Abstract: This paper presents a case history of deformation prediction methods for the ground deformations induced by the shielded tunneling with a 9.0meter diameter Tunnel Boring Machine (TBM) in a metro line construction of the Beijing Daxing International Airport. The ground subsidence characteristics, strata loss ratio, and the coefficient of ground subsidence trough width were back analyzed using 30 sets of monitored data. In addition, influence factors, such as, geological conditions that including weighted deformation modulus of the excavation surface stratum, overlying soil thickness and equivalent deformation modulus of overlying stratum and the shield construction parameters such as, soil pressures, distance of excavation, grouting pressures and grouting volumes on stratum deformation, as well as their characteristic parameters caused by the shielded tunneling with a 9 m diameter TBM are performed. A prediction method using key parameters of Peck Theory for the 9m-diameter TBM is proposed. The data back analysis provides the basis for a reliable method for predicting the surface deformation.

Key words: Shielded Tunneling, Metro Construction, Ground Deformations, Influence Factors, Prediction Method