Abstract

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Title:: Research on Nonlinear Stability of Long-span Composite Girder Cable-stayed Bridge

Author(s):: ZHAO Ren-da; ZOU Jian-bo; LU Liang; XU Zhi-qiang; JIA Yi; School of Civil Engineering, Southwest Jiaotong University

Keywords:: bridge engineering; cable-stayed bridge; nonlinear stability safety factor; construction process; finishing and using stage; instability mode

Abstract:: In order to research the variation law and the instability process of the nonlinear stability of long-span composite girder cable-stayed bridge, the Xigu Yellow River Bridge with 360 m main span was selected as the study object. The nonlinear stability safety factor of the typical construction stage and operation stage of the bridge was calculated by finite element simulation and the structural instability mode was obtained. At the same time, the stress changes of the stay cable and pylon and the load displacement curves of the key control point during the bridge from the beginning to the ultimate load-carrying capacity were analyzed. The results show that the nonlinear stability safety factor of the typical construction stage and the operation stage of the main bridge meet the design requirements, and the structural instability is reflected in longitudinal instability of pylon and in-plane instability of main beam. Part of the stay cable are broken and the connection location of main beam and pylon appears plastic area during the bridge from the beginning to the ultimate load-carrying capacity. The damage process is reasonable. The load-lateral displacement curves of tower and girder show obvious nonlinear effects.