عنوان مقاله [English]
Train induced vibration has always been a matter of major concern for railway engineers. In addition to high track maintenance costs, due to excessive vibration, ground vibration may cause annoyance to people who live near track neighborhoods.One potential solution toward minimizing these effects is the use of Asphalt Concrete (AC) or Rubber Modified Asphalt Concrete (RMAC) instead of a subballast layer, as an efficient method for vibration reduction.This study focuses on the behavior of high-speed railway foundations, using the PLAXIS finite-element code. The track foundation was subjected to dynamic loading in several scenarios, with RMAC, AC and conventional ballast materials. Train loads are assumed to be harmonic, and the predominant frequency of loads is considered to be the bogie passage frequency.The results of the analyses show the effect of train and track parameters on vibration level. Train axle load has a great impact on track accelerations,especially for heavy axle loads, whose increase in vibration becomes highly nonlinear.As load frequency increases, vibration increases. At frequency of 5 Hz, the natural frequency of the track is equal to that of train loads and,consequently, track vibration increases considerably. By varying the properties of foundation materials, the response of points at specified distances from the simulated dynamic loading was monitored. As shown in the paper, RMAC reduces peak acceleration in the tracks up to 15\%.