Resilience analysis and prevention methods for expressway tunnel across the shale gas exploitation area based on the focal mechanism

China ranks as the world’s third-largest shale gas producer, with over 500 wells drilled in the Wufeng – Longmaxi formation of the Sichuan Basin since 2010. These developments raise concerns regarding their impact on transportation tunnels. Hydraulic fracturing perturbs pore elastic stresses, elevates pore pressure, and may induce seismic slip, leading to clustered seismic events. This study investigates the mechanical mechanisms of fault slip triggered by hydraulic fracturing and evaluates its influence on tunnel performance. A three-dimensional nonlinear finite element model is used to analyse tunnel lining deformation and damage under varying fault slip conditions. Results show that tunnels near fault planes suffer substantial damage. Although the fault-plane friction coefficient has limited influence on tunnel strain, it strongly governs fault slip initiation and dislocation magnitude, which are critical to tunnel damage. Enhancing concrete grade can improve tunnel seismic resistance. A resilience evaluation framework is proposed by selecting appropriate indicators and constructing performance recovery functions. The seismic resilience of tunnels decreases significantly with increasing PGA, but improves with higher fault friction coefficients and concrete grades. Key time points are extracted to develop monitoring, early-warning, and disaster prevention strategies for tunnel deformation and damage.HighlightsThe mechanical mechanisms responsible for fault slip induced by hydraulic fracturing are clarified, and the magnitude of such slip is assessed.By employing a three-dimensional nonlinear finite element calculation programme, the study explores the impact of fault slip on the deformation and damage patterns of highway tunnel linings.Based on the numerical calculation results, the seismic resilience indices of the tunnel is analysedThe control methods for shale gas exploitation in the area around highway tunnels have been summarised.