桥梁结构空心构件梯度温度参数研究

目前我国铁路、公路桥梁规范均未考虑南北气候差异对桥梁温度作用的影响,对降温温度梯度曲线的规定也较粗略。针对上述不足,结合哈尔滨40年(1963～2002年)及广州10年(1997～2006年)的气象资料,通过分析气象资料和建立有限元模型,对大型桥梁空心构件日照升温和寒流降温梯度温度参数进行分析研究。对日照升温温度作用,为区分不同地区温度作用的差异,提出其温差极值的预测公式并加以简化,可为建立温度作用分区提供参考依据;对寒流降温温度作用,定性分析壁厚对温差极值和温度梯度曲线的影响,并提出温差极值预测公式。结果表明:哈尔滨地区的日照升温温差极值为35℃,广州地区为20℃,两地温度作用相差较大,有必要考虑气候的影响并建立温度作用分区;寒流降温温度作用对构件的影响深度在0.6 m左右,随着壁厚的增加温差曲线指数相应减小。

Study on Temperature Gradient Parameters of Hollow Members of Bridge Structure

At present,the specifications of bridges of railways and highways prevailing in china do not take into account the influence of the difference between the north and south climates on the temperature action of bridge and instead provide roughly defined regulations about curves of falling temperature gradients.In view of the above deficiencies,by analyzing the meteorological data of Harbin(1963～2002) and Guangzhou(1997～2006) and by establishing the finite element model,the paper studied the parameters of temperature gradients of hollow members of large-scale bridges generated in daylight temperature rising and cold-wave temperature falling.In respect of the daylight temperature rising action,the extremum prediction formula for temperature difference is put forward and simplified,which can be used to distinguish the difference of temperature actions in different areas and provide reference for establishment of temperature action zones.In respect of the cold-wave temperature falling action,qualitative analysis is made on the influence of the thickness of the pier wall on the temperature difference extrema and the curve of temperature gradients and the extremum prediction formula for temperature difference is put forward.The research results as follows: the extremum of the temperature difference in daylight temperature rising is 35℃ for Harbin Area and 20℃ for the Guangzhou Area,therefore it is necessary to consider the effect of climate condition and set up temperature action zones;the thickness of the wall of members affected by the cold-wave temperature falling action is about 0.6m and exponential coefficient of the temperature difference curve decreases with the increasing of the thickness of the wall of members.