基于长期监测的北方跨海斜拉桥钢箱梁截面温差特性分析  

Analysis on Temperature Difference Characteristic of Steel Box Girder Cross-section of Cable-stayed Bridge over North Sea Based on Long-term Monitoring

作　　者：陈一飞[1] 孙宗光[1] 邵元[1] CHEN Yi-fei, SUN Zong-guang, SHAO Yuan(Road and Bridge Engineering Institute, Dalian Maritime University, Dalian Liaoning 116026, Chin)

机构地区：[1]大连海事大学道路与桥梁研究所,辽宁大连116026

出　　处：《公路交通科技》2018年第5期65-72,共8页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51178070);中央高校基本科研业务费专项资金项目(3132014326;3132016216)

摘　　要：钢箱梁斜拉桥受其结构特征影响受力状态非常复杂,钢箱梁结构温度受环境条件影响变化难以预测,截面内温度差异对钢箱梁应力分布具有显著影响,确定钢箱梁截面内温差基准值是确保桥梁结构安全耐久的必要条件。目前国内外设计规范对截面温差基准值的确定尚没有统一的方案。通过坐落于我国北方冰冻海域的大跨度钢箱梁斜拉桥长期监测系统,获取跨中主梁截面温度测点监测数据。对2012年跨中大气温度数据进行整理,年温度变化具有显著的季节性特征。钢箱梁跨中截面的6个主要温度测点的温差分析显示,顶板横向温差与顶底板纵向温差显著,底板横向温差非常小,顶底板温度横向分布呈明显不对称性。采用加权威布尔分布分别建立主要测点间正负温差概率分布模型,分布函数拟合效果良好。在此基础上结合国内外相关规范提出了基于极值分析的截面内温差基准值计算方法。以2012年至2015年的监测数据为样本,在年样本抽样数取12的前提下,对钢箱梁截面上最为显著的两组测点温差的基准值进行了计算。计算结果表明,指定50年重现期下钢箱梁跨中截面顶板横向温差为21.42℃,顶底板竖向温差为28.53℃,超过《公路桥涵设计通用规范》规定的20℃,设计与监测钢箱梁斜拉桥时必须对主梁温度应力给予足够的重视。The stress state of steel box girder cable-stayed bridge is very complex due to its structural characteristics. It is difficult to predict the temperature of the steel box girder under the influence of environmental conditions. Difference of in-plane temperature has significant influence on stress distribution of steel box girder. Determining the reference value of temperature difference of steel box girder section is the requirement for safety and durability. At present,there is no uniform scheme to determine the reference value of the temperature difference of the cross-section at home and abroad. Through the long-term monitoring system on the long-span steel box girder cable-stayed bridge located in Chinese northern frozen sea,the temperature monitoring data of girder mid-span cross-section have been obtained. The atmospheric temperature data over 2012 are sorted out,and the annual temperature variation has significant seasonal characteristics. The analysis of difference between 6 main temperature measuring points at cross-section of girder mid-span shows that the transverse temperature difference of roof and vertical temperature differencebetween roof and floor are significantly,while the transverse temperature difference of the floor is very small,the lateral temperature distributions of the top and bottom plates is obviously asymmetric. The probability distribution models of positive and negative temperature difference among main measuring points are established by weighted Weibull distribution respectively. The fitting effect of distribution function is good.On this basis,the computational method of reference value of section temperature difference is approached based on the relevant standards at home and abroad. Taking the monitoring data from 2012 to 2015 as the samples,the sampling number of the annual samples is 12,the reference values of the temperature difference between the 2 obvious groups of measured points on the steel box girder section are calculated. The result shows that for the specified ret

关 键 词：桥梁工程 截面温差 长期监测 钢箱梁 温差基准值 

分 类 号：U446[建筑科学—桥梁与隧道工程]