Vane shear test device for testing strength of soil body

Abstract

The invention discloses a vane shear test device for testing the strength of a soil body in the technical field of geotechnical engineering, which comprises a power assembly, a second transmission shaft, a first transmission shaft and a screw rod which are sequentially arranged according to a transmission sequence, and the lower end of the screw rod is fixedly provided with a screw rod connector for fixedly connecting a test structure; the vane shear test device has two working modes, namely an up-and-down motion mode and a rotary shear mode: when a third transmission assembly rotates along with a second transmission shaft, the second transmission assembly fixes a first transmission shaft, and a lead screw constraint assembly limits rotation of a lead screw, the lead screw drives a test mechanism to move upwards or downwards; when the first transmission assembly rotates along with the first transmission shaft, the fourth transmission assembly rotates along with the second transmission shaft, and the lead screw constraint assembly releases the lead screw, the lead screw drives the testing mechanism to rotate and shear.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical engineering, and in particular to a cross-plate shear test device for soil strength testing. Background Art

[0002] The cross-plate shear test is a traditional test method for testing the undrained shear strength of saturated clay soil. It has the advantages of avoiding the disturbance of soil extraction and the test principle can directly reflect the natural strength of the soil.

[0003] When conducting the cross-plate shear test, the cross-plate is first pressed into the specified depth of the formation, and then the cross-plate is rotated uniformly at a certain speed to test the cross-plate torque. The measured torque is converted into the undrained shear strength of the clay according to the size of the cross-plate.

[0004] Among the common cross-plate test systems currently, most use a hydraulic system + an electric motor or two electric motors to drive the penetration and rotary shear of the probe rod respectively. Two power systems will increase the weight of the test equipment, making the entire system inconvenient to install and transfer. As for the device that controls the penetration operation of the probe rod, the common cross-plate equipment generally uses a loading beam with a screw or guide rail with a length greater than the stroke. This structural form not only requires the probe rod to be continuously extended during the penetration process, but its guide rail also significantly increases the size of the loading equipment in the vertical direction. Summary of the invention

[0005] The purpose of the present invention is to provide a cross-plate shear test device for soil strength testing, so as to solve the technical problem in the prior art that the pressing process and the rotational shear process of the cross-plate shear test device are performed by two sets of different power equipment, which not only has a large size and weight and is inconvenient to transfer, but also the test process is time-consuming.

[0006] In order to solve the above technical problems, the present invention specifically provides a cross plate shear test device for soil strength testing, comprising a power assembly, a second transmission shaft, a first transmission shaft and a screw rod arranged in sequence according to a transmission sequence, and a screw rod connector for fixing and connecting a test structure is fixedly arranged at the lower end of the screw rod;

[0007] The second transmission shaft is provided with a transmission device input gear and a third transmission assembly and a fourth transmission assembly in sequence which are transmission-connected with the power assembly, the first transmission shaft is provided with a first transmission assembly and a second transmission assembly, and the screw is provided with a screw rotation assembly and a screw constraint assembly; wherein the third transmission assembly, the first transmission assembly and the screw rotation assembly are transmission-connected in sequence, the fourth transmission assembly, the second transmission assembly and the screw constraint assembly are transmission-connected in sequence, the third transmission assembly, the fourth transmission assembly and the first transmission assembly can all choose to rotate with the transmission shaft or not, the second transmission assembly can fix or release the first transmission shaft, and the screw constraint assembly can release or limit the rotation of the screw;

[0008] The cross-plate shear test device has two working modes: up and down motion mode and rotation shear mode:

[0009] When the third transmission assembly rotates following the second transmission shaft, the second transmission assembly fixes the first transmission shaft, and the screw rod constraint assembly restricts the rotation of the screw rod, the screw rod drives the testing mechanism to move upward or downward;

[0010] When the first transmission assembly rotates following the first transmission shaft, the fourth transmission assembly rotates following the second transmission shaft, and the screw rod restraint assembly releases the screw rod, the screw rod drives the testing mechanism to perform rotational shearing.

