Global sensitivity analysis of a cable-stayed bridge model using Sobol indices

One of the key challenges in bridge assessment is to create a representative structural model that reflects adequately the real static and dynamic behaviour, which can vary from those considered in design due to variations in actual mass, stiffness and boundary conditions. It is common practice for engineers to measure the actual modal properties and load testing data of a constructed bridge, and then use these to validate the model. As there is a large number of parameters in the model, engineers must know in advance which parameters are influential. Currently, this is primarily based on engineering knowledge and experience with manual sensitivity analysis of a small subset of parameters. In this paper, we demonstrate the use of a systematic numerical approach to perform a global sensitivity analysis of a cable-stayed bridge model using Sobol indices. The results can be used to inform model calibration as well as structural health monitoring (SHM) strategy.