Izvolt Libor, Dobes Peter, Drusa Marian, Kadela Marta, Holesova Michaela
Department of Railway Engineering and Track Management, University of Žilina, Univerzitná 8215/1, 010 26 Zilina, Slovakia.
Department of Geotechnics, University of Žilina, Univerzitná 8215/1, 010 26 Zilina, Slovakia.
Materials (Basel). 2021 Dec 26;15(1):160. doi: 10.3390/ma15010160.
The article aims to present the modified structural composition of the sub-ballast layers of the railway substructure, in which a part of the natural materials for the establishment of sub-ballast or protective layers of crushed aggregate is replaced by thermal insulation and reinforcing material (layer of composite foamed concrete and extruded polystyrene board). In this purpose, the experimental field test was constructed and the bearing capacity of the modified sub-ballast layers' structure and temperature parameters were analyzed. A significant increase in the original static modulus of deformation on the surface of composite foamed concrete was obtained (3.5 times and 18 times for weaker and strengthen subsoil, respectively). Based on real temperature measurement, it was determined the high consistency of the results of numerical analyses and experimental test (0.002 m for the maximum freezing depth of the railway line layers and maximum ±0.5 °C for temperature in the railway track substructure-subsoil system). Based on results of numerical analyses, modified railway substructure with built-in thermal insulating extruded materials (foamed concrete and extruded polystyrene) were considered. A nomogram for the implementation of the design of thicknesses of individual structural layers of a modified railway sub-ballast layers dependent on climate load, and a mathematical model suitable for the design of thicknesses of structural sub-ballast layers of railway line were created.
本文旨在介绍铁路下部结构底碴层的改进结构组成，其中用于铺设底碴或碎骨料保护层的部分天然材料被隔热和增强材料（复合泡沫混凝土层和挤塑聚苯乙烯板）所取代。为此，构建了现场试验并分析了改进后的底碴层结构的承载能力和温度参数。复合泡沫混凝土表面的原始静态变形模量显著增加（软弱地基和加固地基分别增加了3.5倍和18倍）。基于实际温度测量，确定了数值分析结果与试验测试结果的高度一致性（铁路线路层的最大冻结深度为0.002米，铁路轨道下部结构-地基系统中的温度最大为±0.5°C）。基于数值分析结果，考虑了内置隔热挤塑材料（泡沫混凝土和挤塑聚苯乙烯）的改进铁路下部结构。创建了一个取决于气候荷载的改进铁路底碴层各结构层厚度设计实施列线图，以及一个适用于铁路线路结构底碴层厚度设计的数学模型。
