Study on structural system of multi-pylon cable-stayed bridge

The intermediate pylons of multi-pylon cable-stayed bridges cannot be anchored to fixed points by backstays,indicating that it is possible to cause greater horizontal displacements in the top of towers under the action of external loads. Therefore,it is important to obtain adequate structural stiffness in the design of multi-pylon cable-stayed bridges. In this paper,the structural systems of multi-pylon cable-stayed bridges were investigated. The effect of structural system on mechanical behavior of multi-pylon cable-stayed bridges was analyzed by using a three-pylon cable-stayed bridge and a four-pylon cable-stayed bridge model. The deflection and internal force of models for different structural systems were compared. The results indicated that the best structural system of multi-pylon cable-stayed bridges was the system that had enough structural stiffness and less secondary internal force resulted from concrete shrinkage,creep and temperature effect. Recommendations were given for determining structural system in the design of multi-pylon cable-stayed bridges.