Numerical simulation of the response of a reinforced wall to a high speed train passage (original) (raw)
Related papers
Investigation of Way Embankment Stability on Movement of High Speed Trains
2021
In this paper is considered the problem related with a stressed state of railway embankments taking into account of dynamic loadings from high-speed trains. In the offered technical method is giving wave nature transmissions of dynamic loading from the passenger trains and their interaction of soil layers with various parameters. The design procedure gives a clear physical and mathematical pattern, where all formulas are in detail shown and simple for understanding. Calculation is conducted numerically in two stages. Considering from classical principles of structural mechanics, the first calculation stage of the railway structures includes deformation of the railway sleepers taking into account of a deflection of the soil bases. Further, on the basis of the received data from the first stage is conducting interactions railway roadbed structures with the soil bases. The second stage of calculation includes quasi-static and dynamic parts, where is considering the stressed and deforme...
Numerical analysis of soil vibrations due to trains moving at critical speed
Acta Geotechnica, 2014
High-speed train induced vibrations of track structure and underlying soils differ from that induced by low-speed train. Determining the critical speed of train operation remains difficult due to the complex properties of the track, embankment and ground. A dynamic analysis model comprising track, embankment and layered ground was presented based on the two-and-half-dimensional (2.5D) finite elements combining with thin-layer elements to predict vibrations generated by train moving loads. The track structure is modeled as an Euler-Bernoulli beam resting on embankment. The train is treated as a series of moving axle loads; the embankment and ground are modeled by the 2.5D finite elements. The dynamic responses of the track structure and the ground under constant and vibrating moving loads at various speeds are presented. The results show that the critical speed of a train moving on an embankment is higher than the Rayleigh wave velocity of the underlying soil, attributed to the presence of the track structure and the embankment. It is found that the dynamic response of ground induced by moving constant loads is mostly dominated by train speed. While for the moving load with vibration frequency, the ground response is mostly affected by the vibration frequency instead of train speed. Mach effect appears when the train speed exceeds the critical speed of the track-embankmentground system. Keywords Critical speed Á 2.5D finite element method Á High-speed train Á Mach effect Á Track-embankmentground dynamic interaction
Model quality investigations of induced moving loads of high-speed trains
Numerical Methods in Geotechnical Engineering, 2014
Increasing traffic intensity and train speed in modern railway tracks require complex analysis with focus on soil dynamic behavior. Proper modeling of the dynamic behavior of the railway track system (railway track, trainload, embankment materials, and subsoil) is essential to obtain realistic results. The passing train loads dynamically its subgrade and ballast. It causes different type of deformations in soil embankment. The magnitude of inelastic part of deformations depends on different factors such as, the dynamical stiffness of embankment soil, the type of natural soil under embankment, and its variation along the route. Measurements of dynamical response of embankment and original soil layers for predicting their dynamical stability are essential in design of railway embankments. In recent years, many comprehensive high costly experiments were carried out to obtain dynamical response and property of the soil, for instance, using geophones and accelerometers to measure velocity of the produced waves in soil depth. The main objective of this paper is to propose a method to simulate moving loads of trains in the geotechnical software, which in this moment has limited feature for simulation of moving loads. Here we used this method using the platform of PLAXIS. On the other hand, the railway track embankment was modeled with different constitutive soil models and combination of them such as Linear Elastic (LE), Mohr-Coulomb (MC) and Hardening Soil small-strain (HS-small). Experimental results of a high-speed train embankment on soft subsoil are used to evaluate the results from numerical simulations. The quality of the moving load's model and its sensitivity to different soil constitutive model was also investigated.
Computers and Geotechnics, 2011
The mechanical response of earth structures reinforced with steel strips to loads associated with rail traffic is not well known. In order to better understand the deformations induced by train loads, and to improve design methods, a full-scale structure was built, instrumented, and tested near Rouen, France. Finite-element analyses were performed both in plane-strain and three-dimensional conditions, using different approaches to account for the interaction between the strips and the backfill material. After calibration of the soil-strip interface parameters for a load of 90 kN, simulations of the wall response to a load of 850 kN provided results in good agreement with measurements. Numerical models showed that the soil-strip interface parameters have a major influence on the predicted behavior. The proposed approach could be used for further studies of the influence of geometric and mechanical parameters.
Shock and Vibration, 2017
Transmission of train-induced vibrations to buildings located in the vicinity of the track is one of the main negative externalities of railway transport, since both human comfort and the adequate functioning of sensitive equipment may be compromised. In this paper, a 3D FEM model is presented and validated with data from a real track stretch near Barcelona, Spain. Furthermore, a case study is analyzed as an application of the model, in order to evaluate the propagation and transmission of vibrations induced by the passage of a suburban train to a nearby 3-storey building. As a main outcome, vertical vibrations in the foundation slab are found to be maximum in the corners, while horizontal vibrations keep constant along the edges. The propagation within the building structure is also studied, concluding that vibrations invariably increase in their propagation upwards the building. Moreover, the mitigation capacity of a wave barrier acting as a source isolation is assessed by compari...
Ground Vibrations Induced by High-Speed Trains in Regions with Sudden Foundation Stiffness Change
Proceedings of the Eleventh International Conference on Civil, Structural and Environmental Engineering Computing, 2007
In this paper analytical transient solutions of dynamic response of one-dimensional systems with sudden change of foundation stiffness are derived. In more details, cantilever dynamic response, expressed in terms of vertical displacement, is extended to account for elastic foundation and then two cantilever solutions, corresponding to beams clamped on left and right hand side, with different value of Winkler constant are connected together by continuity conditions. The internal forces, as the unknowns, can be introduced by the same values in both clamped beam solutions and solved. Assumption about time variation of internal forces at the section of discontinuity must be adopted and originally analytical solution will have to include numerical procedure.
MATEC Web of Conferences, 2018
This paper presents a selection of vibration measurement results and analyses performed with regard to their harmfulness to residential buildings. The first part of the paper refers to the analysis of railway vibrations measured in situ at the foundation level of residential building. These vibration records were then used to assess the harmfulness of vibrations relating to each train speed. Assessment of the vibration harmfulness of the building was performed with an indicator of the perceptibility of vibration through a structure (WODB), according to the Polish standard. The second part of the study refers to the creation of dynamic models of buildings with the use of the ‘Diana’ software program and analysis of their responses to railway vibrations. The thresholds specified by the standard in any of the train speeds of up to 250 km/h were not exceeded. Nevertheless, propagation of vibrations induced by train passages and their effect on the structural response of buildings is a c...
Theoretical treatment of ground vibrations from high speed railways
Proceedings of the London Authorities Rail Impact Forum (LARIF), Bromley, Kent, 1999
The increased speeds of modern trains are normally accompanied by increased levels of generated ground vibrations that are especially high when train speeds approach two critical wave velocities in a track-ground system: the velocity of Rayleigh surface wave in the ground and the minimal phase velocity of bending waves propagating in a track supported by ballast, the latter velocity being often referred to as track critical velocity. Both these velocities can be overcome by modern high-speed trains, especially in the case of very soft soil where both critical velocities become very low. As has been earlier predicted by the present author ,