EVALUATION OF SOIL-STRUCTURE INTERACTION GUIDELINES IN INDIAN SEISMIC CODES

According to new guidelines from Indian standards on Earthquake resistant design of structures (IS1893-Part1 and 4), seismic soil-structure interaction (SSI) should be considered if structure is resting other than rock or rock like material having SPT value less than 50. In the present study adequacy of codal provisions related to SSI, given in 1893- part 4 (2005) are evaluated. A parametric study is carried out on a 150 m tall RCC chimney considering the effect of seismic zone on structural response of chimney by incorporating strain dependent shear modulus. The analysis and results show that the time period increases with in crease in soil flexibility, while design base shear and design bending moment decreases with increase i n soil flexibility.