7.2 Ingenieurbau
Filtern
Dokumenttyp
- Beitrag zu einem Tagungsband (66) (entfernen)
Sprache
- Englisch (51)
- Deutsch (14)
- Mehrsprachig (1)
Referierte Publikation
- nein (66) (entfernen)
Schlagworte
- Ground vibration (5)
- Structural health monitoring (5)
- Structural Health Monitoring (4)
- Building vibration (3)
- Damage localization (3)
- Fatigue (3)
- Hammer impact (3)
- Impact (3)
- Layered soil (3)
- Vibration measurements (3)
- Bahnerschütterungen (2)
- Bayesian updating (2)
- Cable failure (2)
- Cable-stayed bridge (2)
- Container loading (2)
- Damage characterization (2)
- Drop test (2)
- Erschütterungen (2)
- Foundation load (2)
- High-strength concrete (2)
- Load vector (2)
- Model interpolation (2)
- Monitoring (2)
- Offshore (2)
- Planar tomography (2)
- Repair (2)
- SDDLV (2)
- Soil-wall-floor model (2)
- Statistical evaluation (2)
- Temperature rejection (2)
- Train passage (2)
- Train-induced ground vibration (2)
- Ultrasonic testing (2)
- Vehicle-track interaction (2)
- Vibration (2)
- 2-span bridge (1)
- Acoustic emission testing (1)
- Amplitude-charge weight laws (1)
- Amplitude-distance laws (1)
- Analysis of variance (1)
- Analytical Design Methods (1)
- Ansys Autodyn (1)
- Apartment building (1)
- Artificial intelligence (1)
- Attenuation (1)
- Axle loads (1)
- Axle-sequence spectrum (1)
- BIM (1)
- Bayesian System Identification (1)
- Bayesian methods (1)
- Belastungsversuch (1)
- Big Data (1)
- Bodenvariabilität (1)
- Bodenübertragungsfunktion (1)
- Box-Behnken (1)
- Bridges (1)
- Brücke (1)
- Changing process noise (1)
- Chemisoprtion (1)
- Climate chamber (1)
- Column/wall resonance (1)
- Compaction Grouting (1)
- Compressive Cyclic loading (1)
- Compressive cyclic loading (1)
- Compressive strength (1)
- Conductor (1)
- Coupler systems (1)
- Crack detection (1)
- Crack formation (1)
- Crack pattern (1)
- Cracks (1)
- Cyclic load (1)
- DEM (1)
- DUCON® (1)
- Damage detection (1)
- Datenmanagement (1)
- Deterioration (1)
- Digital Models (1)
- Digital twin (1)
- Dispersionsmessung (1)
- Displacements (1)
- Drone (1)
- Drop Tests (1)
- Drop tower (1)
- Drucker-Prager (1)
- Ductility (1)
- Dynamische Bodensteifigkeit (1)
- E-modulus (1)
- Earth (1)
- Earth masonry (1)
- Elastische Gleiselemente (1)
- Emission (1)
- Energy (1)
- Environmental effects (1)
- Erschütterungsausbreitung (1)
- Erschütterungsminderung (1)
- Erschütterungsprognose (1)
- Evaluation (1)
- Excitation forces (1)
- Explosion-induced ground vibrations (1)
- Fallturm (1)
- Faseroptik (1)
- Fault detection (1)
- Feuchte (1)
- Filter effects (1)
- Finite Elemente Simulation (1)
- Finite element models (1)
- Floor resonance (1)
- Foundation Pile (1)
- Foundation reliability analysis (1)
- Freight train (1)
- Freileitung (1)
- Gleiströge (1)
- Granular Cohesive Materials (1)
- Ground vibration measurements (1)
- Grout (1)
- Grouted Connection (1)
- Grouted connection (1)
- Grouting (1)
- Großer Fallturm Horstwalde (1)
- HTLS (1)
- Halbraum (1)
- Hard impact (1)
- Harter Anprall an Stahlbetonstrukturen (1)
- High-Rise Building (1)
- High-speed (1)
- High-speed train (1)
- Horizontal stress (1)
- Immission (1)
- Impact damage on reinforced concrete (1)
- Impakt (1)
- Inertial Interaction (1)
- Injection Sequence (1)
- Inspection (1)
- Inspection planning (1)
- Interface (1)
- Irregularities (1)
- Kinematic Interaction (1)
- Knudsen effect (1)
- Laboratory beam structure (1)
- Layered soils (1)
- Lehm (1)
- Linear parameter varying systems (1)
- Load-bearing (1)
- Long-span bridge (1)
- Macromechanical Sample Strength (1)
- Maschinenbetrieb (1)
- Material moisture (1)
- Material tests (1)
- Mauerwerk (1)
- Measurement (1)
- Measurements (1)
- Micro-reinforcement (1)
- Micromechanical Tensile Failure (1)
- Minderungsmaßnahmen (1)
- Mobile elements (1)
- Modal Analysis (1)
- Modal force spectrum (1)
- Modalanalyse (1)
- Modes (1)
- Moisture (1)
- Molecular diffusion (1)
- Monopile installation risks (1)
- Multiple impact (1)
- Nachgiebigkeiten (1)
- Non destructive testing (1)
- Non-destructive testing (1)
- Numeric simulation (1)
- Numerical damage simulation (1)
- Numerical modeling (1)
- Numerical modelling (1)
- Office building (1)
- Office tower (1)
- Offshore Pile Foundation (1)
- Offshore Wind Energy (1)
- Offshore foundations (1)
- Offshore wind energy (1)
- Offshore wind turbines (1)
- Optimal Sensor Placement (1)
- Passenger train (1)
- Physisorption (1)
- Pile Foundation (1)
- Post-impact evaluation (1)
- Prediction of explosion induced ground and building vibration (1)
