Evaluating Soil-Structure Interaction Effects Using Dimensional Analysis

Abstract eng:
Soil-structure interaction can affect seismic responses of structures due to foundation flexibility and energy dissipation. The significance of these effects depends on the dynamic properties of foundation and structure as well as earthquake ground motions. This paper investigates the dynamic response of soil-foundation-structure interacting (SFSI) systems subjected to pulse-type near-fault ground motions. Through rigorous dimensional analysis, the normalized structural responses are represented in terms of dimensionless Π-products. This approach brings forward the self-similarity, an invariance with respect to scale or size, which decisively describes the interactive behavior of SFSI system. By allowing its foundation to translate and rotate, the normalized structural responses of a SFSI system are computed and compared with that of the fixed-base structure counterpart to evaluate the significance of soil-structure interaction. Extensive numerical simulations manifest the dimensionless parameters that dominate SSI effects and reveal the circumstances where SSI effects are of practical importance. For both linear and nonlinear structures with rocking foundation, the SSI effects are insignificant when the structure-to-pulse frequency ratio (Πω) is smaller than 1.5. They can amplify the structural response when Πω is higher than 1.5 and the structure-to-foundation stiffness ratio (Πk) falls into certain range. SSI can result in significant large displacement demand on nonlinear structure. Furthermore, foundation rocking is able to enhance the SSI effects by shifting and enlarging the response amplification zone. The dimensional analysis offers a systematic way of evaluating SSI effects.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket