Automatic drilling shear tester

Abstract

The utility model discloses an automatic drilling shear tester which comprises a normal stress loading device, a drilling shear measuring device, a vertical lifting operation device, a motor driving device, a circuit control device and an operation platform, the drilling shear measuring device comprises a shear probe, a pull rod, a shear displacement detection device and a normal displacement meter mounted on the shear probe; the normal stress loading device is used for providing compressed gas for a cylinder on the shearing probe; the vertical lifting operation device comprises a force transmission base, a sensor, a worm mechanism installed on the force transmission base, a worm gear connected with the worm mechanism and a hollow screw arranged in the worm gear and in threaded connection with the worm gear, the force transmission base is arranged at the upper end of the drill hole, and a pull rod clamp for clamping a pull rod is arranged at the top end of the hollow screw. A torsion arm is arranged on the pull rod clamp, and a bearing is arranged between the worm gear and the sensor. The device is high in automation degree, simple in operation and reasonable in design, and improves the accuracy and efficiency of testing.

Description

Technical Field

[0001] This utility model belongs to the field of in-situ testing technology in geotechnical engineering, and specifically relates to an automated borehole shear tester. Background Technology

[0002] The shear strength of soil has a significant impact on slope stability, and the internal friction angle and cohesion are important parameters of soil shear strength. The internal friction angle reflects the frictional resistance between particles within the soil or granular material, while cohesion reflects the bond strength between soil particles. The internal friction angle and cohesion can be determined through triaxial compression tests, direct shear tests, and in-situ borehole shear tests. In these tests, soil samples are subjected to shear forces under different normal stress levels until failure occurs. By analyzing the test data, the internal friction angle and cohesion of the soil can be determined. While in-situ borehole shear tests exist, they suffer from drawbacks such as long testing cycles, low automation, limited applicability, and cumbersome operation.

[0003] Existing borehole shearing instruments are complex to operate, susceptible to human error, and unable to maintain a stable shearing rate. They also have a low degree of automation and cannot detect the impact of shear rate on soil shear strength parameters. These limitations restrict experimental research. Therefore, there is an urgent market need for an automated borehole shearing instrument that is simple in structure, rationally designed, easy to operate, provides accurate testing, and minimizes human intervention. Summary of the Invention

[0004] This invention addresses the shortcomings of the prior art by providing a highly automated, simple, and rationally designed borehole shearing apparatus. Through simplified structure and optimized design, it makes operation more convenient, while improving the accuracy and efficiency of testing. By reducing manual operation steps, it reduces test errors caused by human factors, lowers labor intensity, and can also change the shearing rate to detect the influence of the shearing rate on the soil shear strength parameters, thus making great use of test resources.

[0005] The technical solution adopted in this utility model is: an automated borehole shear testing instrument, including a normal stress loading device, a borehole shear measuring device, a vertical lifting operation device, a motor drive device, a circuit control device, and an operating platform;

[0006] The borehole shear measuring device includes a shear probe that extends into the borehole, a tie rod connected to the shear probe, a shear displacement detection device mounted on the tie rod, and a normal displacement gauge mounted on the shear probe.

[0007] The normal stress loading device is used to supply compressed gas to the cylinder on the shear probe;

[0008] The vertical lifting operating device includes a force transmission base, a sensor, a worm gear mechanism mounted on the force transmission base, a worm wheel connected to the worm gear mechanism, and a hollow screw rod set inside the worm wheel and threadedly connected to the worm wheel. The force transmission base is set at the upper end of the borehole. A pull rod clamp is set at the top of the hollow screw rod to clamp the pull rod. A torque arm is set on the pull rod clamp. A bearing is set between the worm wheel and the sensor. The pull rod passes through the sensor, the bearing, the hollow screw rod, and the pull rod clamp in sequence.

[0009] The worm gear mechanism includes two worm mounting seats mounted in parallel on the force transmission base, a worm mounted between the two worm mounting seats, and the worm meshing with a worm wheel; a motor drive device is connected to the worm and drives the worm to rotate.

[0010] The circuit control device includes a power supply, a micro switch, a power-on timer, and a potentiometer. The power supply, power switch, power-on timer, potentiometer, micro switch, and motor are connected in sequence to form a circuit.

[0011] Preferably, the normal stress loading device includes an electric air pump, a pressure regulator, a high-pressure air pipe, and a cylinder connected to the pressure regulator. The cylinder drives the shear probe to extend and retract. The pressure regulator is equipped with a knob and a pressure gauge. The pressure regulator is installed between the electric air pump and one end of the high-pressure air pipe, and the other end of the high-pressure air pipe is connected to the cylinder.

[0012] Preferably, the shearing probe includes a first shearing plate, a second shearing plate, a first steel plate mounted above the first shearing plate, a second shearing plate mounted above the second shearing plate, and an arc-shaped connector connecting the first steel plate and the second shearing plate; the first steel plate and the second shearing plate are parallel to each other, and the arc-shaped connector is connected to the pull rod;

[0013] The cylinder and the normal displacement gauge are both installed between the first shear plate and the second shear plate. One end of the cylinder and one end of the normal displacement gauge are connected to one side of the first shear plate. The other end of the cylinder is equipped with a baffle, and the baffle and the other end of the normal displacement gauge are both connected to one side of the second shear plate.

[0014] Preferably, one end of the worm gear is provided with a threaded portion, and the motor drive device includes a motor and a sprocket device. The sprocket device includes a driving wheel mounted on the output shaft of the motor and a driven wheel mounted on the threaded portion at one end of the worm gear. The driving wheel and the driven wheel are connected by a chain.

[0015] Preferably, the shear displacement detection device includes a fixed clamp, with the upper part of the pull rod passing through the fixed clamp. A first adjustment knob is provided on one side of the fixed clamp, and a connecting rod is provided on the other side of the fixed clamp. A fixing ring is provided at the end of the connecting rod away from the fixed clamp, and a second adjustment knob is provided on one side of the fixing ring. A shear displacement meter is installed inside the fixing ring, and the movable end of the shear displacement meter is in contact with the operating platform.

[0016] Preferably, the micro switch includes an operating lever, a drive lever connected to the operating lever, and a contact lever connected to the drive lever. The contact lever is fixedly connected to the negative terminal of the micro switch and is in contact with a first positive terminal or a second positive terminal. The negative terminal of the micro switch is connected to the positive terminal of the motor, the first positive terminal is connected to a potentiometer, and the micro switch is mounted on a support.

[0017] Preferably, the potentiometer has a knob and scale lines on its top. The knob extends out of the circuit control box and has indicator lines corresponding to the scale lines. The indicator lines display the current resistance of the potentiometer. The resistance of the potentiometer is changed by rotating the knob to change the position of the rotating rod. The potentiometer has a left pin, a right pin, and a middle pin. The middle pin is fixedly connected to the rotating rod. The left pin is connected to the negative terminal of the energized timer, and the middle pin is connected to the first positive terminal of the micro switch.

[0018] The beneficial effects of this utility model are:

[0019] 1. Compared with the existing technology, this borehole shear testing instrument is equipped with a normal stress loading device to load the normal stress on the shear probe, and the magnitude of the normal stress is controlled by an air pressure regulator, which improves the accuracy of normal stress loading.

[0020] 2. Compared with existing technologies, this borehole shear tester is equipped with a potentiometer, i.e., a variable resistor. By changing the current in the circuit, the power of the motor is changed, thereby changing the shear rate of the test. This allows for the study of the influence of different shear rates on the shear strength parameters of soil, thus expanding the application range of the test instrument.

