Direct shear tester

Abstract

The utility model discloses a direct shear tester in the field of geotechnical engineering testing, and aims to solve the problem that in the prior art, corresponding resistivity cannot be obtained while mechanical properties of soil are obtained. The shear box comprises an upper box and a lower box which are made of insulating materials, the top of the upper box is covered with a first conductor plate, and the bottom of the lower box is covered with a second conductor plate; the shell is fixedly connected with the lower box and is used for being in sliding connection with a workbench; the motor is in transmission connection with the shell and used for driving the lower box to do shearing motion relative to the upper box; the data acquisition instrument is in electric signal connection with the first conductor plate and the second conductor plate; by means of the two conductor plates located on the upper box and the lower box respectively, current is applied to a soil sample when the motor drives the upper box and the lower box to conduct a shear test, information of the current passing through the soil sample is collected through the data collecting instrument, and therefore the mechanical property of soil and the resistivity corresponding to the mechanical property are obtained at the same time.

Description

Technical Field

[0001] The utility model relates to a direct shear tester, belonging to the field of geotechnical engineering testing. Background Art

[0002] In geotechnical engineering, real-time resistivity is often used to detect soil structure. It is a physical quantity used to measure the characteristics of soil samples during the entire shearing process to understand potential hydrogeological characteristics, rock layer distribution, groundwater flow, etc. It is of great significance for the characterization of soil structural characteristics and has a wide range of applications in the field of geotechnical engineering. The existing real-time resistivity provides limited spatial resolution, and the real-time resistivity test accuracy is insufficient, which may lead to differences between the detection results and the actual soil conditions.

[0003] In existing practical projects, the most commonly used method to obtain soil mechanical properties is the direct shear test, which can be used to study the shear strength and deformation characteristics of soil samples. However, the structure of soil samples in actual projects is complex. If you want to study related properties such as soil type, water content, pore structure, etc., you also need to obtain real-time resistivity data of soil samples. Existing conventional direct shear tests cannot obtain the corresponding real-time resistivity while obtaining soil mechanical properties. Utility Model Content

[0004] The purpose of the present application is to overcome the deficiencies in the prior art and to provide a direct shear tester capable of simultaneously acquiring the mechanical properties of soil and the real-time resistivity corresponding to the mechanical properties.

[0005] In order to achieve the above objectives, this application is implemented by adopting the following technical solutions:

[0006] The present application provides a direct shear tester, comprising:

[0007] A shear box, the shear box comprising an upper box and a lower box both made of insulating materials, the top of the upper box covering the first conductor plate, and the bottom of the lower box covering the second conductor plate;

[0008] A shell, fixedly connected to the lower box, and the shell is used for sliding connection with the workbench;

[0009] A motor, drivingly connected to the housing, for driving the lower box to perform shearing motion relative to the upper box;

[0010] The data acquisition instrument and the current applying device are respectively connected to the first conductor plate and the second conductor plate via electrical signals.

[0011] In some embodiments of the present application, the materials of the upper box and the lower box are both polyvinyl chloride; the first conductor plate and the second conductor plate are both copper plates.

[0012] In some embodiments of the present application, the shear box also includes a box cover made of an insulating material, and a first conductor screw, and the box cover is conductively connected to the first conductor plate through the first conductor screw; the first conductor screw passes through the box cover and is connected to the data acquisition instrument through a first conductor electrical signal.

[0013] In some embodiments of the present application, the upper box includes a first through hole matching the first conductor plate, the first conductor plate and the first through hole are slidably matched, and the first conductor plate and the box cover are used to cover the first through hole.

[0014] In some embodiments of the present application, it also includes a settlement sensor and a fixed rod, and the settlement sensor is in force-transmitting contact with the box cover; one end of the fixed rod is fixedly connected to the motor, and the other end is slidably connected to the settlement sensor along the settlement direction, and at the same time, the position of the fixed rod is relatively fixed with the settlement sensor along the horizontal plane direction.

[0015] In some embodiments of the present application, a vertical load beam is further included, wherein the vertical load beam includes a beam and a vertical rod connected to the beam in force transmission, the settlement sensor is in force transmission contact with the beam, and the beam is in force transmission contact with the box cover;

[0016] The crossbeam is kept horizontal, the vertical rod extends vertically downwardly from the workbench, and two sides of the end of the vertical rod are respectively connected to a balance hammer and a hanging plate, and the hanging plate is used to hold normal load weights of different masses.

