Nonlinear soil response as a natural passive isolation mechanism—the 1994 Northridge, California, earthquake

摘要: Abstract The spatial relationship between areas with severely damaged (red-tagged) buildings and large strains in the soil (indicated by reported breaks water distribution system), observed during 1994 Northridge earthquake, is analysed. It shown that these can be separated almost everywhere. Minimal overlapping only regions very amplitudes of shaking (peak ground velocity exceeding about 150 cm s −1 ). One explanation for this remarkable separation on ‘soft’ soils, which experienced nonlinear strain levels, were to a lesser degree, possibly because absorbed significant portion incident seismic wave energy. As result, total number San Fernando Valley, Los Angeles Santa Monica may have been reduced factor two or more. This interpretation consistent recorded peak accelerations strong motion same area. concluded reduction potential damage wood frame single family dwellings expected where experiences ‘large’ (beyond linear range) earthquake shaking, but not differential motions, settlement lateral spreading, near surface.