Executive Summary : | Natural vibration period is an important parameter in seismic design and response analysis of structures. The Indian standard code (IS 1893(Part 1):2016) provides the natural vibration period by utilizing the height of the structures which is mostly applicable to buildings constructed in plain terrain. It does not provide the natural periods of buildings specifically taking into consideration the ones built in hilly areas. It is worth mentioning that structures located in the hilly regions are more susceptible to seismic effects in comparison to rest of the areas. Therefore, there is a need to develop a unified model to estimate the natural periods for buildings located in hills. There are various experimental methods as well as analytical models of the full structures including the elements that contribute to mass and stiffness to determine natural period. Ambient vibration test (AVT) which is a non-destructive technique unlike forced vibration testing can also be used for the determination of the natural period. In the present study, the estimation of natural vibration period of buildings located on hill slopes or other vulnerable sites in the hilly states of India will be emphasized. Further, the investigation will be based on the natural vibration period of buildings using ambient vibration tests to be performed on different buildings at various locations in the state of Uttarakhand. Empirical relationships between the natural vibration period and height of buildings incorporating the slope conditions along with necessary ground condition variability are proposed to be included in the current work. |