Yielding Cable Bolt for Mechanized Cable Bolting

摘要

The main factors and mechanisms affecting the behavior of the cable boltreinforcement were studied to obtain a more flexible cable bolt with improved cable bolt's displacement capacity. Adjustability in the cable bolt stiffness was particularly sought after for installations in rock masses with large deformations. As a practical limitation, the bolt tested should be based on a standardized seven-wire steel strand and be suitable for mechanized cable bolting. Paraffin, lubricating oil and silicone sprayed on the surfaces of three steel strands were used as debonding agents and were grouted with cement grout into steel pipes. The debonding results of the steel strands surfaces were positive giving an increase in the displacement capacity of the fully grouted cable bolt. Pull-out tests revealed that debonding the surface of the steel strands reduced the pull-out load of the full grouted steel strand.