Optimization analysis of auxiliary pier of cable-stayed bridge with unequal height pylons

Abstract

Because of pylons with unequal height, the mechanical characters of the structure should be considered when the auxiliary pier of long span cable-stayed bridge with unequal height pylons is set up. To investigate the relationship between the number and position of the auxiliary pier and the mechanical behavior of long span cable-stayed bridge with unequal height pylons, a finite element model of cable-stayed bridge with unequal height pylons is constructed as the research object, the variation regularity of effects caused by different positions of single auxiliary pier is fitted on the basis of regression analysis. According to the results, the mechanical behavior of long span cable-stayed bridge with unequal height pylons can be improved by setting auxiliary pier and the bending moment and displacement of side span girder and high pylon under live load decrease obviously, but the improvement effect brought by increasing the number of auxiliary pier is greatly weakened as compared with that of a single auxiliary pier. Thus, single auxiliary pier is the best choice with comprehensive consideration. The bending moment and displacement of side span girder and pylon also are influenced by different position of single auxiliary pier, and there is an optimal position. However, when the position of the auxiliary pier changes within a certain range, the variation trend of comprehensive response of the structure caused by the position change is not obvious. When limited by external conditions, the position of the auxiliary pier can be flexibly selected according to the analysis results.