Optimizing Material Parameters to Best Capture Deformation Responses in Supported Bottom-up Excavation: Field Monitoring and Inverse Analysis

Deep excavation projects in urban areas need to control ground deformation to avoid structural damage from construction activities. Because of the inherent uncertainties of subsurface conditions, it is not easy to predict the ground deformation during the design phase. The inverse analysis technique can be a practical solution, which involves updating the soil parameters to find the best fit to the field observations. This paper describes the inverse analyses and the results for supported bottom-up excavation site located in Incheon, Korea. Observations of the lateral deformation of the excavation support wall were used for the inverse analyses to find the optimized stiffness. To understand how the optimized parameter evolves throughout the excavation process, the Mohr-Coulomb (MC), hardening soil (HS), and hardening soil with small strains (HSS) models were employed in the investigation, and the responses of each model were compared. This paper summarizes the stiffness evolution of each soil model as the excavation proceeded. Ground settlement results with the optimized stiffness were also discussed.