Influence of pylon configuration on the response of cable-stayed bridges to sudden cable loss

This paper presents a finite-element (FE) investigation into the effects of the pylon configuration on the general response of cable-stayed bridges (CSBs) to sudden cable loss. An example CSB is proposed and analyzed using a three-dimensional FE model for the H-, and A-shaped pylon configurations; the effects of p-δ (large stress) and geometric nonlinearities are accounted for. The study is conducted for two scenarios of cable loss that are the simultaneous sudden loss of the longest two adjacent cables in both the mid and side spans. The results of analyses showed that the general responses of the main-span deck structural elements due to breakage of the longest two main-span cables are comparable for both the H- and A-shaped pylons, but those due to breakage of the longest two side-span cables differ from each other. Loss of cables in the side span may cause notable rotation of the main span deck for the bridge with H-shaped pylon, but not for the bridge with A-shaped pylon from a practical viewpoint. The results of this study may be useful when the accidental design situation of cable loss is considered.