A New Method for Analysis of Sliding Cable Structures in Bridge Engineering

Abstract

The Sliding Cable Structure (SCS) is widely used in bridge construction by cable crane method. The SCS generally consists of cables and fixed pulleys and the cables will slide around the pulleys when the cables are loaded until the balanced state is achieved. In this paper, an efficient Angle Bisector Method (ABM) is proposed for the mechanical analysis of SCS. The constraint effect of pulley on the cable is simulated by fixed hinge and the constraint force perpendicular to the angle bisector of cable elements adjacent to the pulley is therefore zero at balanced state. By utilizing “Unit Length Influence Matrix” (ULIM), the adjustment of unstressed length of each sub-cable can be determined. As the angle bisector at each pulley will change when the unstressed lengths of cables are changed, iterative procedures are necessary to find the convergence solutions. The proposed method is firstly verified by two examples and then applied to the analysis of cable crane during construction of the world’s longest steel truss cable-stayed bridge, namely Yachihe Bridge. Satisfactory numerical solutions can be obtained only with several iterations and are in good agreement with field measurements from the cable crane load tests, which confirms the accuracy and validity of the proposed method.