Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-48181 Zeitschriftenartikel Kowitz, Astrid; Wu, Cheng-Chieh; Helmerich, Rosemarie; Hille, Falk; Kadoke, Daniel; Gründer, Klaus-Peter; Hauser, S.; Schwarzinger, H. Bland, S. Impact on a micro-reinforced UHPC: Experimental studies versus numerical modeling Within the presented research project, experimental and numerical investigations were performed to develop a thin-shelled, modular, mobile element system made of a micro-reinforced ultra-high-performance ductile concrete (DUCON®). Material parameters were experimentally determined to adapt the material model within the numerical analysis applying the Drucker-Prager relationship. Afterwards, for validation of the numerical models, quasi-static and high-velocity impact tests were performed on plate-like structures. Finally, a suitable geometry of transportable barrier elements will be designed, which provides a maximum of resistance against impact by a minimum of weight and a maximum of mobility. Amsterdam Elsevier Ltd 2019 Materials Today: Proceedings 12 2 474 483 10.1016/j.matpr.2019.03.152 2019-06-07 OPUS4-48182 Beitrag zu einem Tagungsband Bhuyan, Md Delwar Hossain; Le Touz, N.; Gautier, G.; Döhler, M.; Hille, Falk; Dumoulin, J.; Mevel, L. Load vector based damage localization with rejection of the temperature effect The Stochastic Dynamic Damage Locating Vector (SDDLV) approach is a vibration-based damage localization method based on both a finite element model of a structure and modal parameters estimated from output-only measurements in the damage and reference states. A statistical version of the Approach takes into account the inherent uncertainty due to noisy measurement data. In this paper, the effect of temperature fluctuations on the performance of the method is analyzed in a model-based approach using a finite element model with temperature dependent parameters. Robust damage localization is carried out by rejecting the temperature influence on the identified modal parameters in the damaged state. The algorithm is illustrated on a simulated structure. 2019 Proceedings of IOMAC'19 8. International Operational Modal Analysis Conference Kopenhagen, Denmark 12. Mai 2019 1 10 2019-06-07 OPUS4-48183 Beitrag zu einem Tagungsband Bhuyan, Md Delwar Hossain; Döhler, M.; Lecieux, Y.; Lupi, C.; Thomas, J.-C.; Schoefs, F.; Hille, Falk; Mevel, L. Statistical subspace based damage localization on Saint-Nazaire bridge mock-up The subject of damage localization is an important issue for Structural Health Monitoring (SHM) particularly in mechanical or civil structures under ambient excitation. In this paper, the statistical subspacebased damage localization method has been applied on a benchmark application, namely a 1/200 scale model of the Saint-Nazaire Bridge, which is a cable-stayed bridge located on the Loire River near the river's mouth. The employed damage localization method combines data-driven features with physical parameter information from a finite element model in statistical tests, avoiding typical ill-conditioning problems of FE model updating. Damage is introduced in the mockup for cable failures on some of the 72 cables. The purpose of the experiment is to assess the capability of damage assessment methods to find a cable failure. 2019 Proceedings of IOMAC'19 8. International Operational Modal Analysis Conference Kopenhagen, Denmark 12. Mai 2019 14. Mai 2019 1 9 2019-06-07 OPUS4-48240 Beitrag zu einem Tagungsband Viefhues, Eva; Döhler, M.; Zhang, Q.; Hille, Falk; Mevel, L. Subspace-based Damage Detection with Rejection of the Temperature Effect and Uncertainty in the Reference Temperature variation can be a nuisance that perturbs vibration based structural health monitoring (SHM) approaches for civil engineering structures. In this paper, temperature affected vibration data is evaluated within a stochastic damage detection framework, which relies on a null space based residual. Besides two existing temperature rejection approaches - building a reference state from an averaging method or a piecewise method - a new approach is proposed, using model interpolation. In this approach, a general reference model is obtained from data in the reference state at several known reference temperatures. Then, for a particular tested temperature, a local reference model is derived from the general reference model. Thus, a well fitting reference null space for the formulation of a residual is available when new data is tested for damage detection at an arbitrary temperature. Particular attention is paid to the computation of the residual covariance, taking into account the uncertainty related to the null space matrix estimate. This improves the test performance, contrary to prior methods, for local and global damages, resulting in a higher probability of detection (PoD) for the new interpolation approach compared to previous approaches. 2019 Proceedings of 8th International Operational Modal Analysis Conference International Operational Modal Analysis Conference Copenhagen, Danmark 13.05.2019 15.05.2019 1 11 2019-06-20 OPUS4-48241 Beitrag zu einem Tagungsband Bhuyan, Md Delwar Hossain; Le Touz, N.; Gautier, G.; Döhler, M.; Hille, Falk; Dumoulin, J.; Mevel, L. Load Vector Based Damage Localization with Rejection of the Temperature Effect The Stochastic Dynamic Damage Locating Vector (SDDLV) approach is a vibration-based damage localization method based on both a finite element model of a structure and modal parameters estimated from output-only measurements in the damage and reference states. A statistical version of the Approach takes into account the inherent uncertainty due to noisy measurement data. In this paper, the effect of temperature fluctuations on the performance of the method is analyzed in a model-based approach using a finite element model with temperature dependent parameters. Robust damage localization is carried out by rejecting the temperature influence on the identified modal parameters in the damaged state. The algorithm is illustrated on a simulated structure. 2019 Proceedings of 8th International Operational Modal Analysis Conference International Operational Modal Analysis Conference Copenhagen, Danmark 13.05.2019 15.05.2019 1 10 2019-06-20 OPUS4-48243 Beitrag zu einem Tagungsband Bhuyan, Md Delwar Hossain; Döhler, M.; Lecieux, Y.; Lupi, C.; Thomas, J.; Schoefs, F.; Hille, Falk; Mevel, L. Statistical Subspace-based Damage Localization on Saint-Nazaire Bridge Mock-Up The subject of damage localization is an important issue for Structural Health Monitoring (SHM) particularly in mechanical or civil structures under ambient excitation. In this paper, the statistical subspacebased damage localization method has been applied on a benchmark application, namely a 1/200 scale model of the Saint-Nazaire Bridge, which is a cable-stayed bridge located on the Loire River near the river's mouth. The employed damage localization method combines data-driven features with physical parameter information from a finite element model in statistical tests, avoiding typical ill-conditioning problems of FE model updating. Damage is introduced in the mockup for cable failures on some of the 72 cables. The purpose of the experiment is to assess the capability of damage assessment methods to find a cable failure. 2019 Proceedings of 8th International Operational Modal Analysis Conference International Operational Modal Analysis Conference Copenhagen, Danmark 13.05.2019 15.05.2019 1 9 2019-06-20 OPUS4-48244 Vortrag Viefhues, Eva Subspace-based Damage Detection with Rejection of the Temperature Effect and Uncertainty in the Reference Temperature variation can be a nuisance that perturbs vibration based structural health monitoring (SHM) approaches for civil engineering structures. In this paper, temperature affected vibration data is evaluated within a stochastic damage detection framework, which relies on a null space based residual. Besides two existing temperature rejection approaches - building a reference state from an averaging method or a piecewise method - a new approach is proposed, using model interpolation. In this approach, a General reference model is obtained from data in the reference state at several known reference temperatures. Then, for a particular tested temperature, a local reference model is derived from the general reference model. Thus, a well fitting reference null space for the formulation of a residual is available when new data is tested for damage detection at an arbitrary temperature. Particular attention is paid to the computation of the residual covariance, taking into account the uncertainty related to the null space Matrix estimate. This improves the test performance, contrary to prior methods, for local and global damages, resulting in a higher probability of detection (PoD) for the new interpolation approach compared to previous approaches. 