Cable Replacement Scheme for Low Tower Cable-Stayed Bridges Based on Sensitivity Analysis

Abstract

Cable replacement is a key technique to solve the problems of cable corrosion and strand breakage. Cable removal causes structural changes. The choice of replacement method affects the safety of the bridge during cable replacement. A sensitivity analysis method was used to evaluate the force and deflection changes of Wohu Bridge. A reasonable method for the number and order of cable replacement was proposed; by comparing different cable removal schemes, it was revealed that the cable force and beam stress changes of the cables closest to the removed cable were the most significant. The results showed that the cable force increment of the surrounding cables was the largest when removing the longest cable. The structural impact change was small when removing the shortest cable. The maximum deflection at the top of the tower decreased with the decrease of the length of the removed cable. It was recommended to replace two cables symmetrically from the center of the tower, and the optimal replacement order was from the shortest cable to the longest cable. Furthermore, this paper also studied the influence of variable load on the cable replacement scheme, and demonstrated that the design scheme of opening part of traffic in this paper was safe and feasible.