Abstract:Abstract:Research purposes: The left high and steep slope of super major Shapo bridge 4# ~ 10# pier section,which located in the Guizhou western part of Shanghai - Kunming passenger dedicated line,is a typical dip bedding high - steep slope,and was described as rockfall site in the investigation phase. However,during construction,the site was found that rockfall scale and engineering hazard far exceeds the original understanding. Based on the UAV aerial,and the comprehensive investigation and geological analysis, the causes of collapse and rockfall, slope deformation failure mode were found out,and the feasilsle engineering measures were formulated. Research conclusions:(1) On the left side of the Shapo super major bridge 4# ~ 10# pier was bedding high - steep slope,witli serious rockfall hazards, which was caused by gently inclined bedding slope slip - pressure - induced deformation and damage of crack. (2) The key governance scope of steep - high slope was in the range of 35 m from cliff wall. The measures of section protection, and suitable comprehensive improvement measures are adopted such as the unloading, anchorage ( beam), spray anchor net, active protection networli, anchored anti - sliding pile, anti collision wall,cut - row ditch, etc. (3) Route selection near the side of mountion should be far from steep – high slope # and regard the steep - high slope witli the characteristics of upper harder and lower soft inclined bedding for avoiding the large - scale rockfall hazards. (4) Using the UAV aerial witii advantage of shooting from top to down can play a multiplier effect to survey unfavorable geological hazards of the complicated difficult mountainous areas. (5) The research conclusions can be used to the steep - high slope treatment of tiie Shapo super major bridge 4# ~ 10# pier# and provide reference to the alignment, survey and design of t!ie development rockfall area of railway and expressway.