TY - JOUR A1 - Auersch, Lutz T1 - Train induced ground vibrations: different amplitude-speed relations for two layered soils N2 - Ground vibrations created by running high-speed trains at speeds between 100 and 320 km/h are calculated in detail using transfer functions to model the effects of the moving loads. These transfer functions for layered soils are obtained by integration in the wavenumber domain. The train-induced vibrations in a soil that is considered to consist of single layers of two slightly different soils are analysed for different excitations: for their spectra, attenuation laws and amplitude-speed relations. An important mid-frequency component is shifted through the cut-on region of the layered soil with an increase in the train speed. The cut-on frequency divides the response of the layered soil into a low-frequency low-amplitude range and a high-frequency high-amplitude range. This leads to completely different train speed dependencies for the two soil layers with strongly increasing amplitudes around the cut-on frequency and almost constant amplitudes beyond this frequency. All calculated results closely agree with ground vibration measurements at two corresponding sites, especially if the mid-frequency component is calculated by axle impulses. KW - Ground vibration KW - Layered soil KW - Wavenumber integrals KW - Moving load KW - Excitation forces KW - High-speed trains KW - Measured railway vibrations PY - 2012 DO - https://doi.org/10.1177/0954409712437305 SN - 0954-4097 VL - 226 IS - 5 SP - 469 EP - 488 PB - Sage Publ. CY - London AN - OPUS4-31162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Cunha, A. ED - Caetano, E. ED - Ribeiro, P. ED - Müller, G. T1 - Amplification and reduction phenomena of soil-building interaction by finite-element boundary-element calculations and simplified methods N2 - Vibration of normal apartment, office and production buildings, which are excited by technically induced ground vibrations are considered. Many wavelengths of the Rayleigh waves of the soil fit into the foundation dimensions. The related high discretization effort can nowadays be realized with detailed soil-structure interaction method. The combined finite-element boundary-element method is used here as a detatiled method. Simplified method can be used with less computation time, but these methods must be calibrated by exact results. One simplification is to extent the structure to infinity and to solve the problem by wavenumber domain methods. Another simplification is the use of a Winkler soil instead of the continuous soil. Usually, the Winkler parameters are not only soil parameters but depend also on the rigid or flexible foundation structure. Substructure methods use commercial FEM software for the building part. The contribution will show some detailed and some simplified results on large structural elements such as foundation plates, walls, storey plates on columns as well as results on complete buildings. The reduction of the ground vibration by stiff elements and the amplification due to floor or building resonances are discussed which are the most important phenomena of the soil-building interaction. T2 - EURODYN 2014 - 9th International conference on structural dynamics CY - Porto, Portugal DA - 30.06.2014 KW - Soil-building interaction KW - Foundation reduction KW - Floor amplification KW - FEBEM and simplified methods PY - 2014 SN - 978-972-752-165-4 SN - 2311-9020 SP - 591 EP - 597 AN - OPUS4-31163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Knothe, Esther A1 - Rücker, Werner ED - Cunha, A. ED - Caetano, E. ED - Ribeiro, P. ED - Müller, G. T1 - The dynamic behavior of railway tracks with under sleeper pads, finite-element boundary-element model calculations, laboratory tests and field measurements N2 - 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. T2 - EURODYN 2014 - 9th International conference on structural dynamics CY - Porto, Portugal DA - 30.06.2014 KW - Railway track KW - Track-soil interaction KW - Mitigation KW - Under sleeper pads KW - Laboratory tests KW - Field tests KW - Ground vibration PY - 2014 SN - 978-972-752-165-4 SN - 2311-9020 SP - 805 EP - 812 AN - OPUS4-31164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Schmid, Wolfgang A1 - Wuttke, Wilfried T1 - Experimental and theoretical building and foundation behaviour T2 - EVACES'09 - Experimental vibration analysis for civil engineering structures CY - Wroclav, Poland DA - 2009-10-14 PY - 2009 SN - 978-83-7125-184-9 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings SP - 133 EP - 142 AN - OPUS4-31259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - The use and validation of measured, theoretical, and approximate point-load solutions for the prediction of train-induced vibration in homogeneous and inhomogeneous soils N2 - The layered soil is calculated in the frequency wavenumber domain and the solutions for fixed or moving point or track loads follow as wavenumber integrals. The resulting point load solutions can be approximated by simple formula. Measurements yield the specific soil parameters for the theoretical or approximate solutions, but they can also directly provide the point-load solution (the transfer function of that site). A prediction method for the train-induced ground vibration has been developed, based on one of these site-specific