摘要
Perilous rock is one of the main geological hazards in sandstone grottoes, especially in Yungang Grottoes. The study on causes for perilous rocks is useful for prevention and cure of perilous rocks in sandstone caves. In this paper, the various influence factors of perilous rocks were analyzed in detail by engineering geology method. Box-like synclines and fractures were macroscopic tectonic origins of perilous rocks. The near E-W tensile cracks and N-E shear fissures directly controlled the perilous rocks’ evolution. The result provides an important basis for prevention and cure of perilous rock masses, and is valuable to analyze the stability of Yungang Grottoes.