The steam turbine pedestal foundation is a massive concrete frame structure which sits on soil. It consists of an operating deck (also known as table top), mezzanine slabs, ten vertical elements and a base mat. The layout of the operating deck is controlled by the footprint of the machinery provided by MHI (Mitsubishi Heavy Industries). The deck is 47.70m long in E-W direction (longitudinal direction) and 12.50m wide in N-S direction (transverse direction).
There are four openings in the deck for the connection of various piping and equipment to the underside of the STG machine. For table top structural members, the longitudinal ones in E-W direction are identified as girders and transverse ones in N-S direction as beams. Four columns are provided at the high-intermediate pressure turbine area and another four at the generator area.
The ten columns together with the operating deck girders and beams, comprise the lateral force resisting frame system for the machine and the table top. The base mat provides a uniform support for the pedestal columns, and turbine building columns. The condensers, which are installed underneath the lower pressure turbines, are directly supported by the base mat.