cover plate, and the pressure-bearing piston column is moved from the confining pressure chamber to the center hole of the confining pressure chamber. The upper end surface of the chamber extends out to receive the downward pressure of the vertical pressure / displacement control system, and the driving shaft of the torsional deformation / torque control system extends out from the platform through hole to connect the rotating central axis of the center hole of the annular soil sample. The upper cover plate and the lower cap support plate are provided with a movable rotating plate around the center hole of the annular soil sample on the contact surface with the annular soil sample, and the movable rotating plate is composed of a plurality of circular ring sleeves of different diameters arranged in contact with each other from the inside to the outside, and an arc groove is arranged around the other end surface opposite to the contact surface of the circular ring sleeve and the annular soil sample, and a ball is lying in the circular arc groove. The circular ring sleeve slides and rotates on the upper cover plate and the lower cap support plate through the ball bearing, and the circular ring sleeves of different diameters arranged in contact with each other from the inside to the outside provide conditions for radial layered twisting of the annular soil sample from the inside to the outside.

[0008] The scheme is further as follows: the contact surface between the upper cover plate and the soil sample to be tested is provided with an upper concave annular surface around the center hole of the annular soil sample, the contact surface between the lower cap support plate and the soil sample to be tested is provided with a lower concave annular surface around the center hole of the annular soil sample, the upper / lower concave annular surface is connected with the center hole of the annular soil sample, and the movable rotating plate is placed in the upper / lower concave annular surfaces of the upper cover plate and the lower cap support plate.

[0009] A further solution is that the contact surface between the annular sleeve and the soil sample to be tested is provided with raised ribs, and the ribs are embedded in the annular soil sample.

[0010] A further solution is that after the pressure-bearing piston column passes through, the upper end surface of the confining pressure chamber is covered with a pressure ring to cover the pressure-bearing piston column, and the pressure-bearing piston column and the confining pressure chamber are sealed by an "O"-shaped rubber sealing ring arranged on the inner side of the pressure ring.

[0011] The scheme is further as follows: the confining pressure chamber is a transparent organic glass cover or a steel cover, a water inlet and outlet interface is arranged on the lower end side wall of the confining pressure chamber, a water outlet pressure relief port is arranged on the upper end side wall, a back pressure hole is arranged on the upper cover plate, and a hole pressure hole is arranged on the lower cap support plate; the back pressure hole and the hole pressure hole are arranged opposite to each other.

[0012] The solution is further as follows: the vertical pressure / displacement control system includes a loading moving beam arranged on a frame, the loading moving beam is pushed by a telescopic arm to move vertically up and down along a guide rail, and a vertical loading force and displacement sensor is arranged between the telescopic arm and the loading moving beam; the vertical pressure / displacement application system applies pressure to the pressure-bearing piston column through the loading moving beam, applies vertical pressure of a controllable vertical stress or strain state to the annular soil sample, measures the vertical strain while controlling the vertical stress, or measures the vertical stress while controlling the vertical strain.

[0013] The scheme is further as follows: the torsional deformation / torque control system includes a torsional reducer arranged under the positioning platform, the upward rotating shaft of the torsional reducer is connected to a driving rotating shaft through a torque sensor, and the driving rotating shaft is positioned in a platform through hole arranged in the middle of the positioning platform; the torsional deformation / torque application system applies a controllable angle and rotation speed to the center of the annular soil sample while measuring the torque, or applies a controllable torque and torque speed change while measuring the angle.

[0014] The scheme is further as follows: the axial middle section of the rotating central axis is hollowed out with at least four pits at intervals around the circumference, and the outer edge of the middle section is formed by the connection between the four pits to form a cross-cross paddle plate, which is buried in the annular soil sample to be tested and is used to paddle the annular soil sample. The whole is a cross-plate rotating shaft with closed upper and lower ends.

[0015] The beneficial effects of the present invention are as follows: the movable rotating plate component composed of an improved rotating central axis and a concentric ring sleeve is adopted to overcome the interference problem of the upper and lower control ends of the sample on the radial shear, and the radial shear is uniformly changed. The device can realize vertical axial compression. σ z Greater than confining pressure σ r (= σ θ ) is used to measure the shear viscosity.

