Rigidity Characteristics of Multi-span Suspension Bridges

To probe into the effect of change in structural parameters,the gravity stiffness method was extended and used to investigate the characteristics of vertical deformation of multi-span suspension bridges. Deflection expressions for multi-span suspension bridges were derived by considering the bending stiffness of towers and the elastic extensibility of the main cable. Effects of the number of suspension bridge’s spans on its gravity stiffness distribution and maximum deflection were investigated. Numerical simulations were carried out to probe into the influence of bending stiffness of a mid-tower on deflection. The research result shows that the number of spans and the bending stiffness of the mid-tower have a great effect on the vertical deflection and gravity stiffness of multi-span suspension bridges.