Moving load identification on multi-span continuous bridges with elastic bearings

A method based on modal superposition and regularisation technique is developed to identify moving loads on an elastically supported multi-span continuous bridge deck. The effects of different influencing parameters, such as the measuring noise, sampling rate, vertical and rotational stiffness and the travelling velocity of the moving loads, are studied. Numerical simulations show that the method can identify accurately the moving loads on the bridge supported by elastic bearings using different types of measured responses. The stiffness of the bearing should be large relative to the stiffness of the bridge deck. Measured acceleration gives better results than those from strains, and the number of vibration modes used in the identification should exceed the highest frequency of the excitation forces for an accurate identification.