FORMING HOLES IN COMPRESSIBLE SOIL

摘要

A tool for the formation of holes without extracting the soil comprises a body having a cylindrical calibrating portion, coaxial portions with surfaces for the compaction of the soil and radii decreasing stepwise in the direction away from the calibrating portion, and terminating in an end piece. The body has also transition portions with surfaces for the compaction of the soil, forming a smooth transition from a coaxial portion with a larger radius to an adjacent coaxial portion with a smaller radius. The surface for the compaction of the soil of each coaxial portion is a conical surface having the configuration of a ribbon wound from the calibrating portion to the end piece and comprising the transition portions.