TY - CONF A1 - Auersch, Lutz T1 - Impacts between different drop masses and different targets in different scales N2 - The Federal Institute of Material Research and Testing has performed many impact tests from very small laboratory tests to very big “free-field” tests with heavy containers on stiff foundations. The first measurements have been done on a big foundation where it should be guaranteed that the foundation is rigid and the container is tested properly. Later on, a smaller drop test facility has been built on the ground inside an existing building. It had to be controlled by prediction and measurements that the drop test will not damage the building. Tests from different heights on soft, medium, and stiff targets have been done to find out rules which allow to identify acceptable and unacceptable drop tests. Later on, the biggest drop test facility has been built for masses up to 200 t. It was necessary for the design of the foundation to estimate the forces which oc-cur during the drop tests. In addititon, the acceptable tests should be selected and controlled by measurements where the impact duration is important. Dif-ferent sensors, accelerometers, accelerometers with mechanical filters, geo-phones (velocity transducers), strain gauges, and pressure cells have been ap-plied for these tasks. Signal transformations and model calculations have been used to check and understand the dynamic measurements. The simplest law is the conservation of the momentum which is a good approximation if the impact is short. If the soil under the foundation has an influence on the deceleration of the container, the maximum foundation velocity is lower than the simple esti-mation. T2 - 10th International Conference on Experimental Vibration Analysis for Civil Engineering Structures CY - Milano, Italy DA - 30.08.2023 KW - Drop test KW - Vibration measurements KW - Container loading KW - Foundation load PY - 2023 AN - OPUS4-58504 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Balscheit, Hagen A1 - Victor, A. A1 - Thiele, Marc A1 - Cuéllar, Pablo A1 - Baeßler, Matthias A1 - Lüddecke, F. T1 - Experimental Investigation on Buckling Behavior of soil-embedded Piles N2 - Monopile-Gründungen sind die mit Abstand am häufigsten verwendete Gründungskonstruktion für Offshore-Windenergieanlagen. Ein wesentliches Problem bei der Bemessung ist das lokale Beulen des Gründungspfahls, welches typischerweise im Bereich der Bettung auftritt. Aufgrund der Nichtlinearität der Bettungsrandbedingung sind klassische Bemessungsansätze nicht anwendbar, so dass der Bemessungsingenieur auf eine vollständig numerische Berechnung zurückgreifen muss. In diesem Vortrag wird eine experimentelle Versuchskampagne zur Erzeugung von Kalibrierungsdaten für solche numerischen Modelle vorgestellt. Eine ausführlichere Darstellung findet sich im gleichnamigen Artikel. T2 - EUROSTEEL 2023 CY - Amsterdam, Netherlands DA - 11.09.2023 KW - Wind KW - Wind Energy KW - Offshore KW - Shell Buckling KW - Soil-Structure-Interaction PY - 2023 AN - OPUS4-58365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zinas, Orestis T1 - 3D Probabilistic Site Characterization N2 - The aim of the study is to infer the soil stratification from the provided CPT and borehole data. We infer the soil type at any location within the domain of interest from the SBT index Ic (Robertson, 2009). This index can be directly related to the CPT data through an empirical correlation model. In addition, the soil classes contained in the borehole logs can be expressed as bounds on Ic. A log-transformation was applied to Ic, Y = ln(Ic), and Y was modelled by a 3D Random Field, with a fully Bayesian hierarchical Gaussian Process model to explicitly capture uncertainties. T2 - 19th eawe PhD Seminar CY - Hannover, Germany DA - 06.09.2023 KW - Wind Energy KW - Site-characterization KW - Probabilistic PY - 2023 AN - OPUS4-58940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo T1 - Deep foundations for offshore wind turbines - 2nd part: lateral behavior & advanced topics T1 - Cimentaciones profundas para aerogeneradores marinos. 2a parte: Comportamiento Lateral + Temática avanzada N2 - This presentation deals with the phenomenology and design of pile foundations for offshore wind turbines, and is divided into two lectures. The second lecture continues with the case of laterally 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. T2 - Masters course on Soil Mechanics and Geotechnical Engineering. Geotechnical Laboratory of CEDEX CY - Online meeting DA - 17.03.2023 KW - Pile foundations KW - Offshore wind turbines KW - Physical phenomenology KW - Design methods KW - Numerical modelling KW - Physical testing PY - 2023 AN - OPUS4-57178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Balscheit, Hagen A1 - Cuéllar, Pablo A1 - Geißler, Peter A1 - Thiele, Marc A1 - Schepers, Winfried