ABSTRACT
ABSTRACT: The evaluation of existing bridge for fatigue performance is important in the effort to deal with the deteriorating infrastructure. The effort to prioritize bridge repair and rehabilitation options will highly depend on the identification of live loads and their effects. Bridge live load effects vary for different components and structural details. In many cases, analytical methods do not allow for an accurate estimation of load, in particular the load distribution and actual stress ranges. Structural health monitoring and field testing can be very effective in the evaluation of bridge performance at the serviceability limits. Truck load spectra are site-specific with site to site variations depending on the function of the roadway e.g. local connector, urban expressway, or interstate highway. Additionally, the seasonal variation in truck weight and volume must be investigated. Typically, fatigue analysis uses short term data taken for a few days. The data is then linearly extrapolated to longer periods. Comprehensive fatigue analysis must include site truck load spectra and bridge stress cycles.
