TY - JOUR A1 - Auersch, Lutz T1 - Resonances of railway bridges analysed in frequency domain by the modal-force-excitation, bridge-transfer and axle-sequence spectra N2 - In this article, the passage of different trains over different bridges will be studied for resonant excitation. The intensity of the resonance will be estimated in frequency domain by using three separated spectra. At first, the excitation spectrum of the modal forces is built by the mode shape and the passage time of the train over the bridge. The second spectrum is the frequency response function of the bridge which include the modal frequency, damping and mass. The third part is the spectrum of the axle sequence of the train. The influences of train speed, bridge length, bridge support, track irregularities, and train type on the resonance amplitudes will be analysed for each of these spectra separately for getting a better insight. A variety of axle-sequence spectra and corresponding rules will be presented for different vehicles and trains. As examples, the passage of a slow freight train over a long-span bridge, a normal passenger train over a medium-span bridge, and a high-speed train over a short bridge will be analysed. Corresponding measurements show the amplification, but also the cancellation of the subsequent axle responses. Namely in one of the measurement examples, the first mode of the bridge was amplified and the second mode was cancelled at a low speed of the train and vice versa at a higher speed. KW - Railway bridge KW - Bridge vibration KW - Train passage KW - Axle sequence KW - Resonance KW - Cancellation KW - Fequency domain PY - 2021 U6 - https://doi.org/10.1016/j.engstruct.2021.113282 SN - 0141-0296 VL - 249 SP - 1 EP - 9 PB - Elsevier Ltd. CY - London AN - OPUS4-53766 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Prediction of building noise and vibration – 3D finite element and 1D wave propagation models N2 - Construction work or traffic excite nearby buildings, and the perceptible or audible vibration can be a nuisance for the inhabitants. The transfer of the vibration from the free field to the building has been calculated by the finite element method for many models in consultancy and research work. The analysis for all storeys of certain building points such as walls, columns and floors unveiled some rules, some typical modes, and some wavetype responses. A simplified building-soil model has been created, which includes well these effects of building-soil resonance, wall/column resonance, floor resonances, and the high-frequency reduction. The model consists of one wall for a wall-type apartment building or a column for each specific part (mid, side or corner) of a column-type office building. The building response in the high-frequency (acoustic) region is calculated as mean values over all storeys and over wider frequency bands, by wave-type asymptotes of an infinitely tall building, and by the soil to wall ratio of impedances. The secondary noise is predicted by Transfer values between the building vibration (center of floors, walls at a room corner) and the sound pressure. T2 - Euronoise 2021 CY - Online meeting DA - 25.10.2021 KW - Building vibration KW - Finite element models KW - Soil-wall-floor model KW - Apartment building KW - Office tower PY - 2021 SN - 978-989-53387-0-2 SP - 1792 EP - 1801 AN - OPUS4-53702 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Prediction of building noise and vibration – 3D finite element and 1D wave propagation models N2 - Construction work or traffic excite nearby buildings, and the perceptible or audible vibration can be a nuisance for the inhabitants. The transfer of the vibration from the free field to the building has been calculated by the finite element method for many models in consultancy and research work. The analysis for all storeys of certain building points such as walls, columns and floors unveiled some rules, some typical modes, and some wavetype responses. A simplified building-soil model has been created, which includes well these effects of building-soil resonance, wall/column resonance, floor resonances, and the high-frequency reduction. The model consists of one wall for a wall-type apartment building or a column for each specific part (mid, side or corner) of a column-type office building. The building response in the high-frequency (acoustic) region is calculated as mean values over