TY - CONF A1 - Auersch, Lutz T1 - Some resonance effects of non-typical trains and railway bridges investigated by a frequency-domain method N2 - The resonances of railway bridges have often been analysed for short bridges under periodical high-speed trains, for simply supported one-span bridges, for the fundamental bridge mode, and by time-domain analyses. Many time-consuming calculations have been performed to establish simplified rules for standards. In this contribution, the passage of different (existing, new and hypothetic) trains over different bridges will be analysed in frequency domain by using three separated spectra with the purpose to get a better physical insight in the phenomena. 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 an arbitrary train which is not limited to periodical or specific (conventional, articulated, regular or standard) trains and which does not include any bridge parameters. The final solution in frequency domain is obtained as the product of these three complex, strongly varying spectra for the dominating bridge mode or in general as the sum of these products over all relevant bridge modes. The time domain solution is obtained via the inverse Fourier transform, and the resulting time histories have been successfully compared with some measurement results. The method is applied to the vertical and torsional modes of a mid-long 1-span bridge on elastomeric bearings under standard train speeds, and to a long multi-span integral bridge under long periodical freight trains. Different resonance and cancellation effects have been found for systematically varied train speeds according to the axle sequence of the whole train which is dominated by the two locomotives in that case. To be more specific, the first torsional mode of the mid-span bridge is excited for a train speed of 100 km/h whereas the second bending mode is excited for a train speed of 160 km/h. In both cases, the other mode is suppressed by the minima of the axle-distance spectra. In addition, the case of the German high-speed train ICE4 and the very high-speed hyperloop case will be discussed briefly. In general, it is shown that resonance effects are also worth to be studied for freight and passenger trains with lower speeds. T2 - XII International Conference on Structural Dynamics CY - Delft, The Netherlands DA - 03.07.2023 KW - Railway bridge KW - Transfer function KW - Modal force spectrum KW - Axle-sequence spectrum KW - Freight train KW - Passenger train KW - High-speed train KW - 2-span bridge KW - Long-span bridge PY - 2023 SP - 1 EP - 10 PB - TU Delft CY - Delft AN - OPUS4-57961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Train-induced ground vibrations - the emission and transmission from tunnel and surface lines N2 - Train-induced ground vibrations are quite different for tunnel and surface lines. The excitation of the track and ground vibration by the vehicle-track-soil interaction maybe influenced by the stiffer track support of the tunnel invert. The excited waves are propagating on a different path compared to the surface line. The wave propagation in the interior of the soil is calculated by a wavenumber integral in a similar way as the propagation along the surface and a general reduction of < 0.5 has been found. An additional reduction has been found because of the missing Rayleigh wave. The different excitation of tunnel lines is analysed theoretically by the combined finite-element boundary-element method and some results about the influencing tunnel and soil parameters will be shown. Measurements have been made at the Mühlberg-Tunnel in Germany. The vibrations of the train, the track and the soil have been measured simultaneously at the tunnel and a nearby surface line. Spectra will be shown for different train speeds between 60 and 160 km/h. A clear reduction effect for the tunnel line compared to the surface line has been observed in a specific (train-speed-dependent) frequency range. This agrees well with the observations of other research institutes. The mid-frequency tunnel-surface reduction seems to be a consequence of the stiffer track structure which leads to a wider distribution of the axle loads. Therefore, the axle impulses due to the train passage are longer and have a lower frequency content. This will have an effect on the ground vibrations at some distance which are present in case of an irregular transmission path through a ballast and soil with varying stiffness. A similar reduction effect can also be found for other track forms where the axle impulses are distributed on a longer track segment, for example slab tracks, tracks with under ballast plates, under ballast mats or under sleeper pads. T2 - 29th International Congress on Sound and Vibration CY - Prague, Czech Republic DA - 09.07.2023 KW - Ground vibration KW - Railway tunnel KW - Layered soil KW - Surface-tunnel reduction KW - Measurements PY - 2023 SP - 1 EP - 8 PB - IIAV CY - Auburn, USA AN - OPUS4-57962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Impacts between different drop masses and different targets in different scales N2 - The Federal Institute of Material Research and Testing has performed many impact tests from very small laboratory tests to very big “free-field” tests with heavy containers on stiff 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. Later on, a smaller drop test facility has been built on the ground 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 oc-cur during the drop tests. In addititon, the acceptable tests should be selected and controlled by measurements where the impact duration is important. Dif-ferent sensors, accelerometers, accelerometers