Effects of important factors on surface settlement prediction for metro tunnel excavated by EPB

Due to population growth, people demand more and more transportation services, there can be no doubt that the requirement for tunnels will also grow. Mechanized excavations using EPB have been successfully applied, especially in urban environments where there is less surface space available, over the past twenty years. Because of excavation speed and less hazardous working environments, use of the Earth Pressure Balance Machine (EPB) is a more popular method in metro, railway and road tunnels in urban areas. Control of surface settlement is very important when tunnels are excavated in urban areas or beneath important structures. This research mainly discusses effects of important properties like tunnel depth, overburden pressure, tunnel dimension and face pressure using empirical, theoretical and numerical methods used to control surface settlement. Results of these methods are compared with observation data.

► Effective factors in surface settlement for metro tunnel excavated by EPB were investigated using different methods.
► Tunnel depth, overburden pressure, tunnel dimension and face pressure were investigated to control surface settlement.
► Results obtained from empirical, theoretical and numerical methods are compared with observational data.
► The most significant factor in ground surface settlement was found to be tunnel diameter in all methods.
► Inadequacies of empirical methods used for prediction of surface settlement were put forward.