Seismic Safety Margins Research Program. Identification of sensitive parameters for soil-structure interaction

The effects of soil-structure interaction on the response of the containment building of the Zion Nuclear Power Plant have been studied. The modelling and subsequent analyses were made as part of the Seismic Safety Margin Research Program (SSMRP). The present investigation is divided into three parts. First, the effect of embedment on the total response of an actual containment building was studied by considering surface and embedded foundation models. The bases of the comparison were the floor accelerations, floor response spectra, and base forces and moments for two different control motions. Second, the effect of obliquely incident waves was analyzed by calculating the response of the structure to incident waves with different phase velocities. Finally, approximate methods for extending some key elements of the soil-structure interaction model without tedious recalculations are suggested for special sets of conditions; these methods may be useful in the probabilistic studies contemplated in the SSMRP