seismic risk assessment for portugal
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Seismic Risk Assessment for PortugalTRANSCRIPT
Vitor Silva1,2, Helen Crowley2, Humberto Varum1, Rui Pinho3
1 University of Aveiro, Portugal2 GEM Foundation, Italy3 University of Pavia, Italy
Seismic Risk Assessment for Portugal
Current Seismic Hazard and Risk assessment in Portugal
‣ Portugal is located in a region with low to moderate seismic hazard;
‣ National building portfolio is characterized by a large fraction of masonry construction;
‣ Various Studies already exist regarding the seismic risk assessment in Portugal (LNEC, IST, FEUP, UA, UMinho);
‣ Present study represented a chance to investigate new PSHA models, up-to-date building portfolio and new vulnerability model.
‣ Test the open-source software from the Global Earthquake Model initiative.
Probabilistic Seismic hazard model for Portugal
‣ Hazard model proposed by Vilanova and Fonseca in 2007
Probabilistic Seismic hazard model for Portugal
‣ Consideration of a large logic tree structure
‣ Ground motion models from Akkar and Bommer (2010) and Atkinson and Boore (2007)
Probabilistic Seismic hazard for Portugal
Development of an up-to-date Exposure Model
‣ Strongly based on the CENSUS Survey of 2011
‣ Building distribution at three administrative levels
Development of an up-to-date Exposure Model
‣ Buildings have been organized in terms of construction materials, number of storeys and time of construction (design level)
Development of an up-to-date Exposure Model
‣ Buildings have been organized in terms of construction materials, number of storeys and time of construction (design level)
1985 - 2011
A
B
C
A
B
D
C
1960 - 1985
Development of an up-to-date Exposure Model
a) Reinforced concrete b) common masonry c) weak masonry
Probabilistic Seismic hazard model for Portugal
Development of an up-to-date Exposure Model
1x1 km2
Development of an up-to-date Exposure Model
‣ Two exposure models with different spatial resolutions
Development of a new fragility/vulnerability model
‣ For reinforced concrete (bare-frame) structures, 200 drawings were analyzed
Development of a new fragility/vulnerability model
‣ RC 2D frame representative of a building typology
Development of a new fragility/vulnerability model
100 ground motion records
Development of a new fragility/vulnerability model
‣ Fragility models following two damage criteria
Inter-storey driftGlobal drift
Development of a new fragility/vulnerability model
Development of a new fragility/vulnerability model
‣ For masonry typologies, a simpler methodology was employed
Capacity curves from the work of Carvalho et al. 2002 were combined with the capacity Spectrum method (Freeman, 2002) to derive sets of fragility curves
Seismic risk for Portugal
‣ Probabilistic losses for a 475 years return period (parish resolution)
Seismic risk for Portugal
‣ Probabilistic losses for a 475 years return period (gridded resolution)
Seismic risk for Portugal
‣ Disaggregation of losses per building typology
What can one do with these results?
‣ Identification of the regions where risk mitigation measures should be applied;
‣ Understanding of the expected average annual losses to establish insurance
premiums;
‣ Development of insurance mechanisms (e.g. TCIP);
‣ Identification of the building typologies contributing to the total losses, and
recommend retrofitting interventions;
‣ Evaluation the effectiveness of the current design regulations in terms of
economic losses;
‣ Employ the direct losses (seismic risk) in an integrated risk evaluation (socio-
economic vulnerability/resilience)
Seismic Risk Assessment for Portugal
Thank you
Except where otherwise noted, this work is licensed under: creativecommons.org/licenses/by-nc-nd/4.0/
Please attribute to the GEM Foundation with a link to - www.globalearthquakemodel.org