<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>Railway bridge transition zone design details - a review of current practice</title>
      <link>https://trid.trb.org/View/2350549</link>
      <description><![CDATA[Railway track generally exhibits a significant change in track stiffness where the track transitions from embankment to bridge. Unless adequately designed, the change in stiffness within this transition zone can lead to increased dynamic forces at the wheel/rail interface, resulting in track geometry degradation, a higher rate of ballast breakage and track wearing. Transition zone design requires careful understanding of the impact of varying track stiffness on the dynamic load at the wheel/rail interface, rolling stock behaviour, and how these affect the track, formation and bridge structure. The following sections provide:  - The results of a literature review of railway bridge transitions, with the review predominantly focusing on the application of ‘slab’ type transitions. A review of critical parameters contributing to transition zone design.  - Several problematic transition zones are included to illustrate the contribution of the various elements to track performance and challenges observed.  - Critical design parameters and mitigation options for effective transition design are presented.]]></description>
      <pubDate>Fri, 08 Mar 2024 09:52:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2350549</guid>
    </item>
    <item>
      <title>The role of lubrication in the control of wear and rolling contact fatigue</title>
      <link>https://trid.trb.org/View/1594539</link>
      <description><![CDATA[Curved track simulation modelling for primary sprung bogie vehicles has been used to derme contact conditions at the wheel-rail interface. Contact stresses were evaluated in relation to shakedown limits and were used to assess rolling contact fatigue performance. Vehicles with a lower yaw stiffness are preferred, with a shift to stiffer suspensions being accompanied by significant increases in wheel-rnil energy dissipation, wear and rolling contact fatigne. Lubrication provides a 10-20% reduction in wheel-rail energy dissipation and wear whilst also improving the high-rail fatigue performance.]]></description>
      <pubDate>Fri, 22 Mar 2019 14:48:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1594539</guid>
    </item>
    <item>
      <title>Application of a New Concept and a Method to Estimate the Vertical Impact Forces on Railway Tracks due to Variation of Track Stiffness</title>
      <link>https://trid.trb.org/View/1494414</link>
      <description><![CDATA[The study presented in this paper applies a new concept and a new analytical method to develop a set of equations that estimate the vertical impact forces of train wheels on railway tracks due to variation of track stiffness. A moving railway vehicle may transition from a high stiffness zone of a track to a lower stiffness zone of a track or vice versa. This transition may be gradual or abrupt as it frequently occurs when the railway tracks transition to bridges and tunnels. Increasing or decreasing track stiffness along with the rate of change of stiffness, the train speed and the static track deflection values affect the dynamic impact forces. The study begins by reviewing existing research on the effects of stiffness transitions and their observed and measured effects. The study then proceeds to develop a set of analytical equations that rely on principle of energy conservation, rules of kinematics and a new concept of impact reduction factor. The paper concludes by an in-depth application of the proposed concept and the developed equations, followed by a discussion of the on-going work.]]></description>
      <pubDate>Wed, 21 Mar 2018 10:03:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1494414</guid>
    </item>
    <item>
      <title>Bridge Approach Remedies Implemented at Western Mega Site</title>
      <link>https://trid.trb.org/View/1481456</link>
      <description><![CDATA[As part of the heavy axle load (HAL) revenue service mega site testing program, the Transportation Technology Center, Inc. (TTCI) has worked closely with the Union Pacific Railroad (UP) to address bridge approach problems under HAL operations. The testing program targeted two bridge locations at the western mega site (located near Ogallala, NE, on a heavy haul coal route of UP) for remediation and long-term performance monitoring. One location was selected in September 2007, while the other was selected in June 2009. Before remediation, these two locations required localized maintenance work on a quarterly basis (approximately 63 Million Gross Tons [MGT]) due to excessive track geometry degradation, mud pumping, and track component failure. After remediation, no localized maintenance (except regularly programmed surfacing operations for the entire line) was required for more than 1,000 MGT, which indicated that the problems were effectively addressed. It was discovered that both bridge locations had problems with high track stiffness and low track damping at the track on the bridges, which adversely affected dynamic vehicle-track interaction when differential track settlement started to occur at the bridge approaches. The two bridges were given different remediation strategies: concrete ties fitted with rubber pads on the bottom surface were used for one location, and ballast mats between the ballast layer and bridge deck were used for the other. Both strategies were designed to reduce track stiffness and increase track damping for the track on the bridge. For both bridges, the ballast section was increased to a minimum depth of 12 inches below the bottom of the ties. In addition, drainage improvement was made to ensure that water would not accumulate on the bridges or in the approaches. Long-term performance of these remedies has been excellent, resulting in significant benefits such as reductions in slow orders, train delays, and major track maintenance activities.]]></description>
