Microzonation of seismic risk in a low-rise Latin American city based on the macroseismic evaluation of the vulnerability of residential buildings: Colima city, México

Abstract

Abstract.A macroseismic methodology of seismic risk microzonation in a low-rise city based on the vulnerability of residential buildings is proposed and applied to Colima city, Mexico. The seismic risk microzonation for Colima consists of two elements: the mapping of residential blocks according to their vulnerability level and the calculation of an expert-opinion based damage probability matrix (DPM) for a given level of earthquake intensity and a given type of residential block. A specified exposure time to the seismic risk for this zonation is equal to the interval between two destructive earthquakes. The damage probability matrices were calculated for three types of urban buildings and five types of residential blocks in Colima. It was shown that only 9% of 1409 residential blocks are able to resist to the Modify Mercalli (MM) intensity VII and VIII earthquakes without significant damage. The proposed DPM-2007 is in good accordance with the experimental damage curves based on the macroseismic evaluation of 3332 residential buildings in Colima that was carried out after the 21 January 2003 intensity MM VII earthquake. This methodology and the calculated PDM-2007 curves may be applied also to seismic risk microzonation for many low-rise cities in Latin America, Asia, and Africa.

Assessing the seismic vulnerability of masonry buildings

“…The method relies on the wealth of observed damage data available from past earthquakes, and the correlation of these with construction materials and methods in different geographical and seismic regions. First proposed by Whitman et al (1973) after the San Fernando earthquake of 1971, specifi c applications of this method to masonry structures are numerous (Braga et al, 1982;Corsanego and Petrini, 1990;Di Pasquale et al, 2005) and still widely used in developing countries and regions with extensive historic seismicity records (Askan and Yucemen, 2010;Zobin et al, 2010). Notwithstanding its popularity, the DPM has major limitations: discrete defi nition of damage levels/states and dependence on a specifi c seismic and architectural context.…”