Vulnerability index and capacity spectrum based methods for urban seismic risk evaluation. A comparison

Abstract

This article contributes to the development and application of two latestgeneration methods of seismic risk analysis in urban areas. The first method, namely vulnerability index method (VIM), considers five non-null damage states, defines the action in terms of macroseismic intensity and the seismic quality of the building by means of a vulnerability index. The estimated damage degree is measured by semi-empirical functions. The second method, namely capacity spectrum based method (CSBM), considers four no damage states, defines the seismic action in terms of response spectra and the building vulnerability by means of its capacity spectrum. In order to apply both methods to Barcelona (Spain) and compare the results, a deterministic and a probabilistic hazard scenario with soil effects are used. The deterministic one corresponds to a historic earthquake, while the probabilistic seismic ground motion has a probability of exceedence of 10% in 50 years. Detailed information on the building design has been obtained along years by collecting, arranging, improving, and completing the database of the dwellings of the city. A Geographic Information System (GIS) has been customized allowing storing, analysing, and displaying this large amount of spatial and tabular data of dwellings. The obtained results are highly consistent with the historical and modern evolution of the populated area and show the validity and strength of both methods. Although Barcelona has a low to moderate seismic hazard, its expected seismic risk is significant because of the high vulnerability of its buildings. Cities such as Barcelona, located in a low to moderate seismic hazard region, are usually not aware of the seismic risk. The detailed risk maps obtained offer a great opportunity to guide the decision making in the field of seismic risk prevention and mitigation in Barcelona, and for emergency planning in the city.

Seismic risk analysis of urban non-engineered buildings: application to an informal settlement in Mérida, Venezuela

“…The method is based on building types and the vulnerability classes established in the European Macro-seismic Scale EMS'98. A detailed description of the method can be found in (Giovinazzi, 2005;Giovinazzi and Lagomarsino, 2004;Milutinovic and Trendafiloski, 2003;Lantada et al, 2009;Barbat et al, 2006a;Barbat et al, 2006b). NVIM is versatile and easy to implement because it can be applied to any type of building as long as the appropriate vulnerability indices and vulnerability modifying factors are used.…”

Investigating the Mechanism of Confronting Earthquake Crisis, With the Approach of Rehabilitation of Urban Worn Textures

“…Although these studies have mainly focused on construction techniques in order to set standards for foundation, building structure, ceilings, walls, type of materials, façade and … in order to increase the resistance against earthquakes; however, in the study of earthquakes, buildings are considered only as a component of a bio-complex and other issues are concerned as well. In fact, a city can be designed with the aim of reducing vulnerability against earthquakes (Lantada, 2008).…”

“…Areas which are common among rehabilitation planning and earthquake crisis management include four areas of land use, access, density and open space. The purpose of this research is to study rehabilitation of urban worn textures, by investigating common strategies among two approaches of rehabilitation planning and earthquake crisis management; so that we could combine these two approaches in order to increase the quality of life in worn textures and to reduce their vulnerability in the face of earthquake crisis (Lantada, 2008).…”

Seismic response and torsional effects of RC structure with irregular plant and variations in diaphragms, designed with Venezuelan codes

“…For this has been developed fragility curves based on spectral methods (Milutinovic and Trendafiloski [11], Barbat et al [12], Lantada et al [13]), considering five damage states: None, Slight, Moderate, Extensive, Complete. For each damage state, these cumulative lognormal distribution functions provides the probability of reaching or exceeding a given state of structural damage based on a maximum seismic response.…”