New development of rock bolting technology for coal roadway in China

The research achievements in rock bolting techniques were introduced systematically.As respect to supporting theory,it is thought that the main functions of rock bolting lie in controlling the dilatant displacements and collapse,such as the separation,slip,cracking of surrounding rock mass in the bolting zone,keeping the completeness of surrounding rock mass to the most extent and avoiding disastrous displacements.The geomechanical measuring instruments include the hydraulic fracturing measuring kit of in-situ ground stress in small boreholes,the measuring device of in-situ rock mass strength and the borehole camera,and the technical characteristics and using methods of the geomechanical measuring instruments were described.The characteristics and procedure of the dynamic information designing method of rock bolting were addressed,and the elements and functions of the bolting designing software directing to on-site engineers also were described.The mechanical performance of high strength bolting material was analyzed,and the present developing state of the bolting machines also was introduced.