Seismic Evaluation of RC Framed Irregular Buildings with Soil Structure Interaction

Effect of irregularity and soil structure interaction are the prominent factors for the mega structures resting on highly flexible soil. In the conventional design process effect of soil structure interaction is neglected, as the flexibility of soil increases natural period also increases which intern reduces the base shear. In this paper studied the seismic response of RC special moment resisting frame buildings of 4, 8, 12 storeys regular and irregular structure resting on different types of soil, by linear response spectrum analysis with and without soil structure interaction effect and also found the seismic behavior of mass, stiffness, diaphragm and reentrant corner irregular buildings with the inclusion of soil structure interaction. Seismic response of these buildings in terms of base shear, maximum displacement, natural period, are found and variations of these with building height, type of soil, inclusion of soil interaction by Winkler method are found. Effect of soil structure interaction on regular and irregular buildings with different soil types are also examined. Consideration of irregularity and soil structure interacton effect both reduces the stiffness of structure hence the structure becomes more flexible due to this natural period increase. From the design consideration change in natural period due to irregularity and soil structure interaction is an important issue.