Parametric studies for reactor building raft

The base raft of reactor building (RB) for 500 MWe PHWR, is 62.0 meter in diameter, founded on good rock 20 meters below the finished grade level. Double containments and the internal structures, transmit all vertical and horizontal loads to the base raft. Raft is generally analyzed as a plate on elastic foundation simulating foundation rock as equivalent rock springs applied at the nodes. This being a sub-structure analysis, modelling of geometry and all other parameters viz. effect of super-structure/adjacent rock interface etc. play an important role. This paper explains studies conducted to establish simplistic procedures to account for various complex parameters which influence the design of the raft