PROBABILISTIC AND DETERMINISTIC SEISMIC IN-STRUCTURE RESPONSE SPECTRA OF REACTOR BUILDINGS KKB AND KKG (SWITZERLAND)

摘要

This paper compares deterministic and probabilistic soil structure interaction (SSI) analyses for the reactor buildings Beznau (KKB) and Gosgen (KKG) in Switzerland. The seismic input ground response spectra are UHS at an annual probability of exceedance of 10~(-4) defined at the surface of the KKB and KKG sites, obtained from Probabilistic Seismic Hazard Analysis (PSHA). For the probabilistic SSI analysis, the structural properties (Young's modulus, damping) and the soil properties (shear modulus, damping) of the structural and soil models are scaled by a series of 30 scaling factors randomly generated according to a Latin Hypercube procedure in order to generate an ensemble of 30 soil-structure models. The 30 input motions of the study are generated taking the uncertainty of the ground UHS into account, alternatively without the UHS uncertainty; results are presented from the latter computations. For the deterministic SSI analysis, only the mean soil shear modulus G is varied with a coefficient of variation (COV) of 0.5. COV = 0.5 is justified since the sites are well investigated. The deterministic and probabilistic seismic SSI analyses have been performed by use of the SASSI2010 software. ISRS were developed at foundation level, level of reactor vessel support, and crane runway level. The deterministic spectra are compared to the probabilistic spectra.