all storeys and over wider frequency bands, by wave-type asymptotes of an infinitely tall building, and by the soil to wall ratio of impedances. The secondary noise is predicted by Transfer values between the building vibration (center of floors, walls at a room corner) and the sound pressure. T2 - Euronoise 2021 CY - Online meeting DA - 25.10.2021 KW - Building vibration KW - Finite element models KW - Soil-wall floor model KW - Apartment building KW - Office tower PY - 2021 AN - OPUS4-53703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Die Amplitudenabnahme im Boden bei Punkt- und Zuglast N2 - Die Linienlastgesetzmäßigkeit gilt nicht für Zuganregung. Die Punktlastgesetzmäßigkeit wird bei kurzen Zügen in größeren Entfernungen erreicht. Bei langen Zügen reduziert sich die Abnahme um r-0,3 für die theoretische exponentielle Dämpfungsabnahme, um r-0,5 für die vereinfachte potentielle Dämpfungsabnahme. Die gemessenen Abnahmereduktionen liegen in diesem Bereich. T2 - Norm-Arbeitsausschuss Schwingungsminderung in der Umgebung von Verkehrswegen CY - Cologne/Germany und Online meeting DA - 28.10.2021 KW - Amplituden-Abstands-Gesetze KW - Geometrie KW - Dämpfung PY - 2021 AN - OPUS4-53704 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Zur Prognose von Erschütterungen aus Bahntunneln N2 - Zur Erschütterungsausbreitung an oberirdischen Bahnlinien gibt es gute Übereinstimmungen zwischen Messungen und der Theorie geschichteter Böden. Bei der Interpretation der Ergebnisse spielt die Rayleigh-Welle eine große Rolle. Je nach Frequenz und Wellenlänge hat die Rayleigh-Welle eine bestimmte Eindringtiefe und erreicht damit mehr oder weniger steife Bodenschichten. Damit bekommt man eine frequenzabhängige Bodensteifigkeit für die Erschütterungsprognose. Für die Wellenausbreitung in der Tiefe statt an der Bodenoberfläche müssen eigene Gesetzmäßigkeiten gefunden werden. Es werden die Punktlastlösungen im Frequenz-Wellenzahlbereich und durch Integration über die Wellenzahlen berechnet. Man erhält die Wellenfelder, die Terzspektren für verschiedene Entfernungen und Frequenzen. Es wird die Tiefenlage und das Bodenmodell (homogen, geschichtet und kontinuierlich zunehmende Steifigkeit) variiert. Die Rayleigh-Welle verliert ihre Bedeutung und stattdessen kann die Vollraumlösung zur Interpretation und Prognose verwendet werden. Es werden die Halbraumlösung mit und ohne Rayleigh-Welle und die Vollraumlösung in der Tiefe diskutiert und verglichen. Neben der Wellenausbreitung (der Transmission) werden auch Effekte der Erschütterungsanregung (der Emission) und der Übertragung in Gebäude (der Immission) mit Hilfe der Finite-Element-Randelement-Methode berechnet. Die Verteilung der dynamischen Achslast durch die Tunnelsohle ergibt eine Minderung gegenüber der Punktlastanregung. Bei der Immission hat man keine Freifeldanregung wie an der Bodenoberfläche. Man muss entweder neben der Wellenamplitude (Verschiebung oder Schwinggeschwindigkeit) in der Tiefe auch die Spannung der ankommenden Welle berücksichtigen, oder man muss die Freifeldamplituden nach Bodenaushub berechnen. Die Rechenergebnisse deuten darauf hin, dass man als Freifeldanregung die zweifache Vollraumlösung ansetzen kann. T2 - Wiener Dynamik Tage 2021 CY - Vienna, Austria DA - 22.7.2021 KW - Erschütterungsausbreitung KW - Tunnel KW - Halbraum KW - Vollraum PY - 2021 SP - 1 EP - 11 PB - Steinhauser Consulting Engineers (STCE) CY - Wien AN - OPUS4-53253 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Auersch, Lutz ED - Degrande, G. ED - al., et T1 - Predicted and measured amplitude-speed relations of railway ground vibrations at four German sites with different test trains N2 - The present contribution evaluates four measuring series made by the Federal Institute of Material Research and Testing for the relations between train speed and ground vibration amplitudes. This experimental evaluation is supported by the simulation of the train passages at the different sites by using appropriate excitation mechanisms and forces as well as layered soil models which have been derived from impact measurements at each site. KW - Train speed KW - Ground vibration KW - Excitation forces KW - Layered soils PY - 2021 SN - 978-3-030-70288-5 U6 - https://doi.org/10.1007/978-3-030-70289-2_43 SN - 1612-2909 VL - 150 SP - 411 EP - 419 PB - Springer Nature Switzerland AG CY - Cham AN - OPUS4-52611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, R. A1 - Brechbühl, Y. A1 - Lutzenberger, S. A1 - Said, Samir A1 - Auersch, Lutz A1 - Guigou-Carter, C. A1 - Villot, M. A1 - Müller, R. ED - Degrande, G. ED - al., et T1 - Vibration Excitation at Turnouts, Mechanism, Measurements and Mitigation Measures N2 - There is a strong need for cost-effective mitigation measures for turnouts. SBB has initiated a series of examinations using different methodologies to gain a deeper understanding of the excitation mechanisms at low frequencies, in addition to that obtained in the RIVAS project. To date it is not yet clear what constitutes a complete measurement data set that would enable understanding most of the vibration excitation mechanisms in turnouts. Increasing vibration at turnouts in comparison to normal track is observed for all measured frequencies. The different methodologies are presented in the paper. Under-sleeper pads (USP) are a cost-effective method to reduce vibration at frequencies above 63 Hz (1/3 octave), but there is probably no improvement for frequencies below 63 Hz. A first test of new frog geometry did not show relevant improvements in Vibration emission in comparison to a reference frog geometry. Axle box acceleration measurements are an interesting method to identify defects in a turnout. A specialized measurement system of rail roughness could identify certain geometry Problem areas for some frogs. Noise increases also are observed at turnouts for frequencies ranging between 80 to 1000 Hz. The use of railway source models to calculate contact forces for ballasted track and turnouts seems promising, in particular for understanding the influence of ground. KW - Turnout KW - Switch KW - Vibration excitation KW - Vibration measurements PY - 2021 SN - 978-3-030-70288-5 U6 - https://doi.org/10.1007/978-3-030-70289-2_42 SN - 1612-2909 VL - 150 SP - 403 EP - 410 PB - Springer Nature Switzerland AG CY - Cham AN - OPUS4-52612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Zur Prognose von Erschütterungen aus Bahntunneln N2 - Zur Erschütterungsausbreitung an oberirdischen Bahnlinien gibt es gute Übereinstimmungen zwischen Messungen und der Theorie geschichteter Böden. Bei der Interpretation der Ergebnisse spielt die Rayleigh-Welle eine große Rolle. Je nach Frequenz und Wellenlänge hat die Rayleigh-Welle eine bestimmte Eindringtiefe und erreicht damit mehr oder weniger steife Bodenschichten. Damit bekommt man eine frequenzabhängige Bodensteifigkeit für die Erschütterungsprognose. Für die Wellenausbreitung in der Tiefe statt an der Bodenoberfläche müssen eigene Gesetzmäßigkeiten gefunden werden. Es werden die Punktlastlösungen im Frequenz-Wellenzahlbereich und durch Integration über die Wellenzahlen berechnet. Man erhält die Wellenfelder, die Terzspektren für verschiedene Entfernungen und Frequenzen. Es wird die Tiefenlage und das Bodenmodell (homogen, geschichtet und kontinuierlich zunehmende Steifigkeit) variiert. Die Rayleigh-Welle verliert ihre Bedeutung und stattdessen kann die Vollraumlösung zur Interpretation und Prognose verwendet werden. Es werden die Halbraumlösung mit und ohne Rayleigh-Welle und die Vollraumlösung in der Tiefe diskutiert und verglichen. Neben der Wellenausbreitung (der Transmission) werden auch Effekte der Erschütterungsanregung (der Emission) und der Übertragung in Gebäude (der Immission) mit Hilfe der Finite-Element-Randelement-Methode berechnet. Die Verteilung der dynamischen Achslast durch die Tunnelsohle ergibt eine Minderung gegenüber der Punktlastanregung. Bei der Immission hat man keine Freifeldanregung wie an der Bodenoberfläche. Man muss entweder neben der Wellenamplitude (Verschiebung oder Schwinggeschwindigkeit) in der Tiefe auch die Spannung der ankommenden Welle berücksichtigen, oder man muss die Freifeldamplituden nach Bodenaushub berechnen. Die Rechenergebnisse deuten darauf hin, dass man als Freifeldanregung die zweifache Vollraumlösung ansetzen kann. T2 - Wiener Dynamik Tage 2021 CY - Vienna, Austria DA - 22.07.2021 KW - Erschütterungsausbreitung KW - Tunnel KW - Halbraum KW - Vollraum PY - 2021 AN - OPUS4-53254 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Carletti, E. ED - Crocker, M. ED - Pawelczyk, M. ED - Tuma, J. T1 - Dynamic measurements during drop tests on stiff foundations N2 - Measurements at the foundation, the surrounding soil and nearby buildings have been done during several drop tests of different containers