General Solution for Longitudinal Response of Shield Tunnel Considering the Effects of Joints and Soil Shear Resistance

ABSTRACT This study introduces a general solution for assessing the longitudinal response of shield tunnels, incorporating the combined effects of joints and soil shear resistance. The analysis employs the Timoshenko beam spring model atop a Vlasov foundation, subjected to arbitrary loads and various boundary conditions. Governing equations and relevant boundary conditions are derived using a variational formulation. Validation is conducted against existing simplified analytical solutions and finite element method simulations, showing the efficacy of the proposed solution. Comparative analyses of different models are undertaken based on the potential energy considerations. Additionally, a parametric study explores influential factors such as subgrade shear and reaction coefficients, as well as joint stiffnesses. Findings highlight the significance of accounting for the soil shear resistance and caution against underestimation when using equivalent continuous beam models. The proposed solution improves the prediction accuracy for the longitudinal response of shield tunnels and offers several benefits including compatibility with other analytical models, computation efficiency, and versatility in considering diverse loads and boundary conditions.