Laboratory hydraulic fracturing test on large-scale pre-cracked granite specimens

Hydraulic fracturing could be a useful method for controlling the propagation path of cracks near an injection borehole by means of the perforating technique, pre-manufactured cracks, or the natural defects of the rock mass. The crack propagation path is not commonly along a fixed direction. Rather, it is likely to deflect gradually toward the direction of maximum horizontal stress. In order to study the behaviours of crack deflection in the...