Date Available

10-4-2022

Year of Publication

2022

Degree Name

Master of Science in Civil Engineering (MSCE)

Document Type

Master's Thesis

College

Engineering

Department/School/Program

Civil Engineering

First Advisor

Dr. L. Sebastian Bryson

Second Advisor

Dr. Jerry G. Rose

Abstract

Excessive crosstie wear and abrasion and ballast wear and fouling are two of the fundamental problems contributing to inadequate railroad track performance. This adversely affects the attainment and long-term maintenance of desired track geometric requirements. The magnitudes and distribution of the stresses at the crosstie-ballast (CT-B) interface must be known to determine the stress distribution on the ballast. However, the stresses at the top of the ballast often vary significantly. This study examines a new approach to predicting dynamic contact pressures at the interface of crosstie and ballast using the ‘square wave theory.’ A data set of in-track CT-B interfacial pressures, taken from a freight mainline at Mascot, TN limited to speeds up to 64 km/h, in 2018, was analyzed to develop relationships in the form of equations to predict dynamic contact pressures as a function of specific information, including train speed, weight, number of axles, and wheel spacing. Several equations were developed to predict CT-B interfacial pressures as a function of these variables. Additionally, the developed square wave theory and obtained data are analyzed and compared to traditional recommended design practices. Longitudinal stress distribution over the crossties and the stress distribution along the crossties are presented. Based on the analyzed CT-B interfacial pressures, the ballast stress distribution is discussed, and recommendations are made.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2022.362

Funding Information

Republic of Turkey and the Turkish Ministry of Education

National University Rail Center (NURail)

Norfolk Southern Corporation

Federal Railroad Administration Office of Research Development and Technology

ENSCO Inc.

Volpa National Transportation Systems Center

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