Formulating the optimum parameters of modified hanger system in the cable-arch bridge to restrain force fluctuation and overstressing problems

Abstract

Inclined hangers behave better than vertical ones under lateral loads (i.e., wind or earthquake) despite they are prone to fatigue phenomenon. In some instances, the slackness problem is seen in some inclined hangers, while others may become overstressed. By considering the modified hanger system, the disadvantages of vertical and inclined systems are resolved, while keeping their advantages. The objective of this study is to propose formulations for the optimum application of novel arrangement of hangers in a cable-arch bridge to suppress problems such as overstressing, force fluctuation, and decreasing the probability of fatigue phenomenon in hangers. To define optimum parameters, the modified hanger system was analyzed and compared with vertical and inclined ones considering nonlinear static analysis under dead load as an initial state plus seismic excitation and dynamic impact load of vehicles. Results indicate that the modified hanger system is improved remarkably in comparison with the inclined and vertical hanger systems.