基于监测数据的组合梁斜拉桥温度梯度特性及结构性能影响研究

Study on temperature gradient and structure performance of composite Beam cable-stayed bridge based on monitoring data

选择了中国、美国、欧洲、英国4本规范对于钢混组合梁温度梯度计算模型进行对比分析,指出欧规与英国在定义钢混组合梁温度梯度计算模式时考虑的因素较为全面。以武汉二七长江大桥健康监测系统2015年温度监测数据为基础,分析得到了二七长江大桥年度最大正温度梯度与最大负温度梯度分布。计算对比了4本规范与实测温度梯度的效应,结果表明英规正温度梯度计算模式结果与实测温度梯度模式结果最为接近;英规负温度梯度计算结果远超正常值,其适用性有待商榷;欧规简化模式与实测负温度梯度模式计算结果较为接近;根据实测温度梯度模式计算结果,中规温度梯度模式温度效应偏于不安全,需要给予修正;根据实测温度梯度与4本规范的对比分析,可为中规温度梯度计算模式的修正提供参考。

This paper compared four current codes(JTG D60-2015,AASHTO,BS 5400,Eurocode 2004)of vertical temperature gradient in composite girder,in which British standard and Eurocode were the most detailed.The biggest positive temperature gradient and negative temperature gradient were obtained based on temperature monitored data collected by Wuhan Erqi Yangzi river health monitoring system.The temperature gradient pattern of four codes and monitored data were used to finite element model to analysis temperature gradient effects.The results showed that tested positive temperature gradient pattern effect is close to BS 5400 standard.And the negative temperature gradient pattern of BS5400 is much larger than normal result,its’applicability needs further discussions.The tested negative temperature gradient pattern effect is close to Eurocode 2004.According to temperature gradient analysis results,the pattern of Chinese code is possibly unsafe for temperature gradient effect calculation and the code should be modified.The comparison results of the test temperature gradient and 4standards will provide reference for the correction of Chinese code on temperature gradient pattern define.