Probabilistic approach for cable residual strength assessment

The reliability assessment of suspension cables is today a major topic all around the world. Due to the large number of broken wires found—wide in suspension cables, rational and effective methods are therefore needed for assessing cable safety factors. Based on a simple mechanical and statistical model, this paper tempts to provide an approach for solving this problem. This model allows determining the cable residual strength as far as the behaviour of the constitutive components is correctly characterised. The model is based on Monte-Carlo simulations of individual unbroken wires while broken wires are randomly generated by a binomial distribution. The approach is applied to the Tancarville suspension cables by taking into account tensile test results, inspection data and weigh-in-motion records. The calculation of the residual strength is then compared to the dead and live load effects in order to provide a point-in-time safety factor of the suspension cable.