A1 - Fontoura Barroso, Daniel T1 - Large Monopiles: Experimental and numerical investigation of monopile tip buckling during installation as well as of local pile buckling under operational conditions N2 - The research project Verification of Buckling Assessment and Behaviour in Large Monopiles (VERBATIM) focuses on challenges arising due to the ongoing increase of dimensions of monopiles as foundation for offshore wind turbines. This project is focused on two main topics: - Monopile tip buckling during pile installation - Local buckling of embedded piles during operation It is known from previous investigations and experiences in practice that large deformations of a monopile tip during offshore installation works can occur. These large deformations initiated at the tip of the monopile are commonly referred to as “pile tip buckling”. Own research focuses on optimising monopile dimensions to reduce the cost of monopile foundations for offshore wind turbines while preventing pile tip buckling. Buckling of embedded cylindrical shells for offshore structures is a common engineering task. Structures can be analysed using standard software and have been done so in recent studies e.g., Gottschalk. However, the trend towards larger monopile and optimised structures has led to a fundamental need for better and verified models. A main challenge is the submodelling of the structure-soil-interaction. Developing such complex models is one main goal of the VERBATIM project. For both main topics model tests were performed at the laboratories of BAM and TU Berlin. These experimental results were used to verify related numerical models and simulations. T2 - WindEurope CY - Copenhagen, Denmark DA - 25.04.2023 KW - Monopiles KW - Tip Buckling KW - Pile Buckling KW - Foundations KW - Offshore KW - Windenergy PY - 2023 AN - OPUS4-57405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Balscheit, Hagen T1 - Offshore Gründungen - Nichtlineare Effekte bei der stahlbaulichen Auslegung großer Pfahlgründungen für Offshore Windenergieanlagen N2 - Dieser Kurzvortragg erläutert nichtlineare Phänomene die angesichts der aktuell wachsenden Dimensionen von Monopfahlgründungen für Offshorewindenergieanlagen zunehmend an Bedeutung gewinnen. Insbesondere wird dabei auf das Pfahlfußbeulen sowie das Schalenbeulen des bereits installierten Pfahles eingegangen. T2 - 27. Brandburgischer Bauingeniertag BBIT2023 CY - Cottbus, Germany DA - 09.06.2023 KW - Beulen KW - Pfahlfußbeulen KW - Stabilität KW - Monopile KW - Windenergie PY - 2023 AN - OPUS4-57653 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Stolpe, Heiko A1 - Wiehle, Philipp T1 - Moisture diffusion affected by the Knudsen effect in temporal changing pore networks N2 - Almost all building materials in civil engineering have an open porosity and interact with or are affected by the environmental conditions. Structures might suffer from effects such as moisture adsorption, carbonation, corrosion, penetration of salt ions and chemical substances, etc. In the hygroscopic range, these processes are mostly driven by diffusion. Due to the confinement of small pores ( 1 m), the Knudsen effect reduces the molecular diffusion. This reduction can become more significant in case of temporal changing pore systems because of physisorption of water vapor, carbonation, or chemisorption. In this study, unstabilised earth blocks and earth masonry are investigated. In a first step, the pore size distribution of the blocks is measured and sorption isotherms are recorded in experiments. Besides the ordinary physisorption, the involved clay minerals undergo swelling or shrinking due to chemisorption. The following two effects must be considered: first, the reduction of the available pore space by the adsorbed water layer. For this, the Hillerborg sorption theory is used, which is a combination of the well-known Brunauer-Emmett-Teller sorption theory and the Kelvin equation. This allows the computation of adsorbed water layers even in curved pore geometries. Second, the variation of the initial pore size distribution due to chemisorption needs to be modelled. Based on these two models, the effective diffusion coefficient can be predicted. For validation, arrays of relative humidity sensors were embedded into a free-standing earth masonry wall. This monitoring was carried out over more than a year to have a broad variety of environmental conditions and was located in Berlin, Germany. The prediction of the effective diffusion coefficient can also be transferred to other processes and allows the investigation of materials having temporarily changing pore systems. Examples are the carbonation of cementitious materials, alkali silica reaction, calcium leaching of long-lasting structures, etc. This effect becomes most prominent in the meso-pore range and might alter the effective diffusion coefficient