transfer functions. The ground vibrations strongly depend on the regular and irregular inhomogeneity of the soil. The regular layering of the soil yields a cut-on and a resonance phenomenon, while the irregular inhomogeneity seems to be important for high-speed trains. The attenuations with the distance of the ground vibration, due to point-like excitations such as vibrator, hammer, or train-track excitations, were investigated and compared. All theoretical results were compared with measurements at conventional and high-speed railway lines, validating the approximate prediction method. PY - 2014 SN - 1027-5851 VL - 19 IS - 1 SP - 52 EP - 64 CY - St. Petersburg, Russia AN - OPUS4-30494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Static and dynamic behaviours of isolated and unisolated ballast tracks using a fast wavenumber domain method N2 - 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. KW - Railway track KW - Multi-beam model KW - Layered soil KW - Wavenumber method KW - Track deformation KW - Force transfer KW - Track-soil and vehicle-track resonances PY - 2017 DO - https://doi.org/10.1007/s00419-016-1209-6 SN - 0939-1533 SN - 1432-0681 VL - 87 IS - 3 SP - 555 EP - 574 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-39080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Vibrations of soil and foundation due to railway, blast and impact loading N2 - The vibrations of soil and foundations are demonstrated for different types of loading. Train-induced ground vibrations are studied in a measurement campaign where a test train has run with regularly varied speeds. The measured train-induced soil vibration at 2 to 100 m distance from the track is compared with the wave propagation due to hammer excitation and with the theoretical wave field. The strong influence of the soil and the train speed on the amplitudes and frequencies of the vibration has been analysed for passages of the locomotive and the carriages. - The generation of ground vibration by strong explosions has been studied on a large testing area with sandy soil. The propagating waves were measured in a regular grid of measuring points in 10 to 1000 m. Therefore, the dominance of certain waves at certain distances and the changes of compressional waves and Rayleigh waves could clearly be observed. The results are compared with impulse hammer measurements in the range of 5 to 50 m. - A drop test facility has been built on the testing area of the Federal Institute of Materials Research and Testing (BAM). Heavy masses (containers) of up to 200 t can be dropped from 10 m height on a big reinforced concrete foundation. The foundation was instrumented by accelerometers, strain gauges and pressure cells to give information about the loading condition and by geophones to measure the vibration of the surrounding soil and building. Both excitation processes, the release of the mass and the impact, produce high vibration amplitudes. On a smaller drop foundation, the influence of the drop height and the target stiffness has been studied more systematically. KW - Ground vibration KW - Train passage KW - Explosion KW - Mass drop KW - Amplitude-distance law KW - Filter effect of the soil KW - Train speed KW - Blasting charge KW - Drop height KW - Target stiffness PY - 2016 SN - 2409-4579 VL - 3 IS - 1 SP - 27 EP - 38 PB - Samara State Aerospace University CY - Samara AN - OPUS4-38816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Emission of train-induced ground vibration — Prediction of axle-load spectra and its experimental verification N2 - Train passages induce forces on the track, train-induced vibrations propagate through the soil and excite neighbouring buildings. The emission, which is the first part of the prediction of vibrations near railway lines, is presented by focusing on the dynamic axle loads. The calculation of the axle loads is based on the vehicle-track-soil interaction. This interaction calculus utilises the dynamic stiffness of the vehicle (the inertia of the wheelset) and the dynamic stiffness of the track-soil system. Based on various time consuming finite-element boundary-element calculations, an approximate track-soil model has been established. The vehicle-track-soil analysis yields several transfer functions between the various geometric or stiffness irregularities and the axle loads of the train. Geometric irregularities of the vehicle (the wheels) and the track (rail surface and track alignment) are the simplest components. Geometric irregularities of the subsoil (trackbed irregularities) have to be transferred to effective irregularities at rail level. The bending stiffness of the track is filtering out the short-wavelength contribution. Stiffness irregularities occur due to random variations in the ballast or the subsoil, which must also be transferred to effective track irregularities, and due to the discrete rail support on sleepers. All necessary transfer functions for the prediction of axle-load spectra are presented as general formula and as specific graphs for differing vehicle and track parameters. The prediction method is applied to a ballast track and a slab track and compared with corresponding axle-box measurements. Moreover, ground vibration measurements at numerous sites are exploited for the axle-load spectra and the validation of the prediction method. All theoretical