Rigidity criterion for rockburst in the Yufengsi tunnel in Lijiang City of the Yunnan-Tibet Railway, China.

The rigidity criterion for rockburst of the tunnel wall is studied and applied in the Yufengsi tunnel of the Yunnan-Tibet Railway according to the minimum energy theory, On the basis of the rigid compression experiment for complete stress-strain of representative wall rock specimens from the tunnel, combined With the in-situ stress data and numerical simulation results, the failure processes of three rock types at different confining pressures are analyzed and the rigidity curves of the plastic rock mass and elastic rock mass in the tunnel are obtained, Finally, the rockhurst hazards of the three types of rock in the tunnel are analyzed and evaluated using the rigidity criterion, The degree of rockhurst hazards of basalt is highest, next comes that of limestone, and that of sandstone is lowest, This estimation can he used as reference for the tunnel design.