Rocking isolation of low-rise frame structures founded on isolated footings

Gelagoti, F; Kourkoulis, R; Anastasopoulos, I; Gazetas, G

dc.contributor.author	Gelagoti, F	en
dc.contributor.author	Kourkoulis, R	en
dc.contributor.author	Anastasopoulos, I	en
dc.contributor.author	Gazetas, G	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	00988847	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/30016
dc.subject	Capacity design	en
dc.subject	Foundation uplifting	en
dc.subject	Frame structure	en
dc.subject	Nonlinear dynamic analysis	en
dc.subject.other	Axial forces	en
dc.subject.other	Capacity design	en
dc.subject.other	Dynamic time history analysis	en
dc.subject.other	Frame structure	en
dc.subject.other	Infill walls	en
dc.subject.other	Isolated footings	en
dc.subject.other	Moment resisting frames	en
dc.subject.other	Moment-rotation	en
dc.subject.other	Non-structural elements	en
dc.subject.other	Seismic Performance	en
dc.subject.other	Seismic records	en
dc.subject.other	Seismic shaking	en
dc.subject.other	Static pushover analysis	en
dc.subject.other	Design	en
dc.subject.other	Dynamics	en
dc.subject.other	Finite element method	en
dc.subject.other	Reinforced concrete	en
dc.subject.other	Seismic design	en
dc.subject.other	Soils	en
dc.subject.other	Structural frames	en
dc.subject.other	Foundations	en
dc.subject.other	finite element method	en
dc.subject.other	footing	en
dc.subject.other	foundation	en
dc.subject.other	geometry	en
dc.subject.other	nonlinearity	en
dc.subject.other	reinforced concrete	en
dc.subject.other	seismic design	en
dc.subject.other	seismic response	en
dc.subject.other	strength	en
dc.title	Rocking isolation of low-rise frame structures founded on isolated footings	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/eqe.1182	en
heal.identifier.secondary	http://dx.doi.org/10.1002/eqe.1182	en
heal.publicationDate	2012	en
heal.abstract	This paper explores the effectiveness of a new approach to foundation seismic design. Instead of the present practice of over-design, the foundations are intentionally under-dimensioned so as to uplift and mobilize the strength of the supporting (stiff) soil, in the hope that they will thus act as a rocking-isolation mechanism, limiting the inertia transmitted to the superstructure, and guiding plastic 'hinging' into soil and the foundation-soil interface. An idealized simple but realistic one-bay two-story reinforced concrete moment resisting frame serves as an example to compare the two alternatives. The problem is analyzed employing the finite element method, taking account of material (soil and superstructure) and geometric (uplifting and P-Δ effects) nonlinearities. The response is first investigated through static pushover analysis. It is shown that the axial forces N acting on the footings and the moment to shear (M/Q) ratio fluctuate substantially during shaking, leading to significant changes in footing moment-rotation response. The seismic performance is explored through dynamic time history analyses, using a wide range of unscaled seismic records as excitation. It is shown that although the performance of both alternatives is acceptable for moderate seismic shaking, for very strong seismic shaking exceeding the design, the performance of the rocking-isolated system is advantageous: it survives with no damage to the columns, sustaining non-negligible but repairable damage to its beams and non-structural elements (infill walls, etc.). © 2011 John Wiley & Sons, Ltd.	en
heal.journalName	Earthquake Engineering and Structural Dynamics	en
dc.identifier.doi	10.1002/eqe.1182	en
dc.identifier.volume	41	en
dc.identifier.issue	7	en
dc.identifier.spage	1177	en
dc.identifier.epage	1197	en