LIFE EXPECTANCY OF HIGHWAY BRIDGES DUE TO TRAFFIC LOAD

In this paper the life expectancy of highway bridges to traffic flow is studied. It is assumed that the traffic is a composition of different types of vehicle models. Each type of vehicle is modeled by one or more concentrated random forces. In this idealization the vehicles are regarded as being of random weight and traveling with the same constant speed. The interarrival times of the vehicles are regarded as random variables. For estimation of the life expectancy of the structure one needs to find the joint probability density function of the displacement, velocity and acceleration of the vibrating beam. In the paper the damage process of the bridge is determined by the Palmgren-Miner rule. As an example, the covariance function, the spectral density function and the life expectancy of a bridge modeled as a simply supported beam are determined. © 1990.