Research in Long Hole Exploratory Drilling for Rapid Excavation Underground
Semi-annual technical rept. 27 Feb-27 Aug 1971
JACOBS ASSOCIATES INC SAN FRANCISCO CA
Pagination or Media Count:
A new concept of handling rock drilling tools has been designed. The purpose is to provide a means to drill a four-inch diameter hole 1,000 feet horizontally in moderately hard and hard rock. The hole will be used to probe ahead of tunnel boring machines to sample for rock conditions or hazards such as water or gas. Equipment is being made and assembled in Burlingame, California for a granite quarry test near Watsonville early in 1972. A hollow spindle rotary drill or skids will permit storing 1,000 feet of 2-38 inch diameter flush OD drill rod in one piece in a pipe on the ground behind the drills. This rotates an in-hole percussion device for rapid drilling or a diamond core barrel for sampling. A special rapid rod extractor, using powered opposing wheels, has been designed and is being made.
- Mining Engineering
- Civil Engineering