2019 International Operational Modal Analysis Conference Copenhagen, Danmark 13.05.2019 15.05.2019 2019-06-20 OPUS4-50195 Vortrag Viefhues, Eva Subspace-based damage detection handling temperature effects and uncertainty in the reference Temperature variation can be a nuisance that perturbs vibration based structural health monitoring (SHM)approaches for civil engineering structures. In this paper, temperature affected vibration data is evaluated within a stochastic damage detection framework, which relies on a null space based residual. Besides two existing temperature rejection approaches - building a reference state from an averaging method or a piecewise method - a new approach is proposed, using model interpolation. In this approach, a general reference model is obtained from data in the reference state at several known reference temperatures. Then, for a particular tested temperature, a local reference model is derived from the general reference model. Thus, a well fitting reference null space for the formulation of a residual is available when new data is tested for damage detection at an arbitrary temperature. Particular attention is paid to the computation of the residual covariance, taking into account the uncertainty related to the null space matrix estimate. This improves the test performance, contrary to prior methods, for local and global damages, resulting in a higher probability of detection (PoD) for the new interpolation approach compared to previous approaches. 2019 Abteilungs-Vortragsseminar Abteilung 7 Bauwerksicherheit Berlin, Germany 28.11.2019 2020-01-13 OPUS4-49162 Vortrag Baeßler, Matthias Stability and large deformations of slender structures supported by soil materials Stabilitätsprobleme und große Deformationen schlanker, vorwiegend stahlbaulicher Strukturen sind in einigen Fällen stark von der Belastung und Stützung der Struktur durch den Baugrund abhängig. Der Vortrag verbindet Forschungsansätze zum Thema. 2019 Colloquium on Geotechnical Engineering KIT Karlsruhe, Germany 26.09.2019 27.09.2019 2019-10-01 OPUS4-49163 Vortrag Baeßler, Matthias Impact of environmental based effects on SHM strategies Anwendungen der Bauwerksüberwachung werden häufig stark von jahreszeitlichen Einflüssen wie Temperaturbeanspruchungen beeinflusst. Der Beitrag diskutiert Probleme und Lösungen zum Umgang mit diesen Einflüssen. 2019 SEMC 2019 Cape Town, South Africa 02.09.2019 04.09.2019 2019-10-01 OPUS4-49167 Beitrag zu einem Tagungsband Baeßler, Matthias; Bhuyan, Delwar; Hille, Falk; Viefhues, Eva; Döhler, M.; Mevel, L. Zingoni, Alphose Impact of environmental based effects on SHM strategies Environmental based perturbations influence significantly the ability to identify structural dam-age in Structural Health Monitoring. Strategies are needed to classify such effects and consider them appropri-ately in SHM. It has to be considered if seasonal effects just mask the structural response or if temperature itself correlates to a weakening of the structure. Various methods have been developed and analyzed to separate environmental based effects from damage induced changes in the measures. Generally, two main approaches have emerged from research activity in this fields: (a) statistics-based tools analyzing patterns in the data or in computed parameters and (b) methods, utilizing the structural model of the bridge considering environmental as well as damage-based changes of stiffness values. With the background of increasing affordability of sensing and computing technology, effort should be made to increase sensitivity, reliability and robustness of proce-dures, separating environmental from damage caused changes in SHM measures. The contribution describes an attempt to evaluate both general strategies, their advantages and drawbacks. In addition, two vibration moni-toring procedures are introduced, allowing for temperature-based perturbations of the monitoring data. Boca Raton CRC Press Department of Civil Engineering, University of Cape Town 2019 Advances in Engineering Materials, Structures and Systems: Innovations, Mechanics and Applications 978-1-138-38696-9 SEMC 2019 Cape Town, South Africa 02.09.2019 04.09.2019 Paper 324, 1 Paper 324, 6 10.1201/9780429426506 2019-10-01 OPUS4-49203 Vortrag Herrmann, Ralf Introduction and Current Research in Wind Energy The EERA Wind is a Joint Program for coordination of research in wind energy. In the subprogram SP7 "Structures, materials and components" BAM introduces its current research topics in the field of on- and offshore wind energy and structural health monitoring. 2019 EERA Joint Program Wind: SP7 WORKSHOP on Structures, Materials and Components Amsterdam, Niederlande 24.09.2019 27.09.2019 2019-10-07 OPUS4-49204 Beitrag zu einem Tagungsband Herrmann, Ralf; Moortgat-Pick, A.; Marx, S. Helmerich, Rosemarie; Ilki, A.; Motavalli, M. Vibration Analysis of Structures using a Drone (UAV) based Mobile Sensing Platform The identification of the dynamic behavior of structures, like bridges and towers, is relevant to address multiple issues. In many cases the dynamic parameters should be acquired only once or at a frequency that doesn't justify the installation of distinct vibration sensors for a long-term monitoring. To identify modal frequencies of a structure, a drone based mobile sensing platform has been implemented. This sensing platform measures the relative displacement be-tween the structure and the drone, which also shows a strong dynamic behavior under wind tur-bulences. By regarding the dynamic model of the drone and additional measurements at the dis-tance sensor the absolute movement of the structure can be estimated based on the measured relative distance. This time domain data is a suitable input for various operational modal analysis algorithms. The system has been used to identify the dynamic properties of test and real structure, like a 1.5 MW wind turbine tower. German Society for Non-Destructive Testing (DGZfP e.V.) 2019 Proceedings of the 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) 978-3-947971-07-7 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) Potsdam, Germany 27.08.2019 29.08.2019 We.4.C.3 8 urn:nbn:de:kobv:b43-492045 https://creativecommons.org/licenses/by-nd/4.0/deed.de 2019-10-07 OPUS4-49205 Vortrag Herrmann, Ralf Vibration Analysis of Structures using a Drone (UAV) based Mobile Sensing Platform The identification of the dynamic behavior of structures, like bridges and towers, is relevant to address multiple issues. In many cases the dynamic parameters should be acquired only once or at a frequency that doesn't justify the installation of distinct vibration sensors for a long-term monitoring. To identify modal frequencies of a structure, a drone based mobile sensing platform has been implemented. This sensing platform measures the relative displacement be-tween the structure and the drone, which also shows a strong dynamic behavior under wind tur-bulences. By regarding the dynamic model of the drone and additional measurements at the dis-tance sensor the absolute movement of the structure can be estimated based on the measured relative distance. This time domain data is a suitable input for various operational modal analysis algorithms. The system has been used to identify the dynamic properties of test and real structure, like a 1.5 MW wind turbine tower. 