boring methods in soil exploration

Auger and shell boring

Cylindrical augers and shells containing cutting edge or teeth at Iower end suitable for the formation of deep borings. Manually operated rigs are utilized for depths up to 25 m and automated rigs up to 50 m. Augers are appropriate for soft to stiff clays, shells for very inflexible and hard clays, and shells or sand pumps for sandy soils. Small boulders, thin soft strata or rock or cemented gravel are crushed with chisel bits affixed to drill rods. The hole normally needs a casing.