LIFE SNEAK – optimized Surfaces against NoisE And vibrations produced by tramway tracK and road traffic (LIFE20 ENV/IT/000181)

The overall objective is the reduction of noise from roads inside densely populated urban areas, where tram and traffic noise and vibration superpose, by means of low-noise/vibration surfaces and retrofitting solutions having life cycle costs comparable to those of standard surfaces, while achieving a substantial noise reduction and global comfort. In detail: A) Reducing the noise deriving from the superposition of air-borne noise and ground/structure-borne noise, where air-born noise derives from rail-wheel and pavement-tyre interaction, while groundborne noise derives from the same interactions above with propagation through railway and road superstructure The following main key-factors are addressed: Page 23 of 145 LIFE20 ENV/IT/000181 - B1 - Horizontal surfaces (quiet pavements) able to mitigate air-born noise (rail-wheel and pavement-tyre). This implies minimizing pavement-tyre interaction effects (generation) and also their propagation (reflection-based mechanism) and also able to mitigate ground-borne noise; Materials will be optimized to mitigate the propagation of vibrations through deep layers, to further decrease ground-born noise and related bending resonances in the floors and walls of historical and traditional buildings. Indeed, they radiate a disturbing rumbling noise directly into the rooms of the buildings. - To reduce squeal noise a system of sound-absorbing panels (possibly made of recycled material - rubber), bogie skirts and watering system will be implemented on the tramway. B) Reducing people annoyance due to noise and vibration generated by road and tram Psychoacoustic parameters will be evaluated to assess citizens annoyance before and after the interventions to carry out. Acoustic and vibration comfort will be analyzed from and interior and outdoor perspective. C) Contributing to the Directive 996/2015/EC concerning the CNOSSOS noise assessment method C1) by verifying that (as stated in the Directive) 8 dB for R < 300 m and 5 dB for 300 m < R < 500 m should be added to the rolling noise sound power spectra for squeal noise and C2) by providing measurements of sound power level for different configurations. D) Promoting the transferability/replicability of the implemented solutions against noise/vibrations The delivering of guidelines for the strategic design of surfaces will help other EU cities in managing holistically critical scenarios where tramways, roads, and historical buildings coexist, demonstrating easy-replicable solutions and promoting sustainable public mobility.