中文摘要：

鉴于目前复杂桥梁结构可靠性分析方法的局限性,提出一种新的可靠性综合分析方法。在随机有限元法的基础上,结合了几种常用可靠度计算方法的优点,能较方便得出复杂结构极限状态方程的概率分布及数值特征,进而求得相应的结构可靠度指标及失效概率,可为复杂桥梁结构的可靠性分析提供新的思路。以某大跨径斜拉桥为研究对象,采用ANSYS程序建立随机有限元模型,将结构材料特性、荷载及材料强度等参数模拟成随机变量,采用综合分析法对大桥进行可靠性分析。研究结果表明：在承载能力极限状态下,大桥斜拉索最低可靠度指标为5.89,桥塔的可靠度指标为6.37,主梁最低可靠度指标为5.29,均高于规范容许值4.7,相应最大失效概率为1.01×10-8。正常使用极限状态下,大桥跨中挠度可靠度指标高达3.43,也高于容许值,失效概率仅为3.02×10-4。表明大桥在两种极限状态下均具有较高的可靠性。

英文摘要：

In view of some limitation in the reliability analysis of bridge structures at present, a new comprehensive analysis method was put forward. Based on the stochastic finite element and com-bined with the advantages from the common reliability analysis methods, the new method could con-veniently obtain the probability distribution and numeric attributes of limit state equation of complex bridge structures, and then obtain the reliability index and failure probability, which could provide a new idea for reliability analysis of complex bridge structures. Taking a long-span cable bridge as the research object, its stochastic finite element model was built using ANSYS, some parameters such as material properties, loads, material strength, and so on, were simulated as stochastic variables in this model, and the new method was used to analyze the bridge’s reliability. The analysis results show that, in the ultimate limit state, the lowest reliability indexes of cables, bridge towers and gri-der are 5. 89, 6. 37 and 5. 29, respectively, all of which are higher than the allowable value 4. 7, and the maximum failure probability is 1. 01×10-8. In the serviceability limit states, the reliability index of the mid-span deflection reach 3. 43, which is also higher than the allowable value, and its failure probability is 3. 02 ×10-4 . The results prove that the long-span cable bridge has a higher reli-ability.