Page 57 - SIASATAN TAPAK
P. 57
6. SAMPLING IN BOREHOLES
• Sampling procedures using thin-walled piston sampler:
• A thin-walled sample tube: This tube is sharpened at the end and
contains a close-fitting sliding piston.
• A sliding piston:The piston is slightly coned at its lower face.
• Drive head: The sample tube is fitted to the drive head, which
connects to hollow drill rods.
• During soil sampling, the thin-walled sampler is lowered into a
borehole.
• The piston, located at the lower end of the tube, helps push the soil
into the tube.
• The tube is then extracted from the borehole, preserving the intact soil
sample inside.
