Preliminary Report on the Principal Geotechnical Aspects of the October 17, 1989 Loma Prieta Earthquake.

摘要

The report contains preliminary information and observations regarding the principal geotechnical engineering aspects of the Loma Prieta Earthquake of October 17, 1989. Geotechnical factors exerted a major influence on damage patterns and loss of life in the catastrophic event. The vast majority of damage to structures and other facilities occurred on sites underlain by deep soil deposits which amplified shaking levels at these locations. More than 50 of the 62 deaths attributed to the earthquake occurred on sites underlain by deep, and typically cohesive, soil deposits. Additional significant geotechnical features included: (1) widespread liquefaction which resulted in significant damage to bayshore areas and (2) widespread landslides and rockfalls which closed roads and caused considerable damage in the region near to the zone of fault rupture. Slides and rockfalls also occurred along the Pacific Coast, and small slides and rockfalls were observed at distances of up to 70 miles from the epicentral region. A number of structures and sites in the immediate vicinity of the main fault rupture were simply overwhelmed by strong inertial forces, but the levels of shaking which propagated to the more distant regions of concentrated population were considerably less severe and did not represent a true test of the ability of the region to survive a major earthquake.