ABSTRACT
A large number of highways run across the mountains in the central and western regions of China, therefore, tunnel engineering plays a significant role in the highway construction. Due to the complex topographic and geological conditions, large deformation phenomena in soft rock tunnels are frequently encountered, which induce different degrees of damage of primary support and secondary lining. More seriously, severe extrusion induced by large deformation commonly leads to instability of tunnel, resulting in significant difficulties in tunnel design and construction. Consequently, the proper supporting measures applied in large-deformation tunnels are of importance to complete the constructions safely.
