Wang and Fu 1 STATIC AND STABILITY ANALYSIS OF LONG - SPAN CABLE - STAYED STEEL BRIDGES

The analysis based on an ideal state as well as the simulation and control to reach it are common issues in the design and construction of a cable-stayed bridge. For a long-span cable-stayed bridge, the huge initial stress accumulated in the pylon and the girder will reduce the overall structure stiffness. Thus, the live load evaluation employing influence lines, which is based on the Muller-Breslau Principle, will no longer be an accurate method. When the main span of the bridge is extended longer, some more critical issues, such as large-deformation effects and stability during construction, will arise. This paper includes a feasibility study of a steel cable-stayed bridge with a main span of 1,088 meters. Methodologies for defining the final ideal state, the backward and forward analysis for construction simulation and control, the geometric nonlinearity together with the static stability analysis are discussed briefly. Some features of the Visual Bridge Design System (VBDS), which is adopted as the system for conducting the analysis of the 1,088 meter-cable-stayed bridge, are introduced. The results of the analyses, including the final ideal state, the live load envelope with the consideration of the nonlinear effects of the initial stresses and cable sags, and the stability due to lateral wind and construction loads are summarized. The aerodynamic stability of the structure for flutter and vortex-induced oscillations is not included in this study.