[0011] As a preferred solution of the present invention, the cross plate shear test device further comprises a first mounting plate, a second mounting plate, a third mounting plate and a fourth mounting plate fixedly mounted on the device frame;

[0012] The two ends of the second transmission shaft are fixed on the first mounting plate and the second mounting plate through bearings, and the second transmission shaft is provided with a transmission device input gear, a third clutch, a sixth gear and a fourth clutch in sequence from high to low; the transmission device input gear is key-connected with the second transmission shaft, the input disc of the third clutch is key-connected with the second transmission shaft, the output disc of the third clutch is screwed with the sixth gear, and the sixth gear is installed on the second transmission shaft through bearings; the input disc of the fourth clutch is key-connected with the second transmission shaft, the output disc of the fourth clutch is screwed with the input disc of the reducer, the other end of the input disc of the reducer is linked to the input end of the planetary reducer, the planetary reducer is screwed to the lower end surface of the third mounting plate, and the output end of the planetary reducer is key-connected with the seventh gear;

[0013] The two ends of the first transmission shaft are fixed to the first mounting plate and the fourth mounting plate through bearings, and the first transmission shaft is provided with a first clutch, a third gear, a second clutch, a fourth gear and a fifth gear in sequence from high to low; the input disc of the first clutch is key-connected with the first transmission shaft, and the output disc is screwed with the third gear, and the third gear is mounted on the first transmission shaft through a bearing and meshes with the sixth gear; the input disc of the second clutch is key-connected with the first transmission shaft, and the output disc is screwed with the third mounting plate, and the fourth gear and the fifth gear are both key-connected with the first transmission shaft, and the fifth gear is meshed with the seventh gear;

[0014] The screw rod is the one that is provided with a turbine, a first gear, a key wheel and a second gear in sequence from high to low; the turbine is threadedly connected to the screw rod through an internal thread, the turbine is fixedly arranged in a turbine sleeve, the turbine sleeve is screwed under the first mounting plate, the first gear is keyed to the bottom of the turbine and meshes with the third gear; the key wheel is connected to the keyway on the surface of the screw rod through an internal key, the key wheel is fixedly arranged in the key wheel sleeve, and the key wheel sleeve is screwed under the third mounting plate.

[0015] As a preferred solution of the present invention, the test structure includes a hoop, a test assembly and a shell for protecting the test assembly, and the end of the shell is screwed to the probe rod connector;

[0016] The probe rod connector and the screw rod connector are both provided with circular connecting pieces that can be clamped by the hoop, and one of the circular connecting pieces is provided with a square protrusion, and the other circular connecting piece is provided with a square groove that matches the square protrusion.

[0017] As a preferred solution of the present invention, the test assembly includes a torque sensor, a sensor connector, a sensor connecting shaft, a probe rod and a cross plate, the torque sensor is screwed to the housing, the square protrusion at the measuring end of the torque sensor is connected to the square socket on one side of the sensor connector, the sensor connector is screwed to the sensor connecting shaft, the sensor connecting shaft is screwed to one end of the probe rod, and the other end of the probe rod is screwed to the cross plate;

[0018] Conical bearings are arranged on both sides of the sensor connecting shaft, and the conical bearings are in contact with the housing. Ceramic bearings are arranged at the threaded connection between the probe rod and the sensor connecting shaft, and the ceramic bearings are in contact with the housing.

[0019] As a preferred solution of the present invention, the shell includes a sensor jacket, a bearing group upper jacket, a bearing group lower jacket and a probe rod jacket which are screwed in sequence, the torque sensor is screwed in the sensor jacket, the probe rod connecting piece is screwed to the sensor jacket, the two tapered bearings are respectively in contact with the bearing group upper jacket and the bearing group lower jacket, and the ceramic bearing is in contact with the probe rod jacket.

[0020] As a preferred solution of the present invention, the probe rod is formed by multiple rod sections screwed together end to end, each screwed position is provided with a ceramic bearing, and the probe rod sleeve is formed by multiple sleeve sections screwed together end to end.

[0021] As a preferred solution of the present invention, a conductive slip ring is provided on the probe rod connector, and the electrodes on the fixed ring are connected to the leads of the torque sensor, and the electrodes on the rotating ring are connected to an external measurement and acquisition device.

