Effect of Load Distribution Coefficient on Three-Tower Cable-Stayed Bridge with Crossing Cables

Abstract

The stiffness of the middle tower is lower than the side towers for three-tower cable-stayed bridge. Crossing cables could improve the stiffness of the middle tower. In this paper, the load distribution coefficient of the crossing cables is proposed and its effect on three-tower cable-stayed bridge with crossing cables is investigated. A three-tower cable-stayed bridge with crossing cables is studied with FEM. The geometric nonlinear analysis is carried out with one of the main spans under unbalanced load. Parametric analysis is carried out to present the influence of load distribution coefficient on the deformation of middle tower and main girder. At the same time, the deformation of the middle tower and the main beam of semi-floating system and rigid-frame type is compared. In addition, the effect of reducing the deformation of the middle tower by setting counterweight in the cable crossing zone is also analyzed. The results show that if the load distribution coefficient is 1/2, the displacement of the middle tower under unbalanced load is the minimum. With the increase of the load distribution coefficient, the maximum displacement point of the main girder is close to the mid span. The longitudinal displacement of the middle tower of the semi-floating type is smaller than that of the rigid-frame type. The counterweight in the cross area can reduce the longitudinal displacement of the middle tower.

Keywords

• crossing cables
• deformation
• load distribution coefficient
• structural stiffness
• three-tower cable-stayed bridge