[0017] In some embodiments of the present application, the second conductor plate is connected to a resistor plug via a second conductor electrical signal, the resistor plug is also connected to the first conductor electrical signal, and the resistor plug is electrically connected to the data acquisition instrument.

[0018] In some embodiments of the present application, it also includes a fixed support and a watch rod component fixedly connected to the fixed support, the watch rod component is force-transmittingly connected to the upper box, and the watch rod component is also provided with a shear force sensor.

[0019] In some embodiments of the present application, a displacement sensor is further included which is fixedly connected to the workbench, and an activity sensor of the displacement sensor is transmission-connected to the housing.

[0020] In some embodiments of the present application, the upper box and the lower box are provided with corresponding pin holes, and the pin holes are used for inserting pins in a removable manner to achieve detachable covering of the upper box and the lower box.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The direct shear tester provided in the present application uses two conductor plates respectively located in the upper box and the lower box, and a current applying device to apply current to the soil sample when the motor drives the upper box and the lower box to perform a shear test, and collects the voltage at both ends of the soil sample through a data acquisition instrument. Using the direct shear tester as a test platform, the mechanical properties of the soil and the real-time resistivity corresponding to the mechanical properties can be obtained at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 Schematic diagram of the overall structure of the direct shear tester provided in this embodiment;

[0025] Figure 2 yes Figure 1 Schematic diagram of the external structure of the controller of the direct shear tester;

[0026] Figure 3 yes Figure 1 Schematic diagram of the internal structure of the controller of the direct shear tester;

[0027] Figure 4 yes Figure 1 Schematic diagram of the perspective structure of the middle shear box;

[0028] Figure 5 yes Figure 4 A schematic diagram of the structure of the box cover and the first conductor plate of the middle shear box;

[0029] Figure 6 yes Figure 5 Schematic diagram of the structure viewed from above;

[0030] Figure 7 yes Figure 4 A schematic diagram of the structure of the lower box of the middle shear box;

[0031] Figure 8 yes Figure 4 A schematic diagram of the structure of the upper box of the middle shear box;

[0032] In the figure: 1-vertical load beam; 2-second fixed rod; 3-workbench; 4-sedimentation sensor; 5-fourth wire; 6-third wire; 7-sixth wire; 8-motor; 9-fixing bolt; 10-computer; 11-controller; 12-shear box; 13-ball row; 14-base; 15-1:12 lever; 16-balance hammer; 17-hanging plate; 18-shear force sensor; 19-table rod component; 20-fixed support; 21-USB cable; 22-power socket; 23-power cord; 24-fifth wire; 25-displacement sensor; 26-propulsion device; 27-housing; 28-pin; 29-normal load weight; 30-fixed rod; 31-resistance plug; 32-second wire; 33-first wire;

[0033] 1201-first conductor plate; 1202-box cover; 1203-second conductor plate; 1204-first conductor screw; 1205-upper box; 1206-lower box; 1207-one-way locking bolt; 1208-first punch hole; 1209-second punch hole; 1210-first through hole; 1211-second through hole;

[0034] 1101-fast forward button; 1102-fast rewind button; 1103-cut button; 1105-switch button; 1106-reset button; 1107-stepping motor driver; 1108-ADC analog-to-digital converter; 1109-MCU single-chip microcontroller; 1110-data acquisition instrument. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of this application / this application to clearly and completely describe the technical solutions in the embodiments of this application / this application. Obviously, the described embodiments are only part of the embodiments of this application / this application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the application / this application and its application or use. Example

[0036] This embodiment provides a direct shear tester to solve the problem in the prior art that it is impossible to obtain the corresponding real-time resistivity while obtaining the mechanical properties of the soil.

[0037] refer to Figure 1 and Figure 4 The direct shear tester provided in this embodiment includes a shear box 12,

[0038] The shear box 12 includes an upper box 1205 and a lower box 1206 both of which are made of insulating materials. The top of the upper box 1205 covers the first conductor plate 1201, and the bottom of the lower box 1206 covers the second conductor plate 1203. The first conductor plate 1201 and the second conductor plate 1203 are used to apply current to the soil sample, and the first conductor plate 1201 and the second conductor plate 1203 are connected through the soil sample. The upper box 1205 and the lower box 1206 of insulating materials ensure that the soil sample will not be disturbed when measuring the resistivity of the soil sample.

[0039] The direct shear tester also includes:

[0040] The motor 8 is in driving connection with the housing 27 and is used to drive the lower box 1206 to perform shearing motion relative to the upper box 1205;

[0041] The housing 27 is fixedly connected to the housing 27, and the housing 27 is used for sliding connection with the workbench 3 so that the lower box 1206 is acted upon by the motor 8;

[0042] The data acquisition device 1110 is electrically connected to the first conductor plate 1201 and the second conductor plate 1203 respectively.

[0043] As one embodiment, the data acquisition device 1110 is a resistance meter, which records the real-time resistivity of the soil sample during the shearing process.

[0044] Non-exclusive usage:

[0045] The lower box 1206 is fixedly mounted on the housing 27 and ensures smooth sliding;

[0046] Place the soil sample in the lower box 1206; cover the upper box 1205 on the lower box 1206 so that the lower box 1206 and the upper box 1205 form a space in which the soil sample can be placed;

[0047] Start the data acquisition instrument 1110 and the current application device, check the resistance value to determine that the first conductor plate 1201 and the second conductor plate 1203 are connected through the soil sample;

[0048] The motor 8 is started to drive the lower box 1206 to perform shearing motion relative to the upper box 1205;

[0049] Record mechanical data and collect real-time resistivity of soil samples through data acquisition instrument 1110;

[0050] The motor 8 is stopped and the data is exported.

[0051] It is not difficult for a person skilled in the art to see that when the cohesion of the soil sample is high, the soil sample is placed in the lower box 1206 as a cake and then the upper box 1205 is installed. When the cohesion of the soil sample is low, the soil sample is loose, and the lower box 1206 and the upper box 1205 are installed first to put the soil sample into the shear box 12, and then the first conductor plate 1201 and the box cover 1202 are installed. The height of the soil sample is obtained according to the test requirements or empirical values.

[0052] When using the direct shear tester provided in this embodiment, since the first conductor plate 1201 and the second conductor plate 1203 are arranged at the top and bottom of the upper box 1205 and the lower box 1206 respectively, the current generated by the current application device flows in and out from the complete upper and lower surfaces of the soil sample, and the current flows through the complete depth of the soil sample. By measuring the soil sample voltage between the first conductor plate 1201 and the second conductor plate 1203, the measured resistance value is comprehensive and accurate, and will not affect the shear action of the shear surface; therefore, while obtaining the mechanical data of the soil sample, the resistance value corresponding to the mechanical data can be obtained, thereby paving the way for analyzing the soil type, water content, and pore structure of the sheared soil sample.

[0053] In summary, the direct shear tester provided in this embodiment provides a platform support for simultaneously acquiring the mechanical properties of soil and the real-time resistivity corresponding to the mechanical properties.

[0054] The current applying device can be implemented in other forms known in the art, such as a transmitter, also known as a constant current source, or even more other known forms, which will not be described in detail here. Example

[0055] This embodiment provides a direct shear tester. This embodiment is optimized on the basis of the first embodiment to improve the technical effect and refine the technical solution. For the contents not fully described in this embodiment, please refer to the first embodiment.

[0056] In order to improve the insulation performance, as one embodiment, the materials of the upper box 1205 and the lower box 1206 are both polyvinyl chloride; in order to improve the conductivity, as one embodiment, the first conductor plate 1201 and the second conductor plate 1203 are both copper plates.

[0057] In order to improve the stability of the soil sample in the upper box 1205 during the shear test, optionally, in a further but non-limiting embodiment of the present application, reference Figure 1 , Figure 4 , Figure 5 , Figure 6The shear box 12 also includes a box cover 1202 made of insulating material, the material of the box cover 1202 can be polyvinyl chloride, and also includes a first conductor screw 1204, the box cover 1202 is conductively connected to the first conductor plate 1201 through the first conductor screw 1204; the first conductor screw 1204 passes through the box cover 1202, and is connected to the data acquisition instrument 1110 through the first conductor 33 electrical signal. The first conductor screw 1204 is preferably a metal screw, especially a copper screw. The first conductor screw 1204 not only connects the box cover 1202 to the first conductor plate 1201, but also covers the box cover 1202 on the soil sample through the first conductor plate 1201, and transmits current as a conductive member.

[0058] In order to facilitate applying vertical load to the soil sample through the box cover 1202 and observing the settlement of the soil sample through the box cover 1202, as one embodiment, refer to Figure 4 and Figure 8 The upper box 1205 includes a first through hole 1210 that matches the first conductor plate 1201. The first conductor plate 1201 and the box cover 1202 are used to cover the first through hole 1210. The first conductor plate 1201 and the hole wall of the first through hole 1210 are matched to form a sliding fit between the first conductor plate 1201 and the first through hole 1210. The first conductor plate 1201 and the box cover 1202 can slide vertically in the first through hole 1210. When the soil sample settles, the first conductor plate 1201 and the box cover 1202 slide vertically relative to the box cover 1202, and then the settlement phenomenon is observed. It is worth noting that Figure 1 and Figure 4 In the shear box 12, there is a difference. Figure 1 The size of the middle box cover 1202 and the first conductor plate 1201 matches the outer diameter of the upper box 1205. Figure 4 An improvement has been made, in which the size of the box cover 1202 and the first conductor plate 1201 is smaller than the outer diameter of the upper box 1205 , and is equal to or slightly smaller than the inner diameter of the first through hole 1210 .

[0059] Optionally, refer to Figure 4 In the shear box 12, the depth of the space for accommodating the soil sample formed by the upper box 1205 and the lower box 1206 should not be less than the sum of the height (depth) of the soil sample, the thickness of the first conductor plate 1201, and the thickness of the second conductor plate 1203, to ensure that the soil sample accommodating space remains closed during the entire settlement process.

[0060] As mentioned above, the motor 8 drives the lower box 1206 to perform shearing motion relative to the upper box 1205. In order to improve the accuracy of sedimentation observation, refer to Figure 1The direct shear tester also includes a settlement sensor 4 and a fixed rod 30, the settlement sensor 4, and the settlement sensor 4 is in force transmission contact with the box cover 1202; one end of the fixed rod 30 is fixedly connected to the motor 8 body, and the other end of the fixed rod 30 is slidably connected to the settlement sensor 4 along the settlement direction, and at the same time, the position of the fixed rod 30 and the settlement sensor 4 is relatively fixed along the horizontal plane direction. Therefore, when performing a shear test, the fixed rod 30 fixes the plane position of the settlement sensor 4, so that the settlement sensor 4 is aligned with the settlement observation point on the box cover 1202, and the fixed rod 3 does not hinder the settlement sensor 4 from observing the settlement data. Generally speaking, the fixed rod 30 is fixedly connected to the housing of the motor 8. If the motor 8 is fixedly connected to the workbench 3, the fixed rod 30 can also be fixedly connected to the workbench 3.

[0061] In order to simulate the vertical load above the real soil layer, as one of the embodiments, refer to Figure 1 The direct shear tester also includes a vertical load beam 1, which includes a beam and a vertical rod. The settlement sensor 4 is in force-transmitting contact with the beam, and the beam is in force-transmitting contact with the box cover 1202. The settlement sensor 4 and the vertical load beam 1 are generally metal parts, and direct contact will cause electrical contact with the first conductor plate 1201. Therefore, the box cover 1202 serves as an insulating medium. At the same time, the surface of the first conductor plate 1201 should be flat to reduce interference. Therefore, a connection structure with the vertical load beam 1 and the settlement sensor 4 can be set on the box cover 1202.

[0062] The two sides of the end of the vertical rod are respectively connected to a balance weight 16 and a hanging plate 17, and the hanging plate 17 is used to hold normal load weights 29 of different masses.

[0063] As one example, refer to Figure 1 , the horizontal beam is connected to the upper end of the vertical rod, generally in an orthogonal connection, the horizontal beam remains horizontal, the vertical rod extends vertically downward from the workbench, and branches to both sides into two horizontal rods. A counterweight 16 is inserted into the horizontal rod on one side, and the counterweight 16 is optionally slidably connected to the horizontal rod on that side to adjust the torque. At the end of the horizontal rod on the other side, a hanging plate 17 is vertically arranged, and a normal load weight 29 of mass is placed on the hanging plate 17, which is leveled by the counterweight 16 to keep the vertical rod vertical, thereby keeping the vertical load beam 1 stable. As one embodiment, a 1:12 lever 15 is used as the horizontal rod on the side where the hanging plate 17 is located.

[0064] In order to facilitate the acquisition of real-time resistivity, as one embodiment, refer to Figure 1 The second conductor plate 1203 is electrically connected to the resistor plug 31 through the second wire 32 , the resistor plug 31 is also electrically connected to the first wire 33 , and the resistor plug 31 is electrically connected to the data acquisition instrument 1110 .

[0065] In order to test the shear stress between the upper and lower boxes, as one of the embodiments, refer to Figure 1 The direct shear tester also includes a fixed support 20 and a rod component 19 fixedly connected to the fixed support 20 . The rod component 19 is force-transmittingly connected to the upper box 1205 . The rod component 19 is also provided with a shear force sensor 18 .

[0066] In order to test the size of the shear displacement between the upper and lower boxes, as one embodiment, the direct shear tester also includes a displacement sensor 25 fixedly connected to the workbench 3, and the movable sensor of the displacement sensor 25 is transmission-connected to the housing 27.

[0067] As one embodiment, the upper box 1205 and the lower box 1206 are provided with corresponding pin holes, and the pin holes are used for inserting the pin 28 in a pluggable manner, so as to realize the detachable cover of the upper box 1205 and the lower box 1206. When in use, before testing, the soil sample is placed in the lower box 1206, the upper box 1205 is closed and the pin 28 is inserted; other components on the upper box 1205 are installed, and after the experimental arrangement work is ready, the pin 28 is pulled out to start the test experiment.

[0068] As one example, refer to Figure 2 The direct shear tester includes a controller 11, a data acquisition instrument 1110 is built inside the controller 11, and the controller 11 also has a built-in stepper motor driver 1107. The controller 11 is provided with a fast forward button 1101, a fast rewind button 1102, a shear button 1103, a switch button 1105 and a reset button 1106 connected to the stepper motor driver 1107 by electrical signals. The stepper motor driver 1107 is connected to the motor 8 by electrical signals through a third wire 6. The fast forward button 1101 and the fast rewind button 1102 are used to control the fast forward and fast rewind of the lower box 1206, the shear button 1103 is used to control the lower box 1206 to produce a shearing motion relative to the upper box 1205, the reset button 1106 is used to restore the motor 8 to the initial stroke position, and the switch button 1105 is used to start and stop the motor 8.

[0069] refer to Figure 3 Optionally, in a further but non-limiting embodiment of the present application, the controller 11 also has a built-in ADC analog-to-digital converter 1108 and an MCU single-chip microcontroller 1109, wherein the MCU single-chip microcontroller 1109 is used to control the progress of real-time resistivity testing, and the ADC analog-to-digital converter 1108 is used for digital-to-analog conversion inside the controller 11.

[0070] As one of the embodiments, the controller 11 also has a built-in transmitter, which is electrically connected to the first wire 33 and the second wire 32 respectively, thereby providing a constant current for the soil sample. The ADC analog-to-digital converter 1108 converts the resistivity of the soil sample collected in real time by the data acquisition instrument 1110 into a digital signal, and sends it to the MCU single-chip microcontroller 1109 for identification, and the identification result is sent to the computer 10.

[0071] As one of the embodiments, the controller 11 obtains electrical energy by inserting the power cord 23 into the power socket 22, and the transmitter is electrically connected to the power cord 23; the data acquisition instrument 1110 is connected to the computer 10 through the USB line 21 electrical signal; the controller 11 is connected to the shear force sensor 18 through the fourth wire 5 electrical signal; the controller 11 is connected to the displacement sensor 25 through the fifth wire 24 electrical signal; the controller 11 is connected to the settlement sensor 4 through the sixth wire 7 electrical signal; the motor 8 is connected to the shell 27 through the propulsion device 26 transmission; the direct shear tester also includes a base 14 fixedly connected to the workbench 3, and the shell 27 is slidably connected to the base 14 through a ball row 13; two second fixed rods 2 are fixedly connected to the shell of the motor 8 in parallel with each other, and the controller 11 is fixedly installed on the two second fixed rods 2.

[0072] As one example, refer to Figure 7 and Figure 8 The pin hole includes a first punch hole 1208 located in the upper box 1205 and a second punch hole 1209 located in the lower box 1206 . The positions of the first punch hole 1208 and the second punch hole 1209 correspond to each other and match with the pin 28 .

[0073] As one example, refer to Figure 7 and Figure 8 Similar to the upper box 1205 , the lower box 1206 has a second through hole 1211 , and the second conductor plate 1203 matches the second through hole 1211 . When installing, the second conductor plate 1203 is installed at the bottom of the lower box 1206 through the second through hole 1211 .

[0074] As one of the embodiments, the shear force sensor 18 is bonded to the rod component 19, and the displacement sensor 25 is installed on the upper side of the rod component 19; the base 14 is welded to the upper end of the workbench 3, and the base 14 is on the left side of the rod component 19; the ball row 13 is installed at the upper end of the base 14; the shell 27 is a copper shell, installed at the upper end of the ball row 13, and the shear box 12 is installed at the upper end of the copper shell; the settlement sensor 4 is locked with the fixed rod 30 by bolts, and the fixed rod 30 is locked to the right side of the motor 8 by a one-way locking bolt; the straight load beam 1 and the 1:12 lever 15 are respectively fixed to the workbench by nuts and bolts 3; the balance hammer 16 is fixed to the left side of the 1:12 lever 15 by bolts, the hanging plate 17 is installed on the right side of the 1:12 lever 15 by a hook, and the normal load weight 29 is installed on the upper end of the hanging plate 17; the upper left box and the lower right box of the lower box 1206 are respectively punched, and a one-way locking bolt 1207 is installed; the four walls of the upper box 1205 and the lower box 1206 are made of non-conductive polyvinyl chloride material; the first conductor plate 1201 and the second conductor plate 1203 are copper circular plates; the second wire 32 is led out from the right side of the lower box 1206 of the shear box 12; the first conductor screw 1204 on the cap 1202 is screwed with a ring The first wire 33 is led out of the copper sheet; the controller 11 is installed on the left side of the motor 8 through the second fixing rod 2 and the bolt, and the controller 11 is passed through the hole at the corresponding position of the workbench 3 and fixed with the bolt, so that the controller is fixed on the workbench 3; different shearing speeds are input into the software of the computer 10, the switch button 1104 of the controller 11 is turned on, and the shear button 1103 is turned on, so that the motor 8, under the control of the button, propels the propulsion device 26 forward at different speeds; a shear force sensor 18 is attached to the rod component 19, and the shear force sensor 18 is connected to the controller 11 through the fourth wire 5, and is used to collect shearing speed. Shear force data, at the same time, the displacement sensor 25 is connected to the controller 11 through the fifth wire 24, and is synchronously used to collect shear displacement data. The rod component 19 passes through the hole at the corresponding position of the fixed support 20, and the rod component 19 is fixed to the fixed support 20 through a nut, and passes through the hole at the corresponding position of the workbench 3, so that the fixed support 20 is fixed to the workbench 3 through a one-way locking bolt 9. The propulsion device 26 applies horizontal stress to drive the rod component 19 to move forward; the MCU single-chip microcontroller 1109 is used to test the real-time resistivity of the soil sample, and the data acquisition instrument 1110 is used to collect various data during the test.

[0075] refer to Figures 1 to 8 The direct shear tester provided in this embodiment is not the only method of use:

[0076] Prepare multiple test soil samples according to the needs of the project; put two pins 28 into the two holes of the upper box 1205 of the upper shear box 12; load the prepared soil sample into the shear box 12 through the ring knife, and then cover the box cover 1202; move the vertical load beam 1 so that it is located at the upper end of the shear box 12; move the settlement sensor 4 to the upper end of the vertical load beam 1, so that the tip of the settlement sensor 4 just touches the moving vertical load beam 1; connect the first wire 33 on the box cover 1202 and the second wire 32 on the lower box 1206 to the resistance plug 31; open the software on the computer 10, enter the corresponding test parameters, and enter the required normal pressure, shear rate, sampling mode value (by time interval or by deformation), etc. according to the required requirements; according to the required normal pressure, place the normal load weight 29 of the corresponding weight on the hanging plate 17; after reaching the test end point (such as the predetermined test time or shear displacement), turn off the instrument and disassemble the shear box 12;

[0077] Then take out the soil sample and observe its failure mode to further analyze the mechanical properties of the soil: pull out the pin 28; open the software on the computer 10, click the start test button in the control bar, and click confirm; turn on the switch button 1104 of the controller 11, and when the indicator light 1105 lights up, turn on the shear button 1103; the controller 11 controls the motor 8 through the wire 6 to drive the propulsion device 26 forward, and the shear surface is displaced under the cooperation of the rod component 19; after the test, click end test in the control bar of the computer 10; the computer The real-time resistivity data, settlement data, shear force data, shear displacement data and related images of the soil sample obtained in the test of the machine 10 are saved in EXCEL or other software, and the shear strength and real-time resistivity characteristics of the soil are evaluated according to the relevant information; the reset button 1106 of the controller 11 is turned on to reset the instrument, and the soil sample is taken out and its failure mode is observed to further analyze the mechanical properties of the soil. The soil in the shear box 12 is tested; the above steps are repeated to test different soil samples to obtain the real-time resistivity data, settlement data, shear force data and shear displacement data of each soil sample.

[0078] The computer 10, the software used by the computer 10, the controller 11, and various instruments built into the controller 11 may be implemented in other forms known in the art, which will not be described in detail here.

[0079] The direct shear tester provided in this embodiment refines the technical solution and improves the accuracy of measured data.

[0080] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0081] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "provided at", "provided with", "located", "installed", "set", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. "Hinged" includes "rotational connection".

[0082] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A direct shear tester, characterized in that: include A shear box (12), the shear box (12) comprising an upper box (1205) and a lower box (1206), both of which are made of insulating materials, the top of the upper box (1205) covers the first conductor plate (1201), and the bottom of the lower box (1206) covers the second conductor plate (1203); A housing (27) fixedly connected to the lower box (1206), the housing (27) being used for being slidably connected to the workbench (3); A motor (8) drivingly connected to the housing (27) and used to drive the lower box (1206) to perform a shearing movement relative to the upper box (1205); The data acquisition instrument (1110) and the current application device are both electrically signal connected to the first conductor plate (1201) and the second conductor plate (1203), respectively.

2. The direct shear tester according to claim 1, characterized in that: The materials of the upper box (1205) and the lower box (1206) are both polyvinyl chloride; the first conductor plate (1201) and the second conductor plate (1203) are both copper plates.

3. The direct shear tester according to claim 1, characterized in that: The shear box (12) further comprises a box cover (1202) made of insulating material, and a first conductor screw (1204); the box cover (1202) is conductively connected to the first conductor plate (1201) via the first conductor screw (1204); the first conductor screw (1204) passes through the box cover (1202) and is electrically connected to the data acquisition instrument (1110) via a first conductor (33).

4. The direct shear tester according to claim 3, characterized in that: The upper box (1205) comprises a first through hole (1210) matching the first conductor plate (1201), the first conductor plate (1201) and the first through hole (1210) are slidably matched, and the first conductor plate (1201) and the box cover (1202) are used to cover the first through hole (1210).

5. The direct shear tester according to claim 3, characterized in that: It also includes a settlement sensor (4) and a fixing rod (30), wherein the settlement sensor (4) is in force-transmitting contact with the box cover (1202); one end of the fixing rod (30) is fixedly connected to the motor (8), and the other end is slidably connected to the settlement sensor (4) along the settlement direction, and is fixed relative to the settlement sensor (4) in the horizontal plane direction.

6. The direct shear tester according to claim 5, characterized in that: It also includes a vertical load beam (1), the vertical load beam (1) including a beam and a vertical rod connected to the beam in force transmission, the settlement sensor (4) is in force transmission contact with the beam, and the beam is in force transmission contact with the box cover (1202); The crossbeam is kept horizontal, the vertical rod extends vertically downwardly toward the workbench (3), and the ends of the vertical rod are respectively connected to a balance weight (16) and a hanging plate (17) on both sides, wherein the hanging plate (17) is used to hold normal load weights (29) of different masses.

7. The direct shear tester according to claim 1, characterized in that: The second conductor plate (1203) is electrically connected to the resistance plug (31) via a second wire (32); the resistance plug (31) is also electrically connected to the first wire (33); and the resistance plug (31) is electrically connected to the data acquisition instrument (1110).

8. The direct shear tester according to claim 1, characterized in that: It also includes a fixed support (20) and a meter rod component (19) fixedly connected to the fixed support (20), the meter rod component (19) being force-transmittingly connected to the upper box (1205), and the meter rod component (19) is also provided with a shear force sensor (18).

9. The direct shear tester according to claim 1, characterized in that: It also includes a displacement sensor (25) fixedly connected to the workbench (3), and a movable sensor of the displacement sensor (25) is drivingly connected to the housing (27).

10. The direct shear tester according to claim 1, characterized in that: The upper box (1205) and the lower box (1206) are provided with corresponding pin holes, and the pin holes are used for inserting pins (28) in a pluggable manner to achieve detachable covering of the upper box (1205) and the lower box (1206).

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