中文摘要：

基于大胜关大桥的主梁横向加速度监测数据,采用主成分分析方法建立了高速铁路桥梁动力性能异常预警方法。采用主梁横向加速度的均方根值作为反映桥梁动力性能的监测参数,以其互相关性模型作为桥梁动力性能评价模型,并采用主成分分析方法有效地分离了环境因素变化对桥梁动力性能评价模型的影响,建立了桥梁动力性能异常预警指标。分析结果表明：大胜关大桥主梁不同测点之间均方根值的互相关性可以采用二次多项式拟合;所建立的预警方法可以敏感地发现主梁横向加速度的异常变化,从而对桥梁动力性能及时做出预警。

英文摘要：

Making use of transverse acceleration monitoring data of the main girder of Dashengguan bridge,the monitoring and warning method of abnormal dynamic performance was formulated based on principal component analysis.The root mean square value of transverse acceleration of the girder was used as the monitoring parameter reflecting the dynamic performance.The correlation model of root mean square values was established as the assessment model of the dynamic performance.The influences of environmental conditions on the assessment model were eliminated by using the principal component analysis,the corresponding warning index was proposed.Analysis results show that the correlation of root mean square values measured at different points can be expressed as quadratic polynomials.And the proposed waning method provides a good capability for detecting the abnormal changes of transverse accelerations of the main girder.It is suitable for real-time warning of the dynamic performance.