An Assessment of Unpredictability in the Design of Hydraulic Fractures for Stress Amelioration Around Underground Excavations.

摘要

In underground mining operations, stress-induced hazards such as rock bursts are more likely to occur as mining continues. In cave mining operations, stress concentrations can form around underground openings due to the redistribution of the in situ stress.;Destress blasting is a common method for reducing rockbursts. Recently, hydraulic fracturing has been investigated as an alternative method for stress amelioration in underground mines, for it may provide more control of fracture geometry than blasting; however, the unpredictability in the HF governing parameters must be properly characterized and incorporated into the design and analysis of fracture arrays.;Typically, in the early stages of design, parameter uncertainty is generally epistemic, and the appropriate uncertainty model should be applied. The use of deterministic estimates neglects any parameter uncertainty. It is only when additional data are obtained and the parameters are characterized more precisely that more complex methods of analysis can be applied.