Abstract:

Railway tunnels have high requirements for operation safety, especially for highspeed railway tunnels. The typical diseases of tunnel lining, i.e. inverted arch uplift, water gushing and risk of crown top spalling, are analyzed by systematical research, and suggestions on technical measures for improvement of design and construction are put forward. The advices include: (1) The main reasons for inverted arch uplift are groundwater, tectonic stress, expansion force, construction quality and insufficient structural stiffness; it is suggested to take measures such as strengthening the waterproof and drainage of tunnel bottom, increasing the risespan ratio of inverted arch, strengthening the stiffness and strength of inverted arch structure, and ensuring the construction quality of inverted arch. (2) The main reasons of water gushing are complex hydrogeological conditions such as karst, underutilized drainage facilities and construction quality defects; and it is suggested to take measures such as strengthening hydrogeological investigation and construction geological assessment, optimizing drainage design, improving construction quality of lining, and strengthening operation and maintenance management. (3) The main reasons of the risk of crown top spalling are holes of arch lining, insufficient lining thickness and defects in construction joints; and it is suggested to take measures such as optimizing the structural design of construction joints, strengthening the quality control of excavation and waterproof plate laying, and equipping with advanced tooling equipment.

Key words: railway tunnel, lining disease, inverted arch uplift, water gushing, crown top spalling