富水隧道复合地层断面围岩-支护优化的数值分析OA

To address the issue of secondary lining cracking induced by creep of water-rich surrounding rock in the Yanglin Tunnel,this study employs an established hydro-mechanically coupled rock creep model and embeds it into numerical software for secondary development,enabling accurate simulation of the creep behavior of surround-ing rock in a water-rich environment.On this basis,by combining the convergence-confinement method with or-thogonal experiments,the influence of different support parameters on surrounding rock stability was systematically analyzed,thereby determining a new support scheme for the cracked section.Concurrently,field monitoring was carried out during the actual construction process,and key displacement and stress data were obtained.Finally,the programmed model was utilized to perform a hydro-mechanical coupled numerical simulation of the tunnel section under the new support scheme to evaluate its long-term stability.The results indicate that secondary lining crack-ing is not caused by a single factor but results from the synergistic effect of bias pressure from an inclined shale in-terlayer in the composite stratum and the creep behavior of carbonaceous mudstone.After implementing the new support scheme,surrounding rock displacement,crown settlement,and convergence rates decreased markedly,with displacements eventually converging to stable values,indicating satisfactory engineering performance.The numeri-cal simulation results based on the secondary development model are in good agreement with the actual field moni-toring data,confirming the validity and accuracy of the model in simulating surrounding rock creep during tunnel construction.This study provides an important theoretical basis and practical reference for the optimization of tun-nel support and long-term stability assessment in similar water-rich creeping strata.