Energy methods for assessing dynamic SSI response in buildings

Abstract

An energy approach is employed here for assessing model quality for dynamic soil-structure interaction (SSI) analysis. Concurrently, energy measures are introduced and calibrated as general indicators of structural response accuracy. More specifically, SSI models built at various abstraction levels are investigated according to various coupling scenarios between soil and structure. The hypothesis of increasing model uncertainty with decreasing complexity is first investigated. A mathematical framework is provided, followed by a case study involving alternative models for incorporating SSI effects. During the evaluation process, energy measures are used in conjunction with the adjustment factor approach to quantify SSI model uncertainty. Two types of uncertainty are considered, namely in the numerical model and in the model input parameters. Investigations on model framework uncertainty show that the 3D finite element (FE) model yields the best quality results, whereas the Wolf lumped parameter model produces the lowest model uncertainty in the simple model category. Also, the fixed-base model produces the highest estimated uncertainty and consequently is the worst quality model. The present results confirm the hypothesis that increasing model uncertainty comes with decreasing complexity, but only when the assessment is based on an energy measure as the response indicator.