Development of thin, spray-on liner and composite superliner area supports for damage mitigation in blast- and rockburst-induced rock failure events

摘要

Research has been performed for the Workplace Safety and Insurance Board of Ontario (WSIB) to characterize the capabilities of innovative mining support agents, designated as spray-on lining materials (TSL's), as well as combinations of TSL's and conventional spray supports, for mitigating dynamic failure effects created by simulated rockbursts. The assessment of support capabilities of TSLs and ultra-thin hybrid liner supports (superliners) is novel and constitutes work that is unique in the field of underground excavation support design. This study has been performed to assess the capabilities of TSL and conventional spray-on support systems for preventing rock and support material damage that often results due to rockbursting. In this research, TSL products and superliner combinations of each with ultra-thin shotcrete or fibrecrete layers (at 5 and 3 cm thicknesses, respectively) have been tested. Support performance was studied using field scale explosive detonation trials to simulate dynamic failure effects that are known to develop during typical rockburst events. Multiple seismic and high speed photographic monitoring techniques were used to provide detailed information concerning rock motion, surface fracturing, ejected fragment motion and support liner survivability characteristics. The results of this study have validated that thin, spray-on linings (TSL's) and variant layer combinations may be as effective as or better than conventional support materials for mitigating rockburst or like damage in highly stressed mine environments.