In-situ direct shear test equipment, test system and use method

Abstract

The invention belongs to the technical field of outdoor field in-situ direct shear tests, and discloses in-situ direct shear test equipment, a test system and a use method, the equipment comprises a base, and a shear clamp is arranged at the top of a fixed clamp; through holes are formed in four corners of the fixing clamp and the shearing clamp; a clamp sliding groove is formed in the bottom face of the shearing clamp. A clamp rolling ball is arranged in the clamp sliding groove. A first pressing plate is arranged at the top of the shearing clamp, a second pressing plate is arranged at the top of the first pressing plate, and a pressure plate sliding groove is formed in the bottom of the second pressing plate; a pressure plate rolling ball is arranged in the pressure plate sliding groove. Supporting frames are arranged on the base on the outer sides of four corners of the fixing clamp; a vertical load simulation loading mechanism is arranged at the top of the support frame; a shearing force load simulation loading mechanism is arranged on a supporting body on the right side of the fixing clamp and the shearing clamp. The device is small in occupied space, convenient to carry and transfer and capable of adapting to field direct shearing in various geological environments.

Description

Technical Field

[0001] This invention belongs to the field of outdoor in-situ direct shear testing technology, specifically relating to an in-situ direct shear testing device, testing system, and method of use. Background Technology

[0002] Accurate determination of the shear strength parameters of soil and rock masses is of great significance in geotechnical engineering construction. The direct shear test, also known as the direct shear test, is a test used in geomechanics to determine the shear strength of soil. It is based on Coulomb's law, which states that the internal friction force of soil is proportional to the normal pressure on the shear surface. During the test, the sample is placed in a shear box, with the lower box fixed and the upper box sliding horizontally. First, a vertical pressure is applied, then horizontal shear forces are gradually applied to the upper box until the sample fails. The shear strength of the soil is then determined by collecting test data throughout the process.

[0003] Currently, most commonly used equipment for related geotechnical tests is a large, integrated direct shear apparatus. In contrast, the large direct shear apparatus of this invention has a simple structure and a high degree of modularity, overcoming the shortcomings of existing large direct shear apparatuses such as heavy weight and high cost. It has advantages such as miniaturization and lightweight, and can also better control test conditions to more accurately determine the mechanical properties of the soil, improving the reliability of the large direct shear apparatus in the field and the convenience of test operation. In addition, many devices cannot achieve precise pressure application and accurate data collection.

[0004] Chinese patent publication number CN115541411A, entitled "A Large-Scale Flexible Boundary Direct Shear Test System for Studying Shear Behavior of Soil and Rock Mass," includes a rigid frame, a shear box, a horizontal loading system, a vertical loading system, a flexible boundary control system, and a computer monitoring and management system. This direct shear test system uses a square shear box, larger than those in traditional medium and small-sized direct shear test systems. A small metal box with a latex film is placed at the bottom of the shear box to realistically reproduce the flexible boundary conditions during deformation, instability, and failure of soil and rock mass. However, this patent application's shear test system is inconvenient to disassemble, assemble, and transport, making in-situ shear testing difficult. Summary of the Invention

[0005] In order to overcome the problems existing in the prior art, the purpose of this invention is to provide an in-situ direct shear test device, test system and usage method, which can be easily disassembled and assembled, and the overall device occupies little space, making it easy to carry and transfer. It gets rid of the drawbacks of traditional outdoor in-situ direct shear tests, and the overall device is small and can adapt to various geological environments for on-site direct shear.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An in-situ direct shear testing device includes: a base, one side of which has a through hole, and the other side of which has a support body; a fixing clamp is installed above the through hole, and a shear clamp is provided on top of the fixing clamp; both the fixing clamp and the shear clamp have through holes; a clamp groove is provided on the top surface of the fixing clamp or the bottom surface of the shear clamp, and a clamp ball is provided in the clamp groove; a first pressure plate is provided on top of the shear clamp, and a second pressure plate is provided on top of the first pressure plate; a pressure plate groove is provided on the top of the first pressure plate or the bottom of the second pressure plate; a pressure plate ball is provided in the pressure plate groove; a support frame is provided on the base outside the fixing clamp; a vertical load simulation loading mechanism is provided on top of the support frame; and a shear load simulation loading mechanism is provided on the support body.