[0016] The invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the test assembly structure of the present invention. Figure 1 A magnified view of part A;

[0019] Figure 3 It is a schematic plan view of the inner side of the upper cover plate and the lower cap support plate with a movable rotating plate of the present invention;

[0020] Figure 4 It is a schematic cross-sectional view of the middle section of the rotating central axis of the present invention;

[0021] Figure 5 It is a water-gas pipeline connecting the confining pressure chamber and the sample of the present invention. DETAILED DESCRIPTION

[0022] Test device for measuring shear viscosity of sand under conventional triaxial stress state, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the test device includes a frame 1 and a formed annular soil sample 2 to be tested, as well as a vertical pressure / displacement control system, a torsional deformation / torque control system and a test component 9.

[0023] The vertical pressure / displacement control system includes a loading moving beam 3 arranged between the vertical support beams 101 on both sides of the frame 1, a guide rail 102 is arranged on the inner side of the vertical support beam 101, the loading moving beam 3 is pushed by the telescopic arm mechanism 4 to move vertically up and down along the guide rail 102, a vertical loading force and displacement sensor 5 is arranged between the telescopic arm 401 of the telescopic arm mechanism 4 and the loading moving beam 3, and a positioning platform 103 is arranged under the loading moving beam 3 of the frame 1, and a through hole is arranged in the center of the positioning platform 103.

[0024] The torsional deformation / torque control system includes a torsional reducer 6 arranged under the positioning platform 103 , and the upward shaft 601 of the torsional reducer 6 is connected to a driving shaft 8 through a torque sensor 7 , and the driving shaft 8 is positioned in a platform through hole arranged in the middle of the positioning platform 103 .

[0025] The annular soil sample 2 to be tested is compacted in advance on a test platform by a mold. The annular soil sample 2 to be tested has a vertical center hole. The outer circumference of the annular soil sample 2 to be tested is wrapped with a rubber film 202. The rubber film 202 is transferred by being put on the mold when the annular soil sample is made. After the mold is removed, the rubber film 202 is positioned to wrap the annular soil sample.

[0026] like Figure 1 , 2 and Figure 4As shown, a rotating central axis 201 is arranged in the center hole of the annular soil sample 2, and at least four pits 201-1 are hollowed out inward at intervals around the circumference in the axial middle section of the rotating central axis 201, and a cross-type dial plate 201-2 is formed by connecting the four pits 201-1 at the outer edge of the middle section. The dial plate 201-2 is buried in the measured annular soil sample and is used to move the annular soil sample 2. The rotating central axis 201 as a whole is a cross-plate rotating shaft with closed upper and lower ends.

[0027] The test assembly 9 is placed on the positioning platform to provide a test condition for the annular soil sample to withstand vertical stress, confining pressure and control the layered rotation deformation of the soil sample radially from the center to the outside. The test assembly 9 includes a closed confining pressure chamber 901, which is a transparent organic glass cover or a steel cover. The confining pressure chamber 901 buckles the platform through hole and is sealed and fixed to the positioning platform 103. A penetration hole is provided in the middle of the upper end surface of the confining pressure chamber 901. The tested annular soil sample 2 is placed in the confining pressure chamber 901. The center hole of the tested annular soil sample 2 is opposite to the platform through hole. An upper cover plate 903 is provided around the center hole on the upper end surface of the tested annular soil sample 2, and a lower cap support plate 904 is provided around the vertical hole on the lower end surface of the tested sample. The lower cap support plate 904 is positioned on the positioning platform 103. The upper cover plate 90 3 is provided with a pressure-bearing piston column 905 on the upper end surface, and the pressure-bearing piston column 905 extends from the through hole on the upper end surface of the confining pressure chamber 901 to bear the downward pressure of the moving beam 3 loaded by the vertical pressure / displacement control system, and the driving shaft 8 of the torsional deformation / torque control system extends from the through hole of the positioning platform 103 to connect the rotating central axis 201 in the center hole of the measured annular soil sample. The contact surface between the upper cover plate 903 and the lower cap support plate 904 and the measured annular soil sample is provided with a movable rotating plate 906 around the rotating central axis 201 of the center hole of the annular soil sample. The provision of the movable rotating plate 906 avoids the friction between the annular soil sample 2 and the upper cover plate 903 and the lower cap support plate 904 affecting the circumferential rotation of the sample, and in order to avoid the plane friction between the movable rotating plate 906 and the upper cover plate 903 and the lower cap support plate 904, as shown in FIG. Figure 1 , Figure 2 and Figure 3 As shown, the movable rotating plate 906 is composed of a plurality of circular ring sleeves 906-1 with different diameters arranged from the inside to the outside and connected together ( Figure 2 Only 10 laps are shown. Figure 3 Only 6 circles are shown, and the number of circles should be as many as possible under the processing conditions). An arc groove is arranged around the other end surface of the circular ring sleeve 906-1 opposite to the contact surface of the circular ring sleeve 906-1 and the annular soil sample, and a ball 906-2 lies in the circular arc groove. The circular ring sleeve 906-1 slides and rotates on the upper cover plate 903 and the lower cap support plate 904 through the ball 906-2. A plurality of raised ribs 906-3 are arranged at intervals between the contact surface of the circular ring sleeve 906-1 and the measured annular soil sample ( Figure 3Only one of each circular ring is shown in the figure), the ribs are embedded in the annular soil sample; the circular rings of different diameters arranged from the inside to the outside provide the conditions for the radial layered twisting of the annular soil sample from the inside to the outside, solving the interference problem of the upper and lower control ends on the radial shear.

