دانلود رایگان مقاله انگلیسی یک مدل بهبود یافته برای ارزیابی ریسک لرزه ای در پرتغال - امرالد 2017

Abstract

Purpose – Portugal experienced very destructive earthquakes in the past, such as the wellknown "Lisbon Earthquake" in 1755. With such in mind, accurate estimates of human and economic losses can play a significant role in providing various societal key players with objective information for response strategies. The present paper aims to present the contribution of the most recent study in Portugal (PRISE) concerning comprehensive seismic risk assessment, which can be used as good practice and reproduced in different contexts. Design/Methodology/Approach – PRISE (Earthquake loss assessment of the Portuguese building stock) covered three main lines of research, corresponding to the three components typically considered in any seismic risk assessment study: i) the characterization of the seismic hazard; ii) the identification of the exposure to earthquakes and loss potential; and iii) the vulnerability of the exposed assets. Each of those components was fully characterized through the collection of census and local data (exposure), used to carry out nonlinear analysis (hazard and fragility). Findings – By involving different research institutions and partners with extensive knowledge and expertise in the earthquake domains, the developed model is capable of producing economic and human earthquake loss estimates in real time (through an innovative web-based platform) or for specific event scenarios, considering exposed population, residential and industrial buildings. The platform uses open-source tools hence it can be reproduced in other countries or contexts. Social implications – The findings and loss estimates for different earthquake scenarios show that planned interventions are required. Decision-makers and other relevant stakeholders (Civil Protection) can make use of the developed platform to produce specific estimates, to test the effect of different retrofitting interventions or to plan for emergency scenarios. Research implications – Research wise, the hazard, vulnerability and exposure models can still be significantly improved, by e.g. adding critical infrastructure (hospitals, school buildings, bridges) or updating the nonlinear models, for more accurate loss predictions. Keywords Seismic risk, Loss estimation, Hazard, Exposure, Vulnerability, Real-time platform.

4. Concluding

remarks This paper described an extensive seismic risk assessment study for Portugal, developed within a recent research project – PRISE – covering thoroughly the hazard, vulnerability and exposure components. The most recently available hazard model for the Portuguese territory was presented and used to select and scale ground motion records through PSHA and advanced spectral matching procedures for reduced aleatory uncertainty. Extensive nonlinear dynamic analyses were then carried out for different building typologies in order to produce improved fragility and consequence models for RC and industrial buildings. Further improvement was also obtained for the exposure model by extending the collection of data of the most recent census survey, as well as local/regional databases for increase of accuracy on the loss estimates.

The presented loss assessment framework led to results that differ with respect to state-of-the-art vulnerability assessment methods in a consistent manner across different building typologies and damage state definition criteria. More specifically, it has been verified that state-of-the-art methodologies tend to overestimate the annual rate of exceedance of lower (i.e. more frequent) loss values, with respect to the framework developed in the PRISE initiative. On the other hand, the opposite trend is verified for higher aggregated losses. The latter is shown to be related with the presented methodology’s more robust representation of the impact of record-to-record variability in loss estimations, highlighting its strengths and contribution to the improvement of fragility, vulnerability and loss assessment of building portfolios.