Dimensional analysis of structures with translating and rocking foundations under near-fault ground motions

• Published in: Soil dynamics and earthquake engineering (1984) Vol. 29; no. 10; pp. 1330 - 1346
• Main Authors: Zhang, Jian, Tang, Yuchuan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2009; Elsevier
• Subjects: Bilinear structure; Dimensional analysis; Earth sciences; Earth, ocean, space; Earthquakes, seismology; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; Foundation rocking; Internal geophysics; Natural hazards: prediction, damages, etc; Near-fault ground motion; Seismic response; Soil–foundation–structure system; Soil–structure interaction; Soil–foundation–structure system; Soil–structure interaction; Dimensional analysis; Near-fault ground motion; Foundation rocking; Seismic response; Bilinear structure; Soil-structure interaction; foundations; impedance; digital simulation; damping; case studies; ground motion; stiffness; faults; frequency; structure soil interaction; acceleration; seismic response; ductility; buildings; earthquake engineering; soils; frame structure; Soil-foundation-structure system
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2009.04.002

This paper evaluates the inertial soil–structure interaction (SSI) effects on linear and bilinear structures supported on foundation that is able to translate and rock when subject to near-fault ground motions. Through rigorous dimensional analysis, the peak structural responses (e.g. structural drift and total acceleration) of the soil–foundation–structure interacting (SFSI) systems are characterized by a set of dimensionless Π-parameters, which can decisively describe the interactive behavior of SFSI systems. By comparing the normalized structural responses of various structure–foundation systems with their fixed-base counterparts, the study reveals that SSI effects highly depend on the structure-to-pulse frequency ratio, Π ω , the foundation-to-structure stiffness ratio, Π k , damping coefficient of foundation impedance, Π c , the foundation rocking, and the development of nonlinearity in structures. For linear structures, the SSI effects are insignificant when the structure-to-pulse frequency ratio ( Π ω ) is smaller than 1.5 and can amplify the structural responses when Π ω is higher than 1.5. Foundation rocking can shift and enlarge the response amplification zone of SSI. For nonlinear structures, SSI tends to reduce the structural responses for Π ω <3 while can increase the ductility demands for Π ω ≥3. The bilinear structures may experience more significant SSI effects than linear structures in certain frequency ranges. The numerical simulations on ten real building cases exhibiting significant rocking and a detailed case study on a nine-story frame structure demonstrate the applicability of dimensional analysis results to predict the SSI effects on realistic building structures. The study demonstrates that the dimensional analysis provides a concise and systematic way of evaluating SSI effects.