Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-47106 Posterpräsentation Auersch, Lutz Vehicle-track interaction and soil dynamics The dynamic compliance of different railway tracks on different layered soils have been calculated using a combined finite-element and boundary-element method: conventional track on homogeneous soil with different stiffness, extreme normal and inverse layering of the soil, plates in and on top of the soil (slab track on various soils), conventional track with elastic rail pads. 1997 IAVSD (Vehicle System Dynamics) Budapest, Hungary 25.8.1997 29.8.1997 2018-12-21 OPUS4-13723 Zeitschriftenartikel Auersch, Lutz Dynamic axle loads on tracks with and without ballast mats - numerical results of three-dimensional vehicle-track-soil models Ballast mats are an efficient measure to reduce the vibrations near railway lines. The vehicle-track system gets a low eigenfrequency due to the insertion of an elastic ballast mat under the ballast. For frequencies higher than this low vehicle-track eigenfrequency, the forces, which are generating the vibration of the soil, are considerably reduced. In this contribution, a combined finite-element boundary-matrix method is used to calculate a number of completely three-dimensional track models with and without ballast mats. The influence of the important parameters such as the stiffness of the ballast mat, the unsprung vehicle mass, the mass of the track, and the stiffness of the subsoil is investigated. The numerical results are presented as the transfer functions of the total force that is acting on the soil and generating the vibration of the environment. The effectiveness of ballast mats is achieved by division of two of these force functions. The general tendencies for this insertion loss are discussed and a comparison with measurements is given. To come to an improved practical tool for the design of ballast-mat tracks, the finite-element method results are approximated by a simple two-dimensional model of which the solution is given explicitly. London Institution of Mechanical Engineers 2006 Proceedings of the institution of mechanical engineers F 220 2 169 183 10.1243/09544097F00105 2016-02-19 OPUS4-24556 Beitrag zu einem Tagungsband Auersch, Lutz De Roeck, G.; Degrande, G.; Lombaert, G.; Müller, G. The dynamic force transfer of slab tracks and floating slab tracks and the corresponding ground vibration Katholieke Universiteit Leuven 2011 EURODYN 2011 - 8th International conference on structural dynamics (Proceedings) 978-90-760-1931-4 EURODYN 2011 - 8th International conference on structural dynamics Leuven, Belgium 2011-07-04 2011-07-06 820 827 2016-02-19 OPUS4-26860 Zeitschriftenartikel Auersch, Lutz Dynamic behavior of slab tracks on homogeneous and layered soils and the reduction of ground vibration by floating slab tracks The dynamics of slab tracks and floating slab tracks are analyzed by multibeam models for the track and by integration in the wave-number domain for the soil, which is modeled as a layered half-space. Frequency-dependent compliances and force transfers are calculated for a great variety of track and soil parameters. The distribution of the load and the displacements along the track is investigated as well as the wave propagation perpendicular to the track and the ground vibration amplitudes. The floating slab track has a dominating plate-mat resonance and a strong high-frequency reduction. A track-soil resonance can also be recognized for an unisolated slab track in the case of layered soils. Generally, there is a strong damping of the track by the soil. The reduction effect of the slab mat is mainly owing to the elimination of this strong damping. The continuous soil yields slightly different rules for the displacements and force densities than those of a Winkler support. The total force transfer from the rail to the soil is the best criterion to judge the effectiveness of a floating slab track in reducing the ground vibration at some distance from the railway line. The total force transfer is easier to calculate than the double Fourier integrals of the ground vibration amplitudes, namely in the far field, and it has the best correlation with the reduction of the ground vibration. New York, NY, USA Soc. American Society of Civil Engineers (ASCE) 2012 Journal of engineering mechanics / ASCE 138 8 923 933 10.1061/(ASCE)EM.1943-7889.0000407 2016-02-19 OPUS4-29731 Beitrag zu einem Tagungsband Auersch, Lutz; Said, Samir Gao, G. The influence of soil properties on the ground vibration due to railway traffic and other sources - the comparability of different sites Tongji University Press 2013 6th International symposium on environmental vibration: Prediction, monitoring, mitigation and evaluation - Advances in environmental vibration (Proceedings) 978-7-5608-5303-1 6th International symposium on environmental vibration: Prediction, monitoring, mitigation and evaluation - Advances in environmental vibration Shanghai, China 2013-11-08 2013-11-10 175 186 2016-02-20 OPUS4-31164 Beitrag zu einem Tagungsband Auersch, Lutz; Said, Samir; Knothe, Esther; Rücker, Werner Cunha, A.; Caetano, E.; Ribeiro, P.; Müller, G. The dynamic behavior of railway tracks with under sleeper pads, finite-element boundary-element model calculations, laboratory tests and field measurements A variety of isolation measures exists to reduce the vibration in the neighbourhood of railway lines. They can be roughly classified as elastic or stiffening systems. There are the following elastic elements, rail pads or resilient fixation systems between rail and sleeper, under sleeper pads or sleeper shoes under the sleepers, and ballast mats under the ballast. Stiffening systems (plates) are used as slab tracks, floating slab tracks, or mass-spring systems. In the EU project "Railway induced vibration abatement solutions (RIVAS)", elastic under sleeper pads have been investigated. The dynamic behaviour of the track and the surrounding soil has been calculated by the combined finite-element boundary-element method in a systematic parameter study. It has been shown that the mitigation effect can be improved by soft under sleeper pads or by heavy sleepers. Consequently, such track elements (soft under sleeper pads and heavy sleepers) have been thoroughly investigated in laboratory tests to establish the static and dynamic parameters as well as their serviceability. Finally, field tests at and near railway tracks with and without under sleeper pads have been performed. To determine the reduction effect of the isolated track, the ground vibrations excited by trains or artificial sources have been measured. The soil properties at the different sites have also been measured so that the comparison of the isolated and un-isolated track can take into account possible differences of the soil parameters. The contribution shows how the different (numerical, laboratory and field) methods and results can be combined to achieve an improved mitigation solution with soft under sleeper pads and heavy sleepers for ballasted and slab tracks. 2014 EURODYN 2014 - 9th International conference on structural dynamics (Proceedings) 978-972-752-165-4 EURODYN 2014 - 9th International conference on structural dynamics Porto, Portugal 30.06.2014 02.07.2014 805 812 2016-02-20 OPUS4-38261 Beitrag zu einem Tagungsband Auersch, Lutz; Said, Samir Vibration measurements for the control of damaged and repaired railway tracks The damage detection and repair control have become important tasks for ballast and slab tracks. Measurements which compare the damaged and the repaired status of the same track section at different times, or which compare a damaged and an intact track section at the same time, have been successfully performed at some sites in Germany with slab tracks and ballast tracks and compared with the theoretical behaviour of intact and damaged tracks. The loss of contact between the sleeper and the plate, between the plate and the base layer, and some problems with soft or weakened soil have been analysed. The observed results, changes in the time histories of displacements and velocities due to train passages and in the transfer functions (compliances) due to hammer impacts, are encouraging that these measurements can be used to detect track damage. In addition, calculations with the combined finite-element boundary-element method have been used to confirm the conclusions about intact or damaged railway tracks. Zhejiang University, Hangzhou 2016 Proceedings of the 7th International Symposium on Environmental Vibration and Transportation Geodynmaics 7th International Symposium on Environmental Vibration and Transportation Geodynmaics Hangzhou, China 28.10.2016 30.10.2016 3 19 2016-11-15 OPUS4-39080 Zeitschriftenartikel Auersch, Lutz Static and dynamic behaviours of isolated and unisolated ballast tracks using a fast wavenumber domain method The dynamics of un-isolated and isolated ballast tracks have been analysed by multi-beam models for the track and by a layered half-space model for the soil. The solution is calculated in frequency-wavenumber domain and transformed back to space domain by a wavenumber integral. This is a faster method compared to other detailed track-soil interaction methods and almost as fast as the widely used Winkler-soil method, especially if the compliances of the soil have been stored for repeated use. Frequency-dependent compliances and force transfer functions have been calculated for a variety of track and soil parameters. The ballast has a clear influence on the high-frequency behaviour whereas the soil is dominating the low-frequency behaviour of the track. A layering of the soil may cause a moderate track-soil resonance whereas more pronounced vehicle-track resonances occur with elastic track elements like rail pads, sleeper pads and ballast mats. Above these resonant frequencies, a reduction of the excitation forces follows as a consequence. The track deformation along the track has been analysed for the most interesting track systems. The track deformation is strongly influenced by the resonances due to layering or elastic elements. The attenuation of amplitudes and the velocity of the track-soil waves change considerably around the resonant frequencies. The track deformation due to complete trains have been calculated for different continuous and Winkler soils and compared with the measurement of a train passage showing a good agreement for the continuous soil and clear deviations for the Winkler soil model. Berlin, Heidelberg Springer 2017 Archive of Applied Mechanics 87 3 555 574 10.1007/s00419-016-1209-6 2017-02-06 OPUS4-42581 Zeitschriftenartikel Auersch, Lutz; Said, Samir Track-soil dynamics - calculation and measurement of damaged and repaired slab tracks The damage detection and repair control have become important tasks for ballast and slab tracks. Measurements which compare the damaged and the repaired status of the same track section at different times, or which compare a damaged and an intact track section at the same time, have been successfully performed at some sites in Germany. The loss of contact between the sleeper and the track plate, between the track plate and the base plate, and between the base plate and the base layer have been analysed. The soil properties of each site have been measured and have been used to establish realistic track-soil models. Theoretical results of the wavenumber domain and the finite-element boundary element method have been compared with the experimental results. The observed experimental and theoretical results, changes in the time histories of displacements and velocities due to train passages and in the transfer functions (receptances) due to hammer impacts, are encouraging that these measurements can be used to detect track damage. London Elsevier 2017 Transportation Geotechnics 12 September 1 14 10.1016/j.trgeo.2017.06.003 2017-10-20 OPUS4-51257 Zeitschriftenartikel Auersch, Lutz Vehicle-Track-Soil Interaction of Isolated, Un-isolated and Damaged Railway Tracks This article deals with two topics of vehicle-track-soil interaction, the mitigation of railway induced ground vibration by soft track elements, and the identification of track damage. Theoretical results have been achieved by a combined finite-element boundary-element method (FEBEM). The theoretical results are confronted with measurements at four sites. Improved mitigation effects have been found for soft rail pads under heavy sleepers. The insertion loss, however, can be too optimistic if a strong vehicle track resonance occurs for the un-isolated reference track. Two measurement sites show this strong vehicle-track resonance at about 80 Hz, which has been approximated by using the results of a wide parameter study including the rail pad, ballast, and soil stiffness, as well as the ballast model and the soil layering. - The detection of slab track damage is mainly based on the differences of the receptance or compliance functions. Theoretical results have been confirmed by measurements at one site where a loss of contact between track plate and base layer was visible. Measurements at a second site with a hidden damage have been compared with the theoretical results of a loose sleeper. The differences between intact (or repaired) and damaged tracks are strong enough to encourage the further development of this method for the identification of track damages. London Saxe-Coburg Publications 2020 International Journal of Railway Technology 2 20 21 49 10.4203/ijrt.6.3.2 2020-09-21