含薄层沥青混凝土的CRTSⅢ型轨道结构温度场特性研究

Temperature Field Characteristics of CRTSⅢ Ballastless Track System Inserted with Thin Asphalt Concrete Layer

运用基于有限元方法的三维瞬态热分析技术,研究含沥青混凝土层CRTSⅢ型无砟轨道的温度场特点及沥青混凝土层对温度场的影响,并结合郑州至徐州高速铁路沥青混凝土试验段监测结果对模型进行校准。结果表明:基于瞬态传热的三维有限元分析技术能够较好模拟含沥青混凝土层无砟轨道结构的温度场;CRTSⅢ型无砟轨道结构的横向和竖向温度场分布存在明显的非线性特征;外界环境对无砟轨道结构的日影响深度为0.4 m,累积月影响深度可达2.5 m;含沥青混凝土层无砟轨道温度的横向分布规律与普通CRTSⅢ型无砟轨道系统相似,均呈W形分布,但沥青混凝土层的表面温度比同位置的一般无砟轨道大5~8℃,且基床表层整体温度亦有所增加,这表明沥青混凝土层有一定的保温作用。

Based on thermal principle and meteorological data,a 3D transient model was developed to simulate the temperature field characteristics of ballastless track inserted with asphalt concrete layer and to study the effect of asphalt concrete layer on the temperature field.The model was calibrated based on the monitoring results of asphalt concrete test section of Zhengzhou-Xuzhou High-speed Railway.The results show that the 3D finite element analysis technology based on transient heat transfer can well simulate the temperature field of ballastless track structure with asphalt concrete layer.The analysis shows the manifest nonlinearity of the lateral and vertical temperature distribution of the CRTSⅢballastless track structure.The daily influencing depth of external environment on the temperature of CRTSⅢsystem is about 0.4 m,while the accumulated monthly influencing depth can be up to 2.5 m.The temperature along transverse direction of the CRTSⅢballastless track system with a thin layer of asphalt on the top of subgrade shows a W-shaped distribution,which is identical to the curve shape of the common CRTSⅢsystem.However,the surface temperature of the asphalt concrete layer is about 5-8℃higher than that of the common system and the overall temperature of the top layer of track-bed increases due to the thermal insulation effect of the asphalt concrete layer.