Inverse analysis of Hypoplastic Clay model for computing deformations caused by excavations

For effective applications of the adaptive management approach, inverse analysis procedures are used to update model parameters based on observations made during early stages of construction projects. These updated parameters are then used to compute the responses at later stages. This paper describes the inverse analysis of lateral wall deformations from a deep supported excavation in Chicago using the Hypoplastic Clay model. Initial parameters for the soil model are based on inverse analyses of laboratory test results and site-specific correlations with in situ data of Chicago clays. Field observations made during construction are used to conduct sensitivity and correlation analyses, and the most effective parameters to optimize are selected. These parameters are optimized at three depths during excavation where plane strain conditions were applicable. Changes in the optimized parameters at the excavation levels are analyzed to assess how and if the parameters are optimized satisfactorily. Computed responses using the optimized parameters are compared to field measurements, and recommendations regarding the parameters to optimize are provided.