Numerical analysis has become the most important method for analyzing and predicting the deformation of excavations in close proximity to sensitive properties. One of the key problems in a numerical analysis is to select proper soil constitutive models and their corresponding parameters. HS-Small model including HS model parameters and small strain parameters is suitable for numerical analysis of deep excavations because HS-Small model can not only reflect shear and compression hardening but also account for shear modulus attenuating with strain in tiny strain range. However

it is difficult to obtain the whole set of parameters of HS-Small model. Parameters of HS model which determined by soil tests are firstly checked through numerical analysis of five excavation histories in Shanghai area. Determination of some parameters of HS-Small model is then modified based on parameter sensitivity analysis. The most sensitive parameter is determined by back analysis of the field measurements of five case histories. Validity of the whole set of parameters of the HS-Small model is verified by numerical analysis of several typical excavations in Shanghai.