Semi-shield method and apparatus for the same

Abstract

A semi-shield method is utilized to make it possible to advance pipes for an extremely long distance in the ground. In the method, a semi-shield machine and a plurality of advance pipes are pushed one after another into the ground, and sub-pipes are interposed between adjacent advance pipes. Each sub-pipe is formed with injection holes arranged in the circumferential direction. A tail void filling material is injected under pressure into a tail void provided around the outer circumference of the advance pipes through the injection holes so that the filling material is distributed uniformly over the entire circumference of the advance pipes. With this arrangement, it is possible to reduce the friction between the outer periphery of the advance pipes and the natural ground and thus to advance the advance pipes for an extremely long distance in the ground.

Dependencies are inferred from the claim text.