[0007] Optionally, the base is provided with a fixing clamp connector and a support frame connector; the fixing clamp is connected to the fixing clamp connector; and the support frame is connected to the support frame connector.

[0008] Optionally, the base is provided with a support mounting hole, and the support is mounted on the support mounting hole.

[0009] Optionally, a pressure plate is provided on the top of the second pressure plate.

[0010] Optionally, a force transmission rod is provided on the side of the shear load simulation loading mechanism, and a pressure block is provided at the end of the force transmission rod, the end of the pressure block cooperating with the side of the shear fixture.

[0011] Optionally, the base plate has a ground anchor hole on its edge, and a ground anchor is installed in the ground anchor hole. One end of the ground anchor has a ground anchor head, and a detachable handle is installed on the ground anchor head. The handle has a ground anchor head slot that matches the ground anchor head.

[0012] Optionally, the top surface of the fixing fixture and the bottom surface of the shearing fixture are both provided with fixture grooves, and the fixture ball is movably placed in the fixture grooves; the top of the first pressure plate and the bottom of the second pressure plate are both provided with pressure plate grooves; the pressure plate ball is movably placed in the pressure plate grooves.

[0013] Optionally, a ball bearing hole is provided on one of the top surface of the fixing fixture or the bottom surface of the shearing fixture, and a fixture groove is provided on the other surface, wherein the fixture ball bearing is movably embedded in the ball bearing hole of the fixture groove; a ball bearing hole is provided on one of the top surface of the first pressure plate or the bottom surface of the second pressure plate, and a pressure plate groove is provided on the other surface, wherein the pressure plate ball bearing is movably embedded in the ball bearing hole of the pressure plate groove.

[0014] An in-situ direct shear test system includes an in-situ direct shear test device and a data acquisition system, wherein the data acquisition system includes a pressure sensor and a displacement sensor.

[0015] The method of using the in-situ direct shear testing equipment includes the following steps: S1: Obtain soil samples from the area to be measured; S2: Loosely fit the base through hole of the base onto the soil sample, and install the fixing clamp and shearing clamp so that the fixing clamp and shearing clamp are loosely fitted onto the soil sample; S3: Vertical pressure is applied to the soil sample by simulating the loading mechanism through vertical load; shear force is applied to the soil sample by simulating the loading mechanism through shear load pushing the shear clamp.

[0016] Compared with the prior art, the present invention has the following beneficial effects: Compared to other field equipment, this invention is not only easier to disassemble and assemble, but also occupies less space, making it easier to carry and transfer. It overcomes the drawbacks of traditional outdoor in-situ direct shear tests, and its compact size allows it to adapt to various geological environments for direct shearing. Through testing, soil sample deformation data during the shearing process can be obtained, allowing for the analysis of the corresponding mechanical properties.

[0017] This invention improves the modularity of the overall equipment, making it easy to disassemble, assemble, and transport. It solves the problems of inaccurate horizontal and vertical loading, unloading or stress concentration during normal pressure application leading to inaccurate test results, and instability during horizontal pressure application. It reduces friction between clamps and solves the problem of high friction between pressure plates affecting test accuracy. It reduces the space required for the overall equipment and enhances adaptability to environmental conditions. The components of this device are detachable, small in size and weight, and can prevent injury during assembly, disassembly, and transportation. Attached Figure Description

