Abstract: The SichuanTibet railway tunnels bored by tunnel boring machines (TBMs) are long and deep, some complex and severe geological conditions may be encountered, such as hard rock burst, soft rock large deformation, fault fracture zone, karst, harmful gas, high temperature damage, as well as the construction problems including high altitude hypoxia, and longdistance reverse slope with water inrush. To ensure the safe and efficient construction of TBM, it is essential to carry out TBM adaptive design for SichuanTibet railway tunnels under complex and severe conditions. The difficulties and construction risks of TBM tunnels of SichuanTibet railway are summarized, and based on the previous typical engineering experience, the adaptive design scheme is put forward from the aspects of TBM equipment configuration, structural optimization, and construction measures, which can provide reference for equipment configuration and construction process optimization, and improve the capacity of construction risk response. Meanwhile, based on intelligent and information technology, the intelligent early warning system of complex geological risk, construction collaborative management platform, and online monitoring and diagnosis system of equipment status are integrated on TBM, realizing TBM intelligent auxiliary construction and risk prevention and control.

Key words: railway tunnel, SichuanTibet railway, tunnel boring machine, construction risk, adaptive design