EFFECT OF INCLINATION OF CABLES PLANE ON THE STABILITY OF LONG SPAN CABLE-STAYED BRIDGES

Abstract

Cable stayed bridge is one of the several long span bridge types. It has some beneficial characteristics compared to other long span bridge type either from technical, economic, and also esthetics factor. However, in many circumstances, cable-stayed bridges can provide benefits at relatively moderate increase in cost. Some of the benefits include the following: • long spans with minimal deck thickness • the elimination of piers • increased traffic safety • the minimization of environmental impacts and construction schedule limitations for river crossings • enhanced appearance

The main goal of this research is to investigate the effect of cable plane inclination on the stability of cable stayed bridges with the use of additional cable net. The frequencies of the main girder were investigated on three cable-stayed bridges with different spans. The cable plane inclination was studied at four different angels 0ᵒ, 10ᵒ, 20ᵒ and 30ᵒ. The bridge frequencies were compared for each inclination angle with respect to the normal case, furthermore different types of cable nets: normal, inclined, trajectory, and vertical were also studied. Three major cable-stayed bridges were considered as case of study for this research

Excluding the original basic model of each studied bridges, additional nine models-three for each bridge-with different suggested possible arrangements for additional cable net have been studied. The use of such additional cable net showed a significant improvement in some of the Critical Wind Speed, Horizontal Side Sway, Vertical Bending, and Torsion.