Linear and nonlinear valley amplification effects on seismic ground motion

Psarropoulos, PN; Tazoh, T; Gazetas, G; Apostolou, M

dc.contributor.author	Psarropoulos, PN	en
dc.contributor.author	Tazoh, T	en
dc.contributor.author	Gazetas, G	en
dc.contributor.author	Apostolou, M	en
dc.date.accessioned	2014-03-01T01:26:33Z
dc.date.available	2014-03-01T01:26:33Z
dc.date.issued	2007	en
dc.identifier.issn	0038-0806	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18127
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-66449106693&partnerID=40&md5=ff4981094eed168da38a65c568df43af	en
dc.subject	""Plasticity"" index	en
dc.subject	Finite-element method	en
dc.subject	Soil amplification	en
dc.subject	Soil dynamics	en
dc.subject	Soil nonlinearity	en
dc.subject	Spatial variability	en
dc.subject	Spectral-element method	en
dc.subject	Valley effects (IGC: D7/e8/e13)	en
dc.subject.classification	Engineering, Geological	en
dc.subject.classification	Geosciences, Multidisciplinary	en
dc.subject.other	Soil amplification	en
dc.subject.other	Soil dynamics	en
dc.subject.other	Soil nonlinearity	en
dc.subject.other	Spatial variability	en
dc.subject.other	Spectral element method	en
dc.subject.other	Amplification	en
dc.subject.other	Finite element method	en
dc.subject.other	Landforms	en
dc.subject.other	Plasticity	en
dc.subject.other	Plasticity testing	en
dc.subject.other	Seismology	en
dc.subject.other	Soil structure interactions	en
dc.subject.other	Stratigraphy	en
dc.subject.other	Two dimensional	en
dc.subject.other	Soils	en
dc.title	Linear and nonlinear valley amplification effects on seismic ground motion	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	Records and analyses have shown that, apart from soil stratigraphy, the geomorphic conditions (such as those characterising an alluvial valley) tend to modify the amplitude, the frequency content, the duration, and the spatial variability of seismic ground shaking. As most of the related records and studies to date refer to weak motions (and thereby to linear soil response), the question that has been raised is whether and by how much the unavoidably nonlinear soil behaviour during strong shaking may reduce the unavoidable ""valley amplification"" effects. The paper aims at shedding some light on this important issue by analysing numerically the effects of the sub-surface geomorphic conditions of a valley on its ground surface seismic motion, with emphasis on the influence of soil nonlinearity. Two-dimensional linear and equivalent-linear ground response analyses are performed to study an alluvial valley in Japan, the behaviour of which had been monitored during many earthquakes in the early 1980's. Then, using the geometry of this valley as a basis, a parametric investigation is performed on the effects of potential soil nonlinearity arising from the increased intensity of base excitation and/or decreased ""plasticity'"" index* of the clayey soil material. It is shown that strong soil nonlinearity may depress the amplitude of the multiply-reflected and, especially of the horizontally propagating Rayleigh waves, leading to substantially lower valley amplification.	en
heal.publisher	JAPANESE GEOTECHNICAL SOC	en
heal.journalName	Soils and Foundations	en
dc.identifier.isi	ISI:000252264700004	en
dc.identifier.volume	47	en
dc.identifier.issue	5	en
dc.identifier.spage	857	en
dc.identifier.epage	871	en