Propagation of structure-borne noise in building adjacent to subway lines

Today, the need for development of metro lines in crowded urban environments is inevitable. Construction and operation of metro generally have adverse side effects (such as noise and vibration) on residents of buildings adjacent to the metros. Based on various published reports, train-induced Structural Borne Noise is mostly annoying, causing people discomfort. Addressing this issue, probabilistic assessment of train-induced annoyance level in buildings adjacent to subway lines was made in this study. For this purpose, a numerical model of typical buildings in vicinity of a subway line was developed. The model was validated by field tests performed in this study. Nine different sites along metro lines were selected to obtain vibration characteristics of train-induced accelerations received by the metro adjacent building foundations. Various possible vibration time histories were applied to the foundation of the model, using an Incremental Vibration Analysis. At each step of the analysis, the Sound Pressure Level in the building stories were obtained and compared with the limitations proposed by the Federal Railroad Administration. Using the results obtained, the probability of the Sound Pressure Level exceeding the allowable limits was derived. In this regard, a reliability index was obtained. Based on the reliability index, the propagation level of the impermissible Structure-Borne Noise in different stories of buildings was presented as a function of number of the building stories and the peak ground accelerations. Accuracy of the proposed function was illustrated by applying it to eight different sites, indicating the accuracy of more than 83%.