seen and device for inforing of rorformade building elements in a markformation

摘要

A tubular structural member is inserted in a ground or soil formation by drilling the formation ahead of a cutting edge on the member proper and bringing the member to perform a combined rotary and axial movement so that the cutting edge is driven into the drilled zone. An apparatus for practicing the method comprises a drilling machine having a feed device, a cutting edge at one end of the structural member and a means for rotating and axially displacing the member.