Fine modeling and mechanical analysis of cross-fault railway tunnels
The safety of cross-active fault tunnels poses a significant challenge in current railway engineering construction.Research on such tunnels primarily relies on numerical simulation.However,the refinement level of the finite element structural models used to analyze cross-fault tunnels is often inadequate,and it is difficult to accurately reflect the actual stress and deformation characteristics of the tunnel structure under fault displacement.The influence of invert-filling,railway track foundation,and steel rails are considered in this paper.Three tunnel structure models with different levels of refinement are established by using the finite element software ABAQUS,and the simplified and commonly used ring structure models are compared.The stress and deformation characteristics of the cross fault tunnel structure and its associated track system under the action of active reverse faults are analyzed in detail.The results indicate that the refinement level of the model significantly affects the stress levels and deformation calculation results of the tunnel structures.The longitudinal stiffness and integrity of the tunnel structure are strengthened when considering bottom filling layers and internal auxiliary structures,and the ability of the structure to resist fault is improved.Meanwhile,in light of the severe damage to tunnel tracks and ancillary facilities during the M6.9 earthquake in Menyuan,Qinghai,in 2022,a dedicated study is undertaken to further examine the mechanical behavior and deformation characteristics of tracks under strike-slip fault displacement.This analysis is based on a refined tunnel model,aiming to gain a deeper understanding of how tracks respond and deform under such geological forces.
faulttunnelnumerical simulationfine modelingtrack foundation