中文摘要：

以天兴洲公铁两用斜拉桥为例，建立有限元模型，考虑了制动力作用的极限状态．采用以线型控制的索力迭代分步算法确定斜拉桥成桥索力，按照铁路和公路工程结构可靠度设计统一标准，分析、计算和比较了5种荷载工况的作用效果，确定出最不利荷载工况．计入几何非线性影响，进行斜拉桥承载能力和正常使用极限状态分析．利用Ansys参数化设计语言进行后处理，研究斜拉桥在承载能力极限状态下主要构件的应力水平和应力分布．

英文摘要：

To study the limit state of highway/railway cable-stayed bridges under braking force, the finite element model of Tianxingzhou Yangtze River Bridge is built with Ansys. Using step-by-step algorithm, cable tension adjustment for line-style control of reasonable finished dead state of cable-stayed bridges is discussed. With consideration of the braking force on the bridge, the most disadvantageous loading condition is investigated according to the unified standard of engineering structure design for highway and railroad. Considering the geometric nonlinearity, ultimate limit state and serviceability limit state of cable-stayed bridges are studied. Calculation of stress level and determination of location of maximum stress of main stress components of the cable-stayed bridge are performed based on its ultimate limit state.