2019 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) Potsdam, Germany 27.08.2019 29.08.2019 2019-10-07 OPUS4-49311 Vortrag Cuéllar, Pablo Erosion and soil mechanics for civil constructions. Applications and opportunities of micromechanical modelling This presentation provides an overview on general issues related to erosive failures in civil constructions like hydraulic infrastructures and offshore foundations. A brief introduction to the related research activities of BAM in the field of offshore wind energy is first provided, and the general possibilities for micromechanical modelling approaches are outlined. Finally, the ongoing DFG-ANR research project COMET is introduced. 2019 Vortrag am Lehrstuhl "System simulation" an der FAU Friedrich–Alexander University, Erlangen, Germany 16.10.2019 2019-10-24 OPUS4-49265 Vortrag Simon, Patrick Structural Health Monitoring (SHM) unter Temperatureinflüssen Beim Structural Health Monitoring (SMH) besteht eine der Hauptsächlichen Störgrößen im Einfluss der Umgebungsbedingungen, insbesondere der Temperatur. Es wird ein Einblick in die Problemstellung gegeben sowie Lösungsansätze diskutiert und aktuelle Forschung an der BAM vorgestellt. 2019 Internes Arbeitskolloquium TU Berlin Berlin, Germany 11.10.2019 2019-10-16 OPUS4-49540 Vortrag Nerger, Deborah Improved tomographic investigation for impact damage characterization Reinforced concrete (RC) is used as structural material in most diverse civil engineering applications. For the variability of its physical properties it is still an engineering challenge to meet all necessary requirements for the prediction of dynamic effects under impact loading. In this paper, investigations are shown within the scope of quantifying and evaluating the damage caused by an impact. The experimental investigations are performed in the field of low- and medium-velocity impact. The chosen flat nose shape results in small penetrations on the top side and scabbing on the bottom side. The plate is scanned with an adapted planar tomographic examination after the impact, and the damage is analysed, afterwards. Cracks and spalling are made visible with a reconstruction. The numerical model validated on the tomographic results justifies the application for further predictions of the damage description. 2019 25th International Conference on Structural Mechanics in Reactor Technology - SMIRT25 Charlotte, NC, USA 04.08.2019 09.08.2019 2019-11-18 OPUS4-49541 Beitrag zu einem Tagungsband Nerger, Deborah; Hille, Falk; Moosavi, Robabeh; Grunwald, Marcel; Redmer, Bernhard; Kühn, T.; Hering, M.; Bracklow, F. Improved tomographic investigation for impact damage characterization Reinforced concrete (RC) is used as structural material in most diverse civil engineering applications. For the variability of its physical properties it is still an engineering challenge to meet all necessary requirements for the prediction of dynamic effects under impact loading. In this paper, investigations are shown within the scope of quantifying and evaluating the damage caused by an impact. The experimental investigations are performed in the field of low- and medium-velocity impact. The chosen flat nose shape results in small penetrations on the top side and scabbing on the bottom side. The plate is scanned with an adapted planar tomographic examination after the impact, and the damage is analysed, afterwards. Cracks and spalling are made visible with a reconstruction. The numerical model validated on the tomographic results justifies the application for further predictions of the damage description. IASMIRT 2019 Proceedings of the International conference on structural mechanics in reactor technology 25th International Conference on Structural Mechanics in Reactor Technology - SMIRT25 Charlotte, NC, USA 04.08.2019 09.08.2019 Paper Div 5 S8, 1 9 2019-11-18 OPUS4-49542 Posterpräsentation Nerger, Deborah Post-impact evaluation at RC plates with planar tomography and FEM The aim of the work is to develop experimental investigation strategies to determine damage quantities and the liquid Intrusion behaviour of containment structures in case of aircraft collision. 2019 36th Danubia Adria Symposium on Advances in Experimental Mechanics Pilsen, Czech Republik 24.09.2019 27.09.2019 2019-11-18 OPUS4-48712 Zeitschriftenartikel Shamsuddoha, Md; Hüsken, Götz; Schmidt, Wolfram; Kühne, Hans-Carsten; Baeßler, Matthias Long-term mechanical and shrinkage properties of cementitious grouts for structural repair Grouts have numerous applications in construction industry such as joint sealing, structural repair, and connections in precast elements. They are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23oC and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively. 4 avenue du Recteur Poincaré, 75016 Paris, France RILEM Publications SARL 2019 RILEM Technical Letters 4 International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) Rovinj, Croatia 20.03.2019 22.03.2019 9 15 10.21809/rilemtechlett.2019.82 2019-08-19 OPUS4-48796 Beitrag zu einem Tagungsband Hüsken, Götz; Shamsuddoha, Md; Thiele, Marc; Baeßler, Matthias; Kühne, Hans-Carsten Comparison of cracks formed in scaled grouted connection of offshore energy structures under static and cyclic loads Global energy consumption will increase in the future necessitating both fossil fuels and renewable energy choices - especially wind energy. Such high energy demand requires installation of offshore energy structures, rigs, platforms and towers, which are susceptible to adverse environmental conditions along with maintenances. Due to their large size and remote locations, cylindrical grouted joints are often adopted between substructure and foundation in these offshore platforms and wind structures such as monopiles. However, these connections are composite structures with exterior sleeve, interior pile and infill mortar. Degradation and settlements were reported inside similar connections, which were installed in last three decades. Besides, grouting in the offshore sites were proven difficult to obtain ideal load bearing capacity. In-situ loading conditions were also found to be affecting the failure mechanism inside such connections. This study aims at characterizing the nature of cracks generated in these grouted connections under both static and cyclic loading. Scaled grouted joints were manufactured using a novel reusable mold, and connections were loaded to failure to visualize the main failure patterns. An assessment between failure under these two types of load is drawn along with comparison to previously available literature. 2019 Proceedings of SMAR 2019 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Potsdam, Germany 27.08.2019 29.08.2019 Th.2.A.1-1 Th.2.A.1-9 urn:nbn:de:kobv:b43-487961 https://creativecommons.org/licenses/by/4.0/deed.de 2019-09-02 OPUS4-48797 Vortrag Hüsken, Götz Comparison of cracks formed in scaled grouted connection of offshore energy structures under static and cyclic loads Global energy consumption will increase in the future necessitating both fossil fuels and renewable energy choices - especially wind energy. Such high energy demand requires installation of offshore energy structures, rigs, platforms and towers, which are susceptible to adverse environmental conditions along with maintenances. Due to their large size and remote locations, cylindrical grouted joints are often adopted between substructure and foundation in these offshore platforms and wind structures such as monopiles. However, these connections are composite structures with exterior sleeve, interior pile and infill mortar. Degradation and settlements were reported inside similar connections, which were installed in last three decades. Besides, grouting in the offshore sites were proven difficult to obtain ideal load bearing capacity. In-situ loading conditions were also found to be affecting the failure mechanism inside such connections. This study aims at characterizing the nature of cracks generated in these grouted connections under both static and cyclic loading. Scaled grouted joints were manufactured using a novel reusable mold, and connections were loaded to failure to visualize the main failure patterns. An assessment between failure under these two types of load is drawn along with comparison to previously available literature. 