Analysis of behaviour of raft foundations under seismic and impulsive loading

The present study aims at analyzing behaviour of reactors' raft foundations during earthquake ground motion considering plate-foundation interaction. The foundation parameters characterize the compressive strain and shearing strain in the foundation. In the study two formulations have been investigated for studying dynamic behaviour of moderately thick plates. The first formulation is based on the Reissner-Mindlin plate theory, considering the first order shear deformation effect and including the plate-foundation interaction and thermal effects. The formulations have been extended to the case of large deflections of Reissner-Mindlin plates. The second formulation assumes Mindlin plate theory; the governing equations of dynamic equilibrium have been derived using Hamilton's principle and Euler - Lagrange equation of calculus of variation. Using these two formulations, programs have been prepared and validated