Rapid Assessment and Classification for Seismic Damage of Mountain Tunnel Based on Concentric Circle Method
Table 7
Discretized SDL and description of mountain tunnel.
SDL
Seismic damage description
Discrete value
Extremely severe
Extremely severe degradation and damage of tunnel structure; completely impassable traffic; necessary measures should be taken immediately, otherwise further aggravating SDL
4
Severe
Severe degradation and damage of tunnel structure; traffic safety threatened severely; measures should be taken as early as possible, otherwise further aggravating SDL
3
Moderate
Moderate degradation and damage of tunnel structure; traffic safety threatened moderately; measures should be taken in time, otherwise further aggravating SDL
2
Slight
Slight degradation and damage of tunnel structure; traffic safety guaranteed slightly, normal usage unaffected; targeted and key monitoring necessary
