Initial equilibrium analysis under dead load for cable-stayed suspension bridge

Abstract

This paper proposes new method to determine initial cable forces and target configurations under dead load in the cable-stayed suspension bridge. In the proposed method, initial shape analyses about the structural systems by separating a stay cable-supported part and a suspension cable-supported part are performed and then these resultants are employed to whole model of the cable-stayed suspension bridge. The Newton-Raphson method is applied for the analysis of the suspension cable supported part and optimization method to analyze the stay cable supported part is applied, respectively. The initial cable forces and coordinates satisfying the final design criteria of the cable-stayed suspension bridge can be determined by employing proper boundary conditions. To verify the validity of the proposed method, an initial equilibrium states analysis is performed for an example bridge model whose center span is 2,500m and whole length is 4,000m by applying the proposed algorithm.