Studies of pollutants and modeling
In recent years the problem of building vibrations has gained an increasing importance in relation to both the different structural typology of modern buildings, due to a more rational use of materials with improved mechanical resistance, and to the increase of vibration sources, especially those generated by human activities.
Vibrations may cause discomfort to the building occupants as well as architectural or structural integrity damages resulting in risks for the residents’ safety.
Another critical issue concerns preservation of historical monuments. Nevertheless, in Italy there isn’t any current national regulation that establish quantitative limits for exposure to vibrations.
There are national and international technical standards which are a useful reference for the evaluation of noise in buildings affected by vibration phenomena and help to assess the vibration effects on human bodies and building structures.
Concerning the effects on the human body, the technical standards to refer to are UNI 9614, UNI 11048 and ISO 2631-2. About the possible damages to building integrity, vibration evaluation recalls other technical standards, such as UNI 9916 and DIN 4150-3.
Vibration analysis has always been one of the leading sectors of VDP in the last 25 years, applied in particular to transport infrastructure railway.
Based on the know-how developed, the services that VDP offers are divided into four phases, depending on the design stage developed, ranging from preliminary investigations, to design of mitigation actions and support to Authorities even after the conclusion of the project (e.g. informative meetings with the citizens) .
Vibrations are a phenomenon of transmission of energy by means of waves in different frequency. The noise is due to the propagation of high frequency waves (f> 50Hz), mainly by air, while the vibrations are due to the propagation through solid materials of low frequency waves.
Vibration reduce with distance much more gradually than noise, and are, therefore, more likely to reach receivers located far away from the source of energy. Furthermore, the way of propagation of vibration waves from the source to the receiving point varies in function of many parameters. This makes complex its engineering analysis: type of soil, type of foundation of the building, type of building structure, etc.
