A Fast Solving Method for Curve Profile of Suspension Bridge Catwalk System in Plane

With increasing demands of in plane suspension bridge for mountainous area of P. R. China in recent year, rapid erection of catwalk system has become the researching hotspot for constructors, wherein curve profile is one of the key factors that matter. In this paper, a nonlinear optimization method is introduced for fast solving curve profile of catwalk system. To achieve the goal, statics fundaments and compliant characteristics of general catenary is firstly analyzed. Structural detailing of catwalk system is then described so that segmentation prior to computation can be made as per loads types or requirements of obtaining finer curve coordinates. In addition, nominal curve profile of catwalk system is derived according to segmentation of main cable, based on which the actual catwalk curve profile solving problem is afterwards formulated as an unconstrained nonlinear programming in terms of external penalty parameter and solved by using Levenberg-Marquardt (L-M) algorithm. Finally, a study case is shown to illustrate the effectiveness of proposed method.