Abstract:

This paper deals with the basic mechanical properties of a double-cable suspension bridge system that has wide application prospect in multi-tower suspension bridges. In the investigation,the distribution of uniform loads on the top and the bottom cables are analyzed when the span is fully and uniformly loaded,and the vertical stiffness of the main cable is formulated. The results indicate that the distribution of uniform loads on the top and
the bottom cables depends on the section parameters of the cables and the rise-span ratio and that the vertical stiffness of the main cable under uniform loads increases with the rise-span ratio. Based on the above-mentioned findings,the girder deflection resulting from the cable extension is obtained. In addition,the deformations of the discussed double-cable system respectively due to concentrated loads and uniform loads on the half span are analyzed,and the results are verified by using a finite element model,with good accordance being obtained.

Key words: double-cable suspension bridge, mechanical property, vertical stiffness, deflection