METHOD FOR CALCULATING OPTIMUM SUPPORT OF SOFT ROCK

A method for calculating the optimum support of soft rock is established based on the creep mechanism of rock and surrounding rock and the rule of controlling soft rock flowing deformation, by which two key parameters, i.e. optimum support pressure and maximum allowable deformation, can be obtained. The optimum support means an optimum condition which is both safe and economic as suggested by NATM. Two examples are presented to verify this method in the paper.