Moving forces and their bounds identification method for cable-stayed bridges with uncertain parameters and noisy measurements

An identification method based on interval analysis for moving forces on cable-stayed bridge with uncertain parameters and noisy measurements is presented. Although there have been many reports on moving force identification methods on bridges, they did not pay much attention to the problem of identifying loads on cable-stayed bridge. And the uncertainties of measurements and bridge parameters were ignored in previous studies. The influence matrix model of cable-stayed bridge was established from the finite element model or in-field test in this study - if using in-field test only, the proposed method will be a model-free method. The upper and lower bound of the identified loads is analyzed based on the interval theory, which is caused by the uncertainties of two kinds: 1) noisy cable tension force measurements; 2) uncertain bridge parameters or influence line test noise. The numerical demonstration and validation are carried out based on Nanjing No.3 Yangtze River Bridge. The main contributions of this paper are: a. to propose an identification method for cable-stayed bridge with uncertain parameters and noisy measurements; b. the location, speed and magnitude of vehicle loads can be estimated simultaneously with the upper and lower bounds.