圆曲线段无砟轨道横竖向温度梯度研究

Study on Horizontal and Vertical Temperature Gradient of Ballastless Track on Curve Line

研究目的:为得到设有超高的无砟轨道温度场分布的时变规律,建立无砟轨道横竖向温度梯度荷载模式,在某客运专线圆曲线段上CRTSⅡ型纵连板式无砟轨道中埋设温度传感器对其温度场进行了长期连续观测。研究结论:(1)无砟轨道昼夜温度变化较大,表面最高日温差可达24.7℃,平均日温差达19.0℃;(2)随着距表面深度的增加,无砟轨道温度变化幅值逐渐减小,峰值出现时间不断滞后;(3)底座板底面最大日温差为6.1℃,平均为5.0℃;(4)纵连板式无砟轨道的竖向温度梯度可拟合为指数曲线,与铁路桥梁设计规范规定的箱梁竖向温度梯度分布在形状上较为符合;(5)纵连板式无砟轨道横向温度梯度分为轨道板和底座板两类,轨道板横向温度梯度可采用二次函数拟合回归,底座板横向梯度可采用线性分段函数拟合;(6)研究成果可为我国中部地区高速铁路设计温度荷载模式提供指导作用。

Research purposes： In order to get the time - varying rules of temperature field distribution in the track structure with superelevation and build the horizontal and vertical temperature gradient of ballastless track, a continuous observation of CRTS II by using temperature sensors on curve segment of a passenger dedicated line was held. Research conclusions： （ 1 ） The temperature change of ballastless track between daytime and nighttime is big, the temperature changing value of surface was 24.7°C in maximum, 19% in average. （2） The temperature changing value became small and the time of maximum temperature come late with the increase of distance to surface. （3） At the bottom of the track structure, the temperature changing value was 6. 1°C in maximum, 5.0°C in average. （4） Fitting curve of vertical temperature gradient of longitudinally connected ballastless track on curve line can be exponential curve, and the curve sharp can match the distribution about the vertical temperature gradient of the code for design of bridge and culvert in China. （5） The horizontal temperature gradient of the CRTS II longitudinally connected ballastless track included the track slab and support layer, temperature gradient of track slab could be fitted by using quadratic function, temperature gradient of support layer could be fitted by using piecewise linear function. （6） This study can provide guidance for the temperature load model in the design of high speed railway in central China.