Rocking isolation of frames on isolated footings: Design insights and limitations

Kourkoulis, R; Gelagoti, F; Anastasopoulos, I

dc.contributor.author	Kourkoulis, R	en
dc.contributor.author	Gelagoti, F	en
dc.contributor.author	Anastasopoulos, I	en
dc.date.accessioned	2014-03-01T02:12:08Z
dc.date.available	2014-03-01T02:12:08Z
dc.date.issued	2012	en
dc.identifier.issn	13632469	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/30015
dc.subject	Differential Settlement	en
dc.subject	Frames	en
dc.subject	Parasitic Vertical Acceleration	en
dc.subject	Rocking Isolation	en
dc.subject	Shallow Foundations	en
dc.subject.other	Differential settlements	en
dc.subject.other	Frames	en
dc.subject.other	Rocking Isolation	en
dc.subject.other	Shallow foundations	en
dc.subject.other	Vertical accelerations	en
dc.subject.other	Seismic design	en
dc.subject.other	Seismology	en
dc.subject.other	Design	en
dc.title	Rocking isolation of frames on isolated footings: Design insights and limitations	en
heal.type	journalArticle	en
heal.identifier.primary	10.1080/13632469.2011.618522	en
heal.identifier.secondary	http://dx.doi.org/10.1080/13632469.2011.618522	en
heal.publicationDate	2012	en
heal.abstract	To date, a significant research effort has been devoted attempting to introduce novel seismic protection schemes, taking advantage of mobilization of inelastic foundation response. According to such an emerging seismic design concept, termed rocking isolation, instead of over-designing the footings of a frame (as in conventional capacity design), they are intentionally under-designed to promote uplifting and respond to strong seismic shaking through rocking, thus bounding the inertia forces transmitted to the superstructure. Recent research has demonstrated the potential effectiveness of rocking isolation for the seismic protection of frame structures, using a simple 1-bay frame as an illustrative example. This article: (a) sheds light in the possible limitations of rocking isolation, especially in view of the unavoidable uncertainties regarding the estimation of soil properties; (b) investigates the potential detrimental effects of ground motion characteristics; and (c) assesses the effectiveness of rocking isolation to more complex structures. It is shown that the concept may be generalized to 2-bay frames, and that even when foundation rocking is limited, the positive effect of foundation under-design remains, especially when it comes to very strong seismic shaking. In contrast, its effectiveness may be limited when the frame is subjected to combined horizontal and synchronous vertical acceleration components a possible scenario on the surface of alluvial basins. © 2012 Copyright A. S. Elnashai & N. N. Ambraseys.	en
heal.journalName	Journal of Earthquake Engineering	en
dc.identifier.doi	10.1080/13632469.2011.618522	en
dc.identifier.volume	16	en
dc.identifier.issue	3	en
dc.identifier.spage	374	en
dc.identifier.epage	400	en