Engineered polymer composite (EPC) ties offer a potential alternative to solid sawn timber ties (also known as wood ties), particularly in areas of high rot and high decay. THough research sponsore dby th Federal railroad Administration (FRA), in collaboration with the Association of American Railroads’ (AAR) Strategic Research Initiatives Program, EPC ties are being studied…
The design and performance of concrete ties and elastic fastening systems must be improved to meet demands placed on North America’s railway infrastructure through ever-increasing freight tonnages and development of its high speed rail program. In July 2012, a field experimentation program was performed at the Transportation Technology Center (TTC) in Pueblo, CO by researchers…
This paper examines the issues relating to the use of 6”x 8” timber crossties in low-density heavy axle load operations, such as found on short lines, regional railways or railroad branch lines. This application is of particular importance in light of the requirement for low-density lines to operate 286,000 lb. heavy axle load cars. This…
Concrete tie rail seat abrasion/deterioration (RSA) has been an issue since the inception of concrete ties. As a result of recent derailments involving abraded concrete ties on curved track, the Federal Railroad Administration set up a task force to study abrasion/deterioration mechanisms and develop automated detection methods using existing research vehicles. A portion of this…
This paper reviews the main failure modes of concrete ties observed in the U.S. railroads, including chemical degradation, prestress cracks, flexural cracks, rail seat deterioration, freeze-thaw cracks, and shoulder/fastener wear or fatigue. The observed characteristics, probable causes and detrimental effects of each failure mode are described. A finite element analysis framework aimed at achieving a…
Automated in-plant diagnostic testing of prestressed concrete railroad crossties is now within reach due to recent progress in robust surface strain measurement techniques. The newly developed non-contact Laser Speckle Imaging (LSI) technique has been shown to provide rapid and accurate surface strain profile measurement, which is a key requirement for rapid transfer length assessment. Accurate…
The sealing characteristics of tie pads on concrete-tie rail seats directly influence the intrusion of moisture and fines, which are two of the four primary causes of concrete-tie rail seat deterioration (RSD). The amount of leakage allowed by the tie-pad seal also determines the response of rail-seat surface water to wheel loads. A laboratory test…
After the adoption of the equation EIw^(iv) + kw = q for cross-tie track analyses, a number of methods for the determination of the track modulus k were proposed and used during the past several decades. However, some of these methods are difficult to utilize or are of questionable validity. Therefore, at first, a simple yet…
The wood tie/cut spike fastener system has been in use on North American railroads since the 19th century (2). However, as the nature of the railroad-operating environment has changed over the last decade, there has been an increasing emphasis on long heavy trains with high axle loading. This has placed a severe burden on the…
Completely revised to reflect the new ACI 318-08 Building Code and International Building Code, IBC 2009, this popular book offers a unique approach to examining the design of prestressed concrete members in a logical, step-by-step trial and adjustment procedure.Integrates handy flow charts to help readers better understand the steps needed for design and analysis. Includes…
2017. A mechanistic model of lateral rail head deflection based on fastening system parameters. Journal of Rail and Rapid Transit. 231 (9): 999-1014. doi:10.1177/0954409716642485.
This paper presents a mechanistic model of the rail head lateral deflection with the aim of quantifying the distribution of the lateral wheel load in a concrete sleeper rail track. The model is developed based on observations of the field experimentation and the results of a three-dimensional validated finite element model. The input parameters of…
1997. Analysis of crosstie track in lateral plane using new track equations. American Society of Civil Engineers Journal of Transportation Engineering. 123 (3): 202-208. doi:10.1061/(ASCE)0733-947X(1997)123:3(202).
The analysis of a crosstie railroad track in the lateral plane has traditionally been based on the theory of a beam on an elastic foundation, in which the bending rigidity of the track structure is assumed to be twice the rigidity of a single rail, and the ballast resistance is represented by a linear Winkler…
2008. Behavior of integrated crosstie trackwork system. American Society of Civil Engineers Journal of Structural Engineering. 134 (2): 329-336. doi:10.1061/(ASCE)0733-9445(2008)134:2(329).
Light rail systems are an important transportation mode in urban centers. An advanced rail transit system has been developed that utilizes linear induction motors (LIM) for propulsion and braking of the vehicles. Due to the tight motor-to-rail air gap tolerances required for the efficient operation of the LIM system, the trackwork requires special consideration. An…
2001. Concrete slab track state of the practice. Transportation Research Record: Journal of the Transportation Research Board. 1742: 87-96. doi:10.3141/1742-11.
Railway track technology has evolved over a period of 150 years since the first railroad track on timber ties was introduced. For much of this period, the conventional track system, commonly referred to as the ballasted track system, has consisted of certain components including rails, ties, ballast, and the subgrade (roadbed). Over the last 20…
2018. Evaluation of ballast behavior under different tie support conditions using discrete element modeling. Transportation Research Record: Journal of the Transportation Research Board. 2672 (10): 106-115. doi:10.1177/0361198118790643.
This paper presents findings of a railroad ballast study using the discrete element method (DEM) focused on mesoscale performance modeling of ballast layer under different tie support conditions. The simulation assembles ballast gradation that met the requirements of both American Railway Engineering and Maintenance-of-Way Association (AREMA) No. 3 and No. 4A specifications with polyhedral particle…
2017. Feasibility of digital image correlation for railroad tie inspection and ballast support assessment. Measurement - Journal of the International Measurement Confederation. 103: 93-105. doi:10.1016/j.measurement.2017.02.024.
Structural Health Monitoring (SHM) of aging railway tracks is important for safety, to prevent catastrophic failure, and to reduce maintenance costs. The tracks and foundations are complex systems that may contain defects or damage including internal rail cracks, pitting or surface erosion, degradation of ballast support, or railway crosstie-ballast failures. In recent years, interest has…
2011. Greener and leaner—unleashing capacity of railroad concrete ties via limit states concept. American Society of Civil Engineers Journal of Transportation Engineering. 137 (4): 241-247. doi:10.1061/(ASCE)TE.1943-5436.0000215.
New knowledge has raised a concern about the cost-ineffective design methods and the true performance of railroad prestressed concrete ties. Because of previous knowledge deficiencies, railway civil and track engineers have been aware of the conservative design methods for structural components in any railway track that rely on allowable stresses and material strength reductions. In…
2013. Measuring rail seat pressure distribution in concrete crossties: experiments with matrix-based tactile surface sensors. Transportation Research Record: Journal of the Transportation Research Board. 2374 (1): 190-200. doi:10.3141/2374-22.
A sustained increase in gross rail loads and cumulative freight tonnages as well as growing interest in high-speed passenger rail development is placing an increasing demand on North American railway infrastructure. To meet this demand, improvements to the performance and durability of concrete crossties and fastening systems are necessary. One of the typical failure modes…
1997. Microstructural features of railseat deterioration in concrete ties. American Society of Civil Engineers Journal of Materials in Civil Engineering. 9 (3): 146-153. doi:10.1061/(ASCE)0899-1561(1997)9:3(146).
Deterioration has been observed in concrete railroad ties, producing a loss of up to 40 mm at the railseat and leaving a rough surface formed mainly by aggregates. This deterioration occurs largely in cold and wet regions of western Canada and northern United States. The purpose of the present investigation was to deduce the processes…
2011. Optimization of a prestressed concrete railroad crosstie for heavy-haul applications. American Society of Civil Engineers Journal of Transportation Engineering. 137 (11): 815-822. doi:10.1061/(ASCE)TE.1943-5436.0000256.
In response to rising energy costs, there is increased demand for efficient and sustainable transportation of people and goods. One source of such transportation is the railroad. To accommodate the increased demand, railroads are constructing new track and upgrading existing track. This update to the track system will increase its capacity and make it a…
2017. Pressure distribution under steel and timber crossties in railway tracks. Journal of Transportation Engineering, Part A: Systems. 143 (9): 04017046. doi:10.1061/JTEPBS.0000075.
The pressure distribution under the crossties plays a key role in railroad performance. This study conducts laboratory testing to investigate the pressure distributions under two different types of crossties, steel and timber. For each type, this study employs only a single tie. Five pressure cells are placed equidistantly under the rail crosstie between the two…
2015. Railroad tie spacing related to wheel-load distribution and ballast pressure. Practice Periodical on Structural Design and Construction. 20 (4): 04014047. doi:10.1061/(ASCE)SC.1943-5576.0000243.
Currently, there is no formula for tie and direct fixation fastener (DFF) spacing. Because the rail does not bend between the tie/DFF, it is not possible to calculate spacing by the bending stress formula. Usually, rail-stress analysis confirms a trial spacing. Such analysis may support a longer spacing that might not address issues related to…
1978. Statistical description of service loads for concrete crosstie track. Transportation Research Record: Journal of the Transportation Research Board. 694: 30-39.
Measurements of loads and bending moments on concrete crossties for several days of revenue traffic were used to develop a statistical description of track loads for tangent and curved tracks that have variable tie spacing. The measured data show large tie-to-tie variations in loads and a load-dependent tie support condition. Many ties were center-bound for…
2018. Quantification of rail transit wheel loads and development of improved dynamic and impact loading factors for design. Journal of Rail and Rapid Transit, Part F. 232 (10): 2406-2417. doi:10.1177/0954409718770924.
An increase in the number of rail transit track construction and rehabilitation projects in North America has generated increased interest in optimizing the design of the track infrastructure and its components. Many rail transit track component design guidelines use historical wheel loads and loading factors that were derived from freight railroad design practices. These design…
2018. Quantifying bending moments in rail-transit concrete sleepers. Journal of Transportation Engineering, Part A: Systems. 144 (3): 04018003. doi:10.1061/JTEPBS.0000125.
With use of concrete sleepers increasing for rail-transit applications in the United States, it is becoming more critical to quantify their revenue service flexural demands to improve sleeper design and maintenance practices. Rail-transit concrete sleeper bending moment field data were collected and processed to address topic areas relating to (1) overall field bending moment magnitude relative…
2018. Laboratory characterization of structural capacity of North American heavy haul concrete crossties. Transportation Research Record: Journal of the Transportation Research Board. 2672 (10): 116-124. doi:10.1177/0361198118782250.
Over the past few decades, the use of concrete crossties in North America has increased as a high performance alternative to timber crossties, especially in heavy-haul freight and higher speed rail corridors. To accommodate heavier axle-loads and prevent center cracking, railroads and suppliers have consistently increased the bending moment thresholds that a crosstie must withstand,…
2018. Laboratory analysis of track gauge restraining capacity of center-cracked railway concrete sleepers with various support conditions. Engineering Failure Analysis. 94: 354-363. doi:10.1016/j.engfailanal.2018.08.018.
As the number of concrete railway sleepers has steadily grown in North America, the importance of understanding the performance and failure of these components has also increased. Concrete sleepers typically perform better than timber sleepers to maintain track geometry and have a longer expected service life. Nevertheless, there have been derailments that were caused by…
2018. Laboratory fatigue performance of under-ballast mats under varying loads and support conditions. Journal of Rail and Rapid Transit, Part F. doi:10.1177/0954409718795920.
Primarily being employed in ballasted bridge decks and tunnels, under-ballast mat applications have seen growth in the North American market as a solution to reduce the stress state of the ballast by lowering the track stiffness and reducing ground-borne vibrations. However, the German DIN 45673 standard is currently the sole reference procedure for quantifying under-ballast…
2018. Quantification of loading environment and flexural demand of prestressed concrete crossties under shared corridor operating conditions. Transportation Research Record: Journal of the Transportation Research Board. 2672 (10): 136-145. doi:10.1177/0361198118793500.
Optimization of the design of railway infrastructure and its components requires a comprehensive understanding of the loading demands that are expected. Currently, many design guidelines for track components use historical wheel loads and calculate bending moments based on broad assumptions. However, tools are available to accurately quantify and characterize the variability each load has on…
2018. Support condition and traffic loading patterns influencing laboratory determination of under-ballast mat bedding modulus and insertion loss. Transportation Research Record: Journal of the Transportation Research Board. 2672 (10): 74-84. doi:10.1177/0361198118793501.
In recent years, noise and vibration concerns have grown as environmental regulations and requirements impose greater responsibilities on infrastructure owners. Under-ballast mats, rubber elastomers inserted below the ballast or concrete slab, have been widely deployed and studied in Europe, but the amount of research to date in North America is limited. Current testing practices for…
2019. Railroad infrastructure 4.0: Development and application of an automatic ballast support condition assessment system. Transportation Geotechnics. 19: 19-34. doi:10.1016/j.trgeo.2019.01.002.
Industry 4.0, or the fourth industrial revolution, is the current trend of automation and data exchange in manufacturing technologies. Even though Industry 4.0 emerged as a manufacturing initiative, the idea of bridging digital and physical systems can be expanded beyond the manufacturing industry. “Railroad Infrastructure 4.0” is thus proposed in this study to revolutionize the maintenance operations of the railroad industry. In North…
Many military, short line and low-volume industrial railroad networks require a unique infrastructure management approach that differs from commercial Class I and most regional railroads due to their size and operational characteristics. However, this does not eliminate the need for condition assessment, maintenance and repair, and capital planning. An Engineered Management System, RAILER® EMS, has…
2015. Enhanced Tank Car Design Improves the Safety of Transporting Crude Oil and Alcohol by Rail. TR News. 298: June-August, pp. 41-43.
2006. Deficiency vs. Distress-based Inspection and Asset Management Approaches: A Primer. APWA Reporter, American Public Works Association. 73: June, pp. 50-52.
2002. The Search for Beneficial New Technologies for Rail Transportation - TTCI R&D - Association of American Railroads Technology Scanning Program. Railway Track & Structures. 98: November, pp. 18-20.