Test operation procedures

1、 Test preparation

1. Cut the undisturbed soil sample (or prepare the disturbed soil sample manually) with the ring cutter according to the standard test method;

2. If the soil sample needs to be saturated, the methods of saturation include vacuum pumping method, immersion saturation method and water head saturation method, etc. the soil sample saturation method of this test shall be correctly selected according to the test specifications.

2、 Operation steps

1. Before the test, water shall be injected into the water tank, the needle valve at the top of the plexiglass pipe shall be opened, and then the three-way switch shall be screwed to "make-up water" in order to make the water level of the plexiglass pipe reach the upper limit (50cm water head); the three-way switch shall be screwed to "permeate", the container switch shall be opened, so that the air in the lower permeable stone and the pipeline can be drained out, and the three-way switch shall be screwed to "close" when the water seeps out of the permeable stone, and at the same time, the Close the container switch.

2. Cover both ends of the saturated soil sample with wet filter paper, put it into the permeation container, then place the sealing O-ring, sealing pressing plate, tighten the locking bolt (to avoid bottom leakage) on the outer side of the ring cutter in turn, then place the permeable stone, guide ring and pressure transmitting piston above the soil sample, and press the rubber wood handle against the piston;

3. Open the air inlet switch, adjust the consolidation pressure to the specified value with the pressure regulating valve according to the test requirements, and then adjust the consolidation pressure switch to the open state to start consolidation;

4. After the consolidation is completed, open the three-way switch to make up water in turn, so that the water level of the plexiglass pipe is close to the upper limit (below 50cm), and close the needle valve at the top of the plexiglass pipe;

5. According to the test requirements, use the pressure regulating valve to adjust the permeation pressure to the specified pressure value, successively screw the three-way switch to "Permeation" to start the permeation test operation.

3、 System control

1. Turn on the computer, run the test software, set the relevant parameters on the software interface, start the data collection, turn on the container switch, and start the test.

2. After the test, reset all switches, upload the test data to the computer, and select different time periods to calculate the corresponding permeability coefficient according to the relationship curve between time and water head change.

3. Output and print the test results when necessary;

4. After the test, reset the pressure regulating valve, turn off the air source and power supply, take out the soil sample and clean the container.

4、 Precautions

1. The test personnel shall operate according to the procedures;