Railroad bridge dynamics and ratings
Subtitle: IDEA program final report, for the period May 2013 through November 2014
By: prepared by Kevin Bollinger, Hatch Mott MacDonald
Contributors: Innovations Deserving Exploratory Analysis Program; National Research Council (U.S.). Transportation Research Board
Publisher: IDEA Programs, Transportation Research Board of the National Academies
Published: 2015
Place of publication: Washington, DC
Language: eng
ISBN-13: 9781523108916
Subjects: High speed trains; Railroad bridges; Trains à grande vitesse; Ponts-rails; High-speed trains
Description: Bridge rating calculations are performed to determine the safe capacity of existing structures. The American Railway Engineering and Maintenance-of-Way Association (AREMA) Manual for Railway Engineering (MRE) is the current recommended practice used by the great majority of railroads in North America. The Foreword to MRE Chapter 15, "Steel Structures," limits the application of the chapter to freight train speeds of up to 70 mph, and passenger train speeds of up to 90 mph. Therefore, the chapter provisions do not provide a method to calculate a bridge rating for train speeds beyond 90 mph. As speeds increase, impact values either increase or decrease depending on the dynamic characteristics of the bridge structure and equipment using the track. Currently, Amtrak is operating high-speed passenger trains at speeds of up to 150 mph on the Northeast corridor. The research described in this report investigates impact factors for speeds above 90 mph to be used in capacity ratings of existing bridges. To accomplish this, basic structural dynamic methodologies and current structural engineering codes and procedures are utilized in order to propose an impact evaluation methodology consistent with current North American railroad bridge practice
Notes: "June 2015"--PDF title page

"Prepared for IDEA Program, Transportation Research Board, National Research Council"--PDF title page

Includes bibliographical references.

This research was supported by the National Academies' Transportation Research Board (TRB) IDEA Program. The project, "High-Speed Rail Bridge Dynamics and Ratings," is part of the Safety IDEA Program, which is funded by the Federal Railroad Administration. Charles Taylor was the TRB Project Manager
Table of contents: title: 1 EXECUTIVE SUMMARY ... 1 2 MATERIALS REVIEWED ... 2 3 NORMAL RATING CALCULATION ... 3 3.1 AMTRAK BRIDGE 155.85 OVER THE USQUEPAUG RIVER IN RHODE ISLAND ... 3 3.2 NORMAL RATING CALCULATIONS ... 4 4 DETERMINATION OF DYNAMIC VERTICAL EFFECTS ... 4 4.1 MODELING ... 5 4.2 DYNAMIC EQUATIONS AND CALCULATION SOFTWARE ... 5 4.2.1 The Moving Load Model ... 5 4.2.2 Natural Frequency and Damping Equations ... 7 4.2.3 Moving Load Model with Vehicle-Bridge Interaction Considerations ... 8 4.2.4 Wheel Load Case ... 8 4.3 MODEL AND FIELD RESULTS ... 10 4.3.1 Model Verification ... 10 4.3.2 Work Train Model Information ... 10 4.3.3 Acela Train Model Information ... 12 4.3.4 Byers Report ... 13 4.4 RESONANT SPEEDS ... 15 4.5 CANCELLATION ... 15 4.6 DYNAMIC VERTICAL EFFECT (DVE) ... 15 5 FIELD TESTING ... 16 5.1 OVERVIEW ... 16 5.2 BRIDGE DESCRIPTION ... 16 5.3 INSTRUMENTATION DESCRIPTION ... 17 5.4 MONITORING PROCEDURE ... 17 5.4.1 TRAINS MONITORED ... 18 5.4.2 MONITORING RESULTS ... 19 6 PROPOSED RATING PROCEDURE ... 23 6.1 NORMAL RATINGS CONSIDERING DYNAMIC CHARACTERISTICS ... 23 7 BRIDGE LENGTH AND TRAIN SPEED COMPARISONS ... 24 7.1 COMPARISON OF BRIDGE LENGTHS ... 24 8 CONCLUSIONS AND RECOMMENDATIONS ... 26 9 FUTURE RESEARCH AND CRITERIA DEVELOPMENT ... 26 10 REFERENCES ... 27