7.2 Ingenieurbau
Filtern
Erscheinungsjahr
- 2023 (28) (entfernen)
Dokumenttyp
- Vortrag (28) (entfernen)
Referierte Publikation
- nein (28)
Schlagworte
- Bahnerschütterungen (2)
- Design methods (2)
- Fatigue (2)
- Foundations (2)
- Numerical modelling (2)
- Offshore (2)
- Offshore wind (2)
- Offshore wind turbines (2)
- Physical phenomenology (2)
- Physical testing (2)
- Pile foundations (2)
- Shell Buckling (2)
- Structural Health Monitoring (2)
- Wind Energy (2)
- 2-span bridge (1)
- Achsimpulse (1)
- Artificial Intelligence (1)
- Axle-sequence spectrum (1)
- Base isolation (1)
- Baugrunddynamik (1)
- Bauwerksmonitoring (1)
- Beulen (1)
- Bridge (1)
- Bridges (1)
- Brücken (1)
- Cars (1)
- Chemisoprtion (1)
- Computer Vision (1)
- Container loading (1)
- Crack Luminescence (1)
- Damage Detection (1)
- Damage detection (1)
- Drop test (1)
- Dynamic soil properties (1)
- Dynamische Bodenkennwerte (1)
- Earth masonry (1)
- Elastische Gleiselemente (1)
- Emission (1)
- End-of-life decision making (1)
- Erschütterungsminderung (1)
- Erschütterungsprognose (1)
- Fahrzeug-Fahrweg-Boden-Wechselwirkung (1)
- Flexibility (1)
- Floors (1)
- Footbridge (1)
- Force reconstruction (1)
- Foundation load (1)
- Freight train (1)
- Frequency response function (1)
- Gleiströge (1)
- Ground vibration (1)
- High-rise buildings (1)
- High-speed train (1)
- Inertial interaction (1)
- Inspeciton (1)
- Jacket support structure (1)
- Kinematic interaction (1)
- Knudsen effect (1)
- Layered soil (1)
- Load Test (1)
- Maintal Bridge Gemuenden (1)
- Maintenance (1)
- Material moisture (1)
- Measurements (1)
- Modal load spectrum (1)
- Modal system identification (1)
- Model updating (1)
- Molecular diffusion (1)
- Monitoring (1)
- Monopile (1)
- Monopiles (1)
- Movin load test (1)
- Non-Destructive Evaluation (1)
- Normung (1)
- Numerical analysis (1)
- Offshore wind energy (1)
- Offshore wind-turbine foundations (1)
- Operational modal analysis (1)
- Passenger train (1)
- Pfahlfußbeulen (1)
- Physisorption (1)
- Pile Buckling (1)
- Pile Tip Buckling (1)
- Pile groups (1)
- Probabilistic (1)
- Probability of Detection (1)
- Railbridge (1)
- Railway (1)
- Railway bridge (1)
- Railway tracks (1)
- Railway tunnel (1)
- Reliability (1)
- Repowering (1)
- Risk-based maintenance planning (1)
- Road bridges (1)
- SHM (1)
- Safety (1)
- Simulation and experiment (1)
- Site-characterization (1)
- Soil Struture Interaction (1)
- Soil-Structure-Interaction (1)
- Soil-pile interaction (1)
- Soil-structure interaction (1)
- Stabilität (1)
- Statistical correlations (1)
- Statistische Korrelationen (1)
- Structural health monitoring (1)
- Structural integrity (1)
- Structural integrity management (1)
- Störgrößen (1)
- Substructures (1)
- Surface-tunnel reduction (1)
- System identification (1)
- Tip Buckling (1)
- Transfer fuction (1)
- Tunnelstrecke (1)
- Umwelteinflüsse (1)
- Vibration measurements (1)
- Vibrations (1)
- Water-structure interaction (1)
- Wind (1)
- Wind turbines (1)
- Wind-farm aerodynamics (1)
- Windenergie (1)
- Windenergy (1)
- zerstreute Achslastimpulse (1)
Organisationseinheit der BAM
Eingeladener Vortrag
- nein (28)
Brücken sind Teil der alternden Verkehrsinfrastruktur. Um die Nutzungsdauer zu verlängern und plötzliche Schäden zu detektieren kann Bauwerksmonitoring ("Structural Health Monitoring") eingesetzt werden. Der Einfluss von Umgebungsbedingungen, beispielsweise der Temperatur, auf das Bauwerksverhalten ist meist größer als der Einfluss von Schäden. Diese Einflüsse bestmöglich voneinander zu trennen und Veränderungen im Tragverhalten korrekt Schäden oder Umgebungsbedingungen zuzuordnen ist eine offene Forschungsfrage. Diese Arbeit zeigt eine mögliche Lösung, bei der gekoppelte Modelle von Umwelteinflüssen, Schäden und Tragverhalten des Bauwerks auf Grundlage von Monitoringdaten aktualisiert werden. Das Framework dazu wird vorgestellt und an einem Laborexperiment eines Stahlbetonbalkens in der Klimakammer angewandt. Die Ergebnisse bestätigen die Vorgehensweise. In nächsten Schritten müssen komplexere Tragwerke und die Sensitivität des Ansatzes untersucht werden.
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.
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.
Train-induced ground vibrations – The emission and transmission from tunnel and surface lines
