7.2 Ingenieurbau
Filtern
Dokumenttyp
- Vortrag (169) (entfernen)
Referierte Publikation
- nein (169)
Schlagworte
- Structural Health Monitoring (16)
- Offshore wind energy (9)
- Ground vibration (8)
- Brücken (7)
- Fatigue (7)
- Offshore (7)
- Design methods (6)
- Physical phenomenology (6)
- Pile foundations (6)
- Structural health monitoring (6)
- Offshore wind turbines (5)
- SHM (5)
- Bahnerschütterungen (4)
- Building vibration (4)
- Deterioration (4)
- Foundations (4)
- Gründungsstrukturen (4)
- Model interpolation (4)
- Monitoring (4)
- Numerical modelling (4)
- Structural systems (4)
- Windenergie (4)
- Buckling (3)
- Damage characterization (3)
- Datenmanagement (3)
- Deep foundations (3)
- Erschütterungsminderung (3)
- Grout (3)
- Hammer impact (3)
- Impact (3)
- Inspection (3)
- Leichtbau (3)
- Maintenance (3)
- Monopiles (3)
- Offshore Windenergieanlagen (3)
- Offshore geomechanics (3)
- Physical testing (3)
- Planar tomography (3)
- Probabilistic (3)
- Shell Buckling (3)
- Slab track (3)
- Soil-structure interaction (3)
- Steel structures (3)
- Train passage (3)
- Vibration (3)
- Wind Energy (3)
- Zivile Sicherheit (3)
- AISTEC (2)
- Automatisierte schweißtechnische Fertigung (2)
- Bayesian updating (2)
- Belastungsversuch (2)
- Bridges (2)
- Compaction Grouting (2)
- Container loading (2)
- Coupled fluid-particle simulation (2)
- Crack detection (2)
- Damage detection (2)
- Design (2)
- Dispersionsmessung (2)
- Drop test (2)
- Elastische Elemente (2)
- Elastische Gleiselemente (2)
- Emission (2)
- Environmental effects (2)
- Erosion (2)
- Erschütterungen (2)
- Erschütterungsprognose (2)
- Fault detection (2)
- Foundation load (2)
- GPU parallel computation (2)
- Großer Fallturm Horstwalde (2)
- High-performance computing (2)
- High-strength concrete (2)
- Inspection planning (2)
- Klimakammer (2)
- Layered soil (2)
- Micromechanical modelling (2)
- Modalanalyse (2)
- Numeric simulation (2)
- Offshore Pile Foundation (2)
- Offshore Windenergy Pile Buckling (2)
- Offshore foundations (2)
- Offshore geotechnics (2)
- Offshore wind (2)
- Offshore wind turbine (2)
- Pile Tip Buckling (2)
- Railway (2)
- Railways (2)
- Reinforced concrete structure (2)
- Reliability (2)
- Repair (2)
- Repowering (2)
- Risslumineszenz (2)
- Schwingungsdynamik (2)
- Statistical method (2)
- Subspace-based method (2)
- Suction bucket (2)
- Temperature effects (2)
- Temperature rejection (2)
- Train-induced ground vibration (2)
- Tunnel (2)
- Ultrasonic testing (2)
- Vehicle-track-soil interaction (2)
- Vibration measurement (2)
- Vibration measurements (2)
- Wellengeschwindigkeit (2)
- Wind (2)
- Windenergy (2)
- 2-span bridge (1)
- Achsimpulse (1)
- Acoustic emission testing (1)
- Amplitude-charge weight laws (1)
- Amplitude-distance laws (1)
- Amplituden-Abstands-Gesetze (1)
- Analysis of variance (1)
- Ansys Autodyn (1)
- Apartment building (1)
- Artificial Intelligence (1)
- Artificial intelligence (1)
- Asphalt (1)
- Assessment (1)
- Attenuation (1)
- Automatisierte Fertigung (1)
- Automatisierte schweißtechniche Fertigung (1)
- Axial load bearing (1)
- Axle impulses (1)
- Axle pulses (1)
- Axle-sequence spectrum (1)
- BAM Windenergie Fügetechnik (1)
- Bahngleis (1)
- Ballast track (1)
- Base isolation (1)
- Baugrunddynamik (1)
- Bauwerk-Boden-Wechselwirkung (1)
- Bauwerksmonitoring (1)
- Bauwerksüberwachung (1)
- Bayes'sche Analyse (1)
- Bayesian System Identification (1)
- Bayesian methods (1)
- Bayesian system identification (1)
- Belastungsfahrt (1)
- Belastungszug (1)
- Beulen (1)
- Big Data (1)
- Bionik (1)
- Blast (1)
- Bodenschlitz (1)
- Bodenübertragungsfunktion (1)
- Boundary element method (1)
- Box-Behnken (1)
- Bridge (1)
- Brücke (1)
- Buckling piles circular shells (1)
- Building information modelling (1)
- Bulging (1)
- CFD (1)
- Cars (1)
- Centerline solidification cracking (1)
- Changing process noise (1)
- Chemisoprtion (1)
- Climate Chamber (1)
- Climate chamber (1)
- Compressive Cyclic loading (1)
- Compressive cyclic loading (1)
- Compressive strength (1)
- Computer Vision (1)
- Concrete (1)
- Crack Luminescence (1)
- Crack formation (1)
- Crack pattern (1)
- Crack repair (1)
- Cracks (1)
- Cyclic axial shearing (1)
- Cyclic degradation (1)
- Cyclic load (1)
- DEM (1)
- DEM-LBM simulation (1)
- DUCON® (1)
- Damage Detection (1)
- Damage identification (1)
- Deckeneigenfrequenzen (1)
- Deckenschwingungen (1)
- Design models (1)
- Design practice (1)
- DiMoWind RDS-PP Maintenance Digital Twin Offshore Wind Energy (1)
- Digital Image Correlation (1)
- Digital Twin (1)
- Digital twin (1)
- Digitalisierung (1)
- Displacements (1)
- Drone (1)
- Drop Test (1)
- Drucker-Prager (1)
- Ductility (1)
- Dynamic soil properties (1)
- Dynamische Bodenkennwerte (1)
- Dämpfung (1)
- E-modulus (1)
- EERA Joint Program (1)
- Earth masonry (1)
- Earthen hydraulic constructions (1)
- Earthen hydraulic infrastructures (1)
- Einflusslinie (1)
- Einflusslinien (1)
- Einfügungsdämmung (1)
- Elastische Gebäudelagerung (1)
- End-of-life decision making (1)
- Energy (1)
- Entscheidungsfindung (1)
- Environmental (1)
- Environmental Effects (1)
- Ermüdungsprüfung (1)
- Ermüdungsschäden (1)
- Erneuerbare Energien (1)
- Erosion of cohesive soils (1)
- Erschütterungen im Fernfeld (1)
- Erschütterungsausbreitung (1)
- Evaluation (1)
- Excitation forces (1)
- Explosion-induced ground vibrations (1)
- FEM (1)
- Fahrzeug-Fahrweg-Boden-Wechselwirkung (1)
- Faseroptik (1)
- Fatigue deterioration (1)
- Fiber optic sensing (1)
- Filter effects (1)
- Finite Elemente Simulation (1)
- Finite element models (1)
- Flexibility (1)
- Floors (1)
- Fluid-structure interaction (1)
- Fly ash (1)
- Footbridge (1)
- Force reconstruction (1)
- Freight train (1)
- Frequency response function (1)
- GMNIA (1)
- GNSS (1)
- GPU parallelisation (1)
- Gebäudelagerung (1)
- Gebäudemodelle (1)
- Gebäudeschwingungen (1)
- Gekoppelte Fluid-Partikel Simulationen (1)
- Geomechanics (1)
- Geomechanics of offshore foundations (1)
- Geometrie (1)
- Gleiströge (1)
- Granular Cohesive Materials, (1)
- Ground (1)
- Ground vibration measurements (1)
- Grout Injection (1)
- Grouted Connection (1)
- Grouted connection (1)
- Grouting (1)
- Halbraum (1)
- High-rise buildings (1)
- High-speed train (1)
- Immission (1)
- Impact damage of reinforced concrete (1)
- Impedanzmethode (1)
- Inertial interaction (1)
- Injection Sequence (1)
- Inspeciton (1)
- Interface (1)
- Interface model (1)
- Irregular ballast (1)
- Irregular soil (1)
- Irregularities (1)
- Jacket support structure (1)
- Jet erosion test (1)
- Kinematic interaction (1)
- Knudsen effect (1)
- Kraft auf den Boden (1)
- LBM-DEM (1)
- LBM-DEM coupling (1)
- Laboratory beam structure (1)
- Laser beam welding (1)
- Lateral load bearing (1)
- Layered soils (1)
- Leichtbauprinzipien (1)
- Lifetime Extension (1)
- Linear parameter varying systems (1)
- Load Test (1)
- Load bearing behaviour (1)
