考虑适用性的大跨桥梁主梁动态可靠性融合预测

Dynamic reliability fusion prediction of long-span bridge girder considering structural serviceability

为合理预测考虑适用性的大跨桥梁主梁动态可靠性,利用主梁控制监测点的动态极值挠度信息,建立了多维Gaussian Copula技术、多变量贝叶斯动态线性模型(MBDLM)以及一次二阶矩(FOSM)方法相融合地考虑控制点变形失效非线性相关的大跨桥梁主梁体系动态可靠性预测方法。采用某大跨桥梁主梁3个控制监测点的动态监测极值挠度数据进行验证分析,研究表明:考虑适用性的控制监测点变形失效非线性相关的主梁动态可靠性预测值较不考虑控制监测点变形失效非线性相关性所得结果大,说明不考虑失效动态非线性相关性所得结果偏保守。

To reasonably predict serviceability-based dynamic reliability of the long-span bridge girder,using the dynamic extreme deflection data at the control monitoring points,a dynamic serviceability reliability prediction approach for the long-span bridge girder is presented through the fusion of multidimensional Gaussian copula technique,multivariate Bayesian dynamic linear models(MBDLM)and the First Order Second Moment(FOSM) method. In this approach,the nonlinear correlations among the performance functions for deformation failure modes at the multiple control monitoring points are taken into consideration. The dynamic monitoring extreme deflection data at three control monitoring points from a long-span bridge girder was provided to illustrate the proposed models and methods. The results show that the predicted dynamic reliability of the bridge girder,considering the time-variant nonlinear correlation of deformation failure modes at the multiple control monitoring points,is larger than that without considering the time-dependent nonlinear correlation of deformation failure modes. This suggests that the predicted results without considering the time-variant nonlinear correlation of deformation failure modes at the multiple control monitoring points are conservative.