Linear and nonlinear response of structures and equipment to California and eastern United States earthquakes

This report investigates and compares the response of nuclear-plant structures and equipment subject to small-magnitude, short distance recordings of earthquakes in the central and eastern United States and large-magnitude recordings from California earthquakes. For the structure, this study considers a number of models with several frequencies and numbers of floors. For the equipment, which is modeled as having one degree of freedom, this study considers a wide range of frequencies and locations within the structure. Linear and nonlinear behavior of both structures and equipment is considered. This study concentrates on the response of high-frequency equipment and how this response is affected by high-frequency base motions from small earthquakes in the central and eastern US and by structural nonlinearity induced by the more intense, large-magnitude California records. This study presents simple, fast methods for the preliminary assessment of equipment response to a given ground motion. These methods require minimal amounts of information on the structure and the ground motion, and should prove useful when decisions must be made under time and economic pressures. 31 refs., 46 figs., 6 tabs.