2019 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Potsdam, Germany 27.08.2019 29.08.2019 2019-09-02 OPUS4-48432 Buchkapitel Auersch, Lutz Krylov, Victor Fast trains and isolating tracks on inhomogeneous soils Methods have been presented for detailed studies of railway vibration and for the fast prediction of train-induced ground vibration. The ground vibration is generated by static or dynamic loads. The main purpose of this contribution was to show the influence of inhomogeneous soils on the different vibration components. Layered soils, namely a soft layer on a stiffer half-space, yield a quite specific transmission behavior. The low-frequency and sometimes also high-frequency cut-off of the transfer function of the soil is demonstrated in theory and by experiments at many sites of which the soil model is approximated from dispersion and transfer function measurements. The layer frequency divides the frequency range in a low-frequency range, where the stiff half-space rules the low amplitudes, and a high amplitude high-frequency range which is mainly determined by the softer top layer. A thick soft layer yields a very low layer frequency, so that the higher soft soil amplitudes have a wider range down to low frequencies. A thin layer yields a high layer frequency, so that the high frequencies above this layer frequency are dominant. The higher the contrast between the stiff half-space and the soft layer is, the stronger the increase between the half-space and layer amplitudes, the more characteristic are the spectra of the soil transfer function. The range of measured soils has been from vS1 down to 125 m/s, vS2 up to 1000 m/s and the layer frequencies are within 10 Hz < f0 < 75 Hz. Moreover, during this measuring campaign in Switzerland, all 11 sites showed clearly the layer-on-half-space behaviour. The transfer functions of inhomogeneous soils have been used to predict the ground vibration due to dynamic axle loads which is usually thought to be the most important component. The passage of static loads, in the contrary, results in very small vibration amplitudes for low train speeds, which can only be found at near distances and at low frequencies. They attenuate very rapidly with distance and lose very rapidly the higher frequency content. The passage of static axle loads can be included in the prediction of railway vibration just for completeness. Special attention should be given to the case if the train runs with the Rayleigh-wave speed of the soil (Rayleigh train). The Rayleigh-train effect is strongest for a homogeneous half-space: At the near-field of the track the amplitudes are raised strongly compared to normal trains, and in addition, little attenuation with distance is observed. In case of a layered soil, the low-frequency cut-off reduces the frequency range and the amplitudes of the homogeneous quasi-static ground vibrations. Therefore, the Rayleigh-train effects are clearly reduced by a layered soil and they disappear if the layer frequency (for example for a thin layer) is higher than the frequency band of the axle impulse. The Rayleigh-train effect could completely disappear in a randomly inhomogeneous soil, but this has not been analysed so far. The axle impulses from static loads can have an additional, quite different effect. They can be scattered by a randomly inhomogeneous soil so that a part (the scattered part) of the axle impulse can reach further distances from the track. This can establish a certain mid-frequency component of the ground vibration which becomes dominant in the far-field, and this important component exists for all train speeds. Experimental results from BAM and international measurements show the importance of the corresponding frequency range. The mitigation of train induced ground vibration by elastic and stiff track elements has been analysed threefold. The vehicle-track interaction yields the reduction at high frequencies above the vehicle-track resonance. This is the standard effect. The filtering of trackbed errors by the bending stiffness of the track yields a certain mid-frequency effect. An even stronger mid-frequency effect is predicted for the mitigation of the scattered axle impulses by the bending stiffness and elastic elements of the track. 1 London ICE Publishing 2019 Ground vibrations from high-speed railways 978-0-7277-6379-2 Chapter 2, 27 75 10.1680/gvfhsr.63792.027 2019-07-11 OPUS4-48843 Zeitschriftenartikel Bhuyan, Md Delwar Hossain; Gautier, G.; Le Touz, N.; Döhler, M.; Hille, Falk; Dumoulin, J.; Mevel, L. Vibration-based damage localization with load vectors under temperature changes Damage detection and localization in civil or mechanical structures is a subject of active development and research. A few vibration-based methods have been developed so far, requiring, for example, modal parameter estimates in the reference and damaged states of the investigated structure, and for localization in addition a finite element model. For structures in operation, temperature has been shown to be a major nuisance to the efficiency of such methods because the modal parameters are varying not only with damage but also due to temperature variations. For detection, a few rejection approaches have been developed. Besides the increased complexity, environmental variation is hardly taken into account in localization approaches. In this paper, we propose a sensitivity-based correction of the identified modal parameters in the damaged state with respect to the temperature field in the reference state, on the basis of a sensitivity analysis with respect to temperature dependent Parameters of the finite element model in the reference state. The approach is then applied to the stochastic dynamic damage locating vector method, where its improved performance under nonuniform temperature variations is shown in a numerical application on a beam. John Wiley & Sons, Ltd. 2019 Structural Control and Health Monitoring e2439, 1 16 10.1002/stc.2439 2019-09-04 OPUS4-48873 Vortrag Cuéllar, Pablo Wind energy challenges. An offshore perspective and some possible solutions This talk provides a brief introduction on general engineering challenges for the offshore (marine) wind energy production, focusing on material, structural and hydromechanical aspects. The talk begins with a broad overview on general trends for offshore wind-farms, with insights on some characteristic structural features and their associated loads. Then, some particular open issues for the foundation of the offshore wind turbines into the seabed are introduced. Here, different research approaches are discussed, from experimental investigations to coupled computational analysis at micro- and macroscopic scales. In the second part of the seminar, both the hydromechanical Wave-Tower interaction and some general aspects of the windfarm aerodynamics (wake analysis) are discussed. Some modelling possibilities in the frame of CFD (computational fluid dynamics) are introduced and the relevance of such analyses for a proper windfarm layout optimization is pointed out. Summing up, this seminar aims to show that: i) Numerical analysis of the turbine's interaction with wind/waves and with the seabed is both useful and affordable. ii) Simplified models can provide an insight into windfarm aerodynamics. iii) Turbulent wake analysis is very relevant for the windfarm layout. 