by more than 100 %. T2 - 4th International Congress on Materials & Structural Stability CY - Rabat, Morocco DA - 08.03.2023 KW - Earth masonry KW - Material moisture KW - Molecular diffusion KW - Chemisoprtion KW - Knudsen effect KW - Physisorption PY - 2023 AN - OPUS4-57140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichner, Lukas T1 - Design of offshore jacket support structure for experimental fatigue life evaluation N2 - One crucial metric of interest to wind farm operators is the remaining useful life (RUL) of single components, wind turbines, or even entire wind farms. Occasionally, questions arise regarding how to operate a turbine, even in the presence of manufacturing or design errors, which from a computational design standpoint reduce the remaining lifetime below the intended service life. A typical measure involves adapting the monitoring and inspection plan. Using such a maintenance plan, the author intends to simulate the lifetime of jacket-type structure in a fatigue test. The objective of the experiment is to demostrate that systems like three-dimensional jackets possess redundancies that enable reliable continued operation, despite the reduced fatigue life of individual components due to technical flaws, if an appropriate maintenance concept is in place. This presentation discusses the steps leading to the procedure of the experiment including the design process and the maintenance planning. T2 - 19th eawe PhD Seminar CY - Hannover, Germany DA - 06.09.2023 KW - Offshore wind energy KW - Jacket support structure KW - Simulation and experiment KW - Structural integrity management KW - Risk-based maintenance planning PY - 2023 AN - OPUS4-58240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald A1 - Simon, Patrick A1 - Hille, Falk A1 - Herrmann, Ralf A1 - Baeßler, Matthias T1 - Vibration-based system identification of a large steel box girder bridge N2 - The Bundesanstalt für Materialforschung und -prüfung (BAM) collaborates with TNO to develop a software framework for automated calibration of structural models based on monitoring data. The ultimate goal is to include such models in the asset management process of engineering structures. As a basis for developing the framework, a multi-span road bridge consisting of ten simply supported steel box girders was selected as a test case. Our group measured output-only vibration data from one box girder under ambient conditions. From the data, we determined eigenfrequencies and mode shapes. In parallel, we developed a preliminary structural model of the box girder for the purpose of predicting its modal properties. In this contribution, we provide an overview of the measurement campaign, the operational modal analysis, the structural modeling and qualitatively compare the identified with the predicted modes. As an outlook, we discuss the further steps in the calibration process and future applications of the calibrated model. T2 - XII International Conference on Structural Dynamics (EURODYN 2023)) CY - Delft, Netherlands DA - 02.07.2023 KW - Road bridges KW - Fatigue KW - Operational modal analysis KW - System identification PY - 2023 AN - OPUS4-58101 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gerards-Wünsche, Paul A1 - Ratkovac, Mirjana A1 - Schneider, Ronald A1 - Hille, Falk A1 - Baeßler, Matthias T1 - A framework for assessing the reliability of crack luminescence – an automated fatigue crack detection system N2 - The new crack luminescence method offers the possibility of making fatigue surface cracks in metallic materials more visible during inspections through a special coating system. This coating system consists of two layers, whereby the first layer has fluorescent properties and emits visible light as soon as it is irradiated by UV light. The top layer is black and is designed to prevent the fluorescent layer from emitting if no crack develops in the underlying material. The technique proved particularly useful in a wide variety of fatigue tests of steel components under laboratory conditions. Moreover, it has the potential to be used in various industrial applications. To enable industrial deployment and integration into maintenance strategies, a concept study is developed in this contribution, resulting in a qualification framework that can serve as a foundation for determining the reliability of the crack luminescence system in terms of a probability of detection curve. Within this study, factors causing measurement variability and uncertainty are being determined and their influences assessed. Due to the extension of the system by a moving computer vision system for automated crack detection using artificial intelligence, additional long-term effects associated with structural health monitoring systems need to be incorporated into an extended probability of detection study as part of the technical