The application of the thrust bolting concept for longwall.
Proceedings of the 23rd Annual Institute on Mining Health, Safety and Research, Blacksburg, Virginia, August 24-26, 1992. Tinney G, Bacho A, Karmis M, eds., Blacksburg, VA: Virginia Polytechnic Institute and State University, 1992 Aug; :137-145
An innovation in coal mine roof support, developed by the Bureau of Mines, is currently being used in underground mines in the western United States. The technique, called "Thrust Bolting," converts a traditional passive roof support system, a full or partial column rebar bolt, into an active support system by following a specific installation process. The thrust bolting system provides two advantages for ground control. First, because the system is active, no roof movement is necessary to put the bolt in tension. This minimizes the possibility of strata separations in sedimentary roofs, minimizing progressive-type roof failures. Secondly, the tension placed on the system is independent of mechanical devices or torques. This eliminates the highly variable frictional losses that occur between the bearing plate and the bolt head and in the threaded portions of traditional active support systems. These two improvements create a safer working environment for mining personnel. Thrust bolting has been implemented as the primary support technique for longwall gateroads at several western coal mines. This paper describes the theory, application, and advantages of thrust bolting and presents the results of mine measurements made to assess the support performance during entry development and subsequent longwall retreat.
Coal-mining; Coal-miners; Coal-workers; Mine-workers; Miners; Mining-industry; Underground-mining; Underground-miners; Longwall-mining; Ground-control; Safety-practices; Safety-programs; Safety-measures
Tinney-G; Bacho-A; Karmis-M
Proceedings of the 23rd Annual Institute on Mining Health, Safety and Research, Blacksburg, Virginia, August 24-26, 1992