[关键词]
[摘要]
为研究轨道交通U梁的温度梯度效应,整理并总结了目前国内既有项目对高架U梁进行的温度监测及结果,与铁路规范、常规设计做法的温度荷载进行平行对比,并结合实体有限元模型计算分析,得出了U梁在各温度梯度模式下的温度应力及变形。在梯度温度荷载工况下的U梁纵向正应力值在设计正应力值中占比相对较大,而横向应力和局部变形差相对较小。最后提出了适用于轨道交通线路走向大体呈东西向时的高架U梁运营后的温度梯度荷载模式,其腹板竖向温度梯度采用指数函数,底板竖向温度梯度采用折线函数,结论可为相关工程设计提供参考。
[Key word]
[Abstract]
In order to study the temperature gradient effect of U-beam in rail transit.The temperature monitoring and results of U-beam in existing domestic projects are collated and summarized,in parallel with the temperature load in the current railway code and conventional practice, and combined with solid finite element model calculation, the temperature stress and deformation of U-beam under different temperature gradient modes are obtained.The longitudinal normal stress value of the U-beam under the gradient temperature load condition accounts for a relatively large proportion of the normal stress value, while the transverse stress and local deformation difference are relatively small.Finally,the temperature gradient mode suitable for U-beam is proposed when the trend of the rail transit line is roughly east-west, the vertical temperature gradient of web is an exponential function, and the vertical temperature gradient of bottom is a broken line function,and the conclusion can provide reference for relevant engineering design.
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