TY - CONF A1 - Auersch, Lutz A1 - Said, Samir T1 - Measurement of slab track behaviour at different sites N2 - Measured train passages and hammer impacts in combination with track-soil calculation have been successfully used for the detection of damaged slab tracks. This approach is now extended to intact slab and ballast tracks. The vibrations of many tracks have been measured at several levels from rail, sleeper, track plate, base plate, base layer to the subsoil by velocity or acceleration sensors. The time histories have to be integrated once or twice to get the displacements. The displacement signals include an arbitrary time-dependent shift which must be eliminated or respected in the interpretation. On the other hand, the calculation of slab and ballast tracks have been done in frequency-wavenumber domain. The displacements along the track and the frequency-dependent compliance transfer functions can be calculated. The latter can be compared with the results of the hammer impacts on the track. The deformation of the track can be transformed to time histories for a whole train and compared to the measured train passages. Many slab (and ballast) tracks have been measured at different sites. The displacements of the tracks are presented, and the following parameters have been analysed in the measurement results: slab track vs. ballast track, different types of slab tracks, damaged slab tracks, different trains, switches at different measuring points, an elastic layer, the mortar layer, different soils at different places. The soil should have the dominant influence on the track-plate displacements. Slab and ballast track yield also big differences in maximum displacement and width of deformation. Some of the preceding aspects will be analysed in comparison of measurement and theory. T2 - 26th International Congress on Sound and Vibration (ICSV26) CY - Montreal, Canada DA - 07.07.2019 KW - Displacements KW - Slab track KW - Train passage KW - Hammer impact KW - Vibration measurements PY - 2019 SN - 978-1-9991810-0-0 SN - 2329-3675 SP - T15RS01_316_1 EP - T15RS01_316_8 PB - Canadian Acoustical Association CY - Montreal, Kanad AN - OPUS4-48498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kullolli, Borana A1 - Baeßler, Matthias A1 - Cuéllar, Pablo A1 - Rica, S. A1 - Rackwitz, F. T1 - An enhanced interface model for friction fatigue problems of axially loaded piles N2 - The shaft bearing capacity often plays a dominant role for the overall structural behaviour of axially loaded piles in offshore deep foundations. Under cyclic loading, a narrow zone of soil at the pile-soil interface is subject to cyclic shearing solicitations. Thereby, the soil may densify and lead to a decrease of confining stress around the pile due to microphenomena such as particle crushing, migration and rearrangement. This reduction of radial stress has a direct impact on the shaft capacity, potentially leading in extreme cases to pile failure. An adequate interface model is needed in order to model this behaviour numerically. Different authors have proposed models that take typical Interface phenomena in account such as densification, grain breakage, normal pressure effect and roughness. However, as the models become more complex, a great number of material parameters need to be defined and calibrated. This paper proposes the adoption and transformation of an existing soil bulk model (Pastor- Zienkiewicz) into an interface model. To calibrate the new interface model, the results of an experimental campaign with the ring shear device under cyclic loading conditions are here presented. The constitutive model shows a good capability to reproduce typical features of sand behaviour such as cyclic compaction and dilatancy, which in saturated partially-drained conditions may lead to liquefaction and cyclic mobility phenomena. T2 - Conference: OMAE CY - Glasgow, Scotland, UK DA - 09.06.2019 KW - Soil-structure interaction KW - Interface PY - 2019 VL - 2019 SP - Article Number: UNSP V001T10A013 PB - ASME CY - Glasgow, Scotland AN - OPUS4-48444 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Ruspighi, Emiliano T1 - Vehicle-track-soil interaction and train-induced ground vibration: Theory and measurements in Germany, Switzerland and France N2 - Abstract. Three measurement campaigns of train-induced ground vibrations are evaluated for the vehicle-track-soil interaction. Ground vibrations, track vibrations and vehicle vibrations have been measured for train passages and impulse excitation and compared with theoretical results. The soil and the track-soil system are calculated by wavenumber integrals. The influence of the vehicle is introduced by a substructure method. By comparing theory and measurement the different components of excitation force and ground vibration can be analysed, the quasi-static excitation, track-alignment errors, the out-of-roundness of wheels, the wheel and rail roughness, and moreover, scattered axle impulses and ineffective high-frequency parts of the wheelset accelerations and forces. T2 - 13th International Conference on recent Advances in Structural Dynamics CY - Lyon, France DA - 15.4.2019 KW - Vehicle-track interaction KW - Train-induced ground vibration KW - Ground vibration measurements PY - 2019 SP - 810 EP - 821 PB - University of Southampton CY - Southampton AN - OPUS4-48423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Lombaert, G. ED - Degrande, G. 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. T2 - 13th International Workshop on Railway Noise and Vibration CY - Leuven, Belgium DA - 16.09.2019 KW - Train speed KW - Ground vibration KW - Excitation forces KW - Layered soils PY - 2019 SP - 1 EP - 8 PB - KU Leuven CY - Leuven AN - OPUS4-49440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Adam, C. T1 - Bahnerschütterungen bei verschiedenen Böden und Zuggeschwindigkeiten – Messungen in Deutschland, Österreich und der Schweiz N2 - Die Bundesanstalt für Materialforschung und -prüfung hat in den letzten 30 Jahren an vielen Orten Bahnerschütterungen gemessen. Dabei wurden immer auch Versuche zur Bestimmung der Bodeneigen-schaften durchgeführt, meist mit Hammeranregung, gelegentlich auch mit Schwingeranregung. Es werden verschiedene Auswertemethoden wie Seismogramm-Montage, Spektrale Analyse (SASW), Multistation Analysis of Surface Waves (MASW), f,v-Analyse (Dispersion aus zweifacher Fourier-Analyse), Spatial AutoCorrelation (SPAC, hier auch für deterministische Quellen) vorgestellt. Durch Approximation der frequenzabhängigen Wellengeschwindigkeiten (Dispersion) oder der gemessenen Übertragungsfunktionen erhält man ein passendes Bodenmodell. Zu diesem Bodenmodell kann man dann die Übertragungsfunktionen für Hammer- und Zuganregung berechnen. Mit allgemeinen oder spezifischen Achslastspektren werden dann die Bahnerschütterungen prognostiziert und mit den Messergebnissen verglichen. Bei etlichen Messorten, insbesondere in der Schweiz, wurden deutliche Merkmale einer Bodenschichtung beobachtet. Es ergibt sich eine deutliche Reduktion der tiefen Frequenzanteile durch den steifen unterliegenden Halbraum. Die weiche Deckschicht bestimmt das hochfrequente Verhalten. Hier bewirkt die Materialdämpfung des Bodens oft einen starken Amplitudenabfall, sowohl mit der Entfernung als auch mit der Frequenz. Für den verbleibenden mittelfrequenten Anteil wurde an mehreren Messorten die Amplituden-Fahrgeschwindigkeits-Gesetzmäßigkeiten untersucht. Es gibt konstante bis stark ansteigende Amplituden, und es zeigt sich auch hier, dass der geschichtete Boden von entscheidender Bedeutung ist. T2 - 16. D-A-CH Tagung Erdbebeningenieurwesen & Baudynamik (D-A-CH 2019) CY - Innsbruck, Austria DA - 26.09.2019 KW - Wellengeschwindigkeit KW - Dispersionsmessung KW - Bodenübertragungsfunktion KW - Bahnerschütterungen KW - Zuggeschwindigkeit PY - 2019 SP - 1 EP - 8 PB - Universität Innsbruck CY - Innsbruck AN - OPUS4-49441 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frei, Vivian A1 - Thiele, Marc A1 - Pirskawetz, Stephan A1 - Meng, Birgit A1 - Rogge, Andreas T1 - Characterizing the Fatigue Behavior of High-Performance Concrete for Wind Energy Structures N2 - Severe mechanical fatigue conditions for worldwide proliferating windfarms are a Major challenge for high-performance concrete in towers, connecting joints and foundations of wind turbines. High-performance concrete offers potential for the application in offshore windfarms, not only regarding its good mechanical, but also chemical resistivity due to low diffusivity in the highly densified microstructure. For a more reliable fatigue assessment, monitoring based on nondestructive testing can be a valuable complement to design rules. Both approaches demand reliable experimental data, information about scalability and the development of standardized testing methods. This article presents results of an ongoing research program of BAM (Bundesanstalt für Materialforschung und -prüfung), which is a part of a joint national project (WinConFat) funded by the German Federal Ministry for Economic Affairs and Energy. The subproject implemented by BAM examines the fatigue behavior in dependence of size and slenderness for varying concrete strength at different stress levels. Besides fatigue strength, nondestructive testing is carried out additionally. Methods used are strain measurement and ultrasonic testing. The change of strain, stiffness and ultrasonic pulse velocity in the fatigue process is discussed. Results disclose a deeper insight into the damage process under cyclic loading of high-performance concrete and contribute to improve nondestructive monitoring. T2 - LORCENIS - Long Lasting Reinforced Concrete fpr Energy Infrastructure under Severe Operating Conditions CY - Ghent, Belgium DA - 10.09.2019 KW - Compressive Cyclic loading KW - Fatigue KW - High-strength concrete KW - Non destructive testing KW - Ultrasonic testing PY - 2019 SN - 978-9-463-88638-3 SP - 1 EP - 4 AN - OPUS4-49500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rica, S. A1 - Van Baars, S. A1 - Kullolli, Borana ED - Ülgen, D. ED - Saygili, A. ED - Kahyaoglu, M. R. ED - Durmaz, S. ED - Toygar, O. ED - Göcügenci, A. T1 - The importance of the horizontal stresses on the bearing capacity of a foundation pile N2 - In case one wants to predict or design the bearing capacity of a foundation pile and there are no possibilities to perform an in-situ test, such as a Cone Penetration Test, the pile bearing capacity is in most cases estimated with analytical formulas. The most known and used method is the Meyerhof method published some decades ago. There are also other design methods such as derived from a certain failure mechanism around the pile tip, which is, in most cases, wedge failure mechanism. This failure mechanism was originally developed for a shallow (infinite) strip foundation, though. Therefore, it represents a plane failure mechanism. Numerical simulations on loaded foundation piles performed with the Plaxis software Show however, that the failure mechanism of a foundation pile represents a far more complex threedimensional failure mechanism around the pile tip. In addition, the existing analytical methods for foundation