COMPARATIVE PROBABILISTIC-DETERMINISTIC INVESTIGATIONS FOR EVALUATION OF SEISMIC SOIL-STRUCTURE RESPONSE
George Stoyanov1 and Dan M. Ghiocel2
2 Ghiocel Predictive Technologies, Inc., Rochester, New York, USA
Probabilistic seismic soil-structure interaction (SSI) analysis is theoretically the most appropriate analysis to include the effects of inherent uncertainties related to the seismic input motion and soil and structural material behavior. The paper discusses the application of probabilistic SSI analysis to nuclear structures based on the recent ASCE 04-2013 standard draft (ASCE, 2013) recommendations for deterministic and probabilistic SSI analyses. Probabilistic and deterministic SSI analyses are comparatively performed for two case studies: i) EPRI AP1000 RB stick model and ii) PWR RB stick model. Both soft soil and rock sites are considered. The probabilistic SSI analyses assume that the spectral shape of the site-specific GRS seismic input and the soil profile stiffness and damping profiles are idealized as random fields. The structural stiffness and damping random variations are modeled for each structural element group as a pair of random variables that depend in an opposite way on the structural stress level. To perform the deterministic and probabilistic SSI analyses the ACS SASSI software including Option Pro was used (Ghiocel, 2013). The comparative SSI results include in-structure response spectra (ISRS) at different locations with the two investigated RB complexes. A comparison of probabilistic ISRS computed using different ASCE 04-2103 recommended methods is included.