Study on the anti-dislocation resilience of mountain tunnels crossing normal faults

The performance and resilience of tunnels subjected to fault dislocation have attracted increasing attention. This study proposes an assessment method for the anti-dislocation resilience of mountain tunnels under normal fault dislocation. The mountain tunnel system comprises both structural and non-structural systems. A substructure method is developed to calculate the dislocation response of structural components and determine their fragility characteristics and residual functionality. The fragility and residual functionality of non-structural components are estimated through rational assumptions and simplified methodologies. By establishing hierarchical relationship between components and the tunnel using the hierarchical belief rule base method, the residual functionality of the mountain tunnel under normal fault dislocation is quantified. Integrating the residual functionality with functionality recovery models enables determination of the tunnel's anti-dislocation resilience index. Within the proposed assessment framework, the Monte Carlo simulation method accounts for randomness and uncertainty in component damage state determination. The efficacy of the anti-dislocation resilience assessment method is validated through three representative tunnel case studies, underscoring the importance of anti-dislocation measures. This method is applicable to various tunnel types and fault conditions, providing new insights for evaluating tunnel anti-dislocation resilience.