Abstract:

 Due to multiple types of tunnel lining cross-section, synchronous construction of secondary lining and tunnel boring machine(TBM) excavation is difficult to realize and the advantage of TBM efficient excavation is limited. Accordingly, the distribution of secondary lining with variable diameter in TBM-driven section and the adverse effects of the diversity of secondary lining on the synchronous construction of TBM excavation and secondary lining of plateau railway tunnel project are investigated. Then, the solutions of reducing the types of lining crosssection and using lining trolley with variable diameter are proposed, i.e., the original lining crosssections with six inner contour diameters of 914, 926, 930, 940, 944, and 954 cm are optimized into three of 914, 926, and 940 cm, and lining trolley with variable diameter and a benchmark base diameter of 926 cm is adopted. The proposed scheme can reduce the trolley cost and the fitting error of variable diameter section, and realize the synchronous construction of TBM rapid excavation and secondary lining, providing a reference for the synchronization of TBM rapid excavation and secondary lining under the working condition of continuous belt conveyor.

Key words: plateau railway tunnel, tunnel boring machine, lining crosssection optimization, synchronous lining, trolley with variable diameter