Passive Control System of a Steel Truss Girder Cable-stayed Bridge

摘要

Guozigou Bridge is located in Xinjiang Autonomous Region of China. The bridge is a three-span continuous steel truss girder cable-stayed bridge which has a main span length of 360 m and has two reinforced concrete towers which are 209.5m and 215.5m in height respectively. Although floating system was of advantage to the distribution of internal force of the towers, yet relative longitudinal displacements were so large that deformation ability of the bearings at the side piers can't satisfy the demand of potential earthquake. Semi-floating system could reduce the displacement in the longitudinal, but the results weren't perfect still, so viscous dampers were set at the side piers and two towers. The present focused on damping coefficient and damping exponent of the viscous damper and its reasonable position. According to the site condition, the effect of the dynamic pile-soil-structure interaction was considered. Through non-linear time history analysis, the results indicated that the relative displacement of key positions and the forces of the bridge were reduced obviously by setting the dampers in longitudinal direction of the bridge.