基于长期健康监测数据的混凝土单箱三室箱梁遮阴效应  

Shading Effect of Concrete Three-cell Box Girder Based on Long-term Monitoring Data

作　　者：寇越 刘金义 马彦阳 张峰[2] KOU Yue;LIU Jin-yi;MA Yan-yang;ZHANG Feng(China Railway Construction Investment Group Co.,Ltd.,Beijing 100855,China;Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,China)

机构地区：[1]中国铁建投资集团有限公司,北京100855 [2]山东大学岩土与结构工程研究中心,济南250061

出　　处：《科学技术与工程》2023年第5期2065-2075,共11页Science Technology and Engineering

基　　金：陕西省交通运输厅科研项目(20-40k)。

摘　　要：单箱三室箱梁温度效应复杂,在王家河特大桥箱梁混凝土内埋置了89个温度传感器、并布置了光电辐射传感器与风速传感器,采集频率均为1次/20 min。利用无线采集模块进行数据采集,得到单箱三室箱梁太阳辐射温度场分布规律。研究结果表明:太阳辐射测试结果存在季节性,夏季太阳辐射强烈,风速测试结果无明显季节性;受太阳辐射作用影响,向阳侧边腹板竖向温度梯度大于背阳侧竖向温度梯度,夏季竖向温度梯度大于冬季温度梯度;受对流作用影响,中腹板除顶底部测点外变化极小,可被忽略;受太阳高度角影响,冬季向阳侧照射时间比夏季长。冬季箱梁最大横向温度梯度为12.0℃,大于夏季的4.7℃;箱梁横向温度梯度呈U形分布,背阳侧横向温度梯度的98%超越概率值为6.472℃,首次提出基于向阳侧和背阳侧温度梯度的中国铁路规范的修正公式;建立考虑遮阴长度的温度场模型,揭示了向阳侧腹板横向温度梯度冬季大于夏季的原因。The temperature effect of single-box three-rooms box girder is complicated.89 temperature sensors,solar radiation sensors and wind speed sensors were embedded in the concrete of Wangjiahe grant bridge,and the collection frequency was 1 time/20 min.The wireless acquisition module was used to collect data and obtain the distribution law of solar radiation temperature field of single-box three-compartment box girder.The research results show that the solar radiation test results have seasonality,the solar radiation is strong in summer,and the wind speed test results have no obvious seasonality.Influenced by solar radiation,the vertical temperature gradient of the sunny side web is larger than the vertical temperature gradient of the back sun side,and the vertical temperature gradient in summer is larger than the temperature gradient in winter.Influenced by convection,the change of the middle web except the top bottom measurement point is very small and can be ignored.Influenced by the solar altitude angle,the irradiation time of the sunny side is longer than that of the summer.The exposure time on the sunny side in winter is longer than that in summer.The maximum transverse temperature gradient of box girder in winter is 12.0℃,which is larger than 4.7℃ in summer.The transverse temperature gradient of box girder becomes U-shaped distribution,the 98% exceedance probability value of transverse temperature gradient of back-side sun is 6.472℃,and the correction formula of Chinese railroad code based on the temperature gradient of sunny side and back-side sun is proposed.The temperature field model considering the shade length is established,and the maximum transverse temperature gradient of web appears at the moment when the sunny side web moment of being directly exposed to the sun.

关 键 词：太阳辐射 箱梁 温度 混凝土 数值模拟 

分 类 号：TU375.4[建筑科学—结构工程]