中文摘要：

作为斜拉桥结构主要承重构件的主梁,其可靠性关系到整个结构体系的安全.有限元可靠度方法对于大型复杂结构的可靠度分析有明显的优势,基于此方法研究珠江黄埔大桥斜拉桥的主梁可靠度并对其进行了敏感性分析.考虑几何非线性的影响,建立了基于有限元方法的斜拉桥主梁可靠度计算模型,通过对有限元列式直接微分的方法获得结构响应的梯度,采用一次可靠度方法计算可靠度指标,并根据计算结果直接对随机变量分布参数进行了敏感性分析.计算结果表明,该桥的主梁是足够安全的;布载方式对主梁可靠度有明显影响;主梁可靠度指标β对主梁的抗弯承载能力的均值和标准差最敏感.

英文摘要：

The reliability of the main girder that as one of the most important load-carrying members of the cable-stayed bridge is closely related to the safety of the whole structure.Based on the finite element reliability method,which is very efficient for the reliability analysis of large and complex structures,the reliability and sensitivity analysis of the main girder of Pearl River Huangpu Cable-stayed Bridge was carried out and the reliability analysis model of the bridge was established by considering the geometrically nonlinear influence.The gradients of limit-state functions involving finite element response quantities were computed by the direct differentiation method（DDM）,and the reliability indices β of the cross-sections of the girder were calculated by the first-order method（FORM）.After reliability analysis,the sensitivities of the means and the standard deviations of the random variables were calculated directly.The results showed that the main girder is safe enough and the reliability indices are obviously affected by different load cases.It also showed that the reliability indices β are most sensitive to the mean and standard deviation of the resistance of the sections.