板式无砟轨道温度场和温度梯度监测试验分析

Analysis of Monitoring test for Slab-type Ballastless Track Temperature Field and Temperature Gradient

为研究板式无砟轨道温度场和温度梯度分布规律,通过对北京地区CRTSⅡ型板式无砟轨道结构实尺模型进行温度监测,以春夏季监测数据为样本,分析了无砟轨道温度场分布和轨道结构各层温度梯度变化规律。分析结果表明:轨道板阳面和阴面温度存在明显差异,同一时刻温差最大为9.73℃;轨道结构各层温度最大(小)值出现时间存在滞后性,引起垂向温度不均匀分布,使结构各层间温度梯度存在较大差异,监测期间板表到板中温度梯度最大为121.43℃/m,板表到板底温度梯度最大为78.08℃/m,经统计最大正温度梯度是最大负温度梯度的2.55倍左右,板中温度梯度最大(小)值是板底温度梯度最大(小)值的1.4倍左右。

For studying the distribution law of slab-type ballastless track temperature field and temperature gradient,the change rules of ballastless track temperature field distribution and temperature gradient of each layer of the track structure were analyzed through the temperature monitoring of CRTS Ⅱ slab-type ballastless track structure full scale model in Beijing region and taking the spring and summer monitoring datas as samples.Analysis results show that there are obvious differences between sunny side temperature and shady side temperature of the track slab and the maximum temperature difference is 9.73℃ at a same time,there is time lag in the maximum（minimum）temperature of each layer of the track structure,which could cause uneven temperature distribution and big difference between the temperature gradient of each layer of the track structure,during the monitoring the maximum temperature gradient from slab surface to middle of slab is 121.43℃/m while the maximum temperature gradient from slab surface to slab bottom is 78.08℃ /m through statistical analysis maximum positive temperature gradient is about 2.55 times as much as the maximum negative temperature gradient and maximum（minimum） temperature gradient in the middle of slab is 1.4 times as much as maximum（minimum） temperature gradient in the slab bottom.