Bridges

In cable stayed bridges corrosion and fatigue as well as extreme loadings such as earthquake, lightning strike and blast may lead to loss of cables. The vulnerability of cable stayed bridges for such cable loss scenarios has not been thoroughly investigated yet and is not considered in the current design practice. Accordingly, in this paper a primary study on vulnerability of cable stayed bridges against such extreme scenarios is undertaken. A two-dimensional Finite Element (FE) model of a cable-stayed bridge is developed in ANSYS. The mid-span of the bridge studied in this paper is 600 meter long and made of a steel box. The bridge is supported by two 140 meter tall steel towers and 56 steel cables. The bridge is analysed for two different cable loss scenarios and the global response of the structure (i.e. deformation of the bridge, bending moment at mid-span of the deck and the base of the tower, and axial force for deck and each cable) following the cable loss scenarios are studied. Further, dynamic amplification factors (DAF) for deflections and internal forces are determined by comparing the results of static analysis with the results obtained from transient dynamic analysis.