[0021] 3. Compared with existing technologies, this borehole shear testing instrument is equipped with a micro switch. When the shear displacement gauge reaches the specified displacement, the connecting rod of the shear displacement gauge touches the operating rod of the micro switch, the switch is automatically turned off, and the motor automatically stops working, which improves the automation of the test and reduces the effort required for the operator to observe the displacement gauge.

[0022] 4. Compared with the prior art, this utility model is equipped with a weighing sensor and a shear displacement gauge to obtain the shear stress value and shear displacement of the shear probe. In addition, a pressure gauge is set to obtain the normal loading stress value, which facilitates the obtaining of the shear strength parameters of the soil. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model.

[0024] Figure 2 This is a schematic diagram of the structure of the shear probe, pull rod, shear displacement gauge and data acquisition instrument of this utility model.

[0025] Figure 3 This is a schematic diagram of the worm gear and worm device of this utility model.

[0026] Figure 4 This is a schematic diagram of the micro switch used in this utility model.

[0027] Figure 5 This is a schematic diagram of the external structure of the potentiometer used in this utility model.

[0028] Figure 6 This is a schematic diagram of the internal workings of the potentiometer used in this utility model.

[0029] Figure 7 This is the circuit schematic diagram of this utility model.

[0030] Figure 8 This is a schematic diagram illustrating the working principle of this utility model.

[0031] In the diagram: 1. Shearing probe; 1-1. First shearing plate; 1-2. Second shearing plate; 1-3. First steel sheet; 1-4. Second steel sheet; 1-5. Arc-shaped connector; 2. Drill hole; 3. Tie rod; 4. Cylinder; 4-1. Baffle; 5. Normal displacement gauge; 6. Tie rod clamp; 7. Worm gear; 8. Bearing; 9. Sensor; 10. Force transmission base; 11. Operating platform; 12. Shearing displacement detection device; 12-1. First adjusting knob; 12-2. Fixing ring; 12-3. Connecting rod; 12-4. Fixing clamp; 12-5. Second adjusting knob; 12-6. Moving end; 13. Electric air pump; 13-1. Pressure gauge; 14. Air pressure regulator; 14-1. Air pressure adjusting knob; 14-2. Air pressure gauge; 15. High-pressure air hose; 16. Geotechnical mechanics data acquisition instrument; 17. Worm gear mounting base; 17-1. 17-2 Worm gear, threaded part, 17-3 Torque arm, 17-4 Worm gear mounting base, 18 Motor, 19 Chain, 19-1 Driven wheel, 19-2 Driving wheel, 20 Current control box, 20-1 Glass window, 21 Power-on timer, 21-1 Zero button, 22 Potentiometer, 22-1 Resistance adjustment knob, 22-2 Guide line, 22-3 Scale line, 22- 4. Left pin; 22-5. Middle pin; 22-6. Right pin; 22-7. Rotating rod; 23. Micro switch; 23-1. Operating rod; 23-2. Drive rod; 23-3. Negative terminal; 23-4. First positive terminal; 23-5. Second positive terminal; 23-6. Contact rod; 24. Power supply; 25. Power switch; 25-1. Switch button; 26. Foam board; 27. Bearing; 28. Support. Detailed Implementation

[0032] like Figures 1 to 8 As shown, this utility model includes a normal stress loading device, a drilling shear measuring device, a vertical lifting operation device, a motor drive device, a circuit control device, and an operation platform 11.

[0033] The normal stress loading device includes an electric air pump 13, an air pressure regulator 14, a high-pressure air pipe 15, and a cylinder 4 connected to the air pressure regulator. The cylinder 4 can drive the shear probe 1 to extend and retract, thereby compressing the drilled hole 2. The electric air pump 13 is equipped with a pressure gauge 13-1, which is used to monitor the air pressure inside the electric air pump 13. The air pressure regulator 14 is equipped with a knob 14-1, which can be used to adjust the air pressure output by the electric air pump 13. The air pressure regulator 14 is equipped with a pressure gauge 14-2, which can display the output air pressure value. The air pressure regulator 14 is installed between the electric air pump 13 and one end of the high-pressure air pipe 15, and the other end of the high-pressure air pipe 15 is connected to the cylinder 4.

