Fig. 15From: Assessing the stability of underground caves through iSUMM (innovative, straightforward, user-friendly, mechanically-based method)On the left: topographic survey of the underground quarry before failure, with indication of the sinkhole perimeter (Bonamini et al. 2013). On the right: movements of large volumes of rock along sub-vertical fractures surveyed in 2000 (Vattano et al. 2013)Back to article page