基于贝叶斯理论的随机风荷载作用下斜拉桥颤振可靠性分析

Reliability Analysis of Cable-stayed Bridge Flutter Under Stochastic Wind Loading Based on Bayesian Theory

在现有的结构可靠性理论的基础上,提出基于贝叶斯理论进行极值风速预测方法,并建立大跨度斜拉桥颤振可靠性分析模型。颤振可靠性分析模型极限状态方程中以颤振临界风速、转换因子、阵风因子和桥址处极值风速为随机变量,采用基于一次二阶矩理论的JC法计算大跨度斜拉桥颤振稳定性可靠度指标。计算结果表明,基于贝叶斯理论的随机风荷载作用下的大跨度斜拉桥颤振概率性评价和可靠性分析方法比传统的方法更加精确、科学,采用本文提出的方法具有很好的工程实用价值。

Based on the structural reliability theory,the wind speed forecast method of extreme value was constructed,which was used to establish the reliability model for analyzing the long-span cable-stayed bridge flutter. The limit state equation of reliability analysis model is a function of the flutter critical wind speed,conversion factor,gust factor and extreme wind speed at the bridge site. JC method based on the first order second moment reliability theory was used to calculate the flutter reliability indices of the long-span cable-stayed bridge. The results indicate that probability assessment and reliability analysis of cable-stayed bridge flutter under stochastic wind loading based on Bayesian theory are more precise and scientific,which has high value in application to practical engineering.