Roadway bolts tail broken mechanism and design of reasonable structures

With material mechanics theory, expounded bolt tail subjected to no center load action and roof bolt broken mechanism while roadway was supported with bolts. By theoretical analysis and lab test, put forward a kind of new type bolts which may prevent bolt tails from being broken, bolt construction structure’s pattern, and bolt made technology. It was illustrated that the reasonable grading relationship between bolt body’s diameter and bolt tail’s screw diameter. At the same time, compared disturbed values of the thick tail metal bolt and common bolt under the load action. It is verified that roof bolt broken problem may be solved with new type’s thick tail bolt.