Research on Selection of Prefabricated Lining Design for Single-Track Tunnel of High Speed Railway

Abstract

Research on selection of prefabricated lining design for 350 km/h single-track tunnel of high-speed railway was carried out. The finite element calculation software was used to analyze the internal force characteristics of the whole lining under different surrounding rock pressure conditions based on the “load-structure” model. On this basis, consider reducing the original lining stress forms as much as possible, and dividing the lining structure into 8 parts at the small bending moment corresponding to the overall lining, and analyzing the surrounding rock pressure under the surrounding rock loads of III, IV and V and the force and deformation characteristics of the block assembly structure under joint stiffness. Compared with the overall lining structure, the prefabricated lining structure increases the maximum axial force by 0.3%, 1.6% and 2.4% respectively, increases the maximum bending moment by 16.8%, 11.1% and 0.9% respectively, increases the maximum lateral displacement by 143.1%, 129.2% and 101.1% respectively, and increases the maximum vertical displacement by 14.3%, 17.7%, 8.3% respectively. The safety coefficients of the assembled lining all meet the requirements of the specification, and the joint stiffness has little effect on the lining safety factor.