基于长期监测数据的混凝土箱梁温度梯度取值研究

Research on Temperature Gradient of Concrete Box Girder Based on Long-term Monitoring Data

为研究矮塔斜拉桥混凝土箱梁施工期的温度梯度取值,文中以广东东平水道矮塔斜拉桥为研究对象,详细分析了一年施工期内混凝土箱梁的实测温度结果,通过假设检验、参数估计、极值分析等统计学方法进行温度样本数据分析。结果表明,箱梁顶底板东西两侧的温差分布不同,特别是顶板的东西两侧温差累计概率分布差异较大;箱梁顶板最大正温差出现在西侧位置处,最大负温差出现在东侧,而底板最大负温差与最大正温差均出现在东侧;箱梁混凝土顶板的梯度升降标准值可偏于安全地,取22.5℃,梯度降温可以取9.0℃,底板的梯度升降标准值可偏于安全地,取5.5℃,梯度降温可以取4.0℃。

In order to study the temperature gradient of concrete box girder of low-pylon cable-stayed bridge during construction period,taking the low-pylon cable-stayed bridge in dongping waterway of guangdong province as the research object,the measured temperature of concrete box girder during one year construction was analyzed in detail.Temperature sample data were analyzed by hypothesis testing,parameter estima-tion,extremum analysis and other statistical methods.The analysis results reveal that the temperature difference distribution on the east and west sides of the bottom plate of the box girder is different,especially the cumulative probability distribution of temperature difference on the east and west sides of the roof plate is quite different.The maximum positive temperature difference of the roof of the box girder appears on the west side,the maximum negative temperature difference appears on the east side,and the maximum negative temperature difference and the maximum positive temperature difference of the bottom plate both appear on the east side.The gradient increased temperature standard value of the concrete roof of the box girder can be safely set at 22.5℃,the gradient cooling can be set at 9.0 C,the gradient increased temperature standard value of the bottom plate can be safely set at 5.5,and the gradient cooling can be set at 4.0 C.