[0034] The borehole shear measuring device includes a shear probe 1 that extends into the borehole 2, a pull rod 3 connected to the shear probe 1, a shear displacement detection device 12 mounted on the pull rod 3, and a normal displacement gauge 5 mounted on the shear probe 1.

[0035] The vertical lifting operating device includes a force transmission base 10, a sensor 9, a worm gear mechanism mounted on the force transmission base 10, a worm wheel 7 connected to the worm gear mechanism, and a hollow screw 27 set inside the worm wheel 7 and threadedly connected to the worm wheel 7. The force transmission base 10 is set at the upper end of the borehole 2. A pull rod clamp 6 is set at the top of the hollow screw 27 to clamp the pull rod 3. A torque arm 17-3 is set on the pull rod clamp 6. A bearing 30 is set between the worm wheel 7 and the sensor 9. The pull rod 3 passes through the sensor 9, the bearing 8, the hollow screw 27, and the pull rod clamp 6 in sequence.

[0036] like Figure 3 As shown, the worm gear mechanism includes two worm gear mounting seats 17-4 mounted parallel to each other on the force transmission base 10, and a worm 17-1 mounted between the two worm gear mounting seats 17-4. The worm 17-1 meshes with the worm wheel 7. The worm 17-1 and the worm gear mounting seats 17-4 are rotatably engaged. One end of the worm 17-1 extends out of the worm gear mounting seat 17-4 and is provided with a threaded portion 17-2 at that end.

[0037] The motor drive device includes a motor 18 and a sprocket assembly. The sprocket assembly includes a drive wheel 19-2 mounted on the output shaft of the motor 18 and a driven wheel 19-1 mounted on the threaded portion 17-2 at one end of the worm gear 17-1. The drive wheel 19-2 and the driven wheel 19-1 are connected by a chain 19.

[0038] like Figure 2As shown, the shearing probe 1 includes a first shearing plate 1-1, a second shearing plate 1-2, a first steel plate 1-3 mounted above the first shearing plate 1-1, a second shearing plate 1-4 mounted above the second shearing plate 1-2, and an arc-shaped connector 1-5 connecting the first steel plate 1-3 and the second shearing plate 1-2. The first steel plate 1-3 and the second shearing plate 1-2 are parallel to each other, and the arc-shaped connector 1-5 is connected to the pull rod 3.

[0039] The cylinder 4 and the normal displacement gauge 5 are both installed between the first shear plate 1-1 and the second shear plate 1-2. One end of the cylinder 4 and one end of the normal displacement gauge 5 are connected to one side of the first shear plate 1-1. The other end of the cylinder 4 is provided with a baffle 4-1. The baffle 4-1 and the other end of the normal displacement gauge 5 are both connected to one side of the second shear plate 1-2.

[0040] like Figure 2 As shown, the shear displacement detection device 12 includes a fixed clamp 12-2, the upper part of the pull rod 3 passes through the fixed clamp 12-2, a first adjustment knob 12-1 is provided on one side of the fixed clamp 12-2, a connecting rod 12-3 is provided on the other side of the fixed clamp 12-2, a fixing ring 12-4 is provided at the end of the connecting rod 12-3 away from the fixed clamp 12-2, a second adjustment knob 12-5 is provided on one side of the fixing ring 12-4, a shear displacement gauge is installed inside the fixing ring 12-4, and the movable end 12-6 of the shear displacement gauge is in contact with the operating platform 11.

[0041] The circuit control device includes a power supply 24, a power switch 25, a micro switch 23, and a circuit control box 20. The circuit control box 20 contains a circuit board 25, a power-on timer 21, a foam board 26, and a potentiometer 22 embedded in the foam board 26.

[0042] like Figure 7 As shown, power supply 24, power switch 25, power timer 21, potentiometer 22, micro switch 23, and motor 18 are connected in sequence to form a circuit.

[0043] The power switch 25 is equipped with a switch button 25-1, which controls the circuit to turn on and off by operating the switch button 25-1. The potentiometer 22 is embedded in the reserved hole in the foam board 26 to ensure that it will not slip when adjusting the potentiometer 22. The power-on timer 21 has a zeroing button 21-1. The circuit controller 20 is equipped with a glass window 20-1 corresponding to the power-on timer 21, through which the time of the power-on timer 21 can be observed.

[0044] like Figures 5 to 6As shown, potentiometer 22 has a knob 22-1 and a scale line 22-3 on its upper part. Knob 22-1 extends out of the circuit control box 20. Knob 22-1 has an indicator line 22-2 corresponding to the scale line 22-3. The indicator line 22-2 displays the current resistance of potentiometer 22. Rotating knob 22-1 changes the position of rotating rod 22-7 to change the resistance of potentiometer 22, thereby changing the current in the circuit. Potentiometer 22 has a left pin 22-4, a right pin 22-6, and a middle pin 22-5. The middle pin 22-5 is fixedly connected to the rotating rod 22-7. In this invention, the left pin 22-4 is connected to the negative terminal of the power-on timer 21, and the middle pin 22-5 is connected to the first positive terminal 23-4 of the micro switch 23.

[0045] In this practical application, the resistance is adjusted by rotating the knob 22-1 on the potentiometer 22, which in turn adjusts the current in the circuit. Changing the current adjusts the operating power and speed of the motor 18. A change in motor speed alters the upward movement speed of the pull rod 3, thus changing the shear rate of the shear probe 1. The shear rate of the shear probe 1 can be obtained by comparing the displacement elongated by the shear displacement detection device 12 with the time displayed on the energized timer 21. By measuring the shear strength and shear strength parameters of the soil at different shear rates, the influence of shear rate on the shear strength of the soil can be studied.

[0046] like Figure 4 As shown, the micro switch 23 includes an operating lever 23-1, a drive lever 23-2 connected to the operating lever 23-1, and a contact lever 23-6 connected to the drive lever 23-1. The contact lever 23-6 is fixedly connected to the negative terminal 23-3 of the micro switch 23, and the contact lever 23-6 is in contact with either the first positive terminal 23-4 or the second positive terminal 23-5. In this invention, the negative terminal 23-3 of the micro switch 23 is connected to the positive terminal of the motor 18, and the first positive terminal 23-4 is connected to the middle pin 22-5 of the potentiometer 22. The micro switch 23 is mounted on the support 28.

[0047] like Figure 1 and Figure 3 As shown, after the motor 18 is powered on, the motor 18 rotates, driving the drive wheel 19-2 to rotate. The drive wheel 19-2 drives the driven wheel 19-1 to rotate via the chain 19. The driven wheel 19-1 drives the worm 17-1 to rotate. The worm 17-1 drives the worm wheel 7 to rotate. Under the limit of the torque arm 17-3 and the pull rod clamp 6, the rotation of the worm wheel 7 is converted into the upward movement of the hollow screw 27. The hollow screw 27 drives the pull rod clamp 6 to move upward, which in turn drives the pull rod 3 to move upward. As a result, the shear probe 1 also moves upward. The shear displacement detection device 12 extends, and the shear displacement can be obtained.

[0048] The lever clamp 6 has a limiting groove, through which the lever 3 passes. The cross-section of the part of the lever 3 that mates with the lever clamp 6 is consistent with the cross-section of the limiting groove. The shape of the limiting groove 6 is as follows: Figure 3 As shown. Under the restriction of the lever clamp 6, the lever 3 can only move up and down and cannot rotate around its own central axis.

[0049] In this invention, sensor 9 is a force sensor.

[0050] like Figure 2 and Figure 4 As shown, when the pull rod 3 moves upward, the shear displacement detection device 12 extends to the expected displacement. The connecting rod of the shear displacement detection device 12 will touch the operating rod 23-1 of the micro switch 23. The operating rod 23-1 drives the drive rod 23-2 to move upward. The upward movement of the drive rod 23-2 will cause the contact rod 23-6 to rotate, so that the contact rod 23-6 is disconnected from the positive terminal 1 23-4 and connected to the positive terminal 2 23-5, thereby realizing the circuit power failure. After the circuit is broken, the motor 18 stops rotating, and the pull rod 3 also stops moving.

[0051] In this invention, the output end of sensor 9 is connected to the longitudinal force input end of the geotechnical mechanics data acquisition instrument 16. The force experienced by the upward movement of the pull rod 3 is input to the data acquisition instrument 16 through sensor 9. The geotechnical mechanics data acquisition instrument 16 can obtain the shear force value. The shear stress can be obtained by comparing the shear force with the effective area of ​​the first shear plate 1-1 and the second shear plate 1-2 in the shear probe 1. The output end of the shear displacement detection device 12 is connected to the longitudinal displacement input end of the geotechnical mechanics data acquisition instrument 16. The shear stress-displacement relationship curve can be obtained. The output end of the normal displacement gauge 5 is connected to the lateral displacement input end of the data acquisition instrument 16. The normal stress value can be calculated based on the pressure value displayed by the pressure gauge 14-2 in the pressure regulator 14. Thus, the relationship curve between normal displacement and normal stress can be obtained.

[0052] The geotechnical mechanics data acquisition instrument 16 used in this utility model adopts existing technology. The structure and principle of the geotechnical mechanics data acquisition instrument 16 can be referred to the invention patent with publication number CN100394459C and invention name "Multi-window data acquisition instrument for geotechnical mechanics test".

Claims

1. An automated borehole shear testing instrument, characterized in that, It includes a normal stress loading device, a drilling shear measuring device, a vertical lifting operation device, a motor drive device, a circuit control device, and an operating platform (11). The borehole shear measuring device includes a shear probe (1) that extends into the borehole (2), a pull rod (3) that connects to the shear probe (1), a shear displacement detection device (12) mounted on the pull rod (3), and a normal displacement gauge (5) mounted on the shear probe (1). The normal stress loading device is used to provide compressed gas to the cylinder (4) on the shear probe (1); the normal stress loading device includes an electric air pump (13), a pressure regulator (14), a high-pressure air pipe (15), and a cylinder (4) connected to the pressure regulator. The cylinder (4) drives the shear probe (1) to extend and retract. The pressure regulator (14) is equipped with a pressure adjustment knob (14-1) and a pressure gauge (14-2). The pressure regulator (14) is installed between the electric air pump (13) and one end of the high-pressure air pipe (15), and the other end of the high-pressure air pipe (15) is connected to the cylinder (4). The vertical lifting operation device includes a force transmission base (10), a sensor (9), a worm gear mechanism mounted on the force transmission base (10), a worm wheel (7) connected to the worm gear mechanism, and a hollow screw (27) set inside the worm wheel (7) and threadedly connected to the worm wheel (7). The force transmission base (10) is set at the upper end of the borehole (2). A pull rod clamp (6) for clamping the pull rod (3) is set at the top of the hollow screw (27). A torque arm (17-3) is set on the pull rod clamp (6). A bearing (8) is set between the worm wheel (7) and the sensor (9). The pull rod (3) passes through the sensor (9), the bearing (8), the hollow screw (27), and the pull rod clamp (6) in sequence. The worm gear mechanism includes two worm gear mounting seats (17-4) mounted in parallel on the force transmission base (10), a worm (17-1) mounted between the two worm gear mounting seats (17-4), the worm (17-1) meshing with the worm wheel (7); a motor drive device is connected to the worm (17-1) and drives the worm to rotate; The circuit control device includes a power supply (24), a micro switch (23), a power-on timer (21), and a potentiometer (22). The power supply (24), power switch (25), power-on timer (21), potentiometer (22), micro switch (23), and motor (18) are connected in sequence to form a circuit. The micro switch (23) includes an operating lever (23-1), a drive lever (23-2) connected to the operating lever (23-1), and a contact lever (23-6) connected to the drive lever (23-2). The contact lever (23-6) is fixedly connected to the negative terminal (23-3) of the micro switch (23). The contact lever (23-6) is in contact with the first positive terminal (23-4) or the second positive terminal (23-5). The negative terminal (23-3) of the micro switch (23) is connected to the positive terminal of the motor (18). The first positive terminal (23-4) is connected to the potentiometer (22). The micro switch (23) is mounted on a support (28). Above the potentiometer (22) is a resistance adjustment knob (22-1) and a scale line (22-3). The resistance adjustment knob (22-1) Extend the circuit control box (20). The resistance adjustment knob (22-1) is equipped with an index line (22-2) corresponding to the scale line (22-3). The index line (22-2) displays the current resistance of the potentiometer (22). By rotating the resistance adjustment knob (22-1), the position of the rotating rod (22-7) is changed to change the resistance of the potentiometer (22). The potentiometer (22) is equipped with a left pin (22-4), a right pin (22-6), and a middle pin (22-5). The middle pin (22-5) is fixedly connected to the rotating rod (22-7). The left pin (22-4) is connected to the negative terminal of the power-on timer (21), and the middle pin (22-5) is connected to the first positive terminal (23-4) of the micro switch (23).