(2023)
Train-induced ground vibrations are quite different for tunnel and surface lines. The excitation of the track and ground vibration by the vehicle-track-soil interaction maybe influenced by the stiffer track support of the tunnel invert. The excited waves are propagating on a different path compared to the surface line. The wave propagation in the interior of the soil is calculated by a wavenumber integral in a similar way as the propagation along the surface and a general reduction of < 0.5 has been found. An additional reduction has been found because of the missing Rayleigh wave. The different excitation of tunnel lines is analysed theoretically by the combined finite-element boundary-element method and some results about the influencing tunnel and soil parameters will be shown. Measurements have been made at the Mühlberg-Tunnel in Germany. The vibrations of the train, the track and the soil have been measured simultaneously at the tunnel and a nearby surface line. Spectra will be shown for different train speeds between 60 and 160 km/h. A clear reduction effect for the tunnel line compared to the surface line has been observed in a specific (train-speed-dependent) frequency range. This agrees well with the observations of other research institutes. The mid-frequency tunnel-surface reduction seems to be a consequence of the stiffer track structure which leads to a wider distribution of the axle loads. Therefore, the axle impulses due to the train passage are longer and have a lower frequency content. This will have an effect on the ground vibrations at some distance which are present in case of an irregular transmission path through a ballast and soil with varying stiffness. A similar reduction effect can also be found for other track forms where the axle impulses are distributed on a longer track segment, for example slab tracks, tracks with under ballast plates, under ballast mats or under sleeper pads.
The resonances of railway bridges have often been analysed for short bridges under periodical high-speed trains, for simply supported one-span bridges, for the fundamental bridge mode, and by time-domain analyses. Many time-consuming calculations have been performed to establish simplified rules for standards. In this contribution, the passage of different (existing, new and hypothetic) trains over different bridges will be analysed in frequency domain by using three separated spectra with the purpose to get a better physical insight in the phenomena. At first, the excitation spectrum of the modal forces is built by the mode shape and the passage time of the train over the bridge. The second spectrum is the frequency response function of the bridge which include the modal frequency, damping and mass. The third part is the spectrum of the axle sequence of an arbitrary train which is not limited to periodical or specific (conventional, articulated, regular or standard) trains and which does not include any bridge parameters. The final solution in frequency domain is obtained as the product of these three complex, strongly varying spectra for the dominating bridge mode or in general as the sum of these products over all relevant bridge modes. The time domain solution is obtained via the inverse Fourier transform, and the resulting time histories have been successfully compared with some measurement results. The method is applied to the vertical and torsional modes of a mid-long 1-span bridge on elastomeric bearings under standard train speeds, and to a long multi-span integral bridge under long periodical freight trains. Different resonance and cancellation effects have been found for systematically varied train speeds according to the axle sequence of the whole train which is dominated by the two locomotives in that case. To be more specific, the first torsional mode of the mid-span bridge is excited for a train speed of 100 km/h whereas the second bending mode is excited for a train speed of 160 km/h. In both cases, the other mode is suppressed by the minima of the axle-distance spectra. In addition, the case of the German high-speed train ICE4 and the very high-speed hyperloop case will be discussed briefly. In general, it is shown that resonance effects are also worth to be studied for freight and passenger trains with lower speeds.