[0028] The arrangement of the movable rotating plate 906 is shown in the figure, that is, an upper concave annular surface is arranged around the center hole of the annular soil sample on the contact surface between the upper cover plate and the soil sample to be tested, and a lower concave annular surface is arranged around the center hole of the annular soil sample on the contact surface between the lower cap support plate and the soil sample to be tested, and the upper / lower concave annular surface is connected with the center hole of the annular soil sample, and the movable rotating plate is placed in the upper / lower concave annular surface of the upper cover plate and the lower cap support plate; wherein: the width of the movable rotating plate accounts for one-half to two-thirds of the width of the upper cover plate and the lower cap support plate. In this way, the radially outer plane of the movable rotating plate 906 is used as a fixed non-rotating plate for the upper cover plate and the lower cap support plate.

[0029] During measurement, a control processor (not shown in the figure) controls the telescopic arm mechanism 4, the torsional reducer 6 and the water injection pressure valve (not shown in the figure). The control processor obtains the vertical load force sensor 5, the torque sensor 7 and the water injection pressure signal to measure the shear viscosity of the test sample under axisymmetric pressure.

[0030] The vertical pressure / displacement application system described in the embodiment applies pressure to the pressure-bearing piston column by loading the mobile beam, applies vertical pressure in a controllable vertical stress or strain state to the annular soil sample, and measures the vertical strain while controlling the vertical stress, or measures the vertical stress while controlling the vertical strain, by acquiring the signal of the vertical loading force and displacement sensor 5.

[0031] The torsional deformation / torque application system acquires the signal of the torque sensor 7, measures the torque while applying a controllable angle and rotation speed to the center of the annular soil sample, or measures the angle by setting an angle sensor on the rotating central axis 201 while applying a controllable torque and torque speed change.

[0032] In the embodiment: the driving shaft 8 is positioned in the platform through hole of the positioning platform 103 through the radial thrust bearing 801 and the rolling bearing 802, with the radial thrust bearing 801 on the top and the rolling bearing 802 on the bottom, so that the driving shaft 8 can rotate stably under a large driving torque.

[0033] In order to ensure the sealing of the confining pressure chamber 901: after the pressure-bearing piston column 905 passes through the upper end surface of the confining pressure chamber 901, a pressure ring 908 is used to cover the pressure-bearing piston column, and the "O"-shaped rubber sealing ring arranged on the inner side of the pressure ring 908 is used to seal the pressure-bearing piston column and the confining pressure chamber 901.

[0034] In order to test the soil samples under different conditions: an inlet and outlet water interface 902 is arranged on the lower end side wall of the confining pressure chamber 901, and a water outlet pressure relief port is arranged on the upper end. The inlet and outlet water interface 902 and the water outlet pressure relief port are used for water injection and pressurization and water discharge and pressure relief of the confining pressure chamber 901. A back pressure hole 10 is arranged on the upper cover plate, and a pore pressure hole 11 is arranged on the lower cap support plate. The back pressure hole and the pore pressure hole are opposite to each other or arranged alternately. When the confining pressure and back pressure are applied to the annular soil sample in the confining pressure chamber, the volume deformation and pore pressure of the annular soil sample are measured; the back pressure hole 10 and the pore pressure hole 11 are led out from the positioning platform 103.