justification. Finally, important aspects and findings related to design of experiments are discussed, and a framework for reliability assessment of a new optical crack monitoring method is presented, emphasizing the influence of various uncertainty parameters, including long-term effects such as system ageing. T2 - SPIE Conference Smart Structures + Nondestructive Evaluation 2023 CY - Long Beach, CA, USA DA - 24.03.2023 KW - Structural Health Monitoring KW - Non-Destructive Evaluation KW - Probability of Detection KW - Reliability KW - Artificial Intelligence KW - Computer Vision KW - Crack Luminescence PY - 2023 AN - OPUS4-57245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Schneider, Ronald T1 - OWEC repowering from a structural engineering and research perspective N2 - A significant number of new wind farms has to be installed and, at the same time, existing wind farms reaching the end of their planned life need to be reused efficiently to ensure that the ambitous goals for deploying offshore wind are met. Some relevant reuse alternatives for offshore wind farms are lifetime extension, repowering utilizing existing substructures and full replacement. In this presentation - starting from experience gained from extending the lifetime of the of the U1 metro viaduct in Berlin - we discuss end-of-life decision making in offshore wind. We focus particularly on issues concerning substructures and highlight existing challenges and opprtunities in research and development. T2 - RWE RePowering Event CY - Wilhelmshaven, Germany DA - 10.10.2023 KW - Offshore wind KW - End-of-life decision making KW - Repowering KW - Substructures PY - 2023 AN - OPUS4-58632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Structural integrity management research at BAM N2 - This presentation provides an overview on the structural integrity management research at BAM. In addition, a framework for monitoring and risk-informed inspection and maintenance planning for offshore steel structures is presented. T2 - Structural Health Monitoring Using Statistical Pattern Recognition CY - Berlin, Germany DA - 20.03.2023 KW - Structural integrity KW - Monitoring KW - Maintenance KW - Inspeciton KW - Bridges KW - Offshore wind PY - 2023 AN - OPUS4-57864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf A1 - Simon, Patrick A1 - Schneider, Ronald A1 - Hille, Falk A1 - Baeßler, Matthias T1 - SHM system integration and experiments at a high speed railway bridge N2 - The long-term preservation of our infrastructure requires not only intelligent sensor technology and highly developed monitoring procedures, but also innovative digital tools for analyzing, evaluating and utilizing the results. This includes mathematical and, in particular, probabilistic methods for damage detection and tracking as well as for calculating service life and maintenance cycles and data management. The example project Maintal Bridge Gemuenden as part of the AISTEC project shows the workflow for the implementation of structural health monitoring and experimental tests with a train of Deutsche Bahn. The influence lines, as one possible way for damage detection, were measured with a highly accurate GNSS System to locate the trains position when crossing the bridge. The results were compared to measurements from 1987 just before the bridge went in operation. T2 - Structural Health Monitoring Using Statistical Pattern Recognition CY - Berlin, Germany DA - 20.03.2023 KW - SHM KW - Maintal Bridge Gemuenden KW - Load Test KW - Damage Detection KW - Railway PY - 2023 AN - OPUS4-57242 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald A1 - Simon, Patrick A1 - Hille, Falk A1 - Herrmann, Ralf A1 - Baeßler, Matthias T1 - Vibration-based system identification of a large steel box girder bridge N2 - The Bundesanstalt für Materialforschung und -prüfung (BAM) collaborates with TNO to develop a software framework for automated calibration of structural models based on monitoring data. The ultimate goal is to include such models in the asset management process of engineering structures. As a basis for developing the framework, a multi-span road bridge consisting of ten simply supported steel box girders was selected as a test case. Our group measured output-only vibration data from one box girder under ambient conditions. From the data, we determined eigenfrequencies and mode shapes. In parallel, we developed a preliminary structural model of the box girder for the purpose of predicting its modal properties. In this contribution, we provide an overview of the measurement campaign, the operational modal analysis, the structural modeling and qualitatively compare the identified with the predicted modes. As an outlook, we discuss the further steps in the calibration process and future applications of the calibrated model. T2 - XII International Conference on Structural