A ۲.۵ Dimensional Finite Element Model For Predicting The Vibrations In A Visco-Elastic Multi-Layered Half-Space Subjected To High-Speed Train

High-speed trains are able to produce vibrations which cause serious problem for near buildings and their households and near sensitive infrastructures. Regarding multilayered soil profile in nature, engineers need to use a reliable and low cost approach to predict the vibrations due to high-speed. ۲.۵D finite element models are able to obtain ۳D response from ۲D meshes, and they have lower computational costs than full ۳D models. Moreover, ۲.۵D models are able to stimulate details regarding wheel-track interaction as well. In this paper, a ۲.۵D FEM is proposed for predicting vibration due to high-speed trains. A multilayered profile is modeled, and effects of frequency and velocity ranges, soil dynamics properties are investigated. Displacements are calculated in three speed zones: sub-sonic, tran-sonic and super-sonic. All equation solved in frequency domain for simplicity. It is found out that the vibration amplitude increased with increasing in velocity, however, the maximum magnitude would be around Rayleigh wave velocity. In addition, when the moving load travels under the Rayleigh wave velocity, the vibration amplitude would be lower than tran-sonic and super-sonic speeds. In depths where the soil material changes, the trend of dynamics response changes either. In the other words, the way of wave propagation changes according to the Rayleigh, Shear and Compressional waves velocity of the soil layer.

Keywords:

Moving loads , ۲.۵D FEM , Dynamics Response , Wave propagation , Ground vibration.