and experimental results confirm that the dynamic axle-load spectra have an approximate value of 1 kN per third of octave and increase with train speed, track stiffness and around the vehicle-track resonance. KW - Train induced ground vibration KW - Prediction KW - Emission KW - Axle-load spectra KW - Experimental verification PY - 2017 DO - https://doi.org/10.20855/ijav.2017.22.1453 SN - 1027-5851 VL - 22 IS - 1 SP - 74 EP - 83 PB - Institute of Acoustics and Vibration CY - Auburn, USA AN - OPUS4-39445 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Pombo, Joao T1 - Vehicle-track-soil interaction for track damage, ground vibration and mitigation N2 - A combined finite element boundary element method has been developed to calculate the dynamic interaction of the railway track and the underlying soil. The track-soil results are coupled with a simple vehicle model to establish the force transfer function of the vehicle-track-soil system. Mitigation measures at the track, namely three different tracks with under-sleeper pads, are analysed. The un-sprung vehicle and heavy track masses on soft track elements yield a lower vehicle-tracksoil resonant frequency and a better reduction of the excitation forces at higher frequencies. If the effectiveness of the mitigation is measured as a vibration ratio between the isolated and an un-isolated reference track, the vehicle-track-soil resonance of the reference track has an important influence on the mitigation effectiveness. Therefore, different un-isolated reference tracks are analysed. It is shown how the frequency and amplitude of the vehicle-track resonance are influenced by the stiffness of the rail pads (strongest), the ballast (medium) and the soil (weakest). The reference track models have been compared with shaker tests on two railway tracks with strong resonances. 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 and compared with the theoretical behaviour of intact and damaged tracks. T2 - 3. International Conference on Railway Technology CY - Cagliari, Italy DA - 05.04.2016 KW - undersleeper KW - railway track KW - track-soil interaction KW - ground vibration KW - mitigation PY - 2016 SN - 978-1-905088-65-2 SN - 1759-3433 SP - Paper 273 EP - 19 PB - Civil-Comp Press CY - Stirlingshire, Scotland AN - OPUS4-37084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Vehicle-track-soil interaction for track damage, ground vibration and mitigation N2 - A combined finite element boundary element method has been developed to calculate the dynamic interaction of the railway track and the underlying soil. The track-soil results are coupled with a simple vehicle model to establish the force transfer function of the vehicle-track-soil system. Mitigation measures at the track, namely three different tracks with under-sleeper pads, are analysed. The un-sprung vehicle and heavy track masses on soft track elements yield a lower vehicle-tracksoil resonant frequency and a better reduction of the excitation forces at higher frequencies. If the effectiveness of the mitigation is measured as a vibration ratio between the isolated and an un-isolated reference track, the vehicle-track-soil resonance of the reference track has an important influence on the mitigation effectiveness. Therefore, different un-isolated reference tracks are analysed. It is shown how the frequency and amplitude of the vehicle-track resonance are influenced by the stiffness of the rail pads (strongest), the ballast (medium) and the soil (weakest). The reference track models have been compared with shaker tests on two railway tracks with strong resonances. 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 and compared with the theoretical behaviour of intact and damaged tracks. T2 - 3. International Conference onRailway Technology CY - Cagliari, Italy DA - 05.04.2016 KW - mitigation KW - railway track KW - track-soil interaction KW - ground vibration KW - undersleeper PY - 2016 AN - OPUS4-37087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Vogiatzis, Konstantinos T1 - Modes and waves of coupled roof or floor structures in historical and modern buildings N2 - Long wooden floor beams above a ball room in an old historical palace have been analysed experimentally. The eleven beams are weakly coupled by three layers of floor boards. It has been investigated if the state (the stiffness) of the wooden beams can be determined by vibration measurements of global or preferably local modes. Hammer, heel-drop and ambient excitations have been used. The vibration modes of the structure show dominating local deformations if an impact excitation is applied. This is understood as the positive superposition of several modes which yield the maximum at the excitation point but a cancellation at more distant points. Natural modes have been estimated from these vibration modes by standard and special methods which were necessary for the high damping of the wooden floor. It has been found that all floor beams contribute to each natural mode even for a weak coupling of the beams. In addition to the modal discussion, the impact tests have also been analysed for the wave propagation and amplitude attenuation with distance. The coupling of floor beams has been studied theoretically by an analytic multiple-beam model where the coupling by translational or rotational springs and by a common support motion has been assumed. T2 - 23. International Congress on Sound and Vibration CY - Athen, Greece DA - 10.07.2016 KW - modal analysis KW - floor vibration KW - wave analysis PY - 2016 SN - 978-960-99226-2-3 SN - 2329-3675 SP - Paper 318, 1 EP - 8 AN - OPUS4-37090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Modes and waves of coupled roof or floor structures in historical and modern buildings N2 - Long wooden floor beams above a ball room in an old historical palace have been analysed experimentally. The eleven beams are weakly coupled by three layers of floor boards. It has been investigated if the state (the stiffness) of the wooden beams can be determined by vibration measurements of global or preferably local modes. Hammer, heel-drop and ambient excitations have been used. The vibration modes of the structure show dominating local deformations if an impact excitation is applied. This is understood as the positive superposition of several modes which yield the maximum at the excitation point but a cancellation at more distant points. Natural modes have been estimated from these vibration modes by standard and special methods which were necessary for the high damping of the wooden floor. It has been found that all floor beams contribute to each natural mode even for a weak coupling of the beams. In addition to the modal discussion, the impact tests have also been analysed for the wave propagation and amplitude attenuation with distance. The coupling of floor beams has been studied theoretically by an analytic multiple-beam model where the coupling by translational or rotational springs and by a common support motion has been assumed. T2 - 23. International Congress on Sound and Vibration CY - Athen, Greek DA - 10.07.2016 KW - wave analysis KW - floor vibration KW - modal analysis PY - 2016 AN - OPUS4-37091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - The dynamic behavior of railway tracks with under sleeper pads, finite-element boundary-element model calculations, laboratory tests and field measurements N2 - Results from the calculation of the tracks have been presented. The compliances for the different under sleeper pads have been intensely discussed by the experts. Laboratory tests and field tests have been shortly presented to demonstrate the comprehensive approach of the BAM. N2 - Es werden die Arbeiten der BAM zu schweren Schwellen und weichen Schwellensohlen vorgestellt. Es wurden Berechnungen zum Schwingungsverhalten und zur Erschütterungsminderung durchgeführt. Laborversuche dienten dazu, die elstischen Eigenschaften der Schwellensohlen und die Dauerhaftigkeit der schweren Schwellen zu ermitteln. In Feldversuchen wurde die Minderungswirkung mit Schwingeranregung und mit Zuganregung ermittelt. T2 - Treffen "Schwellen und Schwellensohlen" CY - Berlin, Germany DA - 25.02.2016 KW - sleeper pads KW - railway track KW - ground vibration KW - mitigation PY - 2016 AN - OPUS4-37103 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Realistic axle-load spectra for the prediction of ground vibrations form rail traffic N2 - Train passages induce static and dynamic forces on the track, the train-induced vibrations propagate through the soil and excite neighbouring buildings. The problem of train vibrations is divided into the parts emission, which is the excitation by railway traffic (the present contribution), transmission, which is the wave propagation through the soil, and immission, which is the transfer into a building, - The calculation of the axle loads are based on the vehicle-track-soil interaction. This interaction uses the dynamic stiffness of the vehicle (the inertia of the wheelset) and the dynamic stiffness of the track-soil System. Based on various time consuming finite-element boundary-element calculations, an approximate track-soil model has been established. The vehicle-track-soil analysis yields several transfer functions between the various geometric or stiffness irregularities and the axle loads of the train. Geometric irregularities of the vehicle (the wheels) and the track (rail surface and track alignment) are the simplest components. Geometric irregularities of the subsoil (trackbed irregularities) have to be transferred to effective irregularities at rail level. The bending stiffness of the track is filtering out the short-wavelength contribution. Stiffness irregularities occur due to random variations in the bailast or the subsoil, which must also be transferred to effective track irregularities, and due to the discrete rail support on sleepers. The axle loads due to the effective track errors from stiffness variations have their specific vehicle-track transfer function. - All necessary formula for the prediction of axle-load spectra will be presented. The prediction method is compared with axle-box measurements at a Standard ballasted track. Moreover, ground Vibration measurements at numerous sites are exploited for the axle-load spectra and the Validation of the prediction method. T2 - ICSV22 - 22nd International congress on sound and vibration CY - Florence, Italy DA - 12.07.2015 PY - 2015 SN - 978-88-88942-48-3 SN - 2329-3675 SP - 1 EP - 8 AN - OPUS4-33781 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Force and ground vibration reduction of railway tracks with elastic elements N2 - The reduction of train-induced ground vibration by elastic elements such as rail pads and sleeper pads has been analyzed by a combined finite-element boundary-element method. The dynamic compliance of the track, the transfer function of the total force on the ground and the ground vibration ratios have been calculated for a variety of isolated and un-isolated track systems. It has been found that the soil force transfer, which describes the excitation force of the soil, is an appropriate quantity to predict the reduction of the ground vibration and the effectiveness of isolated tracks. All force transfer functions of isolated tracks display a vehicle–track resonance where the wheelset on the compliant track is excited by wheel and track irregularities. At higher frequencies, considerable reductions of the amplitudes are observed as the benefit of the resilient element. The influence of the stiffness of the rail or sleeper pads, the ballast and the soil, and the mass of the sleeper and the wheelset on the resonance frequency and the reduction has been investigated. Sleeper pads are advantageous due to the higher mass that is elastically supported compared to the rail-pad track system. The combination of elastic rail and sleeper pads has been found to be disadvantageous, as the second resonance occurs in the frequency range of intended reduction. KW - Railway KW - Track KW - Rail pad KW - Sleeper pad KW - Force transfer KW - Ground vibration KW - Reduction PY - 2015 DO - https://doi.org/10.1177/1077546313507099 SN - 1077-5463 SN - 1741-2986 VL - 21 IS - 11 SP - 2246 EP - 2258 PB - Sage Science Press CY - Thousand Oaks, CA, USA AN - OPUS4-33682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Papadrakakis, M. ED - Papadopoulos, V. ED - Plevris, V. T1 - Fast computation of train-induced vibrations in homogeneous and layered soils N2 - The computation of the wave propagation in homogeneous and layered soils can be performed by a numerical integration in wavenumber domain. The numerical difficulties of an infinite integral and an integrand with poles can be solved. But if this computation must be repeated for many distances, many frequencies, many loads, or many soil models, it becomes a time consuming task which is not acceptable for a user-friendly prediction tool for railway induced ground vibration. Therefore, an approximate method for the computation of the wave field has been developed. The computation consists of several steps. At first, an approximate dispersion profile is calculated according to rules which have been derived from exact solutions. Secondly, the dispersion is used to achieve the amplitude for a certain frequency and a certain distance by calculating the approximate solution of a corresponding homogeneous half-space. Thirdly, three layer corrections are added which include lowfrequency near-field effects, high-frequency far-field effects, and a resonance amplification around the layer frequency. This procedure yields the wave field due to a point load. For a train load, many of these point-load responses have to be summed up, and a frequencydependant reduction factor has to be multiplied to incorporate the effect of the load distribution along and across the track. - The prediction method is applied to real sites, and the appropriate soil models are identified by approximating the measured transfer functions (frequency-dependant amplitudes) which is presented as an alternative to the approximation of the dispersion (frequency-dependant wave velocities). These examples demonstrate the general behavior of layered soils: the low amplitudes of the stiff half-space at low frequencies, the high amplitudes of the softer layer at high frequencies, the strong increase of amplitudes and a possible resonance amplification at mid frequencies. The material damping of the layer yields a strong attenuation of the amplitudes with the distance for high frequencies. The response depends strongly on the resonance or layer frequency which is shown for different layer depths and velocities always in good agreement with measurements. The layer frequency can be of immense influence if train-speed effects are analysed in a layered soil. The good agreement with many measurements in this contribution as well as in the references validates the prediction of ground vibration based on the theory of a layered half-space. T2 - COMPDYN 2015 - 5th International conference on computational methods in structural dynamics and earthquake engineering CY - Crete Island, Greece DA - 25.05.2015 PY - 2015 DO - https://doi.org/10.7712/120115.3381.959 SP - 66 EP - 82 AN - OPUS4-33683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Simultaneous measurements of the vehicle, track, and soil vibrations at a surface, bridge, and tunnel railway line N2 - A complex measuring campaign has been performed including the simultaneous measurement of vehicle, track, and soil vibrations during train runs at 16, 25, 40, 63, 80, 100, 125, 140, 160 km/h, and impulse measurements of the passenger car, three track sections and the soil. A ballast track on the soil surface and on a concrete bridge have been investigated as well as a slab track in a tunnel. The evaluation and comparison of all these data shows a generally good agreement for all components if the strong low- and high-frequency cut-off characteristics of the layered and damped soil are incorporated. There is a strong causal correlation between the vehicle and the soil by the dynamic excitation forces and a weak relation between the track and the soil by the axle-sequence spectrum of the train. However, the similarity between the axle-impulse spectrum observed at the track and the spectra of the ground vibration lead to the special excitation component of “scattered axle impulses” which is pre-dominant at the far-field points of the soil. KW - Railway KW - Ground vibration KW - Vehicle-track interaction KW - Track-soil interaction KW - Measurements PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-410224 DO - https://doi.org/10.1155/2017/1959286 VL - 2017 IS - ID 1959286 SP - 1 EP - 18 PB - Hindawi CY - Indien AN - OPUS4-41022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Auersch, Lutz T1 - A user-friendly prediction tool for railway induced ground vibrations: Emission - transmission - immission T2 - 9th IWRN - International Workshop on Railway Noise CY - Munich, Germany DA - 2007-09-04 PY - 2007 SP - S.4.2, 1 EP - 6 PB - International Workshop on Railway Noise CY - München AN - OPUS4-18592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Dynamic stiffness of foundations on inhomogeneous soils for a realistic prediction of vertical building resonance N2 - The aim of this contribution is a practice-oriented prediction of environmental building vibrations. A Green's functions method for layered soils is used to build the dynamic stiffness matrix of the soil area that is covered by the foundation. A simple building model is proposed by adding a building mass to the dynamic stiffness of the soil. The vertical soil-building transfer functions with building-soil resonances are calculated and compared with a number of measurements of technically induced vibrations of residential buildings. In a parametrical study, realistic foundation geometries are modeled and the influence of incompressible soil, deep stiff soil layering, soft top layers, and increasing soil stiffness with depth is analyzed. All these special soil models reduce the resonant frequency compared to a standard homogeneous soil. A physically motivated model of a naturally sedimented soil has a stiffness increasing with the square root of the depth and yields a foundation stiffness that decreases with foundation area considerably stronger than the relatively insensitive homogeneous soil. This soil model is suited for the Berlin measuring sites and reproduces satisfactorily the experimental results. KW - Stiffness KW - Foundations KW - Predictions KW - Resonance KW - Vibration PY - 2008 DO - https://doi.org/10.1061/(ASCE)1090-0241(2008)134:3(328) SN - 1090-0241 SN - 1943-5606 VL - 134 IS - 3 SP - 328 EP - 340 PB - American Society of Civil Engineers CY - Reston, Va. AN - OPUS4-17394 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - The effect of critically moving loads on the vibrations of soft soils and isolated railway tracks N2 - The dynamic response of the railway track is strongly influenced by the underlying soil. For a soft soil and very high train speeds or for a very soft soil and regular train speeds, the train speed can be close to the speed of elastic waves in the soil. This paper presents a detailed study of the so-called “moving-load effect”, i.e. an amplification of the dynamic response due to the load movement, for the tracks on soft soil. The analysis is carried out by evaluating the related integrals in the wavenumber domain. The influence of the load speed is quantified for a large set of parameters, showing that the effect on the soil vibration is reduced with increase of the frequency, track width and inverse wave velocity. Therefore, the moving-load effect associated with vibratory train loads is negligible whereas the amplification associated with the moving dead weight of the train can be significant. The strong moving-load effect on a perfectly homogeneous soil, however, can be strongly diminished by a layered or randomly varying soil situation. This theoretical result is affirmed by measurements at a test site in Germany where the trains run on a very soft soil at a near-critical speed. The results for soft soils are compared with experimental and theoretical results for a stiff soil. It is found that the influence of the stiffness of the soil is much stronger than the moving-load effect. This holds for the soil vibration as well as for the track vibration which both show a minor dependence on the load speed but a considerable dependence on the soil stiffness in theory and experiment. Railway tracks can include soft isolation elements such as rail pads, sleeper shoes and ballast mats. For these types of isolation elements and normal soil conditions, the influence of the load speed is usually negligible. There is only one isolation measure for which the moving load may be effective: a track which is constructed as a heavy mass–spring system. The resonance of this track system is shifted to lower frequencies and amplitudes for increasing train speed. A critical train speed can be reached if the mass–spring system has a marginal bending stiffness along the track. PY - 2008 DO - https://doi.org/10.1016/j.jsv.2007.10.013 SN - 0022-460X SN - 1095-8568 VL - 310 IS - 3 SP - 587 EP - 607 PB - Academic Press CY - London AN - OPUS4-17395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -