Abstract: The construction of urban underground passages will inevitably cause soil disturbance and endanger the safety of surface buildings.Therefore, it is particularly critical to accurately predict the surface settlement caused by tunnel excavation.We comprehensively analyze the similarities and differences between the HSS constitutive model and other commonly used constitutive models and believe that the HSS model is more suitable for describing the physical and mechanical characteristics of red clay.Based on Wuhan Guanggu 1st Road/Gaoxin 4th Road Drainage Channel Project, a three-dimensional numerical calculation on the tunnel constructed by double-side heading method is carried out by the finite element software PLAXIS,and the surface deformation caused by the tunnel construction is studied considering the small strain characteristics of red clay.The results show that the surface settlement formsa ‘groove' shape, and it gradually expands with the tunnel excavation until it finally stabilizes.The maximum surface settlement after completing the construction is 21.0 mm.The surface horizontal displacement increases correspondingly with the tunneling and the maximum horizontal displacement is 7.62 mm.During the construction process, the surface settlement transforms from the asymmetric form at the beginning to the symmetric form along the tunnel axis in the end.The more far away from the excavating front is, the smaller of the ground settlement is.