基于实测数据的悬索桥钢箱梁温度场特性研究
发布时间：2018-08-09 08:15
【摘要】：为明确大跨度悬索桥扁平钢箱梁温度和温度梯度特征,以南溪长江大桥正交异性钢箱梁为研究对象,基于健康监测系统中温度传感器的长期实测数据,采用分段函数描述环境温度和日照辐射共同作用下钢箱梁日温度变化曲线。在此基础上,采用高斯混合模型描述钢箱梁年温度多峰概率分布,并引入赤池信息判别准则(AIC)和贝叶斯信息判别准则(BIC)确定最优高斯分量数。统计钢箱梁一年日温差极值并进行参数评估,得到钢箱梁年温差极值分布模型。对年温差极值分布函数进行外推,得到设计基准期温差的极值分布函数并计算温差标准值。引入相关系数分析法对各温差组进行相关性分析,剔除实际不存在的温差模型。研究结果表明:相比正弦函数,分段函数能更准确地描述太阳辐射作用下箱梁截面日温度变化特征;当高斯分量数为3时,混合高斯模型拟合钢箱梁年温度概率分布最优;外推设计基准期模型能够较好地计算设计基准期温差标准值;通过相关性分析剔除了4组不存在的温差模式;得到顶板和腹板各8组温差模式;最后与《公路桥涵设计通用规范》(JTG D60—2015)中钢混结构竖向正温差设计值进行对比,一、二级温度梯度与设计规范分别相差4.2℃和2.3℃。
[Abstract]:In order to clarify the temperature and temperature gradient characteristics of flat steel box girder of long-span suspension bridge, the orthotropic steel box girder of Nanxi Yangtze River Bridge is taken as the research object, based on the long-term measured data of temperature sensor in health monitoring system. A piecewise function is used to describe the diurnal temperature variation curve of steel box girder under the action of ambient temperature and sunshine radiation. On this basis, the annual temperature multi-peak probability distribution of steel box girder is described by Gao Si mixed model, and the optimal Gao Si component number is determined by introducing the red pool information discriminant criterion (AIC) and Bayesian information discriminant criterion (BIC). The annual temperature difference extreme value distribution model of steel box girder is obtained by calculating the extreme value of annual temperature difference of steel box girder and evaluating the parameters. By extrapolating the extreme value distribution function of annual temperature difference, the extreme value distribution function of temperature difference in the design base period is obtained and the standard value of temperature difference is calculated. Correlation coefficient analysis method is introduced to analyze the correlation of temperature difference groups, and the non-existent temperature difference model is eliminated. The results show that compared with the sinusoidal function, the piecewise function can more accurately describe the diurnal temperature variation of the box girder section under solar radiation, and when the Gao Si component number is 3, the hybrid Gao Si model can best fit the annual temperature probability distribution of the steel box girder. Extrapolation of the design reference period model can better calculate the standard value of temperature difference in the design reference period, eliminate the non-existent temperature difference mode in 4 groups through correlation analysis, and obtain the temperature difference mode of each group of roof and web. Finally, the design values of vertical positive temperature difference of steel-concrete structures in JTG D60-2015 are compared. First, the difference between the second-order temperature gradient and the design code is 4.2 鈩，
本文编号：2173478
[Abstract]:In order to clarify the temperature and temperature gradient characteristics of flat steel box girder of long-span suspension bridge, the orthotropic steel box girder of Nanxi Yangtze River Bridge is taken as the research object, based on the long-term measured data of temperature sensor in health monitoring system. A piecewise function is used to describe the diurnal temperature variation curve of steel box girder under the action of ambient temperature and sunshine radiation. On this basis, the annual temperature multi-peak probability distribution of steel box girder is described by Gao Si mixed model, and the optimal Gao Si component number is determined by introducing the red pool information discriminant criterion (AIC) and Bayesian information discriminant criterion (BIC). The annual temperature difference extreme value distribution model of steel box girder is obtained by calculating the extreme value of annual temperature difference of steel box girder and evaluating the parameters. By extrapolating the extreme value distribution function of annual temperature difference, the extreme value distribution function of temperature difference in the design base period is obtained and the standard value of temperature difference is calculated. Correlation coefficient analysis method is introduced to analyze the correlation of temperature difference groups, and the non-existent temperature difference model is eliminated. The results show that compared with the sinusoidal function, the piecewise function can more accurately describe the diurnal temperature variation of the box girder section under solar radiation, and when the Gao Si component number is 3, the hybrid Gao Si model can best fit the annual temperature probability distribution of the steel box girder. Extrapolation of the design reference period model can better calculate the standard value of temperature difference in the design reference period, eliminate the non-existent temperature difference mode in 4 groups through correlation analysis, and obtain the temperature difference mode of each group of roof and web. Finally, the design values of vertical positive temperature difference of steel-concrete structures in JTG D60-2015 are compared. First, the difference between the second-order temperature gradient and the design code is 4.2 鈩，
本文编号：2173478
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