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Empirical Evaluation of Inertial Soil-Structure Interaction Effects.
Stewart, J. P.; Seed, R. B.; Fenves, G. L.
Geological Survey, Menlo Park, CA., November 1998, 240 p.
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Strong motion data were gathered for 58 sites encompassing a wide range of structural systems, geotechnical conditions, and ground shaking levels. System identification analyses were employed with these records to quantify the effects of inertial interaction on modal parameters of structures. Simple indices of free-field and foundation level ground motions were also compared. From these results, the conditions under which significant SSI effects occur were identified, and simplified analytical techniques for predicting these effects were calibrated. Analytical formulations similar to procedures in contemporary building codes were used to predict inertial interaction effects at the sites for comparison with the 'empirical' results. A collective examination of the empirical and predicted results revealed a pronounced influence of structure-to-soil stiffness ratio on inertial interaction, as well as secondary influences from structure aspect ratio and foundation embedment ratio, type, shape, and non-rigidity.
Earthquake damage; Ground motion; Empirical analysis; SSI (Soil-Structure Interaction); Soil-structure interactions; Foundations (Structures); Vibration damping; Acceleration; Seismic effects; Shaking; Structural response; Stiffness; Soil properties; Soil mechanics; Empirical equations; Inertial interaction