Effects of pylon configuration on the response of cable-stayed bridge to sudden cable loss

This paper presents a finite-element (FE) investigation into the effects of pylon configuration on the general response of cable-stayed bridges (CSBs) in the event of sudden cable loss. An example CSB is proposed and analysed using a three-dimensional FE model for H-shaped pylon (HSP) and A-shaped pylon (ASP) configurations; the effects of p-delta (large stress) and geometric non-linearities are accounted for. The FE study was conducted for two scenarios of cable loss - the simultaneous sudden loss of the longest two adjacent cables in the mid span or the side span. The results showed that the general responses of the main-span deck structural elements due to breakage of the longest two main-span cables were comparable for both HSP and ASP configurations, but the responses due to breakage of the longest two side-span cables differed. From a practical viewpoint, the loss of side-span cables may cause notable rotation of the main-span deck for a CSB with HSPs, but not for a CSB with ASPs. The results of this study may be useful for designing a situation of accidental cable loss.