3D Discrete Fracture Network Modelling from UAV Imagery Coupled with Tracer Tests to Assess Fracture Conductivity in an Unstable Rock Slope: Implications for Rockfall Phenomena

The stability of a rock slope is strongly influenced by the pattern groundwater flow through fracture system, which may lead to an increase in water pressure partly open joints and consequent decrease wall strength. comprehension challenging but vital aspect engineering geology since fractures’ spatial distribution, connectivity, aperture guide both movement quantity within volume. In literature, most accepted methods hydraulically characterise fractured rocks situ are single borehole packer test, high-resolution meters for fractures, artificial tracer tests performed boreholes. However, due high cost requires general absence wells along coastal cliffs, these not be appropriate rockfall-prone areas. this study, unsaturated rocky cliff, affected rockfalls, was investigated combining kinematic analysis, Discrete Fracture Network (DFN) modelling, tests. DFN model potential block failure mechanisms were derived from 3D virtual outcrop models via Structure Motion (SfM) photogrammetry technique. An injected using double ring infiltrometer atop recharge zone determine infiltration rate validate results. test frequently used at different scales disciplines. integration digital photogrammetry, DFN, represent new step rockfall landslide studies. This approach made possible identification patterns system revealed about 10-day transit time injection area monitored slope, with similar conductivity values gathered test. Planar wedge failures volumes ranging 0.1 1 m3 probable results consistent delay between intense rainfall previously documented study their mechanisms.