[0035] In the embodiment: the confining pressure chamber and the water and gas pipelines for connecting the sample to the confining pressure, back pressure application and pore pressure and volume change measurement are as follows Figure 5 As shown in the figure, 902 is the water inlet and outlet interface of the confining pressure chamber, 10 is the back pressure hole, 11 is the hole pressure hole, the water supply pipeline includes a soil sample water tank 12, a soil sample ventilation tank 13, a water measuring pipe 14, a pressure controller 15, a confining pressure controller 16 and a water storage tank 17, the water source is injected into the water storage tank 17 through the water tank water injection port 18 and the water tank water inlet valve 19, and the water storage tank 17 is provided with a water tank pressure relief valve 20, and the water tank outlet is divided into two paths after passing through the first filter 21, one path passes through the first one-way valve 22 to the water inlet of the back pressure controller 15, and the other path passes through the second one-way valve 23 to the water inlet of the confining pressure controller 16;

[0036] The water outlet of the back pressure controller 15 is connected to the back pressure hole 10 of the upper cover plate of the tested sample through the back pressure control valve 24, and the water outlet of the back pressure controller 15 is connected to the water measuring pipe 14 and the sample drain valve 26 through the water measuring pipe control valve 25;

[0037] The water outlet of the confining pressure controller 16 is directly connected to the water inlet and outlet interface 902 of the confining pressure chamber 901, and the water inlet and outlet interface 902 of the confining pressure chamber 901 is connected to the water return port of the water storage tank 17 through the confining pressure chamber water return valve 27 and the second filter 28. A confining pressure chamber air release valve 29 is arranged at the top of the confining pressure chamber 901. The confining pressure chamber air release valve 29 is opened when the confining pressure chamber 901 is filled with water and is closed after the confining pressure chamber 901 is filled with water.

[0038] The water inlet of the soil sample water-passing tank 12 is connected to the pore pressure hole 11 of the lower cap support plate through the water flow regulating valve 30 and then through the pore pressure regulating valve 31, and the air inlet of the soil sample ventilation tank 13 is connected to the pipeline between the water flow regulating valve 30 and the pore pressure regulating valve 31 through the ventilation flow regulating valve 32; the existing pressure volume controller (such as TKA-PVC series pressure volume controller) can be used to realize the confining pressure, back pressure application and volume measurement functions, and the existing pore water pressure sensor (such as HC series) is used to connect the pore pressure hole 11 to realize the measurement of pore water pressure, and the pressure volume controller and the pore water pressure sensor belong to the existing technology.

[0039] The device of this embodiment is a testing equipment for megapascal pressure, so the telescopic arm mechanism for applying pressure adopts a screw drive mode, that is: the telescopic arm mechanism includes a sleeve 402 with an internal thread, the sleeve 402 is rotatably fixed on the frame 1 through a bearing, a screw as the telescopic arm 401 is arranged in the sleeve 402, the lower end of the screw is connected to the loading moving beam 3 through a vertical loading force sensor 5, and a driving motor 403 drives the sleeve 402 to rotate through a belt 404. Since the screw is connected to the loading moving beam 3 and cannot rotate, the rotating sleeve 402 drives the screw to move up and down, so that the loading moving beam is pushed by the telescopic arm mechanism to move vertically up and down along the guide rail; in the embodiment: in order to reduce the overall height of the device, the torsional reducer 6 of the torsional deformation / torque control system with a larger size at the lower part of the device is driven by a horizontal pulley transmission device.

[0040] In this embodiment, rotational shear is achieved by adding a rotating central axis to the center of the soil sample to connect the torsional deformation / torque control system. The upper cover plate and the lower cap support plate structure with a movable rotating plate overcome the interference problem of the upper and lower control ends on the radial shear, thereby realizing the measurement of the shear viscosity of sand under conventional triaxial stress state.

