Exploration of how the natural ground and geological structure of the front of the tunnel face

摘要

PROBLEM TO BE SOLVED: To provide a method of surveying natural ground and geological structure ahead of a tunnel face, by using a borehole camera capable of being applied to soft natural ground on which pit walls do not support themselves.;SOLUTION: By forming a borehole ahead of a tunnel face by using transparent pipe members P as relay pipes 14 of a boring machine B, the transparent pipe members P are installed in the borehole. The transparent pipe members P installed in the borehole have a borehole camera 3 inserted into themselves, and the borehole camera photographs the condition of natural ground via the transparent pipe members P.;COPYRIGHT: (C)2012,JPO&INPIT