- Probabilistic modelling (1)
- Propagation from a tunnel (1)
- Prädiktive Instandhaltung (1)
- Quasi-static and dynamic tests (1)
- Radar (1)
- Railway bridge (1)
- Railway tunnel (1)
- Randomly heterogeneous soil (1)
- Rehabilitation (1)
- Reinforced concrete structure (1)
- Reinforcement (1)
- Reliability (1)
- Research data management (1)
- Residential building (1)
- Risk (1)
- Scattering (1)
- Scherwellengeschwindigkeit (1)
- Schubmodul (1)
- Schwingungsdynamik (1)
- Shearing (1)
- Shell Buckling (1)
- Simple prediction (1)
- Size effect (1)
- Slab track (1)
- Slenderness effect (1)
- Soft impact (1)
- Soil properties (1)
- Soil-Structure-Interaction (1)
- Soil-building interaction (1)
- Soil-building resonance (1)
- Soil-pile interaction (1)
- Soil-structure interaction (1)
- Spatially varying ground conditions (1)
- Static load (1)
- Statistische Auswertung (1)
- Steel structures (1)
- Stereo photogrammetry (1)
- Strength (1)
- Structural systems (1)
- Subspace methods (1)
- Subspace-based residual (1)
- Supplementary cementitious materials (1)
- Surface Foundation (1)
- Surface-tunnel reduction (1)
- System Identification (1)
- Temperature effects (1)
- Tensile Capacity (1)
- Time-variant reliability (1)
- Tomographic damage evaluation (1)
- Tragfähigkeit (1)
- Train speed (1)
- Transfer function (1)
- Transmission (1)
- Tunnel (1)
- Tunnel-pile transfer (1)
- UHPC (1)
- Umwelteinflüsse (1)
- Value of Information (1)
- Varying stiffness (1)
- Vehicle-track-soil interaction (1)
- Vibration measurement (1)
- Vollraum (1)
- Waves (1)
- Wellenausbreitung (1)
- Wellenausbreitung in der Tiefe (1)
- Wellengeschwindigkeit (1)
- Wind (1)
- Wind Energy (1)
- Wind Turbines (1)
- Windenergie (1)
- Windenergieanlagen (1)
- Zerstreute Achsimpulse (1)
- Zuggeschwindigkeit (1)
- building information modelling (1)
- structural health monitoring (1)
- structural integrity management (1)
- support structures (1)
Organisationseinheit der BAM
- 7.2 Ingenieurbau (66) (entfernen)
Support structures of wind turbines in German offshore wind farms are regularly inspected. Currently, inspection outcomes are generally not systematically recorded. This prevents their consistent handling and processing, which is a key requirement to enable an efficient structural integrity management. As part of the DiMoWind-Inspect project, a data model and reference designation system for such inspection results is developed to facilitate their identification, localization, quantification, tracing and linking throughout the lifetime of a wind farm and beyond. The inspection results together with structural health monitoring results and information on repairs form the basis for assessing and predicting the structural condition, estimating the remaining lifetime, and planning of future inspections, structural health monitoring, and repairs. As a basis for developing a digital structural integrity management, a generic framework is proposed in this paper, which describes the stakeholders, data, models, processes and workflows of the integrity management of support structures in offshore wind farms and their interrelations. The framework adopts a building information modelling approach to describe the information relevant to the structural integrity management. The central digital space of the framework is a common data environment. An implementation of the framework will enable a digital structural integrity management in which inspection, structural health monitoring, repair, assessment and planning outcomes generated throughout the life cycle of a wind farm can be consistently collected, managed, shared and processed by the relevant shareholders.
The response of many geotechnical systems, whose structural behavior depends on shearing effect, is closely related to soil structure interaction phenomenon. Experimentally it is found that the localisation of these effect happens at a narrow soil layer next to the structure. Numerically, this behavior can be modelled through inter-face elements and adequate constitutive models. In this work, a constitutive model in the framework of Gen-eralized Plasticity for sandy soils has been chosen to be adapted for the interface zone. From the direct shear experiments a sandy soil at loose and dense states under different normal pressures is considered. The adapted constitutive model is able to reproduce contraction and dilatation of the soil according to its relative density and it shows a good agreement with the experimental data.
