MICROZONATION OF SEISMIC RISK IN A LOW-RISE CITY BASED ON THE MACROSEISMIC EVALUATION OF THE VULNERABILITY OF RESIDENTIAL BUILDINGS

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 calculating of the expert-opinion based damage probability matrix (DPM) for a given level of earthquake intensity and a given type of residential blocks. A specified exposure time for this zoning 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 8% of 1,466 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 a good accordance with the experimental damage curves based on the macroseismic evaluation of 3,332 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 the seismic risk microzoning for many low-rise cities in the world.