Following conclusions were drawn from the present study:
1. The study shows that natural frequency decreases with increase in soil flexibility and percentage decrease in natural frequency decreases with increasing soil flexibility.
2. For Raft deflection criteria, it is concluded that the Deflection reduces as the stiffness of soil is increased, in other words we can say that hard soil medium leads to good seismic response of a chimney structure.
3. Most of the design codes assumes linear displacement in the annular raft, but in reality SSI plays a major role and displacement will always be more under the chimney shield.
4. The effect of soil-structure interaction plays a significant role in decreasing the radial and tangential moments of annular raft when compared with conventional method.
5. The study shows that increase in slenderness ratio of chimney decreases tangential and radial moment of annular raft.
6. It is observed that decrease in radial and tangential moments when decrease in thickness of annular raft.