2019 Bad Honnef Physics School „Energy Science – an interdisciplinary challenge“ Physikzentrum Bad Honnef, Bad Honnef, Germany 01.09.2019 06.09.2019 2019-09-09 OPUS4-48866 Vortrag Auersch, Lutz Wellenmessungen zur Identifikation der dynamischen Eigenschaften von Böden Erschütterungen durch Industrie und Verkehr, Schwingungen von Gebäuden, Fundamenten und Gleisen hängen im hohen Maße vom jeweiligen unterliegenden Boden ab. Die Eigenschaften des Bodens ermitteln wir mit Wellenmessungen vor Ort. Die Wellen werden in der Regel mit einem Impulshammer erzeugt und mit Geophonen als Schwinggeschwindigkeits-signale gemessen. Geophone sind aktive Sensoren, die eine kleine Messspannung liefern. Ein 72-kanaliges Messsystem mit entsprechenden Messverstärkern ist im Messwagen der Arbeitsgruppe eingebaut. Es werden im Vortrag fünf verschiedene Auswertemethoden vorgestellt. Im einfachsten Fall versucht man die Laufzeit von einem Geophon zum andern auszumessen und damit die vorherrschende Wellengeschwindigkeit zu ermitteln. Wir haben Wellengeschwindigkeiten von 30 m/s für Moorboden bis 1000 m/s für Felsboden gemessen. Der Boden hat aber nicht nur eine Wellengeschwindigkeit, sondern mehrere frequenzabhängige Wellen-geschwindigkeiten. Dadurch wird aus einem kurzen Hammerschlag eine längere Schwingung (Zerstreuung, Dispersion). Für die Auswertung von dispersiven Wellen nutzt man die spektrale Analyse, zunächst mit zwei Aufnehmern (SASW Spectral Analysis of Surface Waves), später mit einer ganzen Messachse (Multi-Station SASW). Schließlich kann man eine ganze Messachse auch mit verschiedenen Transformationsmethoden auswerten wie die f,v-Methode und Spatial AutoCorrelation SPAC Methode. Alle diese Methoden wurden von uns auf Messreisen in Deutschland, Österreich und der Schweiz getestet. Durch die Approximation der frequenzabhängigen Wellengeschwindigkeiten erhält man ein passendes Bodenmodell. Zu diesem Bodenmodell kann man die Übertra¬gungsfunktionen für Hammer- und Zuganregung berechnen. Bei etlichen Mess¬orten wurden deutliche Merkmale einer Bodenschichtung beobachtet. Es ergibt sich eine Reduktion der tiefen Frequenzanteile durch den steifen unterliegenden Halbraum. Die weiche Deckschicht bestimmt das hochfrequente Verhalten. 2019 Vortragsseminar der BAM-Abteilung 7 Bauwerkssicherheit Berlin, Germany 27.8.2019 27.8.2019 2019-09-05 OPUS4-48909 Beitrag zu einem Tagungsband Kullolli, Borana; Cuéllar, Pablo; Baeßler, Matthias; Stutz, H. H. Modelling and calibration for cyclic soil-structure interface behaviour 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. Glasgow, Scotland EDP Sciences 2019 92 Konferenz 7th International Symposium on Deformation Characteristics of Geomaterials Glasgow, Scotland 26.06.2019 28.06.2019 13007 13013 urn:nbn:de:kobv:b43-489096 10.1051/e3sconf/20199213007 https://creativecommons.org/licenses/by/4.0/deed.de 2019-09-11 OPUS4-48829 Beitrag zu einem Tagungsband Schneider, Ronald Effect of repair models on risk based optimal inspection strategies for support structures of offshore wind turbines 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. 2019 Proceedings of the 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) Potsdam, Germany 27.08.2019 29.08.2019 Paper Th.2.A.4, 1 8 urn:nbn:de:kobv:b43-488297 https://creativecommons.org/licenses/by/4.0/deed.de 2019-09-03 OPUS4-48830 Vortrag Schneider, Ronald Effect of repair models on risk based optimal inspection strategies for support structures of offshore wind turbines 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. 2019 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) Potsdam, Germany 27.08.2019 29.08.2019 2019-09-03 OPUS4-48943 Beitrag zu einem Tagungsband Thiele, Marc; Hille, Falk; Makris, Ruben Helmerich, Rosemarie; Ilki, A.; Motavalli, M. Comparison of fatigue crack detection methods for high-cyclic loaded steel structures At present, to produce renewable energy offshore wind farms play an important role. The available space combined with the more valuable wind conditions make offshore locations very attractive for wind powered energy production. In Europe a significant number of offshore wind farms already exist, especially in the North and Baltic Sea. In future this trend will continue, and further offshore wind farms will be built. The majority of offshore wind turbines are mounted on steel foundation structures. Due to the high-cyclic loading by wind and waves fatigue stress plays a substantial role regarding structural safety. Besides the consideration of fatigue within the design process, to monitor existing steel structures for potential fatigue cracks during their life time is a major topic and a challenge. For the structures of the offshore wind turbines are large and partially under water effective reliable methods for the detection of fatigue cracks are required. This contribution presents investigations on different crack detection methods applied at high-cycle fatigue tests on small-scale welded steel samples as well as on large-scale welded steel components. The tests were conducted at the BAM laboratories. For crack detection mainly three different methods were used and compared. The first method regards to the measurement of strain by conventionally strain gauges. Secondly, the crack luminescence was used as a new and effective optical method for surface monitoring. And finally, crack detection by pressure differentials of the inner and outer section of tubular steel elements was investigated. A comparison study will emphasize the advantages and disadvantages of the different methods and show which of the described methods is potentially more suitable for an application on real offshore wind structures. 2019 Proceedings of SMAR 2019 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Potsdam, Germany 27.08.2019 29.08.2019 Th.2.A.1-1 Th.2.A.1-8 urn:nbn:de:kobv:b43-489433 https://creativecommons.org/licenses/by/4.0/deed.de 2019-09-16 OPUS4-48944 Vortrag Thiele, Marc Comparison of fatigue crack detection methods for high-cyclic loaded steel structures At present, to produce renewable energy offshore wind farms play an important role. The available space combined with the more valuable wind conditions make offshore locations very attractive for wind powered energy production. In Europe a significant number of offshore wind farms already exist, especially in the North and Baltic Sea. In future this trend will continue, and further offshore wind farms will be built. The majority of offshore wind turbines are mounted on steel foundation structures. Due to the high-cyclic loading by wind and waves fatigue stress plays a substantial role regarding structural safety. Besides the consideration of fatigue within the design process, to monitor existing steel structures for potential fatigue cracks during their life time is a major topic and a challenge. For the structures of the offshore wind turbines are large and partially under water effective reliable methods for the detection of fatigue cracks are required. This contribution presents investigations on different crack detection methods applied at high-cycle fatigue tests on small-scale welded steel samples as well as on large-scale welded steel components. The tests were conducted at the BAM laboratories. For crack detection mainly three different methods were used and compared. The first method regards to the measurement of strain by conventionally strain gauges. Secondly, the crack luminescence was used as a new and effective optical method for surface monitoring. And finally, crack detection by pressure differentials of the inner and outer section of tubular steel elements was investigated. A comparison study will emphasize the advantages and disadvantages of the different methods and show which of the described methods is potentially more suitable for an application on real offshore wind structures. 2019 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures Potsdam, Germany 27.08.2019 29.08.2019 2019-09-16 OPUS4-48945 Vortrag Thiele, Marc Fatigue in Concrete The current knowledge about fatigue behavior of concrete is still incomplete. This concerns especially the progress of fatigue which precedes the fatigue failure. An overview on the fatigue behaviour in concrete is given. Therefore, the process of fatigue itself under cyclic compressive loading was investigated in a systematic and comprehensive way. The aim of this investigation was to obtain a deeper insight and to provide a better understanding of the damage process occurring within the material during fatigue loading. 2019 1st Infrastar Training School IFSTTAR, Nantes, France 08.04.2019 12.04.2019 2019-09-16 OPUS4-48670 Zeitschriftenartikel Auersch, Lutz Vehicle-track-soil interaction and train-induced ground vibration - Theory and measurements in Germany, Switzerland and France 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. IOP Publishing Ltd 2019 Journal of Physics: Conference Series 1264 Artikel 012034-1 12 urn:nbn:de:kobv:b43-486702 10.1088/1742-6596/1264/1/012034 https://creativecommons.org/licenses/by/4.0/deed.de 2019-08-12 OPUS4-48588 Vortrag Cuéllar, Pablo A GPU-based micromechanical simulation model for submerged geotechnical problems Driven steel piles are commonly used as deep foundations for a wide range of engineering structures, particularly in the offshore branch. They are also an interesting example among the broad spectrum of geotechnical applications where the fluid-solid interaction at the pore-scale can play a major role for the macromechanical behaviour of the whole system. In the context of the geotechnical practice for offshore wind-farm structures, both the industrial design and the actual dimensions of the large piles used as foundations in the seabed are often driven by factors such as the soil resistance to driving (SRD), which are still not well understood and often estimated based on mere empirical correlations or overly simplified one-dimensional models. In particular, the role of the micromechanical effects during the installation process (e.g. local dilatancy or contractancy) and their consequences on the pore pressure levels at the pile-tip and on the effective resistance to driving, are generally either disregarded or at most assumed to be covered by the simplified engineering "black-box" solutions. Here, we propose a general framework to address such local aspects of a geotechnical application involving fluid-saturated soils while retaining the focus on the micro-scale phenomena. We advocate for an approach that combines the relative simplicity of the Discrete Element Method (DEM) for the solid mechanics with the capabilities of the Lattice Boltzmann Method (LBM) for the fluid dynamics. In this sense, we aim to compile some useful techniques and practical recommendations for an efficient GPU-based implementation of a micromechanical LBM-DEM simulation tool. 2019 DEM8, the 8th International Conference on Discrete Element Methods University Twente, Enschede, The Netherlands 20.07.2019 26.07.2019 2019-08-01 OPUS4-48089 Vortrag Auersch, Lutz Zur Wirksamkeit und Berechenbarkeit von elastischen Gebäudelagerungen Es wird die Vorgehensweise erläutert wie die Notwendigkeit einer elastischen Gebäudelagerung geprüft wird. Es werden die Möglichkeiten und Schwächen vereinfachter Rechenverfahren dargestellt. Es folgen weitere Beispiele detaillierter Gebäudemodelle und ihres Schwingungsverhaltens. Schließlich greift eine aktuelle Bachelorarbeit die Fragestellung komplexen Gebäudeschwingungsverhaltens auf. Die letzte Folie zeigt dazu Gebäudemodelle, die an die konkreten Erschütterungsprognosen anknüpfen. 2019 Elastische Gebäudelagerungen Berlin, Germany 23.5.2019 23.5.2019 2019-05-29 OPUS4-48504 Vortrag Geißler, Peter Compaction grouting to improve the pile bearing capacity in non-cohesive soil The increasing use of renewable energies leads to a constant search for optimised foundation concepts aiming to reduce the costs for offshore wind turbines. In an ongoing research project, we are developing a design approach for typical offshore driven piles based on the application of injections by compaction grouting directly at the pile shaft. Compaction grouting as a ground improvement technique has been used widely as a countermeasure against liquefaction, settlement and low bearing capacity of soil under new or already existing structures. It is performed by forcing highly viscous grout into the soil to displace and compact the surrounding soil without fracturing or penetrating it. Regarding this injection method, this paper gives a brief overview about general aspects such as appropriate soil characteristics and grouting parameters, grouting equipment and fields of application particularly in the offshore sector. This indicates the ability of our optimisation concept to provide an economic alternative to larger pile dimensions and a retrofitting technique, which is available during the entire lifetime of the foundation and can be deployed only in case of necessity (e.g. excessive deformations or insufficient structural stiffness after an extreme load event). Besides the material feasibility and the constructive realisation of this improvement measure, the development of a corresponding verification concept is crucial in order to ensure the safety and durability of the retrofitted offshore piles. Here we will examine various verification concepts with their respective limitations in the framework of the limit state design. Furthermore, we will present the experimental findings from field tests in sand indicating the advantages of several local injections by compaction grouting for the enhancement of the load bearing behaviour of pile foundations. The test results were also used to validate a numerical model, developed with the finite element program PLAXIS, aiming to predict the expected bearing capacity for different injection scenarios (e.g. grout volume, location of injection points) along a pile shaft. 2019 Twenty-ninth International Ocean and Polar Engineering Conference Honolulu, HI, USA 16.06.2019 21.06.2019 2019-07-22 OPUS4-48505 Beitrag zu einem Tagungsband Geißler, Peter; Schwarz, Johannes; Cuéllar, Pablo; Hüsken, Götz; Baeßler, Matthias; Kühne, Hans-Carsten; Morrone, C. Compaction grouting to improve the pile bearing capacity in non-cohesive soil The aim of an ongoing research project is to develop a design approach for typical offshore driven piles (e.g. Jacket piles) based on the application of injections by compaction grouting directly at the pile shaft. The paper aims to present the results of laboratory and in-situ tests, which reveal the efficiency and the promising potential of the optimised foundation concept for a more economic dimensioning of pile foundations and to increase their bearing capacity in non-cohesive soil at any moment after installation. Cupertino, California, USA International Society of Offshore and Polar Engineers (ISOPE) 2019 Proceedings of the Twenty-ninth (2019) International Ocean and Polar Engineering Conference II 978-1-880653-85-2 Twenty-ninth International Ocean and Polar Engineering Conference Honolulu, HI, USA 16.06.2019 21.06.2019 2178 2184 2019-07-22 OPUS4-48495 Vortrag Said, Samir; Auersch, Lutz Measurement of slab track behaviour at different sites 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. 2019 26th International Congress on Sound and Vibration (ICSV26) Montreal, Canada 07.07.2019 11.07.2019 2019-07-18 OPUS4-48498 Beitrag zu einem Tagungsband Auersch, Lutz; Said, Samir Measurement of slab track behaviour at different sites 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. Montreal, Kanad Canadian Acoustical Association 2019 Proceedings of the 26th International Congress on Sound and Vibration 978-1-9991810-0-0 26th International Congress on Sound and Vibration (ICSV26) Montreal, Canada 07.07.2019 11.07.2019 T15RS01_316_1 T15RS01_316_8 2019-07-18 OPUS4-48444 Beitrag zu einem Tagungsband Kullolli, Borana; Baeßler, Matthias; Cuéllar, Pablo; Rica, S.; Rackwitz, F. An enhanced interface model for friction fatigue problems of axially loaded piles 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. Glasgow, Scotland ASME 2019 OMAE 2019 2019 Conference: OMAE Glasgow, Scotland, UK 09.06.2019 14.06.2019 Article Number: UNSP V001T10A013 2019-07-15 OPUS4-48445 Vortrag Kullolli, Borana An enhanced interface model for friction fatigue problems of axially loaded piles 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. 2019 Konferenz Glasgow, Scotland, UK 09.06.2019 14.06.2019 2019-07-15 OPUS4-48446 Vortrag Kullolli, Borana Modelling and calibration for cyclic soil-structure interface behavior 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. 