Risk assessment of faulted rock slopes during blasting excavation considering copula-based rotational anisotropy random fields

Blasting excavation inevitably causes permanent displacement of faulted rock slops, which threatens the stability of the slope. Previous studies on slope stability during blasting excavation have primarily relied on deterministic analysis, with limited consideration given to the rotational anisotropy spatial variability and cross-correlation of rock properties. In this study, a random analysis framework for assessing the risk of faulted rock slope under blasting excavation is developed by introducing the random field theory and copula theory to consider the effects of rotational anisotropy spatial variability and cross-correlation of rock properties. This study investigates the influence of copula selection and rock spatially variable rotational anisotropy on statistical characteristics of the risk of faulted rock slope. Furthermore, the proposed framework was illustrated by a case study and systematically compared with deterministic analysis. The results reveal that the commonly used Gaussian copula may underestimate the risk of faulted rock slope. The rotational angles of rock strata, scale of fluctuation and cross-correlation coefficient have a significant influence on the risk of faulted rock slope. And the case study indicates that the proposed framework provides a practical and realistic tool for assessment the risk of faulted rock slope under blasting excavation.