[0022] As a preferred solution of the present invention, the power assembly includes a motor, a motor reducer and a reducer output gear, the reducer output gear is installed on the reducer output shaft through a key connection, and the reducer output gear is meshed with the transmission device input gear.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The cross-plate shear test device can enter an up-and-down motion mode or a rotational shear mode by controlling the states of each transmission assembly and the screw constraint assembly. When the third transmission assembly rotates following the second transmission shaft, the second transmission assembly fixes the first transmission shaft, and the screw constraint assembly limits the rotation of the screw, the screw drives the test mechanism to move upward or downward to press the test mechanism into the formation; when the first transmission assembly rotates following the first transmission shaft, the fourth transmission assembly rotates following the second transmission shaft, and the screw constraint assembly releases the screw, the screw drives the test mechanism to perform rotational shearing to test the undrained shear strength of saturated clay. A power system is used to simultaneously realize the penetration and rotational shearing processes of the cross-plate, thereby reducing the volume and weight of the loading equipment and facilitating the installation and transfer of the equipment.

[0025] In the present invention, no guide rail is used, and the lead screw 4 is directly used to drive the testing mechanism to move downward, thereby shortening the length of the device as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0027] Figure 1 It is a schematic diagram of the overall structure of the cross plate shear test device in the present invention;

[0028] Figure 2 It is a structural schematic diagram of the driving component in the present invention from a first perspective;

[0029] Figure 3 A schematic diagram of the structure of the driving component of the present invention from a second viewing angle;

[0030] Figure 4 It is a structural schematic diagram of the driving component of the present invention from a third perspective;

[0031] Figure 5 is a cross-sectional schematic diagram of the testing mechanism in the present invention;

[0032] Figure 6 It is a structural schematic diagram of the connection between the cross plate and the probe rod in the present invention;

[0033] Figure 7 It is a schematic structural diagram of the hoop, the screw rod connector and the probe rod connector in the present invention;

[0034] Figure 8 The invention relates to a cross plate shearing device provided with a lifting guide rail in the prior art.

[0035] The numbers in the figure represent the following:

[0036] 1-power assembly, 101-motor, 102-motor reducer, 103-reducer output gear;

[0037] 2-second transmission shaft, 201-transmission device input gear, 202-third clutch, 203-sixth gear, 204-fourth clutch, 205-reducer input plate, 206-planetary reducer, 207-seventh gear;

[0038] 3-first transmission shaft, 301-first clutch, 302-third gear, 303-second clutch, 304-fourth gear, 305-fifth gear;

[0039] 4-screw, 401-turbine, 402-first gear, 403-key wheel, 404-second gear, 405-turbine sleeve, 406-key wheel sleeve, 407-screw connector;

[0040] 501-first mounting plate, 502-second mounting plate, 503-third mounting plate, 504-fourth mounting plate;

[0041] 6-test structure, 601-hoop, 602-probe connecting piece, 603-torque sensor, 604-sensor connecting piece, 605-sensor connecting shaft, 606-probe, 607-cross plate, 608-tapered bearing, 609-ceramic bearing, 6010-sensor jacket, 6011-bearing group upper sleeve, 6012-bearing group lower sleeve, 6013-probe jacket, 6014-conductive slip ring;

[0042] 7-third transmission assembly, 8-fourth transmission assembly, 9-first transmission assembly, 10-second transmission assembly, 11-screw rotation assembly, 12-screw constraint assembly. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The present invention specifically provides a cross plate shear test device for soil strength testing, comprising a power assembly 1, a second transmission shaft 2, a first transmission shaft 3 and a screw 4 arranged in sequence according to a transmission sequence, and a screw connector 407 for fixedly connecting a test structure 6 is fixedly arranged at the lower end of the screw 4;

[0045] The second transmission shaft 2 is sequentially provided with a transmission device input gear 201, a third transmission assembly 7 and a fourth transmission assembly 8 which are transmission-connected with the power assembly 1, the first transmission shaft 3 is provided with a first transmission assembly 9 and a second transmission assembly 10, and the screw rod 4 is provided with a screw rod rotating assembly 11 and a screw rod restraining assembly 12; wherein, the third transmission assembly 7, the first transmission assembly 9 and the screw rod rotating assembly 11 are transmission-connected in sequence, the fourth transmission assembly 8, the second transmission assembly 10 and the screw rod restraining assembly 12 are transmission-connected in sequence, the third transmission assembly 7, the fourth transmission assembly 8 and the first transmission assembly 9 can all choose to rotate with the transmission shaft or not, the second transmission assembly 10 can fix or release the first transmission shaft 3, and the screw rod restraining assembly 12 can release or limit the rotation of the screw rod 4;

[0046] The cross-plate shear test device has two working modes: up and down motion mode and rotation shear mode:

[0047] When the third transmission assembly 7 rotates with the second transmission shaft 2, the second transmission assembly 10 fixes the first transmission shaft 3, and the screw rod constraint assembly 12 restricts the screw rod 4 from rotating. At this time, the second transmission shaft 2 rotates, the first transmission shaft 3 is stationary, the fourth transmission assembly 8 does not rotate with the second transmission shaft 2, and the first transmission assembly 9 can rotate freely. At this time, the screw rod 4 drives the test mechanism to move upward or downward;

[0048] When the first transmission assembly 9 rotates following the first transmission shaft 3, the fourth transmission assembly 8 rotates following the second transmission shaft 2, and the screw rod restraint assembly 12 releases the screw rod 4. At this time, the first transmission shaft 3, the second transmission shaft 2 and the screw rod 4 can all rotate, and the screw rod 4 drives the test mechanism to perform rotation shearing.

[0049] The cross-plate shear test device can enter the up-and-down movement mode or the rotation shear mode by controlling the states of each transmission component and the screw constraint component 12. That is, when the third transmission component 7 rotates following the second transmission shaft 2, the second transmission component 10 fixes the first transmission shaft 3, and the screw constraint component 12 restricts the screw 4 from rotating, the screw 4 drives the test mechanism to move upward or downward, and the test mechanism is pressed into the formation; when the first transmission component 9 rotates following the first transmission shaft 3, the fourth transmission component 8 rotates following the second transmission shaft 2, and the screw constraint component 12 releases the screw 4, the screw 4 drives the test mechanism to perform rotation shearing to test the undrained shear strength of saturated clay. A set of mechanical devices is used to simultaneously realize the penetration and rotation shearing process of the cross plate 607, thereby reducing the volume and weight of the loading equipment.

[0050] like Figure 8 As shown, for the device for controlling the probe rod to perform the penetration operation, a loading beam is used in combination with a guide rail whose length is greater than the stroke, and the guide rail also significantly increases the size of the loading device in the vertical direction.

[0051] In the present invention, no guide rail is used, and the lead screw 4 is directly used to drive the testing mechanism to move downward, thereby shortening the length of the device as a whole.

[0052] Furthermore, the specific configuration of each transmission assembly, the screw constraint assembly 12 and the screw rotation assembly 11 is as follows:

[0053] The third transmission assembly 7 includes a third clutch 202 and a sixth gear 203. The fourth transmission assembly 8 includes a fourth clutch 204, a reducer input disc 205, a planetary reducer 206 and a seventh gear 207. The first transmission assembly 9 includes a first clutch 301 and a third gear 302. The second transmission assembly 10 includes a second clutch 303, a fourth gear 304 and a fifth gear 305. The screw rotation assembly 11 includes a turbine 401, a first gear 402 and a turbine sleeve 405. The screw constraint assembly 12 includes a key wheel 403, a second gear 404 and a key wheel sleeve 406.

