Comprehensive Assessment of Rock Burst of Yufengsi Deep-buried Tunnel in Three-river Orogenic Belt,Northwest Yunnan

The mechanism and prediction of tunnel rock burst have been two main research issues in engineering geology and rock mechanics for many years,and become the choke points for underground engineering development.Taking an example from Yufengsi deep-buried tunnel of Yunnan-Tibet Railway which passes through the south part of Yulong Mountain of Three-river Orogenic Belt,factors related to tunnel rock burst are systemically analyzed on the basis of field investigation.According to the results of rock mechanics test,field stress analysis and numerical simulation,multiple criterions have been adopted to predict and comprehensively assess the risk of tunnel rock burst,which has important instruction to the deep tunnel design and the prevention of disasters associated to tunnel rock burst.