RESPONSE OF STRUCTURES DUE TO RAILWAY INDUCED VIBRATIONS

Abstract

An important environmental aspect of building and facility design is the evaluation of vibration transmitted to the site, through the ground, from external sources. Such external sources may include surface and subsurface railways, highway traffic, and machinery in nearby locations. To properly predict excitation levels at a building due to such sources, one must be able to predict how much vibration, in terms of both levels and spectra, is transmitted through the ground from the source. Rail traffic vibrations can be caused by train speed, surface irregularities on wheels and rails, and fluctuating forces that are caused by parameter changes such as the stiffness changes on and between sleepers or variable elasticity of the ground. In the present study it has been tried to examine the nature of excitation due to the passing of trains. The response of typical railway signaling cabin due to the passing of passenger and goods trains has been tried to obtain. The measurement for vertical acceleration has been done and its variation with distance from the track has been observed. Also the varying level of acceleration is tried to relate with the passing velocity of the trains. The data has been analyzed and different characteristics of vibrations i.e. the peak acceleration and average frequency have been related to the velocity of trains. For this graphs have been plotted between velocity of trains and peak acceleration as well as velocity of train and average frequency of vibrations for different places such as at the track at the soil surface at the base of the cabin and at the first floor of the cabin.