- Long-term shrinkage (1)
- Macromechanical Sample Strength (1)
- Maintal Bridge Gemuenden (1)
- Maintalbrücke Gemünden (1)
- Maintenance Digital Twin Offshore Wind Energy (1)
- Marine geotechnics (1)
- Material Point Method (1)
- Material moisture (1)
- Material tests (1)
- Measurement (1)
- Measurements (1)
- Mechanical challenges (1)
- Messfahrt (1)
- Metakaolin (1)
- Micro silica (1)
- Micro-reinforcement (1)
- Microfine cement (1)
- Micromechanical LBM-DEM simulation (1)
- Micromechanical Tensile Failure (1)
- Micromechanical analysis (1)
- Micromechanical simulation (1)
- Mitigation (1)
- Mix design (1)
- Mobile elements (1)
- Modal Analysis (1)
- Modal load spectrum (1)
- Modal system identification (1)
- Model Update (1)
- Model updating (1)
- Modellierung (1)
- Modes and waves (1)
- Molecular diffusion (1)
- Monopile (1)
- Monopile Buckling (1)
- Movin load test (1)
- Non destructive testing (1)
- Non-Destructive Evaluation (1)
- Non-destructive testing (1)
- Normung (1)
- Numerical analysis (1)
- Numerical model (1)
- Numerical modeling (1)
- Numerical simulation (1)
- Numerical simulation of impact damage (1)
- Offhore (1)
- Office tower (1)
- Offshore Structures (1)
- Offshore Wind (1)
- Offshore Wind Energy (1)
- Offshore Wind Energy Converter (1)
- Offshore Windenergie (1)
- Offshore pile foundations (1)
- Offshore wind energy foundations (1)
- Offshore wind farm (1)
- Offshore wind farms (1)
- Offshore wind-turbine foundations (1)
- Offshore-Wind (1)
- Offshore-Windenergieanlagen (1)
- Offshore-Windkraftanlagen (1)
- Optimal Sensor Placement (1)
- Passenger train (1)
- Pfahlfußbeulen (1)
- Pfahlnachgiebigkeiten (1)
- Physisorption (1)
- Pile Buckling (1)
- Pile Capacity (1)
- Pile Foundation (1)
- Pile ageing (1)
- Pile groups (1)
- Pile retrofit system (1)
- Pile-Tip-Buckling (1)
- Point Cloud (1)
- Post-impact evaluation (1)
- Prediction (1)
- Prediction of explosion induced ground and building vibration (1)
- Predictive maintenance (1)
- Probabilitische Ingenieurmodelle (1)
- Probability of Detection (1)
- Prognose (1)
- Quasi-static and dynamic tests (1)
- Radar (1)
- Railbridge (1)
- Railway bridge (1)
- Railway tracks (1)
- Railway trafiic (1)
- Railway tunnel (1)
- Randelementmethode (1)
- Randomly heterogeneous soil (1)
- Rayleighwellendispersion (1)
- Rechenmodelle (1)
- Rechenverfahren (1)
- Rehabilitation (1)
- Reinforced concrete (1)
- Research data management (1)
- Residual evaluation (1)
- Richtige Fahrzeugmasse (1)
- Risiko (1)
- Risikoanalyse (1)
- Risk (1)
- Risk-based maintenance planning (1)
- Rissprozes (1)
- Rissprozess (1)
- SHM Environmental (1)
- Safety (1)
- Scaling (1)
- Scattering (1)
- Schadensdetektion (1)
- Schadensüberwachung (1)
- Schienenfahrweg (1)
- Schienenfahrwege (1)
- Schwingungsbasierte Verfahren (1)
- Schwingungsmonitoring (1)
- Shrinkage (1)
- Simple and fast prediction (1)
- Simulation and experiment (1)
- Site-characterization (1)
- Size effect (1)
- Slenderness effect (1)
- Soil Struture Interaction (1)
- Soil erosion (1)
- Soil properties (1)
- Soil-Structure-Interaction (1)
- Soil-pile interaction (1)
- Soil-wall floor model (1)
- Soil-water-structure interaction (1)
- Spektralanalyse (1)
- Stability Buckling soil-structure-interaction piles offshore (1)
- Stabilität (1)
- Static load (1)
- Statistical correlations (1)
- Statistical tests (1)
- Statistische Korrelationen (1)
- Stereo photogrammetry (1)
- Stochastic Subspace Damage Detection (1)
- Structural Systems (1)
- Structural integrity (1)
- Structural integrity maintenance (1)
- Structural integrity management (1)
- Strukturmonitoring (1)
- Störgrößen (1)
- Subspace methods (1)
- Subspace-based residual (1)
- Substructures (1)
- Suction Bucket (1)
- Supplementary cementitious materials (1)
- Support structures (1)
- Surface line (1)
- Surface-tunnel reduction (1)
- System Identification (1)
- Systemidentifikation (1)
- TOP (1)
- Temperatureinflüsse (1)
- Tensile Capacity (1)
- Time-variant reliability (1)
- Tip Buckling (1)
- Tomographic damage evaluation (1)
- Track damage (1)
- Train configuration (1)
- Train excitation (1)
- Train passages (1)
- Train speed (1)
- Tran speed (1)
- Transfer fuction (1)
- Transmission (1)
- Tunnel line (1)
- Tunnelstrecke (1)
- UHPC (1)
- Umwelteinflüsse (1)
- Un- certainty (1)
- Uncertainty (1)
- Uncertainty in reference (1)
- Unterraummethoden (1)
- Value of Information (1)
- Varying soil stiffness (1)
- Varying track stiffness (1)
- Vibration monitoring (1)
- Vibrations (1)
- Vollraum (1)
- Water-structure interaction (1)
- Wave-Tower interaction (1)
- Wellenausbreitung (1)
- Wellenausbreitung in der Tiefe (1)
- Wellenfeldberechnung (1)
- Wind Energy Structures (1)
- Wind Turbines (1)
- Wind energy (1)
- Wind turbines (1)
- Wind-farm aerodynamics (1)
- Windfarm wake analysis (1)
- Zuggeschwindigkeit (1)
- elastische Gebäudelagerungen (1)
- risk, reliability, inspection planning, offshore wind turbines (1)
- zerstreute Achslastimpulse (1)
- Übertragungsmatrizen (1)
- Überwachung (1)
Organisationseinheit der BAM
- 7.2 Ingenieurbau (169) (entfernen)
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.
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.
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.
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 contribution shows measurement examples of cars, floors, foundations, railway tracks, a footbridge, and a railbridge. Vibrations may include modes and waves. Namely in soil-structure interaction, modes are damped, shifted and prevented so that alternatives for the modal analysis are necessary: The approximation of the whole spectrum (flexibility function) and of the whole train passage (moving-load response).
Die Prognose und Minderung von Bahnerschütterungen haben eine lange Tradition in der Bundesanstalt für Materialforschung und -prüfung. Im Jahr 2006 wurde eine Prognose-Software fertiggestellt, die viele Forschungs- und Messergebnisse zusammenfasst. Sie umfasst die Teilbereiche Emission (die Anregung durch die Fahrzeug-Fahrweg-Untergrund-Wechselwirkung), die Transmission (die Ausbreitung durch den Boden) und die Immission (die Übertragung vom Freifeld in ein Gebäude). Die Prognose geschieht in allen Teilen mit einfachen Formeln, die veröffentlicht sind und zur Anwendung für Jedermann zur Verfügung stehen. Es werden Beispiele zur Emission und zur Transmission gezeigt.
Im Bereich Transmissionsprognose werden zu den Anregungskräften (aus dem Emissionsteil) die Bodenerschütterungen als Schwinggeschwindigkeitsterzspektren berechnet. Das Ergebnis hängt stark von der Bodensteifigkeit, -dämpfung und -schichtung ab. Dies wurde später mit einer Messkampagne in der Schweiz an 10 Messorten bestätigt (Bild 1). Die Berechnung erfolgt näherungsweise für einen geschichteten Boden mit einer frequenzabhängigen Wellengeschwindigkeit (Dispersion) oder einem tiefenabhängigen Wellengeschwindigkeitsprofil.
Die Anregungskräfte werden im Prognosebereich Emission mit einem 2-dimensionalen Gleismodell berechnet (Bild 2). 1-dimensionale Modelle liefern meist falsche Ergebnisse und 3-dimensionale Modelle (zum Beispiel mit der kombinierten Finite-Element-Randelement-Methode) sind für eine Erschütterungs¬prognose sicherlich zu aufwändig. Das 2-dimensionale Modell wurde an 3-dimensionale Ergebnisse so angepasst, dass die Ergebnisse für viele Gleise und Böden annähernd zutreffen. Auch Minderungs¬maßnahmen am Gleis können mit diesem Modell sehr gut berechnet werden.
Die Prognoseverfahren wurden in den folgenden Jahren weiter verfeinert. Es wurde die quasi-statische Anregung durch die bewegten statischen Zuglasten mit einer Näherungsformel ergänzt, so dass auch das tieffrequente Nahfeld realistisch erfasst werden kann. Mit der Berücksichtigung der Achsfolge (insbesondere zwischen den Achsen im Drehgestell) ergeben sich zwei typische Minima in den Erschütterungsspektren, die oft auch in den Messungen beobachtet werden. Der Amplitudenanteil zwischen diesen beiden Minima ist oft stärker angehoben, so dass hier eine zusätzliche Erschütterungsanregung vermutet wird. Dieser Anteil kann rein empirisch prognostiziert werden, so wie das in den englischen Prognosen (zuletzt für das Highspeed2-Projekt) enthalten ist. Die Begründung dieses Anteils ist allerdings nicht die Achsfolge, sondern die Zerstreuung der statischen Achslastimpulse durch einen unregelmäßigen Gleisuntergrund und Boden.
Die messtechnische Ermittlung eines Minderungseffektes ist komplizierter als allgemein angenommen. Es reicht nicht aus, jeweils an einem Messpunkt in der Nähe eines Gleises mit und ohne Minderungs¬maßnahme die Erschütterungen zu messen und aus dem Verhältnis der Amplituden (beziehungsweise aus der Differenz der Pegel) „die Einfügedämmung“ zu ermitteln. Es wird an Beispielen gezeigt, wie man hier sinnvoller vorgehen kann.
1. Zunächst ist es wichtig, nicht nur die Einfügedämmung sondern auch die Originalspektren mit und ohne Minderung zu dokumentieren und zu veröffentlichen, damit man kontrollieren kann, ob wesentliche Amplituden und Frequenzbereiche reduziert sind oder ob es sich um eher zufällige Minderungen oder Verstärkungen handelt. (Beispiel Unterschottermatte/Raron, Müller/SBB)
2. Der Messpunkt sollte nicht im Nahbereich des Gleises liegen, da ansonsten eine zu günstige, falsche Einfügedämmung bestimmt wird. (Beispiel Tunnel/ Leipzig/Breitsamter)
3. Um Zufälligkeiten zu vermeiden, sollte man an mehr als einem Punkt messen. (Beispiel Unterschotterplatte/Altheim/Auersch)
4. Man sollte eigentlich immer auch die Bodenkennwerte (Steifigkeit, Dämpfung, Amplituden-abnahme, Übertagungsfunktion) messen. Selbst bei nahegelegene Messquerschnitten kann man Überraschungen erleben. (Beispiel erste ICE-Messungen/bei Würzburg/Auersch)
5. Bei verschiedenen Bodenkennwerten kann man eine Korrektur durchführen. (Beispiel Gleis-tröge/Mistler) Am besten bestimmt man ein äquivalentes Kraftspektrum zu jedem Messort und jedem Messzug (Beispiel Feste Fahrbahn/Gardelegen/Auersch)
6. Prinzipiell gibt es nicht die Einfügedämmung einer Maßnahme. Die Einfügedämmung ist immer boden- und referenzsystemabhängig. Die „beste“ Einfügungsdämmung erhält man mit einem steifen Untergrund (Beispiel Unterschottermatte/Tunnel/München Gasteig/Wettschureck) Das heißt aber nicht, dass die Maßnahme durch einen künstlich versteiften Untergrund besser wird (Beispiel Unterschottermatten/RRT2006/Auersch)
Es werden Messbeispiele gezeigt, die alle neben einer hochfrequenten dynamischen Minderung auch eine mittelfrequente quasi-statische Minderung aufweisen. Dabei wird der mittelfrequente Zerstreuanteil der statischen Achslastimpulse durch die breitere Lastverteilung und damit die Impulsdehnung der Achslastimpulse reduziert. Diese Impulsdehnung lässt sich mit dem 2-dimensionalen Gleismodell berechnen. Die Minderungswirkung hängt aber wiederum vom Referenzsystem und dessen unregel¬mäßiger Steifigkeitsverteilung ab. Je unregelmäßiger der Boden und Gleisuntergrund des Referenz¬systems, desto stärker ist die Minderungswirkung.
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.
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.
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.
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.
The passage of the train is dominated by the impulses of the static axle loads. The response of the regular homogeneous and irregular soils has been calculated by the finite-element method in frequency domain. The superposition of the impulse responses yields the quasi-static component of the ground vibration which is restricted to very low frequencies and to the close near-field of the track. In case of an irregular soil or ballast of which the stiffness varies randomly in space, a mid-frequency ground vibration component is generated by the scattering of the axle impulses. Measurements will be shown which prove the existence of the mid-frequency ground vibration component and the unique explanation by the scattered axle impulses: many international measurements with a raised mid-frequency component, axle-box measurements with a too low mid-frequency dynamic load, amplitude-speed dependencies which are incompatible with irregularity-induced dynamic loads, and ground vibration reductions due to stiff track elements.
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.
A prediction software has been developed by BAM. The following topics have still be solved. A realistic irregularity spectrum can be derived from axle-box measurements. It agrees wel with the spectrum used for the high-speed 2 project in the United Kingdom. In addition, the scattering of axle pulses should be included. This mid-frequency component can also be found in the HS2 procedure. Finally, the reduction in case of a tunnel line compared to a surface line should be included. Some measurement results of BAM, HS2 and other institutes show a certain mid-frequency reduction. This is due to the load distribution of the tunnel which yields softer axle pulses and the scattered axle impulses are reduced.
Dieser Vortrag präsentiert einige Prinzipien und einige Beispiele zur Minderung von Eisenbahnerschütterungen. Die Prinzipien unterscheiden sich für die Minderungsmaßnahmen im Gleis, im Boden und bei Gebäuden. Kraftübertragungsfunktionen isolierter und nicht isolierter Gleissysteme, reflektierte und durchgelassene Wellenamplituden bei gefüllten Bodenschlitzen und die Übertragung der Freifeldschwingungen ins Gebäude werden analysiert. Bei den einfachen Gleismodellen muss der richtige Anteil der unabgefederte Fahrzeugmasse zum eindimensionalen Gleismodell hinzugefügt werden. Der Minderungseffekt eines gefüllten Bodenschlitzes ist von der Steifigkeit und nicht von der Impedanz des Schichtmaterials bestimmt. Bei einer elastischen Gebäudelagerung muss die Minderungswirkung mit der richtigen Boden- (Fundament-) Steifigkeit berechnet werden, und das abgeminderte Gebäudeverhalten hängt wesentlich von der effektiven Gebäudemasse ab, die mit zunehmender Frequenz deutlich kleiner als die starre Gebäudemasse ist.
Eindimensionale Modelle des Gleises aus einem Schienenstützpunkt, zweidimensionale Modelle enthalten die Kraftverteilung der Schiene. Eindimensionale Modelle machen einen Fehler, weil sie eine zu große Fahrzeugmasse berücksichtigen. Man kann jedoch bei der Berechnung der Minderungswirkung von Gleiselementen eindimensionale Gleismodelle verwenden, um die Kraftübertragung des Gleises bzw. die Minderungswirkung des Gleises zu berechnen. Die Wechselwirkung mit dem Fahrzeug kann einfach mit der dynamischen Stützpunktsteifigkeit berechnet werden. Dabei muss die Stützpunktsteifigkeit mit einer charakteristischen Gleislänge multipliziert werden, die frequenz- und systemabhängig ist.
Die Definition und Beschreibung der Einfügedämmung im Normentwurf DIN 45673-4 ist noch nicht richtig. Es wird die Beschreibung aus DIN 45673-3 herangezogen, die für Messungen gilt. Für die drei Rechenverfahren gibt es jeweils eine passende Beschreibung. Mit diesen Vorlagen ist eine vernünftige Definition der Einfügungsdämmung zu finden. Es bedarf einer Abgrenzung gegenüber anderen (falschen) Möglichkeiten. Des Weiteren ist der Anhang 2 erweitert und der Parametersatz im Anhang 1 auf das Wesentliche reduziert worden.
Prediction of building noise and vibration – 3D finite element and 1D wave propagation models
(2021)
Construction work or traffic excite nearby buildings, and the perceptible or audible vibration can be a nuisance for the inhabitants. The transfer of the vibration from the free field to the building has been calculated by the finite element method for many models in consultancy and research work. The analysis for all storeys of certain building points such as walls, columns and floors unveiled some rules, some typical modes, and some wavetype responses. A simplified building-soil model has been created, which includes well these effects of building-soil resonance, wall/column resonance, floor resonances, and the high-frequency reduction. The model consists of one wall for a wall-type apartment building or a column for each specific part (mid, side or corner) of a column-type office building. The building response in the high-frequency (acoustic) region is calculated as mean values over all storeys and over wider frequency bands, by wave-type asymptotes of an infinitely tall building, and by the soil to wall ratio of impedances. The secondary noise is predicted by Transfer values between the building vibration (center of floors, walls at a room corner) and the sound pressure.
Die Linienlastgesetzmäßigkeit gilt nicht für Zuganregung. Die Punktlastgesetzmäßigkeit wird bei kurzen Zügen in größeren Entfernungen erreicht. Bei langen Zügen reduziert sich die Abnahme um r-0,3 für die theoretische exponentielle Dämpfungsabnahme, um r-0,5 für die vereinfachte potentielle Dämpfungsabnahme. Die gemessenen Abnahmereduktionen liegen in diesem Bereich.
Zur Erschütterungsausbreitung an oberirdischen Bahnlinien gibt es gute Übereinstimmungen zwischen Messungen und der Theorie geschichteter Böden. Bei der Interpretation der Ergebnisse spielt die Rayleigh-Welle eine große Rolle. Je nach Frequenz und Wellenlänge hat die Rayleigh-Welle eine bestimmte Eindringtiefe und erreicht damit mehr oder weniger steife Bodenschichten. Damit bekommt man eine frequenzabhängige Bodensteifigkeit für die Erschütterungsprognose. Für die Wellenausbreitung in der Tiefe statt an der Bodenoberfläche müssen eigene Gesetzmäßigkeiten gefunden werden. Es werden die Punktlastlösungen im Frequenz-Wellenzahlbereich und durch Integration über die Wellenzahlen berechnet. Man erhält die Wellenfelder, die Terzspektren für verschiedene Entfernungen und Frequenzen. Es wird die Tiefenlage und das Bodenmodell (homogen, geschichtet und kontinuierlich zunehmende Steifigkeit) variiert. Die Rayleigh-Welle verliert ihre Bedeutung und stattdessen kann die Vollraumlösung zur Interpretation und Prognose verwendet werden. Es werden die Halbraumlösung mit und ohne Rayleigh-Welle und die Vollraumlösung in der Tiefe diskutiert und verglichen. Neben der Wellenausbreitung (der Transmission) werden auch Effekte der Erschütterungsanregung (der Emission) und der Übertragung in Gebäude (der Immission) mit Hilfe der Finite-Element-Randelement-Methode berechnet. Die Verteilung der dynamischen Achslast durch die Tunnelsohle ergibt eine Minderung gegenüber der Punktlastanregung. Bei der Immission hat man keine Freifeldanregung wie an der Bodenoberfläche. Man muss entweder neben der Wellenamplitude (Verschiebung oder Schwinggeschwindigkeit) in der Tiefe auch die Spannung der ankommenden Welle berücksichtigen, oder man muss die Freifeldamplituden nach Bodenaushub berechnen. Die Rechenergebnisse deuten darauf hin, dass man als Freifeldanregung die zweifache Vollraumlösung ansetzen kann.