大跨连续刚构桥梁体及轨道温度分布试验及其影响研究

为了明确大跨连续刚构桥上梁体及轨道温度分布及其对桥上无缝线路力学行为的影响,以1座铁路常用双线特大连续刚构桥为例,针对箱梁及轨道结构的温度分布开展测试研究,分析结果表明:根据实测数据,钢轨温度最高值要高于气温,轨温最低值相对气温也较低。当气温较低时,最低轨温与最低气温虽不完全一致,但两者相差很小,最高轨温与最高气温亦是如此,但当气温较高时,最高轨温要明显高于最高气温;桥梁纵向温度分布差别不大,温差主要表现在竖向和横向上,箱梁温度沿梁高方向自上而下逐渐升高,沿箱梁横向上同样存在差别,但相差均较小;梁体垂向温度梯度对钢轨纵向受力影响较小,但其对线路高低不平顺会有一定影响,且主要是在长波范围内,当温度梯度较大时会出现长波不平顺超限。

Temperature Distribution Test of Large-span Continuous Rigid Frame Bridge and Track and Its Effect

To clarify the temperature distribution of the beam and track on large-span continuous rigid frame bridge and its effect on the mechanical behavior of CWR on bridge,a study is conducted to identify the temperature distribution of box-girder and track structure based on a large double-track railway continuous rigid frame bridge. The results show that,according to the measured data,the maximum temperature of the rail is higher than that of the air,and the minimum temperature is relatively low.When the air temperature is low,even though the minimum rail temperature and the minimum air temperature are not exactly the same,the difference between them is very small,and the same is true for the maximum rail temperature and the maximum air temperature. But when the temperature is relatively high, the maximum rail temperature is significantly higher than the highest air temperature; the longitudinal temperature distribution is not quite different and the temperature difference appears mainly in the vertical and horizontal directions. On the box girder,the temperature gradually increases from top to bottom along the direction of the vertical beam; likewise,difference exists along the transverse,but the difference is small. The rail longitudinal force is less affected by the beam vertical temperature gradient,but it may have some effect on the line vertical profile irregularity largely in the range of long waves,and long-wave irregularity overrun may occur when the temperature gradient is large.