STABILITY ANALYSIS OF SURROUNDING ROCK OF MULTI-ARCH TUNNEL BASED ON COUPLED FLUID-SOLID THEOREM
基于流固耦合理论的连拱隧道围岩稳定性分析

Along the freeway from Changde to Jishou in Hunan Province,some large span multi-arch tunnels have been built to meet the need of engineering.Based on the coupled fluid-solid theorem,numerical analysis for the stability of surrounding rock has been done with fast Lagrangian analysis of continua in three-dimension(FLAC3D) by considering the multiple factors including surrounding rock classes,tunnel depths,groundwater tables,construction methods and initial supporting systems.According to the numerical analysis of surrounding rock with classes III,IV,V under all kinds of calculation cases,the results of principal stresses,displacements,plastic zones,pore pressure distribution and the mechanical characters of supporting system including anchors and shotcrete,have been obtained.The seepage mechanism of multi-arch tunnel has been discussed;and the pore pressure distribution of deep-buried tunnel has been studied.The achieved results are successfully applied to guidance of the tunnel construction for waterproofing of this freeway.Furthermore,the study results can provide a theoretical basis for the design of multi-arch tunnel in aquifer strata.