[0054] The screw rod 4 cross plate shear test device also includes a first mounting plate 501, a second mounting plate 502, a third mounting plate 503 and a fourth mounting plate 504 fixedly mounted on the device frame;

[0055] The two ends of the second transmission shaft 2 are fixed on the first mounting plate 501 and the second mounting plate 502 through bearings. The transmission device input gear 201, the third clutch 202, the sixth gear 203 and the fourth clutch 204 are arranged on the second transmission shaft 2 in sequence from high to low; the transmission device input gear 201 is key-connected with the second transmission shaft 2, the input disc of the third clutch 202 is key-connected with the second transmission shaft 2, the output disc of the third clutch 202 is screwed with the sixth gear 203, and the sixth gear 203 is installed on the second transmission shaft 2 through bearings; the input disc of the fourth clutch 204 is key-connected with the second transmission shaft 2, the output disc of the fourth clutch 204 is screwed with the reducer input disc 205, the other end of the reducer input disc 205 is linked to the input end of the planetary reducer 206, the planetary reducer 206 is screwed to the lower end surface of the third mounting plate 503, and the output end of the planetary reducer 206 is key-connected with the seventh gear 207;

[0056] Both ends of the first transmission shaft 3 are fixed on the first mounting plate 501 and the fourth mounting plate 504 through bearings. The first transmission shaft 3 is provided with a first clutch 301, a third gear 302, a second clutch 303, a fourth gear 304 and a fifth gear 305 in order from high to low; the input disc of the first clutch 301 is key-connected with the first transmission shaft 3, the output disc is screwed with the third gear 302, the third gear 302 is mounted on the first transmission shaft 3 through bearings, and meshes with the sixth gear 203; the input disc of the second clutch 303 is key-connected with the first transmission shaft 3, the output disc is screwed with the third mounting plate 503, the fourth gear 304 and the fifth gear 305 are both key-connected with the first transmission shaft 3, and the fifth gear 305 is meshed with the seventh gear 207;

[0057] The screw rod 4 is the one that is provided with a turbine 401, a first gear 402, a key wheel 403 and a second gear 404 in sequence from high to low; the turbine 401 is threadedly connected to the screw rod 4 through an internal thread, the turbine 401 is fixedly arranged in a turbine sleeve 405, the turbine sleeve 405 is screwed under the first mounting plate 501, the first gear 402 is keyed under the turbine 401, and meshes with the third gear 302; the key wheel 403 is connected to the keyway on the surface of the screw rod 4 through an internal key, the key wheel 403 is fixedly arranged in a key wheel sleeve 406, and the key wheel sleeve 406 is screwed under the third mounting plate 503.

[0058] For each of the above clutches, when the clutch is engaged, the input disc and the output disc of the clutch are fixed together and move synchronously; when the clutch is disengaged, the input disc and the output disc are separated and move independently.

[0059] When the screw rod 4 is required to drive the test mechanism to move upward or downward, the first clutch 301 is disconnected, the second clutch 303 is engaged, the third clutch 202 is engaged, and the fourth clutch 204 is disconnected. The power assembly 1 is started to drive the second transmission shaft 2, the sixth gear 203, the third gear 302, the first gear 402 and the turbine 401 to rotate in sequence. At the same time, due to the engagement of the second clutch 303, the rotation of the key wheel 403 is constrained. At this time, the screw rod 4 moves upward or downward in the vertical direction.

[0060] When the screw rod 4 is needed to drive the test mechanism to perform rotational shearing, the first clutch 301 is engaged, the second clutch 303 is disconnected, the third clutch 202 is disconnected, and the fourth clutch 204 is engaged, and the power assembly 1 is started, which in turn drives the second transmission shaft 2, the planetary reducer 206, the seventh gear 207, the fifth gear 305, the first transmission shaft 3, the fourth gear 304 and the third gear 302, the second gear 404 and the first gear 402, the key wheel 403 and the turbine 401 and the screw rod 4 to rotate, and the screw rod 4 drives the test mechanism to perform rotational shearing.

[0061] For the cross-plate shear test task in the laboratory environment, it has the characteristics of limited test depth, limited test space, high control accuracy of shear rate, simple and fast operation steps, etc. The cross-plate loading equipment used in the existing field survey engineering is no longer suitable for the soil strength test task in the laboratory. The present invention adopts a servo motor as the power source and controls the switching of the above two loading processes with a clutch. It has the advantages of relatively light and compact loading equipment, precise loading speed control, and fast and simple switching speed of penetration-rotation mode, and is suitable for the soil strength test task in the laboratory.