2019 Konferenz :International Symposium of Geomaterials Glasgow, Scotland, UK 26.06.2019 28.06.2019 2019-07-15 OPUS4-48423 Beitrag zu einem Tagungsband Auersch, Lutz Ruspighi, Emiliano Vehicle-track-soil interaction and train-induced ground vibration: Theory and measurements in Germany, Switzerland and France 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. Southampton University of Southampton ISVR 2019 Proceedings of the 13th International Conference on recent Advances in Structural Dynamics (RASD2019) 13th International Conference on recent Advances in Structural Dynamics Lyon, France 15.4.2019 17.4.2019 810 821 2019-07-10 OPUS4-49440 Beitrag zu einem Tagungsband Auersch, Lutz Lombaert, G.; Degrande, G. Predicted and measured amplitude-speed relations of railway ground vibrations at four German sites with different test trains 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. Leuven KU Leuven 2019 Proc. of the 13th International Workshop on Railway Noise and Vibration 13th International Workshop on Railway Noise and Vibration Leuven, Belgium 16.09.2019 20.09.2019 1 8 2019-10-31 OPUS4-49441 Beitrag zu einem Tagungsband Auersch, Lutz Adam, C. Bahnerschütterungen bei verschiedenen Böden und Zuggeschwindigkeiten - Messungen in Deutschland, Österreich und der Schweiz 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. Innsbruck Universität Innsbruck 2019 Tagungsband der 16. D-A-CH Tagung Erdbebeningenieurwesen & Baudynamik (D-A-CH 2019) 16. D-A-CH Tagung Erdbebeningenieurwesen & Baudynamik (D-A-CH 2019) Innsbruck, Austria 26.09.2019 27.09.2019 1 8 2019-10-31 OPUS4-49444 Vortrag Auersch, Lutz Predicted and measured amplitude-speed relations of railway ground vibrations at four German sites with different test trains 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. 2019 13th International Workshop on Railway Noise and Vibration Leuven, Belgium 16.09.2019 20.09.2019 2019-10-31 OPUS4-49445 Vortrag Auersch, Lutz Bahnerschütterungen bei verschiedenen Böden und Zuggeschwindigkeiten - Messungen in Deutschland, Österreich und der Schweiz 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. 2019 16. D-A-CH Tagung Erdbebeningenieurwesen & Baudynamik (D-A-CH 2019) Innsbruck, Austria 26.09.2019 27.09.2019 2019-10-31 OPUS4-49446 Vortrag Auersch, Lutz Four typical errors in train induced ground vibration and ground vibration mitigation Mitigation measures of railway induced vibration have been demonstrated at the emission, transmission and immission part. It must be carefully observed that the correct masses and stiffnesses are used. Typical mistakes have been shown, - 1D models for vehicle-track interaction, - impedance instead of stiffness for the infill material of a trench, - rigid buildings or neglecting the soil-building interaction. The dominant mid-frequency part of the ground vibration is due to the irregular soil. 2019 ISO/TC 108/SC 2/WG 8 Working group Ground-borne noise and vibration from rail systems Milano, Italy 14.10.2019 15.10.2019 2019-10-31 OPUS4-49448 Vortrag Auersch, Lutz Berechnung und Beeinflussung von Deckeneigenfrequenzen Es werden Erfahrungen zur Berechnung von Deckeneigenfrequenzen aus zahlreichen Projekten zusammengetragen. 2019 Projektbesprechung zum Hotelneubau Berlin, Germany 10.07.2019 10.07.2019 2019-10-31 OPUS4-49500 Beitrag zu einem Tagungsband Frei, Vivian; Thiele, Marc; Pirskawetz, Stephan; Meng, Birgit; Rogge, Andreas Characterizing the Fatigue Behavior of High-Performance Concrete for Wind Energy Structures 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. Magnel Laboratory for Concrete Research 2019 Proceedings LORCENIS - Durable Concrete for Infrastructure under Severe Conditions Smart Admixtures, Self-responsiveness and Nano-additions 978-9-463-88638-3 LORCENIS - Long Lasting Reinforced Concrete fpr Energy Infrastructure under Severe Operating Conditions Ghent, Belgium 10.09.2019 11.09.2019 1 4 2019-11-06 OPUS4-49639 Beitrag zu einem Tagungsband Rica, S.; Van Baars, S.; Kullolli, Borana Ülgen, D.; Saygili, A.; Kahyaoglu, M. R.; Durmaz, S.; Toygar, O.; Göcügenci, A. The importance of the horizontal stresses on the bearing capacity of a foundation pile 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. Bodrum, Turkey 1st Mediterranean Young Geotechnical Engineers Conference Turkish Society for ISSMGE (ZMGM) 2019 2019 1st Mediterranean Young Geotechnical Engineers Conference Bodrum, Turkey 23.09.2019 24.09.2019 151 158 2019-11-21 OPUS4-49474 Vortrag Frei, Vivian Characterizing the Fatigue Behavior of High-Performance Concrete for Wind Energy Structures 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. 2019 LORCENIS - Long Lasting Reinforced Concrete for Energy Infrastructue under Severe Operating Conditions Gent, Belgium 10.09.2019 11.09.2019 2019-11-04 OPUS4-49691 Vortrag Nerger, Deborah Post-impact evaluation at RC plates with planar tomography and FEM Due to the many possible applications, the uncomplicated production and the high application range, reinforced concrete is a widely used building material. This large range of physical material properties still poses an engineering challenge in determining all necessary requirements for predicting dynamic effects under impact load. Many aspects of impact have already been examined and some correlations have been studied intensively. Examples are the work of Lastunen and Booker, who studied the influence of projectile properties on the impact form. Li has also investigated the local effects of an impact. The field of detailed damage analysis has not been in focus so far. This presentation shows some studies in medium-velocity impact with the focus on post-impact damage evaluation. The impactor is modified so that the test plates show low penetration on the top and scabbing on the bottom. With the unique tomography lab test stand at BAM the plate is scanned after the impact and the damage is analyzed. Cracks and scabbing are made visible with a reconstruction. The comparison of simulation and tomography allows to create prognosis models for damage characterization. 2019 36th Danubia Adria Symposium on Advances in Experimental Mechanics Pilsen, Czech Republic 24.09.2019 27.09.2019 2019-11-25 OPUS4-47337 Zeitschriftenartikel Herrmann, Ralf Digitale Methoden und Werkzeuge im BIM Kontext Die BAM Tagung "Messen im Bauwesen" widmete sich beim 10 Auftakt den digitalen Methoden und Werkzeugen im Bauwesen. Berlin Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG 2019 Bautechnik 96 Messen im Bauwesen 2018 Berlin, Germany 13.11.2018 13.11.2018 1 78 78 10.1002/bate.201970105 2019-02-08 OPUS4-46434 Beitrag zu einem Tagungsband Schneider, Ronald; Rogge, Andreas; Thöns, S.; Bismut, E.; Straub, D. Caspeele, Robby; Taerwe, Luc; Frangopol, Dan M. A sampling-based approach to identifying optimal inspection and repair strategies for offshore jacket structures Identifying optimal inspection and repair strategies for offshore jacket structures is a challenging task. We pre-sent an approach, which is based on recent developments in the field of risk-based operation and maintenance planning at the structural system level. The approach utilizes heuristics to define inspection and repair strate-gies at the system level and to reduce the search space of possible strategies. For each defined strategy, the expected service life cost of inspection, repair and failure is evaluated based on simulated inspection and re-pair histories. Subset simulation is applied to compute the conditional repair and failure probabilities required for this analysis. It also forms the basis for simulating inspection and repair histories. The strategy that mini-mizes the expected service life cost is the optimal one in the set of pre-selected strategies. The underlying condition and performance model accounts for the stochastic dependence among the deterioration states of the different structural elements and the structural redundancy. The approach is demonstrated in a case study considering a jacket-type frame. In this study, we essentially vary the inspection interval, the minimum num-ber of inspected components and the target reliability, and identify the combination that minimizes the ex-pected total service life cost. London Taylor & Francis Group 2019 Proceedings of the sixth international symposium on life-cycle civil engineering (IALCCE 2018) 978-1-138-62633-1 The sixth international symposium on life-cycle civil engineering (IALCCE 2018) Ghent, Belgien 28.10.2018 31.10.2018 1081 1088 2018-11-05 OPUS4-47624 Vortrag Cuéllar, Pablo Deep foundations for offshore wind turbines This presentation deals with the phenomenology and design of pile foundations for offshore wind turbines, and is divided into two lectures. The first lecture presents a brief introduction to the context and peculiarities of such foundations, and then focuses on the particular case of axially loaded piles. This part is most relevant for the relatively slender piles of the multi-pile substructures (i.e. jackets and tripods). A clear distinction between physical phenomenology and practical design is drawn here. The second lecture continues with the case of lateraly loaded offshore piles, which bears most relevance for the case of the monopile foundations. Here again, a clear separation between physical reality and design methods is intended. Finally, the last part of the second lecture introduces several advanced topics which lie outside the classical design approaches, namely the hydromechanical coupling effects (i.e. the excess pore-pressure generation around the monopiles), the cyclic pile fatigue and the so-called pile Setup (i.e. the time effects on the axial pile capacity). The relevance of the latter two topics is illustrated with experimental results from a field testing campaign on real large-scale piles. 