Injection spike or anchor, for tunneling construction through loose rock, is a construction steel rod with an air slit along its length with a thread at the rear end and welded cutting burrs at the front end

摘要

The injection spike or anchor, for tunneling construction, has a rod (1) of construction steel with an increased tensile strength compared to the anchor pipe. The rod has an air slit (5) for flushing air, and a thread (2) is tapped at the trailing end. Welded burrs (3) at the leading end act as temporary drilling pins as a substitute for a drilling rod with a drilling crown. The slit is cut along the length of the rod, with a width of 8 mm and a depth of 13 mm, and is covered with a construction steel rod (4).