[0018] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the base of the present invention; Figure 3 This is a schematic diagram of the ground anchor of the present invention; Figure 4 This is a schematic diagram of the throttle of the present invention; Figure 5 This is a schematic diagram of the support frame of the present invention; Figure 6 This is a schematic diagram of the installation of the support frame and base of the present invention; Figure 7 This is a schematic diagram of the fixing clamp of the present invention; Figure 8 This is a schematic diagram of the shearing fixture of the present invention; Figure 9 This is a schematic diagram of the ball bearing fixture of the present invention; Figure 10 This is a schematic diagram of the first pressure plate of the present invention; Figure 11 This is a schematic diagram of the pressure plate rolling ball of the present invention; Figure 12 This is a schematic diagram of the second pressure plate of the present invention; Figure 13 This is a structural diagram of the test system of the present invention; The components include: 1. Base; 11. Ground anchor hole; 12. Support body mounting hole; 13. Fixing clamp connector; 2. Support frame; 201. Top frame; 21. Support frame connector; 22. Connector; 23. Tail connecting groove; 3. Fixing clamp; 301. Clamp slide groove; 302. Clamp ball; 31. Fixing clamp through hole; 32. Clamp ball; 33. Handle; 4. Shearing clamp; 41. Shearing clamp hole; 5. Vertical load simulation loading mechanism; 51. First pressure plate; 501. Pressure plate ball; 502. Pressure plate slide groove; 52. Second pressure plate; 53. Pressure plate; 6. Shear load simulation loading mechanism; 60. Support body; 61. Force transmission rod; 62. Pressure block; 7. Ground anchor; 71. Ground anchor head; 72. Ground anchor head slot; 73. Turning handle. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0020] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] The present invention will now be described in detail with reference to the accompanying drawings.

[0023] like Figure 1 As shown, an in-situ direct shear testing device of the present invention includes: a base 1, wherein a base through hole 101 is formed on one side of the base 1 and a support body 60 is installed on the other side; a fixing clamp 3 is installed above the base through hole 101, and a shearing clamp 4 is provided on the top of the fixing clamp 3; both the fixing clamp 3 and the shearing clamp 4 have through holes; a clamp groove 301 is formed on the top surface of the fixing clamp 3 or the bottom surface of the shearing clamp 4, and a clamping ball 30 is provided in the clamp groove 301. 2; The top of the shearing fixture 4 is provided with a first pressure plate 51, the top of the first pressure plate 51 is provided with a second pressure plate 52, and a pressure plate groove 502 is provided on the top of the first pressure plate 51 or the bottom of the second pressure plate 52; a pressure plate ball 501 is provided in the pressure plate groove 502; a support frame 2 is provided on the base 1 outside the fixed fixture 3; a vertical load simulation loading mechanism 5 is provided on the top of the support frame 2; a shear load simulation loading mechanism 6 is provided on the support body 60.

[0024] Pressure sensors, load measuring devices, and displacement measuring devices are installed on both the shear load simulation loading mechanism 6 and the vertical load simulation loading mechanism 5 to ensure accurate data collection.

[0025] An in-situ direct shear testing device of the present invention includes the following steps in use: S1: Obtain soil samples from the area to be measured; S2: Place the base through hole 101 of the base 1 onto the soil sample, and install the fixing clamp 3 and the shearing clamp 4 so that the fixing clamp 3 and the shearing clamp 4 are loosely placed on the soil sample. S3: Vertical pressure is applied to the soil sample by the vertical load simulation loading mechanism 5; shear force is applied to the soil sample by the shear load simulation loading mechanism 6 pushing the shear clamp 4.

[0026] Based on existing outdoor in-situ direct shear test standards, this invention designs the overall structure of the device to facilitate disassembly, assembly, and transportation, while reducing friction and optimizing the overall equipment while ensuring safety.

[0027] Example 1 An in-situ direct shear test device of the present invention includes a base 1, wherein the plate edge of the base 1 is provided with ground anchor holes 11. A base through hole 101 is provided on one side of the base 1 for loosely fitting onto a soil sample.

[0028] Specifically, the base 1 is a rectangular plate, and four anchor holes 11 are equidistantly arranged along a straight line on one of the opposite sides of the base 1.

[0029] Specifically, the base 1 adopts an integrated structure, which has good bending and torsional strength.

[0030] An anchor 7 is installed on the anchor hole 11. One end of the anchor 7 has an anchor head 71. A handle 73 is detachably installed on the anchor head 71. The handle 73 has an anchor head groove 72 that matches the anchor head 71. Specifically, the anchor head 71 is a hexagonal prism.

[0031] Specifically, the ground anchor 7 has downward threads.

[0032] The base 1 is provided with a support mounting hole 12, and a fixing clamp connector 13 and a support frame connector 21 are provided next to the support mounting hole 12.

[0033] Specifically, the fixing clamp connector 13 is a short column, and there are four fixing clamp connectors 13 arranged in the form of the four corner points of a rectangle.

[0034] Specifically, the support frame connector 21 is a threaded tube with internal threads. There are four support frame connectors 21, all of which are arranged on the outside of the fixing clamp connector 13. The four support frame connectors 21 are arranged in the form of a rectangular four corner points.

[0035] The support frame connector 21 is connected to the support frame 2.

[0036] Optionally, the support frame 2 is a telescopic support.

[0037] Optionally, one end of the support frame 2 is a connector 22, and the support frame 2 is connected to the support frame connector 21 through the connector 22; further, the connector 22 has threads.

[0038] Furthermore, the other end of the connector 22 is a tail connection groove 23, which is a threaded tube with internal threads.

[0039] The fixing clamp 3 is connected to the fixing clamp connector 13.

[0040] Specifically, the bottom of the fixing clamp 3 has an extension plate with a through hole, and the fixing clamp 3 is connected to the fixing clamp connector 13 through the through hole on the extension plate.

[0041] The fixed clamp 3 has a fixed clamp through hole 31 in the center, and a clamp ball 302 is provided in the clamp slide groove 301.

[0042] The top of the fixing clamp 3 is provided with a shearing clamp 4. A vertical shearing clamp hole 41 is opened in the center of the shearing clamp 4. One or both of the top surface of the fixing clamp 3 or the bottom surface of the shearing clamp 4 are provided with horizontal clamping grooves 301.

[0043] Optionally, both the top surface of the fixing clamp 3 and the bottom surface of the shearing clamp 4 are provided with clamp grooves 301, and the clamping ball 302 is movably placed in the clamp grooves 301. Further, the clamp grooves 301 of the fixing clamp 3 and the shearing clamp 4 are positioned correspondingly. Preferably, the diameter of the clamping ball 302 is larger than the diameter of the clamp groove 301. Preferably, the clamp groove 301 is an arc-shaped groove with a minor arc, and its diameter is larger than that of the clamping ball 302.

[0044] Specifically, the fixing clamp 3 and the shearing clamp 4 are respectively provided with two clamping grooves 301 that pass through the fixing clamp through hole 31 and the shearing clamp hole 41.

[0045] Optionally, a ball bearing hole is provided on one of the top surface of the fixing clamp 3 or the bottom surface of the shearing clamp 4, and a clamp groove 301 is provided on the other, wherein the clamp ball 302 is movably embedded in the ball bearing hole of the clamp groove 301.

[0046] Optionally, the shearing fixture hole 41 is a blind hole.

[0047] Optionally, both the fixing clamp 3 and the shearing clamp 4 are straight octagonal prisms.

[0048] The two ends of each clamping groove 301 on the fixed clamp 3 are located on both sides of the clamping through hole 31. The two ends of each clamping groove 301 on the shearing clamp 4 are located on both sides of the shearing clamp hole 41.

[0049] Optionally, each clamp groove 301 is provided with four clamping balls 302 to reduce friction, so that the soil is sheared between the fixed clamp 3 and the shear clamp 4. The fixed clamp 3 is used to hold the test soil column, and the shear clamp 4 is used to withstand the shear force.

[0050] The two clamping grooves 301 of the fixed clamp 3 and the two clamping grooves 301 of the shearing clamp 4 are positioned correspondingly. When the clamping ball 302 is not placed in the clamping groove 301, the clamping groove 301 of the fixed clamp 3 and the clamping groove 301 of the shearing clamp 4 form a cylindrical through hole. Specifically, the clamping groove 301 is an arc-shaped groove.

[0051] Optionally, the side of the fixing clamp 3 is provided with a handle 33.

[0052] The shearing clamp 4 is provided with a first pressure plate 51 at its top, and a second pressure plate 52 is provided at the top of the first pressure plate 51.

[0053] A horizontal pressure plate groove 502 is provided at the top of the first pressure plate 51 or at the bottom of the second pressure plate 52, and a pressure plate ball 501 is provided in the pressure plate groove 502.

[0054] Optionally, pressure plate grooves 502 are provided on the top of the first pressure plate 51 and the bottom of the second pressure plate 52, and the pressure plate ball 501 is movably placed in the pressure plate groove 502. Further, the pressure plate grooves 502 of the first pressure plate 51 and the second pressure plate 52 are positioned correspondingly. Specifically, the pressure plate groove 502 is an arc-shaped groove. When the pressure plate ball 501 is not placed in the pressure plate groove 502, the pressure plate grooves 502 of the first pressure plate 51 and the second pressure plate 52 form a cylindrical through hole. Specifically, there are two pressure plate grooves 502 on both the first pressure plate 51 and the second pressure plate 52. Preferably, the diameter of the pressure plate ball 501 is larger than the diameter of the pressure plate groove 502. Preferably, the pressure plate groove 502 is an arc-shaped groove with a minor arc, and its diameter is larger than that of the pressure plate ball 501.

[0055] Optionally, a ball bearing hole is provided on one of the top of the first pressure plate 51 or the bottom of the second pressure plate 52, and a pressure plate groove 502 is provided on the other, wherein the pressure plate ball bearing 501 is movably embedded in the ball bearing hole of the pressure plate groove 502.

[0056] A pressure plate 53 is provided on the top of the second pressure plate 52 to ensure uniform stress on the soil sample. A vertical load simulation loading mechanism 5 is provided above the pressure plate 53 to provide vertical load during the test.

[0057] The top frame 201 is installed on the top of the support frame 2, and the vertical load simulation loading mechanism 5 is fixed on the top frame 201.

[0058] Specifically, the top frame 201 includes a rectangular frame, the four corners of which are connected to four support frames 2 respectively, and an X-shaped frame is connected to the two diagonals of the rectangular frame. The central bottom of the X-shaped frame is connected to the top of the vertical load simulation loading mechanism 5.

[0059] A support body 60 is installed on the mounting hole 12 of the support body. A shear load simulation loading mechanism 6 is provided on the support body 60. A force transmission rod 61 is provided on the side of the shear load simulation loading mechanism 6, and a pressure block 62 is provided at the end of the force transmission rod 61. The end of the pressure block 62 cooperates with the side of the shear clamp 4. During the test, the force load simulation loading mechanism 6 steadily advances the shear clamp 4, providing a horizontal load, so that relative shearing occurs between the shear clamp 4 and the fixed clamp 3.

[0060] Specifically, the shear load simulation loading mechanism 6 is made of electric steel, and the vertical load simulation loading mechanism 5 is a CNC jack.

[0061] The shear load simulation loading mechanism 6 is electrically connected to an electrical control cabinet. The electrical control cabinet is used to collect shear force and displacement data of the shear load simulation loading mechanism 6 and to provide power and control support to the shear load simulation loading mechanism 6. The electrical control cabinet includes a cabinet, a controller, and low-voltage components.

[0062] Specifically, the shear load simulation loading mechanism 6 is equipped with a rope displacement sensor, and the front loading point is equipped with a tension / compression sensor. The upper end of the vertical load simulation loading mechanism 5 is equipped with a tension / compression sensor. These sensors are connected to the PLC system via an analog input interface, and the current loading force value is displayed after calculation. The final data processing adopts a fully digital calibration method and software linearization to reduce calibration errors.

[0063] Example 2 In this embodiment, the method of using the in-situ direct shear testing device of the present invention includes the following steps: Before excavating the test pit, the layout of the test pit and samples should be determined on-site based on the spatial distribution of structural planes within the soil and rock mass and the direction of the shear test. Test wells should be constructed at both ends of the planned trench to determine the target layer before excavation of the test pit. The geometric dimensions of the test pit should meet the testing and safety requirements. When used as a horizontal inclined support for reaction loading, the strength of the pit wall should meet the maximum load requirement; if the strength is insufficient, reinforcement measures should be taken. Sample preparation should be determined based on the development characteristics of structural planes within the soil and rock mass or the homogeneity and particle composition of the soil.

[0064] When conducting an in-situ direct shear test, first obtain a soil sample from the area to be tested. Note that it is not necessary to remove the soil sample in blocks; simply excavate the soil sample within the area. In this example, the soil sample is a cylindrical soil body with a height of 340 mm and a diameter of 500 mm.

[0065] Place the base through hole 101 of the base 1 and the through hole of the shearing clamp 4 onto the soil sample, and install the support frame 2.

[0066] The fixing clamp 3 is then placed on the fixing clamp connector 13 on the base 1 to fix the clamp 3. Place the shearing clamp 4 onto the soil and align it with the fixing clamp 3, ensuring that the two are smooth and free of impurities.

[0067] After placement, the soil should be 30-50 mm higher than the upper surface of the shear clamp 4 to ensure compression space during preloading. Ideally, the upper surface of the soil should be level with the upper surface of the shear clamp 4 after preloading.

[0068] A first pressure plate 51 is placed on the upper surface of the soil, with its four sides aligned with the four sides of the shearing clamp 4. A second pressure plate 52 is then placed on the first pressure plate 51.

[0069] When the second pressure plate 52 is placed, the side of it closest to the shear load simulation loading mechanism 6 is offset by 150-250 mm from the side of the first pressure plate 51 closest to the shear load simulation loading mechanism 6. During shearing, the shearing clamp 4 and the first pressure plate 51 will slide due to the forward push of the shear load simulation loading mechanism 6. At this time, the second pressure plate 52 moves toward the shear load simulation loading mechanism 6.

[0070] Simultaneously, the vertical load mechanism 5 continuously provides vertical load to the soil through the second pressure plate 52 and the first pressure plate 51. The vertical load mechanism 5 is connected to the top frame 201, and the vertical load mechanism 5 is in close contact with the pressure plate 53 on the second pressure plate 52 to achieve pressurization.

[0071] The shear load simulation loading mechanism 6 is fixed on the support body 60, and the force transmission rod 61 of the shear load simulation loading mechanism 6 contacts the pressure block 62 at the center of the shear clamp 4.

[0072] Connect the vertical load sensor, shear force sensor, and displacement sensor to the electrical control cabinet respectively. Set the horizontal shear rate and vertical load on the electrical control cabinet, click enable, record the data, and start the test.

[0073] Connect the computer to the electrical control cabinet via network cable, record test data, observe the maximum shear force, and stop the test and save the data after the peak value is reached and the condition stabilizes.

[0074] Example 3 An in-situ direct shear test system includes the in-situ direct shear test equipment described in Example 2 and a data acquisition system, wherein the data acquisition system includes a pressure sensor and a displacement sensor.

[0075] The in-situ direct shear test system has leakage protection and electrostatic protection functions; the test system housing should be safely grounded, with a grounding terminal and a grounding mark, and a comprehensive alarm system with alarm, protection, and human intervention functions in abnormal situations, which improves the overall safety factor of the equipment.

[0076] Unless otherwise specified, the equipment components involved in the above embodiments are all conventional equipment components, and the structural settings, working methods or control methods involved are all conventional settings, working methods or control methods in the art unless otherwise specified.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. An in-situ direct shear test apparatus characterized by, include: A base (1) has a base through hole (101) on one side and a support body (60) on the other side; a fixing clamp (3) is installed above the base through hole (101), and a shearing clamp (4) is provided on the top of the fixing clamp (3); both the fixing clamp (3) and the shearing clamp (4) have through holes; a clamp groove (301) is provided on the top surface of the fixing clamp (3) or the bottom surface of the shearing clamp (4), and a clamp ball (302) is provided in the clamp groove (301); the top of the shearing clamp (4) has a through hole. The first pressure plate (51) is provided in the part, and the second pressure plate (52) is provided on the top of the first pressure plate (51). A pressure plate groove (502) is provided on the top of the first pressure plate (51) or the bottom of the second pressure plate (52). A pressure plate ball (501) is provided in the pressure plate groove (502). A support frame (2) is provided on the base (1) outside the fixed clamp (3). A vertical load simulation loading mechanism (5) is provided on the top of the support frame (2). A shear load simulation loading mechanism (6) is provided on the support body (60).

2. An apparatus for in-situ direct shear testing according to claim 1, wherein, The base (1) is provided with a fixing clamp connector (13) and a support frame connector (21); the fixing clamp (3) is connected to the fixing clamp connector (13); the support frame (2) is connected to the support frame connector (21).

3. An apparatus for in-situ direct shear testing according to claim 1, wherein, The base (1) is provided with a support mounting hole (12), and the support (60) is mounted on the support mounting hole (12).

4. An apparatus for in-situ direct shear testing according to claim 1, wherein, The second pressure plate (52) is provided with a pressure plate (53) on its top.

5. An apparatus for in-situ direct shear testing according to claim 1, wherein, The shear load simulation loading mechanism (6) has a force transmission rod (61) on its side, and a pressure block (62) is provided at the end of the force transmission rod (61). The end of the pressure block (62) cooperates with the side of the shear clamp (4).

6. An in-situ direct shear test apparatus according to claim 1, wherein, The base (1) has a ground anchor hole (11) on its edge. A ground anchor (7) is installed in the ground anchor hole (11). One end of the ground anchor (7) has a ground anchor head (71). A throttle (73) is detachably installed on the ground anchor head (71). The throttle (73) has a ground anchor head slot (72) that matches the ground anchor head (71).

7. An apparatus for in-situ direct shear testing according to claim 1, wherein, The top surface of the fixing clamp (3) and the bottom surface of the shearing clamp (4) are both provided with clamp grooves (301), and the clamp ball (302) is movably placed in the clamp groove (301); the top of the first pressure plate (51) and the bottom of the second pressure plate (52) are both provided with pressure plate grooves (502); the pressure plate ball (501) is movably placed in the pressure plate groove (502).

8. An apparatus for in-situ direct shear testing according to claim 1, wherein, A ball bearing hole is provided on one of the top surfaces of the fixing clamp (3) or the bottom surface of the shearing clamp (4), and a clamp groove (301) is provided on the other. The clamp ball (302) is movably embedded in the ball bearing hole of the clamp groove (301). A ball bearing hole is provided on one of the top surfaces of the first pressure plate (51) or the bottom surfaces of the second pressure plate (52), and a pressure plate groove (502) is provided on the other. The pressure plate ball (501) is movably embedded in the ball bearing hole of the pressure plate groove (502).

9. An in-situ direct shear testing system, characterized in that, The invention includes an in-situ direct shear testing device and a data acquisition system as described in any one of claims 1 to 8, wherein the data acquisition system includes a pressure sensor and a displacement sensor.

10. A method of using the in-situ direct shear testing apparatus according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1: Obtain soil samples from the area to be measured; S2: Place the base through hole (101) of the base (1) onto the soil sample, and install the fixing clamp (3) and the shearing clamp (4) so ​​that the fixing clamp (3) and the shearing clamp (4) are loosely placed on the soil sample; S3: Apply vertical pressure to the soil sample by the vertical load simulation loading mechanism (5); apply shear force to the soil sample by the shear load simulation loading mechanism (6) pushing the shear clamp (4).

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