Fatigue Load Model for Highway Bridges in Heavily Loaded Areas of China

Fatigue is one of the main factors that cause the collapse of steel bridges. Anti-fatigue design therefore draws close attention all over the world. The design must have a fatigue load model based upon native traffic load conditions. But the Chinese steel bridge design specification does not include any fatigue load model for anti-fatigue design. So it is imperative to develop the model. This paper proposes a single vehicle fatigue load model and a 5-vehicle fatigue load spectrum model, which are based upon the latest weigh-in-motion data collected from heavily loaded area of China. Taking the effects of multi-vehicle presence into account on the basis of queuing theory, the proposed fatigue load models could be easily adapted to real traffic, thus providing substantial support to the bridge structural fatigue evaluation in the heavily loaded areas of China.