Simplified method for static analysis of bi-cable triple-pylon suspension bridges

Abstract

A bi-cable scheme of a triple-pylon suspension bridge can greatly decrease the unbalanced horizontal force on the top of mid-pylon and is more economical compared with a single-cable scheme. This article proposes an appropriate simplified method for static analysis of bi-cable triple-pylon suspension bridges in the conceptual design phase. First, theoretical analysis was performed considering the elastic extension of hangers. And the analytical solutions to cable extension under live-load, dead-load intensity, and the static characteristics were obtained. Second, verification of the accuracy of the analytical solutions was conducted by establishing FEM model of triple-pylon steel-box-girder suspension bridges with main spans from 1500 to 2500 m. The comparative analysis shows that the results of the analytical solutions are in good agreement with the Finite Element Models and of great reference value in the conceptual design phase.