2. The automated borehole shear testing apparatus according to claim 1, characterized in that, The shearing probe (1) includes a first shearing plate (1-1), a second shearing plate (1-2), a first steel plate (1-3) installed above the first shearing plate (1-1), a second shearing plate (1-2) installed above the second shearing plate (1-2), and an arc-shaped connector (1-5) connecting the first steel plate (1-3) and the second shearing plate (1-2); the first steel plate (1-3) and the second shearing plate (1-2) are parallel to each other, and the arc-shaped connector (1-5) is connected to the pull rod (3); The cylinder (4) and the normal displacement gauge (5) are both installed between the first shear plate (1-1) and the second shear plate (1-2). One end of the cylinder (4) and one end of the normal displacement gauge (5) are connected to one side of the first shear plate (1-1). The other end of the cylinder (4) is provided with a baffle (4-1). The other end of the baffle (4-1) and the other end of the normal displacement gauge (5) are both connected to one side of the second shear plate (1-2).

3. The automated borehole shear testing apparatus according to claim 1, characterized in that, One end of the worm (17-1) is provided with a threaded part (17-2). The motor drive device includes a motor (18) and a sprocket device. The sprocket device includes a drive wheel (19-2) mounted on the output shaft of the motor (18) and a driven wheel (19-1) mounted on the threaded part (17-2) at one end of the worm (17-1). The drive wheel (19-2) and the driven wheel (19-1) are connected by a chain (19).

4. The automated borehole shear testing apparatus according to claim 1, characterized in that, The shear displacement detection device (12) includes a fixed clamp (12-2), the upper part of the pull rod (3) passes through the fixed clamp (12-2), a first adjustment knob (12-1) is provided on one side of the fixed clamp (12-2), a connecting rod (12-3) is provided on the other side of the fixed clamp (12-2), a fixed ring (12-4) is provided at the end of the connecting rod (12-3) away from the fixed clamp (12-2), a second adjustment knob (12-5) is provided on one side of the fixed ring (12-4), a shear displacement meter is installed in the fixed ring (12-4), and the movable end (12-6) on the shear displacement meter is in contact with the operating platform (11).

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