      <pubDate>Wed, 13 Sep 2017 16:27:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1481456</guid>
    </item>
    <item>
      <title>Development of a New and an Explicit Analytical Equation that Estimates the Vertical Dynamic Impact Loads of a Moving Train</title>
      <link>https://trid.trb.org/View/1468679</link>
      <description><![CDATA[One can only estimate the dynamic vertical impact loads under motion, since there are many effective parameters some of which are unrepresented in an equation and since the values of the considered parameters are not deterministic but estimations. Many empirical and semi-empirical equations in the literature correlate dynamic impact loads to train speed and measurable aspects of train and track components. These aspects frequently relate to track and train geometry and track stiffness. However, the development of these equations relies on load and deflection measurements from particular in-service tracks or especially set-up test tracks. The constants that frequently appear in these equations are particular to the conditions that generated them. Therefore, one lacks an explicit understanding of these equations unless one takes the time to investigate in detail the particular study and the particular set of data that generated these equations. Train speed limits also bound the applicability of these equations. This paper concentrates on the development of an explicit mathematical equation aimed to provide an explicit analytical estimate for the dynamic impact loads that develop on any railway track by the axles of a moving train. This paper introduces the concept of impact reduction factor and introduces a new equation that relies on the principle of conservation of energy and kinematic principles along with the impact reduction factor to estimate the impact loads generated by a moving train. The introduced equation analytically relates the dynamic impact load factor to train speed, track stiffness and vertical irregularity development along the track horizontal alignment.]]></description>
      <pubDate>Fri, 23 Jun 2017 14:03:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468679</guid>
    </item>
    <item>
      <title>Squats management: a Queensland rail experience</title>
      <link>https://trid.trb.org/View/1468499</link>
      <description><![CDATA[Queensland Rail acknowledges the risk that squats pose to the operations of the network, as a result a two year self-funded program was initiated to improve the management of the squat population. This paper presents the initial findings, preliminary results and planned actions. The investigation includes the characterisation of squats into two distinct groups: Thermal and Mechanical. This has been done to achieve a more rational and cost efficient asset management approach. It also examines the causal relationship between the inappropriate use of head hardened rails and the increased number of squats. The influence of track stiffness and the wheel and rail interaction on turnouts are also points of interest. Conventional non-destructive testing methods are relatively ineffective for squat testing. The work here presented attempts to introduce alternative testing options, using eddy currents, and advanced ultrasonic. The development these techniques will allow more accurate assessment and mapping of the problematic areas. This present work concludes with a discussion on the risks posed by squats to Queensland Rail’s operations and a plan to manage the defects more rationally.]]></description>
      <pubDate>Tue, 30 May 2017 15:31:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468499</guid>
    </item>
    <item>
      <title>Influence of rail track properties on vehicle–track responses</title>
      <link>https://trid.trb.org/View/1404292</link>
      <description><![CDATA[]]></description>
      <pubDate>Wed, 20 Apr 2016 13:53:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1404292</guid>
    </item>
    <item>
      <title>Measuring track vertical stiffness through dynamic monitoring</title>
      <link>https://trid.trb.org/View/1401608</link>
      <description><![CDATA[]]></description>
      <pubDate>Mon, 21 Mar 2016 11:49:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/1401608</guid>
    </item>
    <item>
      <title>Mechanical state of the rail underhead region under heavy haul operations</title>
      <link>https://trid.trb.org/View/1317438</link>
      <description><![CDATA[The occurrence of tensile stresses in the underhead region as a result of localised vertical and lateral head bending on the web is significant, and can potentially contribute to fatigue cracking. Field measurements under heavy haul conditions have shown that these stresses occur as a tension spike when the instrumented location is directly beneath the wheel. The aim of this study was to evaluate the stress state of the rail underhead region with respect to changes of the rail profile due to wear. The study was undertaken using the finite element method (FEM) involving a static stress analysis. The analysis revealed that the longitudinal stress at the rail gauge corner of the outer rail in curved track is highly dependent on several operational parameters including the offset of the contact patch location from the rail centreline, the ratio of lateral (L) to vertical (V) loads (L/V ratio), the direction of lateral traction, foundation stiffness and the head wear (HW). The magnitude of the tension spike at the surface of the rail in the underhead region is increased, but the depth below the contact surface at which the stresses become tensile is reduced when increasing the offset of contact patch location, the L/V ratio, the foundation stiffness and the HW. Both residual (RS) and thermally induced stresses increase the value of the stress in this region. The tensile stresses could potentially cause fatigue crack initiation at the rail underhead region and, in particular, could cause rolling contact fatigue (RCF) cracks on the gauge corner of the rail to turn downwards into transverse defects (TDs).]]></description>
      <pubDate>Tue, 29 Jul 2014 11:57:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1317438</guid>
    </item>
    <item>
      <title>Development of a simple prediction model for slab track vibration using field measurements</title>
      <link>https://trid.trb.org/View/1300680</link>
      <description><![CDATA[Structural vibration in the frequency range 10Hz to 400Hz can cause considerable disturbance in railway tunnels and on elevated structures. Within the track structure, the primary method of reducing the transmission of vibration from rail traffic is to either add mass and/or reduce the dynamic stiffness of the track support. One way of reducing the support stiffness is to incorporate a low stiffness track fastener that will permit large vertical rail deflections under load. Such a product has replaced traditional fasteners on concrete slab track in a number of metro systems worldwide, under varying local traffic conditions. In each case slab vibration has been monitored, data being obtained before and after installation of the low stiffness fasteners. Results indicate low stiffness rail support offers significant reductions in slab vibration. The degree of reduction is shown to be largely dependent on the degree of stiffness change between the original and replacement fastener.  This has lead to the development of a simplified model for predicting changes in ground borne vibration.]]></description>
      <pubDate>Tue, 04 Mar 2014 19:57:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1300680</guid>
    </item>
    <item>
      <title>Effects of vibration in desert area caused by moving trains</title>
      <link>https://trid.trb.org/View/1254274</link>
      <description><![CDATA[The ballast layer, filled with fine particles like blown sand, is one of the important problems of ballasted railway tracks in desert areas. Blown sand, as a contaminator of ballast layer, increases track stiffness and may cause serious damage to sleepers, pads, rails, and vehicles. In this paper, the effects of increasing track stiffness due to windy sands in the ballast layer and the train induced vibrations due to this phenomenon were studied. Based on field studies in a desert area in Iran, a two-dimensional finite/infinite element model for a railway track with plane strain condition was analyzed using the software ABAQUS, and the track vibrations were examined by changing the values of stiffness of ballast layer. Vibrations caused by the load of train at different distances from the cross-section of track were investigated, and the values of vertical vibration displacement, velocity, and acceleration were calculated. Results show that acceleration values of vertical vibration increase with the increasing of ballast layer stiffness caused by the filling of sand, while the vertical vibration velocity of track and the induced ground displacement decrease. The farther the distance from the source of vibration, the less the displacement, velocity, and acceleration. In addition, the methods for reducing train-induced vibrations were introduced.]]></description>
      <pubDate>Wed, 17 Jul 2013 09:19:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1254274</guid>
    </item>
    <item>
      <title>Measurement of Vertical Track Deflection from a Moving Rail Car</title>
      <link>https://trid.trb.org/View/1244484</link>
      <description><![CDATA[The University of Nebraska has been conducting research sponsored by the Federal Railroad Administration’s Office of Research and Development to develop a system that measures vertical track deflection/modulus from a moving rail car. Previous work has suggested the system can find critical maintenance problems not found by other inspection methods including standard track geometry. The University of Nebraska system uses cameras and lasers to measure a portion of the track deflection basin, and this measurement is used to estimate vertical rail deflection and/or track modulus. This report presents the measurement system along with development of the theory behind the measurement to support diagnosis of track conditions. The results of significant field testing are presented, including the results of a test designed to verify the accuracy of the measurement. A Finite Element Analysis of the measurement is presented along with several variations on closed form solution analysis, based on beam on elastic foundation as well as a discrete support model for rail. The University of Nebraska system has identified several critical maintenance problems not found by other inspection methods, and all previous studies indicate that measuring track deflection provides unique and valuable insight to track conditions that can improve inspection, maintenance, and safety. Finally, some guidelines are suggested for development of thresholds to guide data interpretation and track condition assessment, but more study and tests are needed to better define threshold criteria.]]></description>
      <pubDate>Thu, 28 Feb 2013 14:44:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1244484</guid>
    </item>
    <item>
      <title>The dynamic stiffness as an indicator of the effectiveness of a resilient rail fastening system applied as a noise mitigation measure: laboratory tests and field application</title>
      <link>https://trid.trb.org/View/1160657</link>
      <description><![CDATA[]]></description>
      <pubDate>Thu, 23 Aug 2012 09:06:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1160657</guid>
    </item>
    <item>
      <title>Influence of Track Stiffness Distribution on Vehicle and Track Interactions in Track Transition</title>
      <link>https://trid.trb.org/View/1084233</link>
      <description><![CDATA[A model for dynamic analysis of the vehicle–track–subgrade coupling system was developed by utilizing the finite-element method. Based on the model, new types of vehicle and track elements are presented and their associated stiffness matrix, mass matrix, and damping matrix are formulated. Computational software is coded with Matlab. As an application example, influences of 4 kinds of transition patterns--abrupt change, step-by-step change, linear change, as well as cosine change for track stiffness distributions in track transitions--on dynamic behavior of the vehicle and the track are investigated. The computational results show that the transition pattern of the track stiffness has primary influence on the dynamic behavior of the vehicle and the track, and smoothing of the track stiffness distribution can significantly reduce the wheel–rail interaction forces and the rail vertical accelerations. From abating wheel–rail impact and improving traffic operation's point of view, the cosine change has the most effect, the linear change is somewhat effective, and the abrupt change is the least effective for the 4 kinds of transition patterns of the track stiffness. However, the transition patterns of the track stiffness have essentially no influence on the vehicle vertical accelerations, due to the excellent behavior of vibration isolation resulting from the primary and the secondary suspension systems of the vehicle.]]></description>
      <pubDate>Mon, 20 Dec 2010 08:25:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1084233</guid>
    </item>
    <item>
      <title>Force Characteristics of Longitudinally Coupled Slab Track Turnout on Bridges Under Temperature Action</title>
      <link>https://trid.trb.org/View/910293</link>
      <description><![CDATA[With a longitudinally coupled slab track turnout on LeiDa Bridge on the Wuhan–Guangzhou passenger dedicated line in China as an example, an integral finite element model of a turnout (crossover)–slab track–bridge–pier was developed. This model considered two No. 18 welded turnouts with movable frogs in the form of crossover, longitudinally coupled slab track, bridges, and piers as one system. The computational results included the temperature force and the displacement regularity of the turnouts, slab track, bridges, and piers. Their effect parameters, such as the extensional stiffness of the track slab, the friction coefficient of the sliding layer, and the setting of the anchor point, were also investigated. The key findings are that (a) the additional longitudinal forces and the displacement of rails induced by temperature changes increased with reduced slab extensional stiffness, whereas the corresponding forces of the turnout components decreased significantly; (b) the longitudinal distortions of the track structure were insensitive to the failure of the sliding layer but posed negative impacts on the forces and anchor points of the piers; and (c) it was necessary to arrange anchor points on large-span bridges to prevent rail displacement and reduce the negative effects of forces on the piers.]]></description>
      <pubDate>Mon, 24 May 2010 14:08:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/910293</guid>
    </item>
  </channel>
</rss>