Dynamic response of cable-stayed bridge under blast load

Over the past two decades, blast loads have been recognised as one of the extreme loading events that must be considered in the design of important structures such as cable-stayed bridges. However, design provisions for blast-resistant bridges are very limited and mostly empirical owing to an inadequate understanding of the local and global dynamic response of the bridge components (piers, deck and cables) subjected to blast loading scenarios. Accordingly, this study develops detailed finite element models of a steel cable-stayed bridge and it is analysed using an explicit solver. Three different explosive sizes, i.e. small (01W), medium (04W) and large (10W), are considered (W being the TNT equivalent explosive weight index) and placed at different locations above the deck level to determine the influence of the size and location of the blast loads on the global and local response of the bridge components. In particular, the results of the computer simulations are employed to characterise the type and extent of damage on the pylon and deck, and additionally to investigate the potential cable loss scenarios associated with a loss of anchorage. Furthermore, the results of the finite element simulations are used to assess the potential progressive collapse response of a cable stayed bridge subject to various blast loading scenarios.