Patania F., Gagliano A., Nocera F.

Recent Italian laws oblige Local Authority of each city of Italy to execute a plan of acoustical zonation of the whole territory of city to the aim to identify that areas where noise levels exceeds the alarm law limits so that it can be possible to plan interventions of mitigation and control such as to reduce the value of noise levels below the dangerous ones for public health. The so called “AcousticalCleaningPlan” must be implemented in that areas which can be classified as hazardous ones as like that crossed or bordered by railway or underground. Because of previously referred, people carried out an applied research having as target the investigation about noise problems in that areas of CataniaCity showing high density of residential building surrounding railway lines called “CircumEtenea”. In first step people carried out preliminary and suitable studies about ground geometry, type of uttering sources of areas, layout of receptors, meteoclimatic data, scheduling of trains and so on. Than has been carried out an aimed campaign of phonometric measurements in suitable zones of investigated areas to the aim to prepare input data to a 3Dcomputer code able to define the acoustical maps. Finally, people carried out the acoustical maps of areas crossed by railway. The aim of paper is to show: - The methodologies and techniques to draw the investigation with the backing of a 3Dcomputer code suitable for this use (Mithra code); -Anomalous situations drawing out by comparison between data forecasted by code and that ones measured in situ; -Status of noise pollution with particular reference to contribution coming from railway noise. -Some particular and highlighted acoustical maps in the zones closed to railway; -Some possible techniques to reduce noise levels in the areas in the case of overcoming of law limits.