Die natürliche Variabilität des Bodens bewirkt, dass jegliche in-situ Messung dynamischer Bodenparameter stets nur den Untersuchungsort beschreiben, und jede Verwendung für benachbarte Orte bereits eine Extrapolation ist. Gleichzeitig ist die Ermittlung von Bodeneigenschaften in-situ mit erheblichen Kosten verbunden, insbesondere bei Standorten wie z. B. Offshore-Windparks. Im innerstädtischen Raum sind seismische Messungen wegen der vorhandenen Bebauung und Flächenversiegelungen nur eingeschränkt möglich. Es bietet sich daher an, indirekte Methoden auf Basis von Drucksondierungen anzuwenden, weil diese Untersuchungen inzwischen zum Standardrepertoire selbst bei kleineren Bauvorhaben gehören.
Der neue nationale Anhang zu DIN EN 1998-1 erlaubt die Anwendung von Korrelationen zwischen Sondierergebnissen und dynamischen Bodeneigenschaften zur Anwendung bei seismischen Standortanalysen. Es werden jedoch keine Hinweise zur Auswahl geeigneter Korrelationen gegeben. Mit ISO/TS 14837-32 liegt ein Standard vor, in dem sogar für sandartigen Boden und tonartigen Boden zwei konkrete Korrelationen zur Anwendung vorgeschlagen werden. Dasselbe gilt für den Entwurf des Eurocode 7-2, prEN 1997-2 von 2022.
Untersuchungen zeigen, dass seismische Verfahren, wenn sie nicht unter Labor-Freifeldbedingungen durchgeführt werden, signifikante Streuungen aufweisen. Sofern statistische Korrelationen eine Streuung aufweisen, die in derselben Größenordnung liegen wie Ergebnisse seismischer Verfahren, können beide Verfahren in Grundsatz alternativ eingesetzt werden.
Wir zeigen, dass bei homogenen ausgeprägt sandartigen Böden mit statistisch ermittelten Korrelationen die dynamischen Bodensteifigkeiten mit einer Genauigkeit abgeschätzt werden können, die mit der Ungenauigkeit der seismischen Verfahren übereinstimmt. Mit zunehmenden Feinkornanteil werden die Unsicherheiten der statistischen Korrelationen größer. Bei stark überkonsolidierten glazialen Böden sollte von der Anwendung empirischer Korrelationen Abstand genommen werden.
Erschütterungen, die durch Eisenbahnverkehr erzeugt werden, breiten sich durch den Erdboden aus und regen benachbarte Gebäude zu Schwingungen an. Es wurde ein Prognoseverfahren für Bahnerschütterungen ent-wickelt, das mit einfachen Modellen schnell Ergebnisse liefert. Dies sind physikalische Modelle, zum Beispiel 1-dimensionale Modelle mit Übertragungsmatrizen für die Fahrzeug-Fahrweg-Boden-Wechselwirkung und für die Gebäude-Boden Wechselwirkung. Damit werden die komplexen Verhältnisse bei der Emission (dem Zusammen¬wirken von Fahrzeug und Fahrweg), bei der Transmission durch den homogenen oder geschichteten Boden und bei der Immission in Gebäuden näherungsweise erfasst. In (Auersch, 2020) wird gezeigt, dass diese einfachen Prognosemodelle die Ergebnisse von detaillierten Modellen wie der Finite-Element-Randelement-Methode für das Gleis, die Wellenzahlintegrale für den Boden und 3-dimensionale Finite-Element-Modelle für das Gebäude gut wiedergeben können. Dies entspricht auch der Absicht, die Prognosemodelle aus den Ergebnissen der Detailmodelle abzuleiten. Die drei Prognoseteile werden getrennt berechnet, aber es werden physikalisch sinn¬volle Schnittstellen verwendet. Für die Emission und Transmission sind es die auf den Untergrund wirkenden Erregerkräfte von Fahrzeug und Fahrweg, für die Transmission und Immission sind es die Freifeldamplituden des Bodens.
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.
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.
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.
In recent years, several high temperature low sag conductors (HTLS) have been developed and are now commercially available. Very few utilities have long-term experience with all the technologies. Moreover, most of the operational experience is at low temperatures. An independent testing program at maximum operational temperatures comparing most of the available technologies would provide useful guidance to utilities considering using such conductors.
This paper describes the approach and results of an international research project assessing the long-term reliability of a wide range of commercially available high temperature conductor systems. Each system was exposed to 4,400 hours of simultaneous mechanical and electrical stresses. A set of standard mechanical and electrical tests were carried out to determine any changes. A conventional ACSR conductor was also tested and provided a validation that the testing program was realistic.
The majority of the conductor systems performed satisfactorily. However the ACSS system joint resistance and the grease on the TACSR performed poorly.
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.
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.