[0062] Furthermore, the general structure of the test mechanism and the connection method between the test mechanism and the screw rod 4 are as follows:

[0063] The test structure 6 includes a hoop 601, a test assembly and a shell for protecting the test assembly, and the end of the shell is screwed to the probe rod connector 602;

[0064] Both the probe rod connector 602 and the screw rod connector 407 are provided with circular connecting pieces that can be clamped by the hoop 601, and one of the circular connecting pieces is provided with a square protrusion, and the other circular connecting piece is provided with a square groove that matches the square protrusion.

[0065] Further, the test assembly includes a torque sensor 603, a sensor connector 604, a sensor connecting shaft 605, a probe rod 606 and a cross plate 607, the torque sensor 603 is screwed to the housing, the square protrusion at the measuring end of the torque sensor 603 is connected to the square socket on one side of the sensor connector 604, the sensor connector 604 is screwed to the sensor connecting shaft 605, the sensor connecting shaft 605 is screwed to one end of the probe rod 606, and the other end of the probe rod 606 is screwed to the cross plate 607;

[0066] Conical bearings 608 are arranged on both sides of the sensor connecting shaft 605, and the conical bearings 608 are in contact with the shell. Ceramic bearings 609 are arranged at the threaded connection between the probe rod 606 and the sensor connecting shaft 605, and the ceramic bearings 609 are in contact with the shell. The ceramic bearings 609 provide measurement constraints for the probe rod 606, so that the probe rod 606 will not buckle and become unstable due to excessive axial pressure during the penetration process.

[0067] The vertical penetration speed can be controlled with high precision. After replacing the test head, the power subsystem (i.e. the transmission system composed of the multiple transmission shafts and transmission components) can also perform penetration geotechnical test operations such as cone penetration testing (CPT) and in-situ soil sampling.

[0068] The power subsystem and test structure are easy to assemble and disassemble, and can be quickly changed to other test types such as cone static penetration after completing the cross-plate shear test.

[0069] Furthermore, the shell includes a sensor sleeve 6010, a bearing group upper sleeve 6011, a bearing group lower sleeve 6012 and a probe rod sleeve 6013 which are screwed in sequence, the torque sensor 603 is screwed in the sensor sleeve 6010, the probe rod connector 602 is screwed to the sensor sleeve 6010, the two tapered bearings 608 are respectively in contact with the bearing group upper sleeve 6011 and the bearing group lower sleeve 6012, and the ceramic bearing 609 is in contact with the probe rod sleeve 6013.

[0070] The probe sheath design eliminates the interference of soil resistance around the probe on the torque measurement value.

[0071] The end of the probe rod jacket 6013 is conical, which can reduce the soil resistance during the pressing process.

[0072] When the probe rod 606 and the cross plate 607 rise or fall, the probe rod 606 transmits the torque of the cross plate 607 to the tapered bearing 608 via the sensor connecting shaft 605, and is further borne by the upper sleeve 6011 of the bearing group and the lower sleeve 6012 of the bearing group, thereby preventing the torque sensor 603 from being disturbed or even damaged by the axial pressure.

[0073] When the probe rod 606 and the cross plate 607 rotate, the probe rod 606 transmits the torque of the cross plate 607 to the torque sensor 603 via the sensor connecting shaft 605 and the sensor connecting member 604 .

[0074] Furthermore, the probe rod 606 is formed by multiple rod sections screwed together end to end, each screwed position is provided with a ceramic bearing 609, and the probe rod sleeve 6013 is formed by multiple sleeve sections screwed together end to end.

[0075] Furthermore, a conductive slip ring 6014 is provided on the probe connecting member 602, and the electrodes on the fixed ring are connected to the leads of the torque sensor 603, and the electrodes on the rotating ring are connected to the external measurement and acquisition equipment. The conductive slip ring 6014 can prevent the wires of the external measurement and acquisition equipment from being entangled on the test structure 6 when the cross plate 607 rotates.

[0076] Furthermore, the power assembly 1 includes a motor 101 , a motor reducer 102 and a reducer output gear 103 . The reducer output gear 103 is mounted on the reducer output shaft through a key connection, and the reducer output gear 103 is meshed with the transmission device input gear 201 .

[0077] In summary, the method for carrying out the cross plate 607 shear test using the above test device is as follows:

[0078] The test structure 6 is mounted on the screw connector 407 and the device is placed above the designated test position.

[0079] The first clutch 301 is disconnected, the second clutch 303 is engaged, the third clutch 202 is engaged, and the fourth clutch 204 is disconnected. The motor 101 is started, and the screw rod 4 drives the cross plate 607 to penetrate downward into the soil in the vertical direction.

[0080] When the cross plate 607 penetrates to a specified depth, the motor 101 is stopped.

[0081] The first clutch 301 is engaged, the second clutch 303 is disconnected, the third clutch 202 is disconnected, and the fourth clutch 204 is engaged, the motor 101 is started, and the screw rod 4 drives the cross plate 607 to rotate and shear.

[0082] After the shear test of the cross plate 607 is completed, the screw rod 4 drives the cross plate 607 upward and away from the soil in the vertical direction.

[0083] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A cross-plate shear test device for soil strength testing, characterized in that: It comprises a power assembly (1), a second transmission shaft (2), a first transmission shaft (3) and a screw rod (4) which are arranged in sequence according to a transmission order, and a screw rod connector (407) for fixedly connecting to a test structure (6) is fixedly arranged at the lower end of the screw rod (4); The second transmission shaft (2) is provided with a transmission device input gear (201) and a third transmission assembly (7) and a fourth transmission assembly (8) in sequence, the first transmission shaft (3) is provided with a first transmission assembly (9) and a second transmission assembly (10), and the screw (4) is provided with a screw rotation assembly (11) and a screw constraint assembly (12); wherein the third transmission assembly (7), the first transmission assembly (9) and the screw rotation assembly (11) are in sequence transmission connection, the fourth transmission assembly (8), the second transmission assembly (10) and the screw constraint assembly (12) are in sequence transmission connection, the third transmission assembly (7), the fourth transmission assembly (8) and the first transmission assembly (9) can all choose to rotate with the transmission shaft or not, the second transmission assembly (10) can fix or release the first transmission shaft (3), and the screw constraint assembly (12) can release or limit the rotation of the screw (4); The cross-plate shear test device has two working modes: up and down motion mode and rotation shear mode: When the third transmission assembly (7) rotates following the second transmission shaft (2), the second transmission assembly (10) fixes the first transmission shaft (3), and the screw rod restraint assembly (12) restricts the rotation of the screw rod (4), the screw rod (4) drives the testing mechanism to move upward or downward; When the first transmission component (9) rotates following the first transmission shaft (3), the fourth transmission component (8) rotates following the second transmission shaft (2), and the screw rod restraining component (12) releases the screw rod (4), the screw rod (4) drives the testing mechanism to perform rotational shearing.

2. A cross plate shear test device for soil strength testing according to claim 1, characterized in that: The cross plate shear test device also includes a first mounting plate (501), a second mounting plate (502), a third mounting plate (503) and a fourth mounting plate (504) fixedly mounted on the device frame; The two ends of the second transmission shaft (2) are fixed to the first mounting plate (501) and the second mounting plate (502) through bearings; the second transmission shaft (2) is provided with a transmission device input gear (201), a third clutch (202), a sixth gear (203) and a fourth clutch (204) in sequence from high to low; the transmission device input gear (201) is key-connected to the second transmission shaft (2); the input disc of the third clutch (202) is key-connected to the second transmission shaft (2); the output disc of the third clutch (202) is key-connected to the sixth gear (203); and the output disc of the third clutch (202) is key-connected to the sixth gear (204). The sixth gear (203) is screwed to the second transmission shaft (2) through a bearing; the input disc of the fourth clutch (204) is keyed to the second transmission shaft (2); the output disc of the fourth clutch (204) is screwed to the reducer input disc (205); the other end of the reducer input disc (205) is linked to the input end of a planetary reducer (206); the planetary reducer (206) is screwed to the lower end surface of the third mounting plate (503); the output end of the planetary reducer (206) is keyed to the seventh gear (207); The two ends of the first transmission shaft (3) are fixed on the first mounting plate (501) and the fourth mounting plate (504) through bearings; the first transmission shaft (3) is provided with a first clutch (301), a third gear (302), a second clutch (303), a fourth gear (304) and a fifth gear (305) in order from high to low; the input disc of the first clutch (301) is key-connected to the first transmission shaft (3), the output disc is screwed to the third gear (302), the third gear (302) is mounted on the first transmission shaft (3) through bearings and meshes with the sixth gear (203); the input disc of the second clutch (303) is key-connected to the first transmission shaft (3), the output disc is screwed to the third mounting plate (503), the fourth gear (304) and the fifth gear (305) are both key-connected to the first transmission shaft (3), and the fifth gear (305) is meshed with the seventh gear (207); The screw rod (4) is the one that is provided with a turbine (401), a first gear (402), a key wheel (403) and a second gear (404) in sequence from high to low; the turbine (401) is threadedly connected to the screw rod (4) through an internal thread, the turbine (401) is fixedly arranged in a turbine sleeve (405), the turbine sleeve (405) is screwed to the bottom of the first mounting plate (501), the first gear (402) is keyed to the bottom of the turbine (401) and meshed with the third gear (302); the key wheel (403) is connected to the key groove on the surface of the screw rod (4) through an internal key, the key wheel (403) is fixedly arranged in a key wheel sleeve (406), and the key wheel sleeve (406) is screwed to the bottom of the third mounting plate (503).

3. A cross plate shear test device for soil strength testing according to claim 1, characterized in that: The test structure (6) comprises a hoop (601), a test assembly and a shell for protecting the test assembly, and an end of the shell is threadedly connected to the probe rod connector (602); The probe rod connector (602) and the screw rod connector (407) are both provided with circular connecting pieces that can be clamped by the hoop (601), and one of the circular connecting pieces is provided with a square protrusion, and the other circular connecting piece is provided with a square groove that matches the square protrusion.

4. A cross plate shear test device for soil strength testing according to claim 3, characterized in that: The test assembly comprises a torque sensor (603), a sensor connector (604), a sensor connecting shaft (605), a probe rod (606) and a cross plate (607); the torque sensor (603) is screwed to the housing; a square protrusion at a measuring end of the torque sensor (603) is connected to a square socket at one side of the sensor connector (604); the sensor connector (604) is screwed to the sensor connecting shaft (605); the sensor connecting shaft (605) is screwed to one end of the probe rod (606); and the other end of the probe rod (606) is screwed to the cross plate (607); Conical bearings (608) are arranged on both sides of the sensor connecting shaft (605), and the conical bearings (608) are in contact with the shell. Ceramic bearings (609) are arranged at the threaded connection between the probe rod (606) and the sensor connecting shaft (605), and the ceramic bearings (609) are in contact with the shell.

5. A cross plate shear test device for soil strength testing according to claim 4, characterized in that: The housing comprises a sensor housing (6010), an upper housing (6011) of a bearing group, a lower housing (6012) of a bearing group and a probe housing (6013) which are screwed in sequence; the torque sensor (603) is screwed into the sensor housing (6010); the probe connecting piece (602) is screwed to the sensor housing (6010); the two tapered bearings (608) are respectively in contact with the upper housing (6011) of the bearing group and the lower housing (6012) of the bearing group; and the ceramic bearing (609) is in contact with the probe housing (6013).

6. A cross plate shear test device for soil strength testing according to claim 5, characterized in that: The probe rod connector (602) is provided with a conductive slip ring (6014), and the electrodes on the fixed ring are connected to the leads of the torque sensor (603), while the electrodes on the rotating ring are connected to an external measurement and collection device.

7. A cross plate shear test device for soil strength testing according to claim 5, characterized in that: The probe rod (606) is formed by screwing multiple rod sections end to end, and each screwing position is provided with a ceramic bearing (609). The probe rod sleeve (6013) is formed by screwing multiple sleeve sections end to end.

8. A cross plate shear test device for soil strength testing according to claim 2, characterized in that: The power assembly (1) comprises a motor (101), a motor reducer (102) and a reducer output gear (103); the reducer output gear (103) is mounted on the reducer output shaft via a key connection; the reducer output gear (103) is meshed with the transmission device input gear (201).

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