应用静力弹性稳定研究方法和有限元实现,对以边中跨为非对称结构、大跨度混合梁的鄂东长江斜拉大桥通过建立LSB和ANSYS模型,分析施工过程中的稳定性。对弹性稳定安全系数的计算结果与规范值进行了比较。研究结果表明:钢箱梁悬臂施工过程中结构弹性稳定安全系数呈现逐渐增大-缓慢平稳变化-明显下降的趋势,在每段钢箱梁施工过程中有明显的波动;成桥后主要运营阶段没有明显的波动处于一种相对恒定的承载能力状态等的变化规律;施工过程呈现索塔纵向失稳和钢箱梁竖向失稳的组合失稳模式。
Applied the research method and finite element implementation of static elastic stability,the LSB model and ANSYS model of East Hubei Yangtze River Cable-stayed Bridge,which has a long-span hybrid girder,asymmetric side spans and middle span,were built to analyze the stability during construction.The calculation result of elastic stability safety coefficient was compared with the standard value.The result shows that(1) the elastic stability safety factor of steel box girder cantilever increased gradually,then changed smoothly,and decreased obviously at last during construction,it fluctuated obviously during construction of each segment of steel box girder;(2) the safety factor did not fluctuated apparently,and the bridge has relatively constant load bearing capacity after completion and during operation;(3) pylon longitudinal instability and steel box girder vertical instability mode occurred during construction.