基于长期监测数据的润扬大桥斜拉桥钢箱梁横向温差特性研究

CHARACTERISTICS OF TRANSVERSE TEMPERATURE DIFFERENCES OF STEEL BOX GIRDER IN RUNYANG CABLE-STAYED BRIDGE USING LONG-TERM MONITORING

基于润扬大桥北汊斜拉桥结构健康监测系统的监测数据,详细分析了润扬大桥斜拉桥扁平钢箱梁为期一年的实测温度结果,借助聚类分析、相关性分析、极值分析、参数估计、假设检验等统计学方法进行了温度筛选样本的典型性验证、温度统计特性的对称性验证以及钢箱梁横向温差统计特征研究。分析结果表明:钢箱梁横截面温度的统计特性具有对称性,并且钢箱梁顶板存在明显的横向温差;在此基础上进一步建立了钢箱梁横向温差极值的概率分布模型,确定了具有50年重现期的温差标准值,并针对顶板提出了4种类型的横向温度梯度模式。研究结果可为大跨桥梁全寿命设计和评估提供参考。

Based on long-term monitoring data measured by the structural health monitoring system instrumented on Runyang Cable-stayed Bridge, the thermal characteristics of the steel box girder in Runyang Cable-stayed Bridge are analyzed using one-year temperature data. By means of statistical methods such as the clustering analysis, correlation analysis, extreme value analysis, parameter estimation and hypothesis testing, the representativeness of screening temperature samples and symmetry of statistical characteristics of temperature are verified, and the statistical characteristics of transverse thermal differences of a steel box girder are investigated. The analysis results reveal that the transverse distribution of statistical characteristics of temperature is symmetrical, and there exist dominant transverse temperature differences in the top plate of the steel box girder. The probability distribution models of extreme values of the transverse temperature differences are further established, based on which the thermal difference standard values in a 50-year return period are obtained. Moreover, the four types of transverse thermal gradient models with regard to the top plate are presented. These research results can supply references for the life-cycle design and evaluation of long-span bridges.