Railroad track fastening system demands and response: Implications for mechanistic design

Dersch, Marcus Scott

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https://hdl.handle.net/2142/114509 Copy

Description

Title

Railroad track fastening system demands and response: Implications for mechanistic design

Author(s)

Dersch, Marcus Scott

Issue Date

2022-04-20

Director of Research (if dissertation) or Advisor (if thesis)

Edwards, J. Riley

Doctoral Committee Chair(s)

• Edwards, J. Riley
• Barkan, Christopher P.L.

Committee Member(s)

• Tutumluer, Erol
• Popovics, John
• Freudenstein, Stephan

Department of Study

Civil & Environmental Eng

Discipline

Civil Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Railroad
• Infrastructure
• Fastening System
• Design
• Failure Analysis
• Mechanistic Design
• MEPDG
• Spikes

Abstract

Rail fastening systems, in conjunction with the crosstie, secure the rail to maintain gauge, transmit thermal and service loads, and anchor the rail-crosstie structure against lateral and longitudinal movements. In doing so, fastening systems must transmit vertical, lateral, and longitudinal loads. Fastening systems have evolved iteratively, through a trial-and-error design approach aimed at addressing conditions symptomatic of track strength and force transfer deficiencies. These deficiencies have led to a variety of track component failures that have, in-turn, caused derailments. Many of these failures were a result of an excessive combination of applied vertical, lateral, and longitudinal loads. Because fastening systems developed using a trial-and-error design process are failing due to force-transfer deficiencies, there is an opportunity to develop and apply the principles of mechanistic-empirical (M-E) analysis and design to fastening systems. Therefore, this dissertation advances the M-E analysis and design of fastening systems through the deployment of field instrumentation, execution of experiments in the laboratory, and development and validation of multiple analytical models. Deployment of vertical, lateral, and longitudinal wheel-rail load instrumentation in track with a history of broken spikes identified that friction is critical at the plate-crosstie interface and balanced operations have an impact on a component’s failure threshold. A novel spike-in-timber 3D analytical model was validated and found a longitudinally applied load is more detrimental than an equivalent magnitude lateral load. A novel 2D analytical model leveraging beam on elastic foundation (BOEF) principles and a novel 3D fastening system in tie-block model were developed, validated, and used to establish methods to accurately and economically analyze fastening system design variable’s effect on component stress in an effort to reduce spike fatigue failures. The most feasible finding to implement was to develop friction at the plate-tie interface via a vertical plate hold-down force using screw spikes and spring washers. The model and associated laboratory work found that applying 1,000 lb./spike of hold-down force reduced spike stress by 70%. Finally, a novel 3D nonlinear parametric track model was developed, validated, and used to quantify the effect of various fastening system and track conditions on the longitudinal fastening system load demand. In one example, it was found that when a railroad changes from timber crossties with anchors to elastic fastening systems, the longitudinal rail seat load increases by 24%, due to the direct logarithmic relationship between track stiffness and longitudinal load. The novel field and laboratory data and validated analytical methods described in this dissertation directly contribute to advancing the M-E analysis and design of railroad fastening systems as they provide direct inputs required for design and methods to quantify component response required for analysis.

Graduation Semester

2022-05

Type of Resource

text

Copyright and License Information

Copyright 2022 Marcus Dersch

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