Analysis of the design of railroad track superstructure components for rail transit applications

concrete crosstie;temperature effect;rail displacements

Canga Ruiz, Alvaro Emilio ; Lange ; David A. ; Edwards ; John Riley ; Qian ; Yu

关键词: concrete crosstie;    temperature effect;    rail displacements;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/101134/CANGARUIZ-THESIS-2018.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

An extensive study of the performance of railroad superstructure in rail transit systems was conducted at the University of Illinois at Urbana-Champaign (UIUC) as part of a research program funded by the Federal Transit Administration (FTA).Focusing on field characterization of the performance of prestressed monoblock concrete crossties and premium elastic fastening systems, this project aimed to quantify the behavior of the aforementioned track superstructure elements under different rail transit loading conditions.Instrumentation was deployed at three different North American rail transit agencies; on a light rail transit system, on a heavy rail transit system and on a shared corridor with both commuter rail and freight train traffic, targeting specific aspects for each of the track components included in the study.Extensive field monitoring spanned over several months for all the sites and large data sets were developed.Flexural performance results of crossties under light rail loading conditions were compared with projected design capacities obtained from the application of current design standards, and a structural reliability analysis (SRA) was employed to study the flexural capacity of the sleeper design, calculating the probability of failures.Furthermore, results from an extensive field study of temperature effects on the flexural behavior of rail transit concrete crossties is presented.The temperature study comprised the analysis of the relationship between temperature in the crosstie and the ambient temperature, the effect of curling due to temperature gradient on the flexural performance of concrete crossties, and the potential additional stresses due to nonlinear temperature gradient, shedding additional light on their effect on the design of prestressed monoblock concrete crossties.To complete the railroad superstructure analysis, rail displacements of different fastening system designs and under varied loading scenarios were analyzed and compared.This thesis aimed to provide additional insight into the design of railroad track components for rail transit applications.Current design methodologies used in the rail transit industry do not always lead to accurate, optimal designs.To aid in closing this gap and improving the efficiency of designs, this thesis proposes a probabilistic-based design approach, quantifies the effect of temperature on concrete crosstie flexural behavior, and presents the advantages of using field instrumentation to analyze the behavior of railroad track components.