Analysis of Bridge Truck Loads

The development of the reliability-based load and resistance factor design (LRFD) methodology requires uncertainties in loads and resistance be quantified. In the load capacity evaluation of bridge structures, it is recognized that randomness/uncertainty associated with the live load effect is by far the greatest and deserves closer scrutiny. Further development in the information-sensitive code formulation provides the facility to refine the uncertainty analysis which would explicitly account for the site-to-site variability in the live load. Another development in recent years which makes this scrutiny possible is that, for the first time, unbiased truck load data are collected on a large scale. In this paper, statistics of truck loading variables at several sites are presented and the implications to site-specific load model development are discussed.