This paper deals with the seismic vulnerability assessment analysis of some existing typified school buildings in Albania. This is particularly important for the estimation of probable damages and buildings’ behaviour in case of strong earthquakes. Three typified of R/C school buildings are selected for evaluation. Conclusions are only referred to the selected buildings. However, the developed approach may be used for the analysis of other structural types.The first step of the study is the identification of the seismic zones — where the buildings are located — and the period of their constructions. Second, information on the seismic design conditions of the buildings is used and pushover analyses are performed in order to provide their respective capacity curves. Subsequently, using the procedures developed in the L2-Method — i.e.: modeling bilinear capacity curves in AD format, defining the damage threshold levels, calculating cumulative probability, and performing regression analysis — the fragility curves are obtained.After considering the different seismic sites reviewing code requirements (the existing Albanian Code KTP-N2-89 and Eurocode 8) and analyzing performance points, the probable damage levels of the buildings is assessed.
A framework for the analysis of seismic risk to lifelines, with references to the case of Vrancea earthquakes, is presented. The framework dealt with is probability based. It relies on the use of stationary, Poissonian, models, while complications raised by the consideration of non-stationarity (as e.g. those raised by the consideration of the evolutionary character of vulnerability of some elements at risk) are avoided. The elements at risk considered may be lifelines as a whole, or components of them. Seismic action and seismic hazard are considered, alternatively, at source level or at site level. Radiation/attenuation features are defined in this frame. Adverse effects of earthquakes (referred to in general as damage) may be related alternatively, in specific ways, to the various elements at risk considered. Seismic vulnerability may be considered as source related or as site related, too. Various exposure patterns are considered. Alternative models of functionality are discussed and risk characteristics are generally related to them. The definition of entities referred to are expressed in probabilistic terms and convolution relations, leading up to risk estimates, are given, basically in discrete terms. In connection with the features of Vrancea earthquakes, specific recurrence characteristics and needs of additional specification, considering the variability of source mechanisms, are discussed. Possibilities of simplification of the approach, in order to avoid the excessive needs of basic data and of computing effort raised by a rigorous approach, are discussed, too.
Authors:S Radeva, I Paskaleva, D Radev, and G Panza
The problem of site dependent estimation of the seismic strong motion for Sofia region is discussed. Deterministic modelling for micro-zonation of Sofia region is implemented for receiving an estimation of local site conditions as result of displacements provoked by seismic events in Sofia region with stochastic and neural modelling. An approach for seismic waves classification on the base of principal axis transformation, long-range dependence time series analysis and neural modelling is suggested. With the help of scene oriented model are determined the boundaries of destructive phase of strong motion acceleration. For selected diapason of destructive phase is implemented two-dimensional vector quantization for transformed accelerograms with maximal and middle values. With self-organizing map are determined weight centres of selected classes of destructive phase. Learned and trained self-organizing map optimize selected target classes and determine probability density function. Suggested model helps to provide side dependent estimation of the seismic strong motion for Sofia region.
Authors:DONATELLA FIORANI, MARTA ACIERNO, SILVIA CUTARELLI, and ADALGISA DONATELLI
– Alberto Lemme : The 31 st October 2002 Earthquake in Molise (Italy): A New Methodology for the Damage and SeismicVulnerability Survey of Churches . In: 13th World Conference on Earthquake Engineering , conference proceedings (Vancouver, Canada, 1