Dynamics (EURODYN 2023) CY - Delft, Netherlands DA - 02.07.2023 KW - Bridge KW - Safety KW - Fatigue KW - Modal system identification KW - Model updating PY - 2023 AN - OPUS4-57863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Wave propagation from hammer, vibrator and railway excitation – theoretical and measured attenuation in space and frequency domain N2 - The attenuation of wave amplitudes is ruled by the planar, cylindrical or spher-ical geometry of the wave front (the geometric or power-law attenuation) but also by the damping of the soil (an exponential attenuation). Several low- and high-frequency filter effects are derived for the layering and the damping of the soil, for the moving static and the distributed train loads and for a homoge-neous or randomly heterogeneous soil. Measurements of hammer- and train-induced vibrations at five sites have been analysed for these attenuation and filter effects. The measured attenuation with distance can be discribed by gen-eralised power laws and some reasons will be discussed. The theoretical filter effects can well be found in the measurements. T2 - 10th Wave Mechanics and Vibration Conference (WMVC)nce CY - Lisbon, Potugal DA - 04.07.2022 KW - Hammer impact KW - Train passage KW - Layered soil KW - Attenuation KW - Filter effects KW - Randomly heterogeneous soil KW - Scattering PY - 2022 AN - OPUS4-55246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Rohrmann, Rolf T1 - Measurement and evaluation tools for ground and building vibrations from industrial process-es, construction work, traffic and other sources N2 - Vibration measurements have many causes and many technical and natural sources. Problems can sometimes be solved by short-term measurements, but in many cases, a long-term measurement is necessary. In long-term measurements of days, weeks, months and even years, it is easy to collect a huge quantity of raw data, but at the end, the post-processing of these data can be exhausting (for example one-year vibration data of a wind energy tower). A software has been developed which con-sists of measuring and evaluation routines where the measuring routines can operate different meas-uring systems and different measuring cards. The main advantage of this software is the fact that the interesting evaluations can be integrated in the measuring process so that the characteristics of the vibration can be extracted without storing all the raw data. Only important time segments are stored, for example train passages. The overall concept of the software and the main evaluation routines will be described in some details. Examples of our measurement experience will illustrate the capabilities of the software. 1) Surveying construction work in nearby sensitive buildings (for example an old wind tunnel), including a stable alarm system and meaningful vibration limits. 2) Prediction of train-induced vibration for a planned building to prevent annoyance and to improve the building design. 3) Modal analysis and long term measurements of several single- or multi-span, concrete or steel bridges 4) Modal and wave analysis of coupled floors in a historical building (“Neues Palais” at Potsdam). 5) Soil properties of various measurement sites (different routines to evaluate the dispersion). Moreover, from many projects, amplitudes, frequencies, and attenuation laws have been collected and analysed for the different sources such as vibratory or impact pile driving and ground compaction, demolition work with different machines, blasting in quarries and in tunnel works, bomb and mine clearing. T2 - 28th International Congress on Sound and Vibration (ICSV28) CY - Online meeting DA - 25.07.2022 KW - Ground vibration KW - Building vibration KW - Measurement KW - Evaluation KW - Modes and waves PY - 2022 AN - OPUS4-56035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Effects of a varying track and soil stiffness on ground vibrations near railway lines N2 - Usually, geometric irregularities are considered as the main cause of ground vibrations from trains. A varying stiffness of the track, the track support and the soil can also generate ground vibrations. The regular stiffness variation of the track on and between the sleepers results in a deterministic dynamic axle load. The random stiffness variation of the track support yields also dynamic axle loads. The dynamic axle loads are generated by the varying wheel displacements under the static axle load by the acceleration of the unsprung mass of the rail vehicle. The random stiffness variation has a second effect. The pulses from the passage of the static axle loads are superposed regularly to the quasi-static response, but also irregularly to yield a “scattered” part of the axle pulses. The same holds for a random variation of the soil stiffness. All these effects of stiffness variations have been calculated