Seismic Soil-Structure Interaction Effects at Humboldt Bay Power Plant

The results of a study of the distribution of ground motions and structural response in the Humboldt Bay Nuclear Power Plant during the Ferndale earthquake of June 7, 1975 are presented. Based on a knowledge of the motions recorded at the ground surface in the free-field, computations are made to determine the characteristics of the motions likely to develop at the base of the buried reactor caisson at a depth of 85 ft (26 m) below the ground surface and within the Refueling Building at the ground surface level. The computed motions are shown to be in reasonably good agreement with those recorded at these locations in the same earthquake.