DYNAMIC-RESPONSE OF HIGHWAY BRIDGES TO HEAVY VEHICLE LOADS - THEORY AND EXPERIMENTAL VALIDATION

A calculation procedure is developed to predict the dynamic response of a bridge to a given set of vehicle wheel loads. The method involves convolution of the vehicle loads with modal responses of the bridge and the convolution integral is solved by transformation to the frequency domain using the fast Fourier transform. The method is then extended by an iterative procedure to include dynamic interaction between the bridge and an arbitrary mathematical model of a vehicle. Examples are presented to illustrate the effectiveness of the convolution method, and to demonstrate the convergence of the iterative procedure. Experimental measurements on a highway bridge are presented and used to validate the calculation method. The modal properties of the bridge were measured by impulse tests with an instrumented hammer and compared with simple mathematical models. Single vehicle tests, in which the wheel loads and dynamic response of the bridge were measured simultaneously, are discussed. The measured dynamic wheel loads were convolved with the measured modal properties of the bridge and the predicted responses are compared with the measured responses. Good agreement is found. © 1994 Academic Press Limited.