RESPONSE SPECTRA ANALYSIS OF SYMMETRIC AND ASYMMETRIC BUILDINGS WITH VARIATION IN NATURAL PERIOD AND SOIL STRATA

Rajesh Kadiyala, Tejaswi Kota

Abstract: Seismic analysis and design of any structure requires time history data. Unavailability of records at all the locations makes response spectra as a powerful analysis tool. As a scope of this paper, a set of 10 buildings with their period varying from 0.1 to 1.18 sec were considered and response spectra analysis was carried out for the soil site conditions as per IS code. The variation of acceleration, velocity and displacement responses with respect to change in period of the structure and the soil type were compared. This study is extended to buildings with asymmetry as well. Another set of asymmetric buildings whose time periods were varied from 0.1 to 1.19 sec are also analyzed for the same above mentioned soil conditions. It was observed that all buildings with fundamental mode period between 0.1 to 0.4 sec in the chosen direction have same response irrespective of the soil type. The maximum variations in the responses for building resting on stiff medium and soft strata are presented for both the buildings with symmetry and asymmetry. The results obtained shows need to carefully study responses of buildings with smaller frequencies and that resting on less stiffer soils.

Keywords: Response Spectra, Soil Amplification.

DOI: https://doi.org/10.15623/ijret.2016.0514004