piles are based on the vertical stresses in the soil, as if the failure mechanism is the same as of a shallow foundation. Numerical simulations, performed in Plaxis show that, not the vertical, but the horizontal stresses, play an important role on the pile bearing capacity. Plaxis represents the stresses in the soil by using the procedure. So, different horizontal soil stresses are obtained for different values of the lateral earth pressure coefficient. The results show that the pile tip bearing capacity depends strongly on the horizontal stresses in the soil, but only for. The same results were observed by using a Material Point Method (MPM). Consequently, the analytical methods should estimate the pile bearing. T2 - 1st Mediterranean Young Geotechnical Engineers Conference CY - Bodrum, Turkey DA - 23.09.2019 KW - Analytical Design Methods KW - Foundation Pile KW - Horizontal stress PY - 2019 UR - http://mygec2019.org/ VL - 2019 SP - 151 EP - 158 PB - 1st Mediterranean Young Geotechnical Engineers Conference CY - Bodrum, Turkey AN - OPUS4-49639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Vehicle-track-soil interaction and train-induced ground vibration – Theory and measurements in Germany, Switzerland and France N2 - Three measurement campaigns of train-induced ground vibrations are evaluated for the vehicle-track-soil interaction. Ground vibrations, track vibrations and vehicle vibrations have been measured for train passages and impulse excitation and compared with theoretical results. The soil and the track-soil system are calculated by wavenumber integrals. The influence of the vehicle is introduced by a substructure method. By comparing theory and measurement the different components of excitation force and ground vibration can be analysed, the quasi-static excitation, track-alignment errors, the out-of-roundness of wheels, the wheel and rail roughness, and moreover, scattered axle impulses and ineffective high-frequency parts of the wheelset accelerations and forces. T2 - Recent Advance in Structural Dynamics CY - Lyon, France DA - 15.04.2019 KW - Vehicle-track-soil interaction KW - Train-induced ground vibration KW - Vibration measurements PY - 2019 SP - 810 EP - 821 PB - University of Southampton CY - Southampton AN - OPUS4-47892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Effect of repair models on risk based optimal inspection strategies for support structures of offshore wind turbines N2 - Owners or operators of offshore wind farms perform inspections to collect information on the condition of the wind turbine support structures and perform repairs if required. These activities are costly and should be optimized. Risk-based methods can be applied to identify inspection and repair strategies that ensure an optimal balance between the expected total service life cost of inspection and repair, and the achieved risk reduction. Such an optimization requires explicit modeling of repairs. In this paper, the impact of different repair models on the results of a risk-based optimization of inspection and repair strategies is quantified in a numerical example considering a jacket-type steel frame subject to high-cycle fatigue. The example showed that, in this specific application, there is no need for detailed modeling of the behavior of repaired welded connections. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) CY - Potsdam, Germany DA - 27.08.2019 KW - Risk KW - Reliability KW - Inspection planning KW - Offshore wind turbines PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-488297 UR - https://www.smar2019.org/Portals/smar2019/bb/Th.2.A.4.pdf SP - Paper Th.2.A.4, 1 EP - 8 AN - OPUS4-48829 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kullolli, Borana A1 - Cuéllar, Pablo A1 - Baeßler, Matthias A1 - Stutz, H. H. T1 - Modelling and calibration for cyclic soil-structure interface behaviour N2 - The structural performance of many geotechnical systems (e.g. axially-loaded pile foundations), depends on the shearing resistance at the soil interface, which may govern the load bearing capacity of the foundation. Experimental investigations have shown that this interaction is mainly localised within a narrow shear band next to the structure. Under cyclic loading, a contraction of the soil at the interface may arise (net volume loss), possibly leading to a stress relaxation and thus to a reduction of the load bearing capacity (the so-called friction fatigue). Based on the constitutive similarities between soil continua and interfaces, we propose here the adaption of a Generalized Plasticity model for sandy soils for the numerical analysis of interface problems. In this contribution, the results of an experimental campaign for the parameter calibration of the constitutive model are presented. The tests have been conducted with a ring shear device involving different normal stresses, roughness of the steel plates as well as cyclic loading. The new modelling approach shows promising results and has the additional practical advantage that the interface zone and the soil continuum can both be described with the same constitutive model in general boundary value problems. T2 - Konferenz 7th International Symposium on Deformation Characteristics of Geomaterials CY - Glasgow, Scotland DA - 26.06.2019 KW - Soil-structure interaction KW - Offshore foundations PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-489096 DO - https://doi.org/10.1051/e3sconf/20199213007 VL - 92 SP - 13007 EP - 13013 PB - EDP Sciences CY - Glasgow, Scotland AN - OPUS4-48909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -