ABSTRACT
Huangmaohai Bridge is the control project of the Huangmaohai Sea-crossing Channel in Guangdong Province. It will become the world's largest single-column, double-plane three-tower cable-stayed bridge. The low vertical stiffness of the whole structure is the key problem in the design of the three-tower cable-stayed bridge. Based on Huangmaohai Bridge, this paper studies the influence of auxiliary pier, tower height, tower stiffness, and beam height on the vertical stiffness of a three-tower cable-stayed bridge. The results show that: 1) With the increase of the number of auxiliary piers, the deflection of the main beam decreases gradually, which can effectively improve the overall stiffness of the three-pylon cable-stayed bridge. When two auxiliary piers are set up, the deflection-span ratio limit of the steel structure cable-stayed bridge in the code can be satisfied; 2) In a small range, the overall rise of all towers, the rise of middle towers and the decrease of side towers have little influence on the vertical stiffness of main beam; 3) With the increase of the stiffness of the main tower, the mid-span deflection decreases gradually, and the deflection-span ratio of the steel structure cable-stayed bridge can meet the specification limit of 1/450 when the mid-span section increases 2 m along the bridge; 4) Increasing the height of the main beam can improve the vertical stiffness of three-tower cable-stayed bridge is not obvious.
