Improvements to field and remote sensing methods for mapping discontinuity persistence and intact rock bridges in rock slopes

We apply a fracture network engineering approach to discontinuity trace mapping, using new intensity factors to describe intact rock bridge trace intensity R21, and blast-induced fracture intensity B21. We emphasize the importance of multi-scale characterisation of discontinuity persistence and rock bridges in rock slopes, and we distinguish between different classes of intact rock bridges based on scale and geometry, with particular attention given to the distinction between laboratory sample scale intact rock bridges on incipient discontinuities, and larger rock mass bridges, which represent metre or larger scale intervals of fractured rock mass that may exist between very high persistence joints and faults.