with mechanical filters, geo-phones (velocity transducers), strain gauges, and pressure cells have been ap-plied for these tasks. Signal transformations and model 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 esti-mation. T2 - 10th International Conference on Experimental Vibration Analysis for Civil Engineering Structures CY - Milano, Italy DA - 30.08.2023 KW - Drop test KW - Vibration measurements KW - Container loading KW - Foundation load PY - 2023 AN - OPUS4-58504 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Impacts Between Different Drop Masses and Different Targets in Different Scales N2 - The Federal Institute of Material Research and Testing has performed many impact tests from very small laboratory tests to very big “free-field” tests with heavy containers on stiff 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. Later on, a smaller drop test facility has been built on the ground 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 oc-cur during the drop tests. In addititon, the acceptable tests should be selected and controlled by measurements where the impact duration is important. Dif-ferent sensors, accelerometers, accelerometers with mechanical filters, geo-phones (velocity transducers), strain gauges, and pressure cells have been ap-plied for these tasks. Signal transformations and model 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 esti-mation. T2 - Experimental Vibration Analysis for Civil Engineering Structures (EVACES 2023) CY - Milano, Italy DA - 30.08.2023 KW - Drop test KW - Vibration measurements KW - Container loading KW - Foundation load PY - 2023 SN - 978-3-031-39116-3 DO - https://doi.org/10.1007/978-3-031-39117-0_60 SN - 2366-2557 SP - 592 EP - 602 PB - Springer Nature Switzerland CY - Cham, Schweiz AN - OPUS4-58503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Reduction in Train-Induced Vibrations—Calculations of Different Railway Lines and Mitigation Measures in the Transmission Path N2 - The reduction in train-induced ground vibrations by different railway lines and by mitigation measures in the propagation path was analysed in a unified approach by two-dimensional finite element calculations. In general, there was no reduction at low frequencies, and the reduction be-came stronger with increasing frequencies. A maximum reduction of 0.1 at high frequencies was established with an open trench. Reductions between 0.7 and 0.2 have been found for the other sit-uations, filled trenches, walls, plates, and blocks, as well as for railway lines on dams, in cuts and in a tunnel. Bridges can produce amplifications due to their resonance frequencies, but also strong reductions due to massive bridge piers. The influence of some parameters has been analysed, such as the bridge span, the inclination of the dam and the cut, the stiffness of the soil, and the tunnel structure. The dynamic track stiffnesses of a surface, bridge, and tunnel track have been calculated using the 3D finite-element boundary-element method for comparison with corresponding meas-urements. KW - Train-induced vibration KW - Mitigation KW - Trench KW - Obstacles KW - Tunnel KW - Bridge KW - Finite element KW - Boundary element PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579573 DO - https://doi.org/10.3390/app13116706 VL - 13 IS - 11 SP - 1 EP - 19 PB - MDPI CY - Basel AN - OPUS4-57957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Site-specific amplitude-distance laws, wave velocities, damping, and transfer functions of the soil from hammer impacts and application to railway-induced ground vibration – Similarities and mid-frequency differences N2 - The propagation of ground vibrations is theoretically analysed with frequency-wavenumber and simplified methods. Experimental methods are presented which can characterise the site-specific ground vibrations by wave velocities, stiffness and damping. Measurements with hammer and train excitation have been performed at several sites. The one-third octave spectra show the stiffness-dependent amplitudes and the low- and high-frequency filter effects due to the layering and the damping of the soil. Specific train effects, an additional high-frequency filter, the sleeper passage frequency, and an amplified mid-frequency component can be clearly found. The attenuation with distance is analysed in detail where the theoretical exponential and the empirical frequency-dependent power law are considered. Hammer and train excitation show the same site-specific effects which are mainly due to the stronger or weaker damping of the soil. The train attenuation is generally weaker than the hammer attenuation. The attenuation exponent of the power law, which is strongly dependent on the site and the frequency, is reduced for the train vibration by 0.3 to 0.5 in agreement with the theory. Reasons are discussed for the overall power law and for the dominating mid-frequency component. KW - Hammer impact KW - Train passage KW - Layered soil KW - Attenuation KW - Filter effects KW - Randomly heterogeneous soil KW - Scattering PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-585020 DO - https://doi.org/10.1007/s42417-023-01095-0 SN - 2366-2557 SP - 1 EP - 17 PB - Springer AN - OPUS4-58502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Song, Jiaojiao T1 - Dynamic damage detection of slab tracks – finite element models on Winkler soil and finite-element boundary-element models on continuous soil N2 - The train passages over intact or damaged slab tracks on different soils have been calculated by two methods. The finite element method (FEM) uses a Winkler soil under the track model by adding a thin “soil