Noise in european railway under modernization and its reduction

This research work presents various noise reduction measures, which, taking into account the relief of the country and the location of urban areas, should be designed during modernization of railway lines. European project "Silence" is dedicated to the reduction of railway noise in urban areas. Attention in this paper is devoted to the impact of infrasound on the people living near the railway. Here we present the study of propagation of vibrations through the ground to the residential buildings. With this aim in view, experimental tests were performed for clarification of vibration propagation process from the railway lines (railings) to the residential building. Evaluation of possible impact of noise caused by the trains on the environment is presented. The report provides sound pressure levels from the moving trains, which will run until the reconstruction of the main line. Moreover, noise levels are predicted when modernizing road and railway transport means (locomotives, vans, etc.). This research work studies spectrum composition of noise produced by the train in terms of quantity and quality of the radiated energy with respect to the human body, i.e. not only by the sound level dBA, but also by the spectrum composition of sound pressure level. Attention is focused on the impact of very low sound frequencies and infrasound. On the basis of the measured and calculated noise levels propagated by various future railway trains, the impact of noise produced by the trains on the environment is specified. Based on the results of noise analysis, measures are foreseen for the reduction of harmful noise propagated by the trains. The article presents the research on reduction of noise and vibrations by means of barriers theory and their implementation in practice. Acoustic barriers are divided according to their usage and structures. The article deals with the presentation of implementation of screens in practice together with their theoretical evaluation as well as dependences on structure and materials of the screens. Evaluation of their positive and negative acoustic properties is provided as well. The obtained results will be used in the recommendations when designing noise reduction measures and expanding a railway network in the Baltic countries.