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    <title>Transport Research International Documentation (TRID)</title>
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    <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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Perspectives de valorisation de matériaux excavés riches en sulfates dans le béton du futur Tunnel de base Lyon-Turin</title>
      <link>https://trid.trb.org/View/1899507</link>
      <description><![CDATA[Le Tunnel de base du Montcenis est l'ouvrage principal de la nouvelle liaison ferroviaire Lyon-Turin. Sa construction constitue l'un des grands projets du 21ème siècle. Il s'inscrit dans les corridors ferroviaires européens de transport favorisant la circulation des marchandises et des passagers grâce à un moyen de transport écologique: le train. Cette liaison transalpine permettra ainsi d'acheminer 40 millions de tonnes de marchandises et 5 millions de voyageurs par an. La gestion économe et durable des ressources naturelles est un des enjeux de ce projet. Ainsi, le creusement du Tunnel de base génèrera plus de 37 millions de tonnes de matériaux excavés, dont 28% sont destinés à être utilisés en granulats à béton. L'utilisation des ressources locales vise notamment à diminuer l'impact environnemental en limitant l'extraction et le transport de granulats issus des carrières. Par ailleurs, il s'agit de limiter au mieux la mise en dépôts des matériaux excavés. Les sondages géologiques et les creusements des galeries de reconnaissance ont mis en évidence la présence d'anhydrites, appelées également sulfates de calcium anhydres sur certains secteurs du projet. De manière générale, les sulfates sont à proscrire dans le béton, car ils peuvent être à l'origine de désordres dans les structures en béton par la formation d'espèces minérales expansives. Afin de s'affranchir de ce risque, la teneur en sulfates dans les granulats à béton est limitée par les normes à un seuil très faible. Il convient donc de s'assurer, par une étude préalable, qu'un béton contenant ces granulats remplit bien les conditions requises et présente une bonne durabilité dans les conditions de fonctionnement du tunnel.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:47:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899507</guid>
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    <item>
      <title>Hydraulics and bridges: A French case study of monitoring of a bridge affected by scour</title>
      <link>https://trid.trb.org/View/1899416</link>
      <description><![CDATA[Bridges are one of the oldest types of civil engineering structures and the interaction between the transport and hydrographic networks represents a significant issue in a country such as France. Recently, various cases highlight the importance and vulnerability of civil transport works in relation to their environmental hazards, e.g. floods, and therefore the need to develop integrated observation tools and warning systems in the aim both of optimizing the management system and of increasing the knowledge on real scour processes. This paper reports on the field approach task of a research project aiming at improving continuous monitoring in order to follow the evolution of the scour processes of a given bridge or abutment. The first step has been to identify a pilot site, representative of scour vulnerability. After a report of the scour parameters to be monitored, the benchmark study and the choice of monitoring devices available on the market are detailed. Instrumentation, sensor adaptability, limitations (actual measurement ranges, ergonomics, energy supply limits ...) and in situ implementation are then presented and discussed. Finally, preliminary measurements, post-treatments and interpretation are detailed.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:43:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899416</guid>
    </item>
    <item>
      <title>MTBF (Metric That Betrays Folk)</title>
      <link>https://trid.trb.org/View/1899371</link>
      <description><![CDATA[Each industrial field seems affected by revolutionary innovations that will push forward the quality and variety of disparate services: driverless trains running 24 hours/day, self-driving cars and interconnected objects are only some of the latest trends. The intrinsic common aspect among all these promising concepts is the increase in reliability needs: human intervention for restoring and rescuing is not tolerated anymore. Despite this consideration, electronic equipment datasheets of many vendors do measure reliability through fuzzy metrics, the MTBF (Mean Time Between Failures) being the first among those. Firstly, this paper aims to provide information on the origin of the MTBF and on the reason why it is nowadays the most common mean for referring to reliability. Furthermore, the reasons behind the fallacy of the MTBF are explained. Using MTBF as synthetic indicator of reliability does often represents the wrong choice. Indeed, high MTBF figures could be measured even if the actual reliability is low. However, MTBF use is often imposed by regulations or contracts, and some examples are reported in this paper related to the railway signaling domain. Finally, alternative structured ways of communicating about reliability, based on further concepts than the bare MTBF, are provided as conclusion of the article.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:40:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899371</guid>
    </item>
    <item>
      <title>Influence of the bituminous layer on temperature and water infiltration in railway structures of the Bretagne-Pays de Loire High-Speed line</title>
      <link>https://trid.trb.org/View/1899320</link>
      <description><![CDATA[The phenomena of settlement and wear of the ballast under dynamic stresses lead to high frequencies and high maintenance costs on high-speed railway lines. Studies have shown that these settlements are linked to high accelerations produced in the ballast by the passage of high-speed trains (HST). A layer of asphalt concrete (GB) was introduced under the ballast layer on the high-speed line Bretagne-Pays de Loire (BPL HSL). It is intended, among other things, to reduce the amplitude of accelerations produced at the passage of the HST and thus improve the durability of the track. The BPL HSL spans 105 km, with a sublayer of asphalt concrete under the ballast and 77 kmwith a granular sublayer (UGM). To evaluate the performance of the structures with bituminous sublayer and to compare it with traditional structures with granular sublayer, four track sections have been instrumented during construction. This article presents the different sensors of the instrumentation, as well as the acquisition system installed to collect measurements. The focus, in this study, concerns the temperature, water content, and vertical settlement measurements made on the instrumented sections. Temperature variations recorded during two years on the railway structure with bituminous sublayer were analyzed and compared with those measured on a classical bituminous pavement. Influence of the bituminous layer on water infiltration and track settlements has also been studied.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:37:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899320</guid>
    </item>
    <item>
      <title>Energy consumption induced by operation phase of railways and road infrastructures</title>
      <link>https://trid.trb.org/View/1681747</link>
      <description><![CDATA[Up to now, transport systems have mainly been designed by considering time-efficiency, mobility and safety criteria. Today hard constraints on resources savings and environment preservation have to be taken into account at the different phases of design, maintenance and operation of these networks. This study, focused on the operation phase, aimed to provide a common framework for rail and roads energy consumption assessment. For that, the influence of infrastructure characteristics on energy consumption of vehicles was assessed, in a optimization perspective. A method for energy consumptions evaluation by exploiting contact forces models was proposed. Two models were developed, for a road and for a railway, and validated with experimental data of a vehicle on a test track and full-scale measurement of a high speed train on a given line. At last, numerical simulations are worked out with the validated models to exhibit the influence of successions of uphill and downhill on energy consumptions. These simple mechanical models pointed out the differences of the two transportation systems, in terms of developed contact forces and consumed energy.]]></description>
      <pubDate>Tue, 28 Jan 2020 16:18:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1681747</guid>
    </item>
    <item>
      <title>A vibration-based framework for structural health monitoring of railway bridges</title>
      <link>https://trid.trb.org/View/1681633</link>
      <description><![CDATA[One main objective of structural health monitoring (SHM) is to assess the performance of structures. In this paper, the authors focus on the damage assessment problem based on a vibration-based detection approach specifically designed for a bridge in real environment and traffic conditions. For this purpose, a cluster-based approach is proposed to discriminate abnormal changes from normal changes in the structural behavior. Besides, symbolic data analysis (SDA) is introduced to process and analyze large amounts of data. At the same time, some novelty detection strategies using original symbolic objects and principal component analysis (PCA) are proposed to extract useful information related to structures from large amounts of data. The efficiency and reliability of this approach is checked using both simulation and real data for a road-rail bridge.]]></description>
      <pubDate>Tue, 28 Jan 2020 16:15:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1681633</guid>
    </item>
    <item>
      <title>Fatigue safety verification of a steel railway bridge using short term monitoring data</title>
      <link>https://trid.trb.org/View/1681541</link>
      <description><![CDATA[The case study of the fatigue safety examination of the 120 years old steel riveted bridge carrying a single railway track on two main girders is presented. The overall assessment according to the Swiss Standard SIA 269 for existing structures indicated sufficient resistance at Ultimate Limit State but not at Fatigue Limit State, and the replacement of girders was recommended. To challenge this, the detailed examination was performed using data obtained from short term monitoring by the system installed on the main girders of one span over a period of four weeks. Fatigue stress histograms were constructed, and it was shown that measured stress ranges are smaller than the fatigue endurance limit, indicating a theoretically infinite fatigue life. No structural intervention is thus necessary. This case study shows that a simple short term monitoring is very useful for the fatigue examination of bridges allowing for reducing or avoiding (costly) interventions on structures.]]></description>
      <pubDate>Tue, 28 Jan 2020 16:13:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1681541</guid>
    </item>
    <item>
      <title>Improvement of existing railway subgrade by deep mixing</title>
      <link>https://trid.trb.org/View/1673707</link>
      <description><![CDATA[Many old railway lines in Europe need to be reinforced as they no longer meet the requirements of modern traffic. This paper presents the results of field tests carried out, as part of the French RUFEX research project (Reinforcement of railway tracks), to study the feasibility of the installation of 600 mm diameter vertical soil-cement columns under existing railway lines without removing the tracks or cementing the ballast. These columns were installed under an existing track using a spreadable mixing tool. The execution procedure is described and the quality / homogeneity of the mixed material is studied with excavated columns after curing periods of 28 and 180 days and several samples were taken for laboratory testing. The tests included unconfined compressive strength tests, splitting tensile strength tests, porosity and ultrasonic wave velocity measurements. The results show an increase in strength of 30% between 28 and 180 days. A linear correlation between compressive  and tensile strengths is proposed. Besides, data obtained from ultrasonic wave velocity measurements suggests that this test can be used for the estimation of index parameters such as density and porosity but also for preliminary assessments of static stiffness and strength by correlation with the dynamic elastic modulus.]]></description>
      <pubDate>Wed, 18 Dec 2019 12:14:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1673707</guid>
    </item>
    <item>
      <title>GEORAIL 2014: 2nd International Symposium Railway geotechnical engineering, Paris, 6-7 november 2014</title>
      <link>https://trid.trb.org/View/1673581</link>
      <description><![CDATA[The Second International Symposium on Railway Geotechnical Engineering was held in Marne-la-Vallée (France) on November 6-7, 2014. The proceedings of this symposium contain the papers presented at the Symposium. These papers cover a large range of subjects dealing with all aspects of geotechnical engineering as applied to railways an the mechanical behavior of platforms and superstructure of the track. They are grouped into five themes: - mechanical behavior of platforms and superstructure of the railway, - design of new railway lines and restoration of existing lines, - natural hazards and railway operation, - insertion in landscape and cities, - maintenance, rehabilitation and safety. Researchers, students and practicing engineers working in the field of geotechnical engineering and professionals of railways will find in this book a panorama of present practices and ongoing research in the field of geotechnical engineering applied to railways and track-ground interaction.]]></description>
      <pubDate>Wed, 18 Dec 2019 12:11:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1673581</guid>
    </item>
    <item>
      <title>Characterisation of the acoustic field radiated by a rail with a microphone array: The SWEAM method</title>
      <link>https://trid.trb.org/View/1575235</link>
      <description><![CDATA[Beamforming methods are widely used for the identification of acoustic sources on rail-bound vehicles with microphone arrays, although they have limitations in case of spatially extended sources such as the rail. In this paper, an alternative method dedicated to the acoustic field radiated by the rail is presented. The method is called SWEAM for Structural Wavenumbers Estimation with an Array of Microphones. The main idea is to replace the elementary fields commonly used in beamforming (point sources or plane waves) by specific fields related to point forces applied on the rail.  The vertical bending vibration of the rail is modelled using a simple beam assumption so that the rail vibration depends only on two parameters: the wavenumber and the decay rate of the propagative wave. Together with a radiation model based on a line of coherent monopoles, the acoustic field emitted by the rail is easily derived. The method itself consists in using the signals measured on a microphone array to estimate both the structural parameters and the global amplitude of this specific source. The estimation is achieved by minimising a least squares criterion based on the measured and modelled spectral matrices. Simulations are performed to evaluate the performance of the method considering one or several sources at fixed positions. The comparison of the simulated and reconstructed fields are convincing at most frequencies. The method is finally validated in the case of a single vertical excitation using an original set up composed of a 30 m long experimental track excited by an electrodynamic shaker. The results show a great improvement of the wavenumber estimation in the whole frequency range compared with the plane wave beamforming method and a fair estimation of the decay rate. The underestimation of some low decay rates due to the poor selectivity of the criterion occurring in these cases requires further study.]]></description>
      <pubDate>Tue, 18 Dec 2018 10:20:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1575235</guid>
    </item>
    <item>
      <title>Modélisation et analyse non linéaire des vibrations auto-entretenues de freins à disque crissants</title>
      <link>https://trid.trb.org/View/1575219</link>
      <description><![CDATA[Dans cet exposé nous illustrons à l'aide d'un modèle simplifié de frein à disque ferroviaire les phénomènes essentiels qui nous semblent intervenir dans l'apparition des vibrations auto-entretenues à l'origine du crissement des freins et en particulier la manière dont les perturbations vibratoires instables de l'équilibre glissant du système sont stabilisées par les phénomènes non linéaires de décollement et d'adhérence au contact. Des simulations effectuées avec des lois de contact frottant très simples (Signorini/Coulomb) suffisent à mettre en évidence ces phénomènes de saturation et à obtenir des spectres vibratoires réalistes.]]></description>
      <pubDate>Tue, 18 Dec 2018 10:20:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1575219</guid>
    </item>
    <item>
      <title>Dynamic behavior of a Mechanically Stabilized Earth wall under harmonic loading: Experimental characterization and 3D finite elements model</title>
      <link>https://trid.trb.org/View/1575214</link>
      <description><![CDATA[This article presents an analysis of a full-scale experimental Mechanically Stabilized Earth (MSE) wall under harmonic loading. Experimental results are shown and discussed, and compared with 3D finite element simulations. The experimental results indicate that the embankment behavior is linear, and that the displacements of the wall, the tensile forces in the reinforcements, and the stresses in the backfill material are strongly frequency-dependent. The numerical analysis is performed in the time domain with Rayleigh damping and includes special modeling strategies to represent the facing, the ground reinforcement interface and the overburden pressure. Experimental and numerical values are found to be in good agreement.]]></description>
      <pubDate>Tue, 18 Dec 2018 10:20:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1575214</guid>
    </item>
    <item>
      <title>Projet SIL, L4. Méthodologie générique d'allocation des SIL aux fonctions de sécurité - Guide d'application</title>
      <link>https://trid.trb.org/View/1491933</link>
      <description><![CDATA[Ce livrable L4 présente la méthodologie générique proposée pour l'allocation des SIL aux fonctions de sécurité d'un matériel roulant ferroviaire pour pouvoir répondre aux problématiques d'allocation des SIL soulevées dans le livrable L2 du projet SIL. Les étapes de la méthodologie sont illustrées par des exemples du domaine (certains étant repris du livrable L3) pour constituer, dans le même temps, un guide d'application pratique de l'approche proposée.]]></description>
      <pubDate>Thu, 14 Dec 2017 16:06:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1491933</guid>
    </item>
    <item>
      <title>Detection of electromagnetic jamming signals interfering with a railway track-to -train radio communication</title>
      <link>https://trid.trb.org/View/1395468</link>
      <description><![CDATA[Global System for Mobile communications-Railways (GSM-R) is now widely used for train-to-track radio communication. As for any radio communication system, non-intentional and intentional ElectroMagnetic Interference (EMI) can affect this track-to-train radio link. This paper studies the impact of low-power electromagnetic jammers on this communication. Firstly, experiments performed on a dedicated test bench are presented to evaluate the impact of selected jamming signals on a GSM-R radio communication. In certain jamming conditions, loss of connection can result. Then, a method to detect these jamming signals is presented. We considered and modelled a simplified GSM-R communication chain using a GMSK modulation. This was used to evaluate the impact of the jammer on the IQ constellation representation. As for the experimental part, the same interfering signals are applied. We then use the Error Vector Magnitude parameter to detect the presence of these jamming signals. Depending on the parameters of the modulation chain, we adapt our processing to detect the disturbance. A good detection of the jammed signal is obtained by analysing the EVM parameter while trying to detect these signals in an AWGN channel.]]></description>
      <pubDate>Tue, 19 Jan 2016 11:56:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1395468</guid>
    </item>
    <item>
      <title>Squeal noise of railway disc brakes: correlation between experiments and transient computations from updated simplified pad models</title>
      <link>https://trid.trb.org/View/1395421</link>
      <description><![CDATA[The goal of this research is to explore the relations between the disc brake noise and the design of the pad from an experimental and a numerical point of view. Transient and stability analysis have been conducted on large industrial models with the numerical tool developed in the “Acoufren” french project. This tool allows introducing simplified 3D Finite Elements (FE) pad models built from 2D drawings. The objective is to conclude on the ability of the tool to distinguish brake vibration/noise from different specific pad. The method to reach the objective is to conduct both experimental campaign and numerical study on a set of 3 existing pads. For each of the pads, squeal measurements (noise and vibration) are conducted on a test bench for several configurations (velocities, pressures, direction of rotation). For the numerical study, both stability and transient simulation are conducted on an assembled brake model. This global brake model is not updated but the FE models of each component of the brake (calliper, disc) are updated from experimental modal analysis. The “Acoufren” tool allows to import a simplified pad model (built from 2D drawings) which complete the global brake model. A specific method has been developed here to update the simplified pad model according to specific measurements. The final step is the comparison between measurements and numerical results for the 3 kind of pads. Relations between experimental noise/vibration of the brake and mechanical parameters of the pads have been found. The simplified pad FE model is updated in 2 phases: measurements of the elastic moduli / damping of friction material and measurements of the modal parameters of the first modes of the pad in free conditions and/or clamped on a marble (depending of the mechanical architecture of the pad). A good agreement can be found on some pads between numerical results and experimental results. The study is limited here to one brake type only (but with variability of pad). A strategy has been proposed to explore the relations between the disc brake noise and the design of the pad. With the numerical tool developed in the “Acoufren” french project, a good agreement has been found on some pads between numerical results and experimental results. This result is a new step in the prediction of noise/vibration railway disc brakes related to pads.]]></description>
      <pubDate>Tue, 19 Jan 2016 11:53:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1395421</guid>
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