by wavenumber-domain multi-beam track models, a random finite-element soil model and the superposition of axle impulses in a stochastic simulation. The results are confronted with many measurements at different sites. It is concluded that the stiffness variation of the track and the soil generate an important ground vibration component near railway lines. T2 - Railways 2022 CY - Montpellier, France DA - 22.08.2022 KW - Ground vibration KW - Railways KW - Varying track stiffness KW - Varying soil stiffness PY - 2022 AN - OPUS4-56036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Railway-induced ground and building vibrations – Analysis in frequency-wavenumber domain and fast prediction with approximate models N2 - A simple and fast prediction scheme is presented for train-induced ground and building vibrations. For the emission, finite-element boundary-element or multiple-beam-on-continuous-soil models of the track have been analysed and approximated by faster track-on-Winkler-soil models. The vehicle-track interaction due to irregularities yields the excitation forces. For the transmission of waves in the soil, the wavenumber integral of the compliance of layered soils has been evaluated. The calculation time is reduced for the prediction by using the solution of a homogeneous half-space with a frequency-dependent wave velocity (the dispersion) of the soil. For the immision, many 2 and 3-dimenisonal finite-element building models have been investigated, and a good approximation has been established by a 1-dimensional soil-wall-floor model. In addition, the axle sequence of the train, the quasi-static and the “scattered” response of the soil, and the wave propagation from a tunnel to a pile foundation of a building have been included. T2 - ISMA-Conference CY - Leuven, Belgium DA - 12.09.2022 KW - Ground vibration KW - Building vibration KW - Railways KW - Simple and fast prediction PY - 2022 AN - OPUS4-56038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cuéllar, Pablo A1 - Geißler, Peter A1 - Baeßler, Matthias T1 - Geotechnical challenges in the field of Offshore Wind Energy. Micromechanical perspectives beyond the FEM N2 - This talk provides a brief overview on some geomechanical phenomena and problematic issues in the field of offshore wind-energy geotechnics, with reference to their associated challenges for a numerical analysis/simulation. These may include large deformations, fluid coupling and grain-scale phenomena, all of which are generally difficult to be addressed with conventional FE techniques. These challenges are illustrated here with a practical example for the retrofit of axially loaded piles using compaction grouting techniques. In this case, the mechanical effects of the retrofit may be analysed with standard FE techniques, but require the adoption of strong assumptions, while the injection process itself can only be analysed with special techniques such as the MPM. Finally, an LBM-DEM framework for the micromechanical analysis of such problems is introduced and a practical application for the estimation of the soil resistance to driving (SRD) in layered profiles is discussed. T2 - Online Symposium on Meshfree models for Engineers: Where are they really worthwhile? CY - Online meeting DA - 01.12.2022 KW - Offshore wind energy KW - Offshore geotechnics KW - Micromechanical simulation KW - LBM-DEM KW - Pile retrofit system PY - 2022 AN - OPUS4-56450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Wellenausbreitung und Pfähle im inhomogenen Boden – Gesetzmäßigkeiten für die Gründung von Windenergieanlagen und für die Prognose von Bahnerschütterungen aus Tunneln N2 - Es wird eine gekoppelte Finite-Element-Randelementmethode zur Berechnung von Pfahlgrün-dungen in inhomogenen (geschichteten) Böden vorgestellt. Sie beruht auf den Greenschen Funktionen (Punktlastlösungen) für inhomogene Böden. Diese Lösungen können auch für die Wellenausbreitung in der Tiefe, zum Beispiel von einem Bahntunnel zu einem eingebetteten Gebäude, dem Kellergeschoss benutzt werden. Die Punktlastlösungen in der Tiefe werden mit der Halbraumlösung an der Bodenoberfläche und mit der Vollraumlösung verglichen und Gesetzmäßigkeiten für geschichtete Böden abgeleitet. Zu den Pfahlgründungen werden die Horizontalnachgiebigkeiten von Pfählen in geschichteten Böden dargestellt. Für den homoge-nen und den kontinuierlich steifer werdenden Boden werden Potenzgesetze für den Boden- und Pfahleinfluss aufgestellt. Der Vergleich mit dem Winkler-Modell der rein lokalen Boden-reaktion zeigt, dass die Winkler-Bettung in allen Fällen einen zu kleinen Bodeneinfluss ergibt. T2 - 7. VDI-Fachtagung Baudynamik CY - Würzburg, Germany DA - 27.4.2022 KW - Wellenausbreitung in der Tiefe KW - Pfahlnachgiebigkeiten KW - Erschütterungen KW - Tunnel PY - 2022 AN - OPUS4-54769 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -