The large-scale deep-buried tunnel group of JinpingⅡhydropower project consists of 4 headrace tunnels,2 auxiliary tunnels,and 1 drainage tunnel,with a total length of 118 km.These tunnels are deelply buried with high insitu stress.The geological situation is very complicated.During the tunnel excavation,damages occurred due to high insitu stress.Through statistical analysis on the rockburst occurred in the tunnels,and considering the experiences on the rockburst prevention and treatment accumulated during t...