influences of railway track geometry parameters on ground-borne vibration

one of the most important challenges in the development of urban railways network is the effects of railway vibrations on human and adjacent structures. although various investigations into the sources of railway vibrations have been conducted, very few research works have been reported on the influences of track geometry parameters on the level of vibrations. this is addressed in this research. the influences of railway track geometry parameters including rail cant, track gage, super-elevation, curve radius, profile, alignment and twist on ground-borne vibration were investigated by sensitivity analyses of a numerical model developed in this research. the model was validated using data obtained from a comprehensive field measurement conducted in tehran metro lines (iran). results indicate that the effects of geometry parameters on track vibration levels are considerable. based on the results obtained, the current code of practice was improved by establishing new limitations on the allowable track geometry parameters tolerances. it was shown that consideration of these new limitations ensures that the induced track vibrations remain within the allowable limits.