2019 MASTERS COURSE 2019 CEDEX-UNED: MECÁNICA DEL SUELO E INGENIERÍA GEOTÉCNICA Laboratorio de Geotecnia, CEDEX, Madrid, Spain 25.03.2019 2019-03-26 OPUS4-47625 Vortrag Hüsken, Götz Long-term mechanical and shrinkage properties of cementitious grouts for structural repair Grouts are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23 °C and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively. 2019 International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) Rovinj, Croatia 20.03.2019 22.03.2019 2019-03-27 OPUS4-47702 Vortrag Simon, Patrick Untersuchungsmethoden klimatisch belasteter Bauteile - Projektupdate BAM Kontinuierliche Sensorbasierte Bauwerksmessungen leisten einen wichtigen Beitrag zur Sicherheit von Verkehrsbauwerken. Hierzu werden im Vorhaben AISTEC Referenzbauwerke und Referenzverfahren untersucht mit Schwerpunkt auf den Einfluss klimatischer Bedingungen. Der Vortrag stellt den aktuellen Projektstand des FB 7.2 vor. 2019 Erstes Verbundtreffen AISTEC Weimar, Germany 21.03.2019 21.03.2019 2019-04-02 OPUS4-47511 Zeitschriftenartikel Teng, Jun; Tang, De-Hui; Zhang, Xiao; Hu, Wei-Hua; Said, Samir; Rohrmann, Rolf G. Automated modal analysis for tracking structural change during construction and operation phases The automated modal analysis (AMA) technique has attracted significant interest over the last few years, because it can track variations in modal parameters and has the potential to detect structural changes. In this paper, an improved density-based spatial clustering of applications with noise (DBSCAN) is introduced to clean the abnormal poles in a stabilization diagram. Moreover, the optimal system model order is also discussed to obtain more stable poles. A numerical Simulation and a full-scale experiment of an arch bridge are carried out to validate the effectiveness of the proposed algorithm. Subsequently, the continuous dynamic monitoring system of the bridge and the proposed algorithm are implemented to track the structural changes during the construction phase. Finally, the artificial neural network (ANN) is used to remove the temperature effect on modal frequencies so that a health index can be constructed under operational conditions. Basel, Switzerland MDPI AG 2019 Sensors 19 4 927, 1 23 urn:nbn:de:kobv:b43-475116 10.3390/s19040927 https://creativecommons.org/licenses/by/4.0/deed.de 2019-03-11 OPUS4-47751 Vortrag Baeßler, Matthias; Babutzka, Martin; Trappe, Volker Vorstellung des Aktivitätsfelds Erneuerbare Energie Auf der Beiratssitzung des TF Energie wurde das Aktivitätsfeld Erneuerbare Energien in seinem breiten Spektrum (aber selektive Auswahl) vorgestellt. 2019 Beiratssitzung TF Energie BAM Berlin-Adlershof, Germany 09.04.2019 2019-04-10 OPUS4-47831 Beitrag zu einem Tagungsband Shamsuddoha, Md; Hüsken, Götz; Schmidt, Wolfram; Kühne, Hans-Carsten; Baeßler, Matthias Superplasticizer and Shrinkage Reducing Admixture Dosages for Microfine Cement in Grout Systems Grouts have numerous applications including crack repair as maintenance in construction industries. Microfine cements are intensively used for high strength mortar and grout products. They are ideal for injection grouting in structural repair. Such grouts should have suitable rheological properties to be injectable, especially those used in repair and rehabilitation. The use of superplasticizers (SP) in these products is thus becoming increasingly crucial to achieve favorable workability and viscosity properties. A difficulty in such grouts is the plastic shrinkage due to finer particles used. It is thus necessary to determine optimum SP and shrinkage reducing admixture (SRA) dosages for a microfine cement based grout. In this study, a saturation dosage was decided from two Polycarboxylate ether (PCE) based SPs in relation to neat cement using slump flow and rheological parameters. A range of grout mixtures was formulated containing micro silica (MS) and fly ash (FA), and tested for suitable rheological and mechanical parameters. Based on the results, a grout mixture with MS and FA was selected to determine optimum SRA content. According to the results, a SP dosage of 3% by weight of neat cement is sufficient to achieve saturation. The grout material including MS and FA can produce comparable properties to neat cement grout. MS is found to improve compressive strength within the range considered, whereas a higher FA content provides favourable rheological properties. Finally, a SRA dosage of 4%, which could reduce the shrinkage by about 43% after 28d days, is determined for the grout system. EDP Sciences 2019 MATEC Web of Conferences 278 2nd International Conference on Building Materials and Materials Engineering (ICBMM 2018) University of Lisbon, Portugal 26.09.2018 28.09.2018 Article Number 01001 urn:nbn:de:kobv:b43-478319 10.1051/matecconf/201927801001 https://creativecommons.org/licenses/by/4.0/deed.de 2019-04-17 OPUS4-47891 Zeitschriftenartikel Auersch, Lutz Compliance and damping of piles for wind tower foundation in nonhomogeneous soils by the finite-element boundary-element method A combined finite-element boundary-element method for the dynamic interaction of the soil with flexible structures such as single piles or complete wind energy towers has been developed. Flexible piles in different soils are analysed in frequency domain. The different parameters such as the stiffness of the soil, the bending stiffness and the radius of the hollow pile are analysed for their influence on the complex compliances. The results have been determined as specific power laws which are different for the different load cases (horizontal, rocking, coupling) and for the different soil models (Winkler, continuum with constant, root-parabolic and proportional-linear stiffness variation). The strongest influence of the soil stiffness can be found for the homogeneous soil and the horizontal component. Winkler soils have a weaker influence than the corresponding continuous soils. An offshore wind energy tower has been modeled and calculated for wind and wave loads. London Elsevier 2019 Soil Dynamics and Earthquake Engineering 120 5 228 244 10.1016/j.soildyn.2018.12.005 2019-05-08 OPUS4-47892 Beitrag zu einem Tagungsband Auersch, Lutz Vehicle-track-soil interaction and train-induced ground vibration - Theory and measurements in Germany, Switzerland and France 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. Southampton University of Southampton Institute of Sound and Vibration Research 2019 Recent Advance in Structural Dynamics Recent Advance in Structural Dynamics Lyon, France 15.04.2019 17.04.2019 810 821 2019-05-08 OPUS4-47893 Vortrag Auersch, Lutz Vehicle-track-soil interaction and train-induced ground vibration: Theory and measurements in Germany, Switzerland and France 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. 2019 Recent Advance in Structural Dynamics Lyon, France 15.04.2019 17.04.2019 2019-05-08 OPUS4-47894 Vortrag Auersch, Lutz Roughness and wheelset acceleration from axle-box measurements for understanding the generation and mitigation of ground vibrations Two 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. 2019 ISO/TC 108/SC 2/WG 8 Working group Ground-borne noise and vibration from rail systems Berlin, Germany 12.03.2019 12.03.2019 2019-05-08