on different foundations. The first measurements have been done on a big foundation where it should be guaranteed that the foundation is rigid and the container is tested properly. It was controlled that the foundation does not absorb more than 2 percent of the energy of the container. Most of the drop energy is lost in shock absorbers. Later on, a smaller drop test facility has been built on the ground but inside an existing building. It had to be controlled by prediction and measurements that the drop test will not damage the building. Tests from different heights on soft, medium, and stiff targets have been done to find out rules which allow to identify acceptable and unacceptable drop tests. Later on, the biggest drop test facility has been built for masses up to 200 t. It was necessary for the design of the foundation to estimate the forces which occur during the drop tests. On the other hand, the acceptable tests should be selected and controlled by measurements where the impact duration is important. Different sensors, accelerometers, accelerometers with mechanical filters, geophones (velocity transducers), strain gauges, and pressure cells have been applied for these tasks. The signals have been transformed to displacements which proved to be best suited for the interpretation of the impact mechanism. Modell calculations have been used to check and understand the dynamic measurements. The simplest law is the conservation of the momentum which is a good approximation if the impact is short. If the soil under the foundation has an influence on the deceleration of the container, the maximum foundation velocity is lower than the simple estimation. The amplitudes of the foundation could also be estimated from the ground vibrations and their amplitude-distance law. T2 - 27th International Congress on Sound and Vibration (ICSV27) CY - Online meeting DA - 11.07.2021 KW - Drop test KW - Vibration measurement KW - Container loading KW - Foundation load PY - 2021 SN - 978-83-7880-799-5 SN - 2329-3675 SP - 1 EP - 8 PB - Silesian University Press CY - Gliwice, Poland AN - OPUS4-53255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Dynamic measurements during drop tests on stiff foundations N2 - Measurements at the foundation, the surrounding soil and nearby buildings have been done during several drop tests of different containers on different foundations. The first measurements have been done on a big foundation where it should be guaranteed that the foundation is rigid and the container is tested properly. It was controlled that the foundation does not absorb more than 2 percent of the energy of the container. Most of the drop energy is lost in shock absorbers. Later on, a smaller drop test facility has been built on the ground but inside an existing building. It had to be controlled by prediction and measurements that the drop test will not damage the building. Tests from different heights on soft, medium, and stiff targets have been done to find out rules which allow to identify acceptable and unacceptable drop tests. Later on, the biggest drop test facility has been built for masses up to 200 t. It was necessary for the design of the foundation to estimate the forces which occur during the drop tests. On the other hand, the acceptable tests should be selected and controlled by measurements where the impact duration is important. Different sensors, accelerometers, accelerometers with mechanical filters, geophones (velocity transducers), strain gauges, and pressure cells have been applied for these tasks. The signals have been transformed to displacements which proved to be best suited for the interpretation of the impact mechanism. Modell calculations have been used to check and understand the dynamic measurements. The simplest law is the conservation of the momentum which is a good approximation if the impact is short. If the soil under the foundation has an influence on the deceleration of the container, the maximum foundation velocity is lower than the simple estimation. The amplitudes of the foundation could also be estimated from the ground vibrations and their amplitude-distance law. T2 - 27th international Congress on Sound and Vibration (ICSV27) CY - Online meeting DA - 11.07.2021 KW - Drop test KW - Vibration measurement KW - Container loading KW - Foundation load PY - 2021 AN - OPUS4-53256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -