Design Criteria for Turbine-Generator Pedestals

American design practices and criteria for large turbine generator pedestals is reviewed. Parametric studies show that, irrespective of its rigidity, the mat should be included as part of the pedestal for both dynamic and static analyses. It is argued that differential rather than absolute deflections are more meaningful design constraints. Arbitrary specification of dynamic loads should be discontinued since dynamic loads are a function of both the forcing property and the dynamic characteristics of the structure. Temperature, shrinkage and creep, especially as they affect large sized members, need to be given further consideration. To attain the required accuracy in deflection calculations, torsional and bending stiffnesses of reinforced concrete pedestals must be better defined. Examples are given t illustrate that the design of large-size reinforced concrete members for flexure, torsion and shear cannot be extrapolated from findings n the laboratory sized specimens.