Soil improvement techniques are widely used in deep excavation projects near metro stations; however, there remains a lack of reliable guidance for determining the parameters of the Hardening Soil model with smallstrain stiffness (HSS model) for cement-stabilized soils. Laboratory tests on cement-stabilized soils from the Shanghai West Station project were performed at curing ages of 3, 7, 14, and 28 days to determine the corresponding HSS model parameters. By comparing these results with the parameters of in-situ soil, the strength development and interrelationships among the parameters at different curing ages were analyzed, leading to the establishment of an HSS parameter determination method based on curing-age evolution. Numerical analysis of an engineering case shows that the calculated horizontal deformation of the retaining wall agrees well with the measured values, validating the applicability of the proposed parameter determination method for excavations involving cementstabilized soils; furthermore, the effects of curing age and related parameters on excavation behavior are analyzed to provide references for engineering design.
