Fatigue reliability assessment of a three-tower four-spansuspension bridge under stochastic traffic loads

Abstract

This paper aims to study the fatigue performance of three-tower four-span suspension bridges. For this purpose, the Oujiang River North Estuary Bridge which is a three-tower four-span suspension bridge with two main spans of 800m under construction in China is taken as an example in this study. This will be the first three-tower suspension bridge with steel truss girders in the world. This paper uses a random traffic load model to evaluate the fatigue reliability of the orthotropic steel bridge decks of three-tower four-span suspension bridges. In the study traffic load is simulated by random variables, and Monte Carlo simulation method is used to calculate the fatigue reliability index of the steel bridge deck. The parametric analysis is also carried out to clarify the influence of traffic growth rate, target reliability index and axle lateral distribution coefficient. It is found that the growth of traffic volume has the greatest impact on the evaluation results of the fatigue life, and the growth of traffic volume can result in a decrease of fatigue reliability of orthotropic steel bridge decks. The research results can provide a reference for the fatigue life and reliability assessment of three-tower four-span suspension bridge.