METHOD FOR SURVEYING GEOLOGY IN FRONT OF FACE OF TUNNEL

摘要

PURPOSE: To provide a survey method for geology in front of face with ease and at a low cost without disturbing excavation work in a tunnel and obtain sure information on survey in front of face which is easy to evaluate. CONSTITUTION: A pit hole 7 for an acoustic source is drilled in front ground 3 of a face 2 for a desired distance with a drill machine 10. The thrust sound generated in the pit 12 of the drill machine 10 in the drilling work is detected with an acceleration sensor 20 put on the end of the drilled hole for reception 5. From the variation pattern and acoustic characteristics of the detected signal, geology of the front ground 3 of the face 2 are grasped.