无铺装层PK断面混凝土梁日照温度场分析

Analysis of Temperature Field of PK Section Concrete Girder without Pavement Caused by Solar Radiation

针对我国桥涵设计规范未给出无铺装层PK断面混凝土梁日照梯度温度及国内外缺乏研究的现状,应用ANSYS求解了马鞍山长江公路大桥右汊斜拉桥无铺装层混凝土主梁温度场,并进行了现场实测,计算值与实测值吻合较好。对无铺装层混凝土梁日照温度场的参数分析表明,吸收率对无铺装层混凝土梁最大竖向温差影响较大,风速次之。计算得到了该桥主梁在施工过程中出现的最大竖向梯度温度及其分布的指数函数的梯度温度模式。该模式与现有各国规范的梯度温度模式比较表明,本文研究得到的无铺装层混凝土梁梯度温度分布趋势与各国规范已有相关规定的分布趋势基本吻合。但温度分布受地域影响,各国规范梯度温度取值存在差异,建议补充完善我国公路桥规中关于无铺装层混凝土梁梯度温度的规定。

Aiming at lack of solar gradient temperature of PK section concrete girder without pavement in Chinese highway bridge design specifications and few research has been done at home and abroad,the temperature filed of Maanshan Yangtze River expressway right branch cable-stayed bridge concrete girder without pavement is calculated by ANSYS software,and the result agrees well with the field measured values.The parameter analysis on the concrete girder without pavement shows that the absorptivity has significant influence on its maximum vertical temperature,while the wind speed is another important influencing factor.The vertical maximum gradient temperature of the girder in the worst environment and the mode of its exponential function mode in the course of the bridge construction are calculated. Compared with the modes of gradient temperature in the current specifications of different countries,it shows that the distribution trend of the gradient temperature obtained from our research basically tallies with those in existing regulations in the specifications of different countries. Owning to the effect of geography,the temperature values of gradient temperature are different. Therefore, it is suggested to add and improve the specification of gradient temperature for concrete girder without pavement in Chinese highway bridge regulations.