The soil-foundation-structure interaction is always important when building vibrations due to train passages have to be considered. The frequency range for train vibrations is up to 100 Hz. Normally, soft surface soils are crucial so that the wavelength can be much smaller than the foundation dimensions. Three topics are of interest for the prediction and the under-standing of building vibrations. 1. The „kinematic interaction“ or the „added foundation ef-fect“, which is calculated either by the combined boundary-element finite-element method or by the wavenumber domain method, results in a reduction of the free-field vibration. The stiff-ness of the foundation resists the wave deformation, plates and walls for horizontally propa-gating waves or piles for vertically incident waves. 2. The „inertial interaction“ or the „added building effect“ yields an amplification around the vertical building resonance, which may be a rigid mode on the compliant soil or a flexible mode for high-rise buildings, and a reduction at higher frequencies. This has been analysed by detailed finite element models of apartment and office buildings. 3. Base isolation is a method to further reduce building vibrations. It is important to know the soil-foundation impedance for the possible reduction, as well as the correct building impedance. A high-rise building cannot be considered as a rigid mass model. It has a frequency-dependent behaviour with longitudinal waves travelling from the founda-tion to the top of the building which include the effect of floor vibrations. Experiences from building projects in Vienna, Frankfort and Berlin will give some additional results for the ex-citation from tunnel lines, the kinematic response of pile foundations, and the inertial re-sponse of the flexible multi-storey buildings.
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.
Nowadays geotechnical engineering firms have powerful software tools to extent their consulting business also into dynamic soil-structure interaction, which before has been restricted to a rather small community of specialized experts in this field, and they certainly do. This is particularly true with respect to non-seismic sources, that is all kinds of human induced vibrations. Hence, there is a demand from clients as well as from contractors to have guidance on the requirements as well as the limits of numerical modelling of soil-structure interaction. From the literature as well as from relevant standards, recommendations for the numerical modelling of soil-structure interaction problems involving seismic actions are well known, e. g. ASCE/SEI 4-16. There are, however, some particularities when dealing with human-induced vibrations, which are absent in seismic analyses. For human-induced excitations very little specific guidance has been published in the past. A machine foundation on a homogeneous half space excited by harmonic loads with excitation frequency between 4 Hz and 64 Hz has been analysed by means of several commercially available software packages. Parametric studies have been performed to verify if recommendations for seismic soil-structure analyses are valid for non-seismic analyses as well. This paper provides details on the benchmark example and the most important conclusions from the undertaken parametric studies.
Die VDI Richtlinie 3837 enthält detaillierte Angaben zur Erschütterungsemission. Die DIN 45672-3 enthält nur den Tunnel- oder einen Bodenmesspunkt als Ausgangspunkt der Prognose. Die Erschütterungsanregung durch die Fahrzeug-Fahrweg-Wechselwirkung wird beschrieben. Die ERgebnisse der BAM stimmen sehr gut mit dem Prognosekonzept von Highspeed 2 überein. Dies wird an den Punkten 1. Störgrößen, 2. Achsimpulse, 3. Tunnelstrecken aufgezeigt.