Hill Slope Falls and Long-Runout Rockslides under Large-Scale Underground Blasting

Resumo

The collected data on long-runout rockslides induced be large-scale underground blasts are presented. The critical conditions of the rockslides are determined as a function of the dynamic impact, rockfall volume, as well as the slope height and gradient. It is shown that the main condition for the mobile rockslides is their volume exceeding 10⁶-10⁸ m³. A collateral effect for rockslides in case of smaller volume of 10⁶-10⁷ m³ is the presence of an acceleration phase at the slope toe and the absence of a counter slope. The relations of the avalanche front range, rockslide volume and fall height are given. It is mentioned that the avalanche range is associated with their composition, in particular, rock-and-ice or rock-and-snow avalanches feature increased mobility starting from their volumes of 10⁵ m³. A brief review of theoretical and modeling studies intended to explain the reduced friction in large avalanches is provided.