Topography and soil effects in the M-S 5.9 Parnitha (Athens) Earthquake: The case of Adames

Gazetas, G; Kallou, PV; Psarropoulos, PN

dc.contributor.author	Gazetas, G	en
dc.contributor.author	Kallou, PV	en
dc.contributor.author	Psarropoulos, PN	en
dc.date.accessioned	2014-03-01T01:18:27Z
dc.date.available	2014-03-01T01:18:27Z
dc.date.issued	2002	en
dc.identifier.issn	0921-030X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15016
dc.subject	Finite Element	en
dc.subject	Soil Profile	en
dc.subject	Structure Factor	en
dc.subject	Two Dimensions	en
dc.subject	Uniform Distribution	en
dc.subject	Wave Propagation	en
dc.subject	Finite Element Analyses	en
dc.subject.classification	Geosciences, Multidisciplinary	en
dc.subject.classification	Meteorology & Atmospheric Sciences	en
dc.subject.classification	Water Resources	en
dc.subject.other	WAVES	en
dc.subject.other	MOTION	en
dc.subject.other	CALIFORNIA	en
dc.subject.other	HILL	en
dc.title	Topography and soil effects in the M-S 5.9 Parnitha (Athens) Earthquake: The case of Adames	en
heal.type	journalArticle	en
heal.identifier.primary	10.1023/A:1019937106428	en
heal.identifier.secondary	http://dx.doi.org/10.1023/A:1019937106428	en
heal.language	English	en
heal.publicationDate	2002	en
heal.abstract	Large concentration of damage to residential and industrial buildings occurred in regions near the banks of the Kifisos river canyon during the 7-September-1999 Parnitha (Athens) Earthquake. One such region, which experienced unexpectedly heavy damage, was the small community of Adames, which borders the canyon near its deepest point. To explore whether in addition to structural factors the particular topographic relief and/or the actual soil profile contributed to the observed concentration and non-uniform distribution of damage within a 300 m zone from the edge of the canyon cliff, wave propagation analyses are conducted in one and two dimensions. Finite-element and spectral-element formulations are used to this end. To avoid spurious wave reflections at the artificial boundaries, our two-dimensional (2-D) finite-element analyses utilize Bielak's Effective Seismic Excitation method. Soil layering and stiffnesses are determined from 10 SPT-boreholes and 4 crosshole tests. Ricker wavelets and six realistic accelerograms are used as excitation; two of the latter are selected from the literature and four are obtained on the basis of the four strongest motions of the earthquake, recorded in central Athens. The results show that the 2-D topography effects are substantial only within 50 meters from the canyon ridge. These effects materialize only in the presence of the relatively soft soil layers that exist in the profile at a shallow depth. The so-called Topographic Aggravation Factor (TAF), defined as the 2-D over 1-D Fourier spectral ratio, varies around 1.4 over a broad frequency band which covers the significant excitation frequencies. At the location of four collapsed buildings, about 250 m from the edge, 2-D (topography) effects are negligible, but the specific soil profiles amplify one-dimensionally all six ground base excitations to spectral acceleration levels that correlate well with the observed intensity of damage, at least in a qualitative sense.	en
heal.publisher	KLUWER ACADEMIC PUBL	en
heal.journalName	NATURAL HAZARDS	en
dc.identifier.doi	10.1023/A:1019937106428	en
dc.identifier.isi	ISI:000177678600008	en
dc.identifier.volume	27	en
dc.identifier.issue	1-2	en
dc.identifier.spage	133	en
dc.identifier.epage	169	en