Numerical evaluation of code live-load models for estimating forces at bridge supports

In this paper, the efficacy of code-based live-load models is assessed. The paper focuses on their ability to accurately estimate vehicular loads transferred to bridge substructures, including abutments, piers and foundations. Realistic traffic vehicle data are represented using four weigh-in-motion databases, which provide an authentic representation of vehicle information, thus providing a truthful basis for the examination of the bridges studied. The evaluation includes girder bridge models with single span, as well as two-, three- and four-span continuous pinned support. By analysing exceedance rates, the study compares the extreme force values (i.e. maximum and minimum) obtained from vehicles in the databases with those predicted by selected code live-load models. These exceedance rates are presented in spectra format, as a function of the span length. The significant variations observed in the exceedance rates highlight the need for improving existing live-load models to achieve more accurate estimations of the forces transferred to bridge substructures. Such improvements would lead to more uniform reliability levels for any limit state, such as resistance, fatigue, serviceability and cracking.