Coarse-grain soil direct shear tester test method - Database & Sql Blog Articles

Test - lowercase jpg

Kaixin micro test

Test probe P100-M3

Direct shear test method for coarse-grained soil:

1. Place a pad on the top of the sample. If the surface is uneven, fill it with sand and compact it, or use cement mortar to level it.

2. Select the appropriate reaction device based on the maximum vertical load. Install the vertical and shear loading devices according to the dry testing setup requirements. When conducting the test in a test pit, use the top and side walls of the pit as the reaction force.

3. Place the roller, pad, jack, and vertical column on the pad and connect them to the reaction device, ensuring that all components are aligned along the same axis.

4. Position the vertical and horizontal displacement side tables on the top of the sample and the thrust surface symmetrically using the magnetic table on the steel beam. There should be at least two side tables. The fulcrum of the steel beam should be placed outside the influence zone of the sample.

5. Adjust the displacement side tables and record the initial readings. Align the horizontal jack axis according to the settlement amount.

6. Apply the estimated maximum shear load in 8–10 steps. Immediately after each load step, measure the shear and normal displacements. After 5 minutes, apply the next load increment. If the increase becomes significant, reduce the load step size. The applied load before reaching the peak should not be less than 8 steps.

7. Record the peak shear load when it occurs, and continue shearing until the shear displacement reaches 10% of the sample's side length or diameter. If no peak is observed, use the shear load at 10% displacement as the failure value.

8. Document all phenomena observed during the test, such as ground heave, settlement, crack propagation, and any sounds or movements within the sample. This helps in understanding the behavior and failure mechanism of the soil under shear stress.