Study on Earthquake Damage Characteristic on Mountain Tunnel and Analysis

This paper collects earthquake damage data and research on tunnel in recent years(Wenchuan earthquake,Ms 8.0;Yushu earthquake, Ms 7.1, Chi-Chi Earthquake,Ms 7.6 and so on). Damage patterns and characteristics of mountain tunnels in severe earthquake region are classified: Slope failure near tunnel portal; Spalling and collapse of tunnel portal and end wall; Lining collapse; Longitudinal and transverse cracks of lining; Slant and transverse fracture of lining; Sheared off lining in fault region; Steel frame damage of primary support; pavement or bottom cracks. The damage mechanisms are analyzed and some proposals are put forward for tunnel rehabilitation and new tunnel construction: It is suggested that in strong earthquake areas, a comprehensive aseismic design should be conducted considering tunnel portal structure and slope. Line selection should avoid or reduce passing through active faults and avoid placing tunnels too close to slope faces when planning future tunnels. The paper provides a reference for seismic design and construction procedures of tunnel.