Electric strain direct shear apparatus for geotextile

Electric strain direct shear apparatus for geotextileUsed to determine the shear strength of soil,Adopting high-resolution color screen display and intelligent microcomputer control, the work process is automated, easy to operate, and has high precision,Stable speed、Reliable performance、attractive appearanceThe instrument uses high-performance servo motors as the driving source, greatly reducing instrument vibrationElectricityOptional dynamic shear rateIt can quickly change the speed, is easy to use, durable, and has an automatic shutdown mechanism when returned.The main features are: the transmission mode has been changed from the original DC servo motor to a compact stepper motor, and the motor power supply has been changed from the original220Vchange to24VThe safety voltage and lever force point have been improved from the original blade type to a bearing type. This instrument is safer, more sensitive, compact, more suitable, and has lower noise than before. Therefore, the use of this instrument lays a solid foundation for laboratory automation.

Electric strain direct shear apparatus for geotextileMainly used to determine the shear strength of the graph. Under different vertical pressures（400KpaThe300KpaThe200 KpaThe100KpaThe50KpaOptionally, apply horizontal force for shear to obtain the shear stress at failure, and then determine the soil's shear strength parameters, internal friction angle, and cohesion based on Coulomb's law. (Execution standard:50123-2019 GB/T50123-2019JTG E40-2007inT0140-1993/T0141-1993/T0142-1993/0143-1993/T0176-2007）.

Net weight of single electric instrument95kg(including weights), external dimensions（850*550*1100）mm... "

Technical Indicators:

1、 最大垂直荷重：≥400 KPa；

2Pressure level:50、100、200、300The400KPa；

3Corresponding weight of weights:1.275、2.55、5.1、7.65The10.2KPa(The hanging disc is the first level);

4Leverage ratio:1:12；

5Soil sample:30cm²；

6Maximum horizontal shear force:1.2KN；

7Power type: electric;

8Motor speed:0.1、4The12r/min；

9The displacement of the propulsion rod is driven by each rotation of the motor0.2mm；

10Corresponding cutting speed:0.02、0.8The2.4mm/min；

11Power supply:220V 50HZ.

1Usage:

1The instrument should be placed on a dry cement floor indoors to adjust its level and stability, and the instrument workbench should be leveled with a spirit level

2. Slightly tighten the lever leveling device (the top thread at the bottom of the 17th balance bracket on the quadruple link is leveled; on the single link, rotate the 20th leveling handwheel to make the lever horizontal), so that the frame and lever are basically stable.

3. Check whether the two sides of the lever are rubbing against the suspension ring, and whether the bearing rolling should be flexible. Adjust the balance hammer, hold one side of the crossbeam with a right angle ruler to balance the weight of the lever, fasten it with a nut and the balance hammer, loosen the lever leveling device (remove the top screw of the 17th balance bracket on the fourth link and remove the leveling rod; for the single link, rotate the 20th leveling handwheel counterclockwise to separate it from the lever), fully detach it from the lever, and place the lever in the middle position of the column.

4. Check the cutting box, the rolling steel ball should be square, placed in the ball frame, and roll flexibly. Place the soil sample according to the regulations, place the permeable stone and pressure plate, check the power supply, and turn on the equipment after connecting it to the power supply

5. Press the adjustment button to set the device to manual mode, shake the handwheel to make the upper box just touch the force ring, and zero the dial gauge (a pointer type dial gauge is required for the force ring). At the same time, reset the vertical dial gauge to zero. Rotate the pressure transmission rod and raise the lever appropriately. If the sample is not preloaded, it can be slightly raised to prevent the soil sample from sinking after pressurization and causing the lever to tilt too much.

6. Select the shear rate according to the test requirements and choose the working mode of the equipment (can be switched manually/automatically by pressing the knob)

7. Apply vertical load according to the actual needs of the project (the lever should be located basically in the middle of the column). After the soil sample is subjected to or consolidated, unscrew the screw pin, loosen the rotating screw on the lever fulcrum device frame, and then unscrew the rotating screw on the adjustment and balance bracket to remove it. Prepare to conduct experiments. The experiment can be divided into two modes:

Automatic mode: Press 【 Forward 】/Press the 'Stop' button to cut at a uniform speed, and then press the 'Forward/Stop' button again to stop cutting.

Manual mode: When the knob is turned evenly, the device cuts at a uniform speed.

When the pointer of the equivalent force ring dial gauge no longer moves forward or moves backward, record the value. When there is no peak reading on the dial gauge during the general cutting process, it can be cut to6mm。

8. After the cutting is completed, exit the cutting and restore the vertical position (by pulling out the pin numbered [20], the push rod can be quickly rotated back).

Auto mode: Reset Press 【 Return 】/Press the 'Stop' button to return at a uniform speed, and then press the 'Return/Stop' button again to stop the device.

Manual mode: When the knob is turned evenly, the device returns at a uniform speed.