layer”. The combined finite element boundary element method has a continuous soil model which is included by the boundary element method. The basic results are the distributions of the track (rail, track plate, and base layer) displacements along the track for a single axle laod. These solutions are superposed to a complete train load and transformed to time histories. The influence of track and soil parameters has been analysed. The main interest is the influence of the track damage. A gap between track plate and base layer of different lengths has been studied for changes in amplitudes and widths of deflection. A best fit to measured track displacements has been found so that the track damage can be identified and quantified. The FEM model with Winkler soil cannot be fitted to the amplitude and width with the same soil parameters. Therefore, the FEBEM model is preferable for these railway track problems. KW - Track damage quantification KW - Finite element method KW - Combined finite-element boundary-element method PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-562207 DO - https://doi.org/10.3390/civileng3040055 SN - 2673-4109 VL - 3 IS - 4 SP - 979 EP - 997 PB - MDPI CY - Basel AN - OPUS4-56220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz T1 - Zur Entstehung und Ausbreitung von Schienenverkehrserschütterungen: Theoretische Untersuchungen und Messungen am Hochgeschwindigkeitszug Intercity Experimental N2 - Neuere Ergebnisse insbesondere zur Erschütterungsproblematik, damit verbunden auch Ergebnisse zur Fahrzeugdynamik und zur Fahrweg- und Untergrundbelastung. Theorie und Praxis ergeben übereinstimmend wichtige Folgerungen für Hochgeschwindigkeitsverkehr. T3 - BAM Forschungsberichtreihe - 155 KW - Erschütterungen KW - Schienenverkehr KW - Hochgeschwindigkeitszüge KW - Fahrzeugdynamik KW - Fahrwegdynamik KW - Bodendynamik KW - Wellenausbreitung KW - Kopplung des Fahrzeug-Fahrweg-Untergrund-Systems KW - Schwellenabstandsanregung KW - Parametererregung PY - 1988 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2951 SN - 978-3-88314-825-3 SN - 0938-5533 VL - 155 SP - 1 EP - 194 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-295 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz T1 - Wechselwirkung starrer und flexibler Strukturen mit dem Baugrund insbesondere bei Anregung durch Bodenerschütterungen N2 - Es wird ein Rechenverfahren vorgestellt, das die Randelementmethode zur Beschreibung des Bodens mit der Finite-Element-Methode für das Bauwerk verbindet. Am Grundproblem der Bauwerk-Boden-Wechselwirkung, der dynamischen Steifigkeit starrer Fundamente auf dem Baugrund, werden diese Verfahren und einige Verfahrensvarianten erprobt und miteinander verglichen. T3 - BAM Forschungsberichtreihe - 151 KW - Bauwerk-Boden-Wechselwirkung KW - Baudynamik KW - Erschütterungen KW - Wellenfeld KW - Fundamente KW - Randelementmethode PY - 1988 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2990 SN - 978-3-88314-785-0 SN - 0938-5533 VL - 151 SP - 1 EP - 132 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-299 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz A1 - Said, Samir A1 - Rücker, Werner T1 - Das Fahrzeug-Fahrweg-Verhalten und die Umgebungserschütterungen bei Eisenbahnen N2 - In dem Forschungsvorhaben „Das Fahrzeug-Fahrweg-Verhalten“ im Hinblick auf die Prognose von Zugerschütterungen und die Optimierung von Minderungsmaßnahmen – Förderkennzeichen BMBF 9346 - wurden sehr komplexe, vielfältig ineinander verzahnte und simultane Fahrzeug-, Fahrweg-, Brücken- und Zugmessungen durchgeführt. Mit diesem umfangreichen Arbeitsprogramm wurde die Relevanz verschiedener Anregungs- und Beanspruchungsanteile untersucht und eine Reihe von Messmethoden für diese Anteile herausgearbeitet, sowie Minderungsmöglichkeiten für die dynamischen Radlasten und für die Erschütterungen in der Umgebung von Bahnlinien zusammengestellt und bewertet. T3 - BAM Forschungsberichtreihe - 243 KW - Fahrzeugschwingungen KW - Fahrwegnachgiebigkeit KW - Dynamische Radlasten KW - Simultanmessungen KW - Bodenerschütterungen KW - Feste Fahrbahn KW - Brückengleis KW - Fahrgeschwindigkeit PY - 2001 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2073 SN - 978-3-89701-565-X SN - 0938-5533 VL - 243 SP - 1 EP - 168 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-207 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz T1 - Fundamentschwingungen und Wellenausbreitung bei inhomogenen Böden – Beiträge zur Dynamik der Verkehrssysteme N2 - Dieser Bericht gliedert sich in drei Abschnitte, in denen der Einfluß inhomogener Böden auf die Dynamik von Verkehrssystemen untersucht wird. In erster Linie werden dabei geschichtete Böden behandelt, für die ein Rechenverfahren entwickelt wurde. Als elementares Ergebnis werden die Wellenfelder geschichteter Böden bei einer punktförmigen Belastung dargestellt. Mit diesen Punktlastlösungen können dann die Schwingungen von starren oder flexiblen Strukturen auf geschichteten Böden berechnet werden. Es wird die dynamische Steifigkeit und Dämpfung starrer Fundamentflächen dargestellt, an der das stark frequenzabhängige Verhalten geschichteter Böden besonders deutlich wird. T3 - BAM Forschungsberichtreihe - 226 KW - Dynamik KW - Fundamentschwingungen KW - Wellenausbreitung KW - Geschichter Boden KW - Schichtresonanz KW - Schiffstoß KW - Brückenpfeiler KW - Schienenverkehr KW - Gleisschwingungen KW - Achslasten KW - Erschütterungen PY - 1998 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2246 SN - 978-3-89701-161-1 SN - 0938-5533 VL - 226 SP - 1 EP - 69 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-224 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -