7.2 Ingenieurbau
Filtern
Dokumenttyp
- Zeitschriftenartikel (41)
- Beitrag zu einem Tagungsband (14)
- Buchkapitel (2)
Sprache
- Englisch (57) (entfernen)
Referierte Publikation
- ja (57) (entfernen)
Schlagworte
- Compressive strength (4)
- Train passage (4)
- Damage detection (3)
- Fatigue (3)
- Hammer impact (3)
- Reliability (3)
- Slab track (3)
- Statistical tests (3)
- Structural health monitoring (3)
- Axle impulses (2)
- Axle sequence (2)
- Bridge (2)
- Earth block masonry (2)
- Ground vibration (2)
- Irregular soil (2)
- Model interpolation (2)
- Moisture content (2)
- Relative humidity (2)
- Resonance (2)
- Soil erosion (2)
- Static axle loads (2)
- Structural systems (2)
- Subspace-based method (2)
- Train-induced ground vibration (2)
- Vehicle–track interaction (2)
- Wind turbine tower (2)
- Achsfolgespektren (1)
- Acoustic emission (1)
- Acoustic emission analysis (1)
- Ambient excitation (1)
- Ansys Autodyn (1)
- Artificial Intelligence (1)
- Attenuation (1)
- Automated Modal Analysis for Tracking Structural Change during Construction and Operation Phases (1)
- Automated operational modal analysis (1)
- Autonomous underwater vehicles (1)
- Ballast track (1)
- Bauteile (1)
- Bauwerke (1)
- Bayesian analysis (1)
- Bayesian system identification (1)
- Benchmark (1)
- Boundary element (1)
- Box-Behnken (1)
- Bridge resonance (1)
- Bridge vibration (1)
- Brücken (1)
- Buckling soil-structure-interaction offshore piles track (1)
- Building and Construction (1)
- Cancellation (1)
- Cement-based composites (1)
- Civil and Structural Engineering (1)
- Coating (1)
- Cohesive granular materials (1)
- Compaction grouting (1)
- Compliance function (1)
- Compression tests (1)
- Computational (1)
- Computer Vision (1)
- Concrete (1)
- Condensed Matter Physics (1)
- Continuous soil (1)
- Continuously inhomogeneous geological media (1)
- Continuously inhomogeneous soils (1)
- Crack Luminescence (1)
- Crack damage detection (1)
- Cracks (1)
- Cyber security (1)
- DUCON® (1)
- Damage characterization (1)
- Damage evolution (1)
- Damage identification (1)
- Damage localization (1)
- Decision matrix analysis (1)
- Deterioration (1)
- Digital Image Correlation (DIC) (1)
- Discrete Element Method (1)
- Discrete element method (1)
- Drucker-Prager (1)
- Ductility (1)
- Dynamic axle loads (1)
- E-modulus (1)
- Earth blocks (1)
- Earth masonry (1)
- Environmental changes (1)
- Environmental effects (1)
- Erosion (1)
- Estimation (1)
- Fatigue strength (1)
- Fault detection (1)
- Fault detectionchanging (1)
- Features (1)
- Fequency domain (1)
- Fibre optic sensors (1)
- Filter effects (1)
- Finite element (1)
- Finite element analysis (1)
- Finite elements (1)
- Finite-element boundary-element method (1)
- Fly ash (1)
- GPA (1)
- GPU Parallel computing (1)
- General Materials Science (1)
- Geology (1)
- Geometric vehicle and track irregularities (1)
- Granular cohesion (1)
- Grout (1)
- Grouted connection (1)
- Grouting (1)
- HAZID (1)
- High-rise building (1)
- Horizontal wind turbine (1)
- Hydraulic jet erosion (1)
- Impact (1)
- Impact loading (1)
- Impinging jet (1)
- Inclination angle (1)
- Inspection (1)
- Inspection planning (1)
- Interface (1)
- Irregular ballast (1)
- Jacket support structure (1)
- Jet erosion test (1)
- Jet impingement (1)
- LBM-DEM (1)
- Laminar flow (1)
- Large components (1)
- Lateral dynamic displacement (1)
- Lattice Boltzmann Method (1)
- Lattice Boltzmann method (1)
- Layered soil (1)
- Layered soils (1)
- Linear parameter varying systems (1)
- Load identification (1)
- Load vector (1)
- Load-bearing behaviour (1)
- Local approaches (1)
- Luminescence (1)
- Material Point Method (MPM) (1)
- Metakaolin (1)
- Micro-reinforcement (1)
- Microfine Cement (1)
- Micromechanical modelling (1)
- Microsilica (1)
- Mitigation (1)
- Mix design (1)
- Mixed formulation (1)
- Mobile elements (1)
- Modal analysis (1)
- Modalanalyse (1)
- Model updating (1)
- Modulus of elasticity (1)
- Moisture (1)
- Monitoring (1)
- Monitoring-informed inspection and maintenance planning (1)
- Multi-beam track model (1)
- Non-Destructive Evaluation (1)
- Numerical modeling (1)
- Obstacles (1)
- Offshore (1)
- Offshore geomechanics (1)
- Offshore pile foundation (1)
- Offshore steel structures (1)
- Offshore wind turbine (1)
- Optimal sensor placement (1)
- Perfectly Matched Layer (PML) (1)
- Piaui state (1)
- Pile bending stiffness (1)
- Pile foundation (1)
- Planar tomography (1)
- Post-impact evaluation (1)
- Pressure (1)
- Probability of Detection (1)
- Process noise (1)
- Quasi-static and dynamic tests (1)
- Quasi-static response; (1)
- Rail roughness (1)
- Railway (1)
- Railway bridge (1)
- Random dynamics and vibrations (1)
- Random stiffness variation (1)
- Randomly heterogeneous soil (1)
- Recovery experiments (1)
- Rehabilitation (1)
- Reinforced concrete structure (1)
- Remote sensing vibrometer (1)
- Repair (1)
- Residual evaluation (1)
- Risk (1)
- Risk-based design (1)
- SHCC (1)
- SHM (1)
- SHM environmental bridges (1)
- Safety (1)
- Sandstone (1)
- Santa-marta (1)
- Scattered axle impulses (1)
- Scattering (1)
- Serra da cangalha (1)
- Shell buckling (1)
- Shrinkage Reducing Admixture (1)
- Soil forces (1)
- Soil stiffness (1)
- Soil-structure interaction (1)
- Sorption isotherm (1)
- Static loading (1)
- Statistical evaluation (1)
- Statistical method (1)
- Statistical pattern recognition (1)
- Stereo photogrammetry (1)
- Stiffness variation (1)
- Strain (1)
- Strength (1)
- Stress-strain relation (1)
- Stress–strain-relation (1)
- Structural Health Monitoring (1)
- Subspace methods (1)
- Subspace-based residual (1)
- Superplasticizer (1)
- Supplementary Cementitious Materials (1)
- Sustainable binders (1)
- System identification (1)
- TRC (1)
- Temperature effect (1)
- Temperature effect rejection (1)
- Temperature modeling (1)
- Temperature rejection (1)
- Track deflection (1)
- Track displacements (1)
- Track filter (1)
- Track filtering (1)
- Track-soil interaction (1)
- Train-induced vibration (1)
- Transverse butt weld (1)
- Trench (1)
- Tunnel (1)
- Tunnel-to-surface reduction (1)
- UHPC (1)
- Ultrasonic testing (1)
- Unbounded domain (1)
- Uncertainty (1)
- Uncertainty in reference (1)
- Uncertainty quantification (1)
- Value of information (1)
- Variational Bayesian statistics (1)
- Vehicle-track interaction (1)
- Vibration measurement (1)
- Vibration measurements (1)
- Vibrations (1)
- Viscosity (1)
- Water Science and Technology (1)
- Wavenumber domain (1)
- Weld imperfections (1)
- Wheelset (1)
- Wind (1)
- Wind energy (1)
- Wind energy tower (1)
- Workability (1)
- layered soil (1)
- temperature (1)
Organisationseinheit der BAM
- 7.2 Ingenieurbau (57) (entfernen)
Paper des Monats
- ja (4)
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 train passages over intact or damaged slab tracks on different soils have been calculated by the finite-element boundary-element or the wavenumber-domain method. The influence of track and soil parameters on the distribution of the track displacements and the soil forces has been analysed. The measured and calculated displacement time histories of train passages could be used to identify track damages such as lose sleepers or a lose track plate. The time histories and spectra of the soil forces can explain the measured ground vibration reduction of slab tracks. The calculated displacement and force distributions of slab tracks on continuous soils do not fulfil the Winkler hypothesis and Winkler models should not be used for track analysis.
Many measurements of train induced ground vibrations show high amplitudes for a certain mid-frequency range. This ground vibration component cannot be well explained by dynamic loads of the train. Many characteristics indicate that the axle impulses, which are scattered by an irregular soil, are the excitation. This new understanding of railway-induced ground vibration is verified by numerical analysis. The response of the regular homogeneous and irregular inhomogeneous soils has been calculated by the finite-element method in frequency domain. A specific superposition of the impulse responses has been invented including time shift, axle sequence, track filter and hanning filter. The superposition 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 of which the stiffness varies randomly in space, the superposition yields a mid-frequency ground vibration component from the scattering of the axle impulses. The existence and the importance of this component can thus be demonstrated by the calculations. Some rules of the influence of distance, train speed, soil stiffness, strength and width of the stiffness variation have been derived from the calculations. Many measurements show the unique explanation of the mid-frequency ground vibration component by the scattered axle impulses.
A combined finite-element boundary-element method for the dynamic interaction of the soil with flexible structures such as single piles or complete wind energy towers has been developed. Flexible piles in different soils are analysed in frequency domain. The different parameters such as the stiffness of the soil, the bending stiffness and the radius of the hollow pile are analysed for their influence on the complex compliances. The results have been determined as specific power laws which are different for the different load cases (horizontal, rocking, coupling) and for the different soil models (Winkler, continuum with constant, root-parabolic and proportional-linear stiffness variation). The strongest influence of the soil stiffness can be found for the homogeneous soil and the horizontal component. Winkler soils have a weaker influence than the corresponding continuous soils. An offshore wind energy tower has been modeled and calculated for wind and wave loads.
The reduction in train-induced ground vibrations by different railway lines and by mitigation measures in the propagation path was analysed in a unified approach by two-dimensional finite element calculations. In general, there was no reduction at low frequencies, and the reduction be-came stronger with increasing frequencies. A maximum reduction of 0.1 at high frequencies was established with an open trench. Reductions between 0.7 and 0.2 have been found for the other sit-uations, filled trenches, walls, plates, and blocks, as well as for railway lines on dams, in cuts and in a tunnel. Bridges can produce amplifications due to their resonance frequencies, but also strong reductions due to massive bridge piers. The influence of some parameters has been analysed, such as the bridge span, the inclination of the dam and the cut, the stiffness of the soil, and the tunnel structure. The dynamic track stiffnesses of a surface, bridge, and tunnel track have been calculated using the 3D finite-element boundary-element method for comparison with corresponding meas-urements.
The vehicle–track interaction generates forces and consequently vibrations in the environment. The interaction has been analysed by the simultaneous measurements of vehicle, track and ground vibrations during test runs with varied train speeds. The special effects of the passage over a bridge and through a tunnel are studied and compared with the measurements on a conventional ballasted surface line. The maximum amplitudes, narrow band and one-third octave band spectra are presented for the axle-box accelerations and for the track, bridge and ground vibrations. The different frequencies and frequency bands are related to wheel out-of-roundness, track alignment errors, the sleeper passage and the wheelset–track resonance. An axle impulse component has been observed at the track, at the near-field soil and as a scattered version in the far field. Specific results can be found for the bridge track, where clearly speed-dependent bridge resonances occur due to the axle sequence of the train, and for the tunnel track where soft rail pads are responsible for a strong amplification around the wheelset–track resonance. On the other hand, the axle impulses are strongly reduced by the tunnel track, and the scattered axle impulse component is not as relevant as for the surface track. As a consequence, a strong mid-frequency amplitude reduction of the tunnel compared to the surface line has been measured for low and high train speeds by the Federal Institute of Material Research and Testing (BAM) and by other institutes.
The propagation of ground vibrations is theoretically analysed with frequency-wavenumber and simplified methods. Experimental methods are presented which can characterise the site-specific ground vibrations by wave velocities, stiffness and damping. Measurements with hammer and train excitation have been performed at several sites. The one-third octave spectra show the stiffness-dependent amplitudes and the low- and high-frequency filter effects due to the layering and the damping of the soil. Specific train effects, an additional high-frequency filter, the sleeper passage frequency, and an amplified mid-frequency component can be clearly found. The attenuation with distance is analysed in detail where the theoretical exponential and the empirical frequency-dependent power law are considered. Hammer and train excitation show the same site-specific effects which are mainly due to the stronger or weaker damping of the soil. The train attenuation is generally weaker than the hammer attenuation. The attenuation exponent of the power law, which is strongly dependent on the site and the frequency, is reduced for the train vibration by 0.3 to 0.5 in agreement with the theory. Reasons are discussed for the overall power law and for the dominating mid-frequency component.