基于监测数据的混凝土箱梁温度与应变多尺度相关性分析

Analysis of Correlation for Temperature and Strain of Concrete Box Girder Based on Monitoring Data

不均匀的温度分布会使混凝土箱梁产生显著的应力和变形,进而危及结构安全。基于一座在役混凝土箱梁的温度与应变监测数据,分析了其温度分布特征及应变演化规律,结果表明:箱梁结构竖向以及沿顶板、腹板厚度方向均存在明显的不均匀温度分布;箱梁结构的温度和应变在年和日两个时间尺度上均表现出明显的周期性变化。此外,初步研究了温度与应变的相关性,发现二者的Spearman相关系数达0.911。在此基础上,利用小波变换将应变监测数据分离为不同频率组分,其中a6层和d6层分别与年温度变化和日温度变化具有显著的关联性,从而进一步揭示了温度对应变的影响机理。研究成果对增强其运营期安全性和耐久性具有指导意义。

The uneven temperature distribution causes significant thermal stress and deformation of concrete box girder,endangers the structural safety.Based on the monitoring data of temperature and stress of a concrete box girder bridge in service,the temperature distribution characteristics and stress evolution laws of structure were amply analyzed.The results indicate that there are obvious uneven temperature distributions in the vertical direction of the box girder structure and along the thickness of the roof and web.Simultaneously,the temperature and strain of the box girder structure have obvious periodic changes on the annual and daily time scales.Subsequently,the correlation between temperature and strain is preliminarily investigated,it is found that the Spearman correlation coefficient reached 0.911.On basis of this,the monitoring strain data are separated into different frequency components by wavelet transform,in which layer a6 and layer d6 are significantly correlated with yearly and daily temperature variations,respectively.Therefore,the effect mechanism of temperature on strain is further revealed.The research results are of guiding significance to enhance the safety and durability during operation phase.