Method of driving an underground cavity

摘要

Method of driving an underground cavity in unstable ground, mainly consisting of loose rock, by forepoling advance, in which the heading face is worked section by section and a supporting arch is placed at the end of each working section, and forepoling elements resting on this supporting arch are driven into the ground in the direction of advance. The forepoling elements extend right into the next working section but one and are located at a radial distance from the forepoling elements of the preceding working section. In this arrangement, the intermediate space between the forepoling elements of the successive working sections at the heading face is protected against the trickling-out of loose rock. Before the forepoling elements (31) of a new working section (II) are driven in, the ground (18), at least in the marginal area (32) between the forepoling elements (31), still to be driven in, of the new working section (II) and the front ends (17), extending into the new working section (II), of the already driven-in forepoling elements (13) of the preceding working section (I) is stabilised and/or consolidated by injecting a cohesive filling material.