基于可靠指标的桥梁结构稳定安全系数研究

发布时间：2019-03-18 15:02

【摘要】：桥梁相关规范规定,结构的第一类稳定安全系数不应小于4,但当第一类稳定安全系数取4时,能否保证结构在更可能出现的第二类失稳发生时的可靠指标达到目标可靠指标则值得研究。以钢筋混凝土受压构件为例,分别进行弹性和弹塑性稳定计算,取第一类稳定安全系数等于4,采用一次可靠度方法FORM得出第一类弹性失稳时的可靠指标,利用计算该可靠指标时的荷载效应和弹塑性临界荷载计算第二类弹塑性失稳时的可靠指标。结果表明:某些情况下,当第一类稳定安全系数取4时并不足以保证结构发生第二类失稳时的可靠指标达到目标可靠指标。文中还讨论了结构参数变化对结构第一类和第二类失稳时可靠指标及稳定安全系数的影响,得出第二类稳定安全系数和可靠指标的关系,并给出第二类稳定安全系数的取值建议。
[Abstract]:The relevant specifications of the bridge specify that the first type of stability safety factor of the structure should not be less than 4, but when the first type of stability safety factor is 4, it is worth to study whether the reliability index of the structure when the second type of instability is more likely to occur reaches the target reliability index. The elastic and elastic-plastic stability calculation is carried out by taking the reinforced concrete pressure-receiving member as an example, and the stable safety factor of the first type is equal to 4, and the reliability index of the first type of elastic instability is obtained by adopting the one-time reliability method FORM. The reliability index of the second kind of elastic-plastic instability is calculated by the load effect and the elastic-plastic critical load when the reliable index is calculated. The results show that, in some cases, when the first type of stable safety factor is 4, it is not sufficient to ensure that the reliability index of the second type of instability of the structure reaches the target reliability index. In this paper, the effect of structural parameter variation on the reliability index and the stability safety factor of the first and second types of instability of the structure is also discussed, and the relation between the second type of stable safety factor and the reliable index is obtained, and the value of the second type of stability safety factor is given.
【作者单位】：湖南大学土木工程学院;湖南理工学院土木建筑学院;
【基金】：国家自然科学基金(51078134) 湖南省教育厅科研项目(13C373)
【分类号】：U441

【参考文献】