Claims

1. A test device for measuring the shear viscosity of sand under conventional triaxial stress state, comprising a frame, a vertical pressure / displacement control system, a torsional deformation / torque control system and a test assembly, wherein the frame is provided with a positioning platform, a through hole is provided in the center of the positioning platform, and the test assembly is placed on the positioning platform, characterized in that: The test assembly includes a closed confining pressure chamber, which buckles the platform through hole and is sealed and fixed to the positioning platform. The annular soil sample to be tested is placed in the confining pressure chamber, and the central hole of the annular soil sample is provided with a rotating central axis. An upper cover plate is provided around the central hole on the upper end surface of the annular soil sample, and a lower cap support plate is provided around the central hole on the lower end surface of the annular soil sample. The lower cap support plate is positioned on the positioning platform, and a pressure-bearing piston column is provided on the upper end surface of the upper cover plate. The pressure-bearing piston column extends from the upper end surface of the confining pressure chamber to bear the downward pressure of the vertical pressure / displacement control system, and the driving shaft of the torsional deformation / torque control system extends from the platform through hole. A rotating central axis is provided to connect the central hole of the annular soil sample. The upper cover plate and the lower cap support plate are provided with a movable rotating plate around the central hole of the annular soil sample at the contact surface with the annular soil sample. The movable rotating plate is composed of a plurality of circular rings of different diameters arranged in contact with each other from the inside to the outside. An arc groove is arranged around the other end surface opposite to the contact surface of the circular ring and the annular soil sample. A ball is laid in the circular arc groove arranged in the surrounding manner. The circular ring slides and rotates on the upper cover plate and the lower cap support plate through the ball. The circular rings of different diameters arranged in contact with each other from the inside to the outside provide conditions for the radial layered twisting of the annular soil sample from the inside to the outside. The contact surface between the upper cover plate and the soil sample to be tested is provided with an upper concave annular surface around the center hole of the annular soil sample, the contact surface between the lower cap support plate and the soil sample to be tested is provided with a lower concave annular surface around the center hole of the annular soil sample, the upper / lower concave annular surface is connected with the center hole of the annular soil sample, and the movable rotating plate is placed in the upper / lower concave annular surface of the upper cover plate and the lower cap support plate; The contact surface between the annular sleeve and the soil sample to be tested is provided with raised ribs, and the ribs are embedded in the annular soil sample; The axial middle section of the rotating central axis is hollowed out with at least four pits at intervals around the circumference, and the outer edge of the middle section is formed by the connection between the four pits to form a cross-cross paddle plate. The paddle plate is buried in the annular soil sample to be tested and is used to paddle the annular soil sample. The whole is a cross-plate rotating shaft with closed upper and lower ends.

2. The test device according to claim 1, characterized in that: After the pressure-bearing piston column passes through, the upper end surface of the confining pressure chamber is covered with a pressure ring to cover the pressure-bearing piston column, and the pressure-bearing piston column and the confining pressure chamber are sealed by an "O"-shaped rubber sealing ring arranged on the inner side of the pressure ring.

3. The test device according to claim 1, characterized in that: The confining pressure chamber is a transparent organic glass cover or a steel cover, and a water inlet and outlet interface is arranged on the side wall of the lower end of the confining pressure chamber, a water outlet pressure relief port is arranged on the upper end, a back pressure hole is arranged on the upper cover plate, and a hole pressure hole is arranged on the lower cap support plate; the back pressure hole and the hole pressure hole are arranged opposite to each other.

4. The test device according to claim 1, characterized in that: The vertical pressure / displacement control system includes a loading moving beam arranged on a frame, and the loading moving beam is pushed by a telescopic arm to move vertically up and down along a guide rail, and a vertical loading force and displacement sensor is arranged between the telescopic arm and the loading moving beam; the vertical pressure / displacement application system applies pressure to a pressure-bearing piston column through the loading moving beam, applies vertical pressure of a controllable vertical stress or strain state to the annular soil sample, and measures the vertical strain while controlling the vertical stress, or measures the vertical stress while controlling the vertical strain.

5. The test device according to claim 1, characterized in that: The torsional deformation / torque control system includes a torsional reducer arranged under the positioning platform, the upward rotating shaft of the torsional reducer is connected to a driving rotating shaft through a torque sensor, and the driving rotating shaft is positioned in a platform through hole arranged in the middle of the positioning platform; the torsional deformation / torque application system applies a controllable angle and rotation speed to the center of the annular soil sample while measuring the torque, or applies a controllable torque and torque speed change while measuring the angle.

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