Sensitivity Based Model Updating Parameter Identification for Concrete Arch Dams

Finite element models play a critical role in evaluating the structural behaviour of concrete arch dams. The challenge in finite element analysis is generating reliable and accurate models that represent the dam's current condition due to unknown or uncertain system properties. In this paper we investigated the sensitivity of the structural response (displacements, natural frequency & mode shapes) to variation in the material properties (dam system stiffness, Poisson’s ratio, concrete density and coefficient of thermal expansion) of various arch dam configurations (under operational conditions in non-seismic regions where the behaviour of arch dams is driven by thermal loads) to identify the best parameters to update to this end. It was observed that both the natural frequency and thermal displacements are sensitive to the system stiffness. In addition, the thermal displacements are sensitive to the coefficient of thermal expansion and the natural frequencies sensitive to the concrete density. We conclude that the system stiffness is best updated using natural frequencies and the coefficient of thermal expansion using the thermal displacements.