EVALUATION OF THE URBAN SEISMIC RISK USING A DIGITAL MODEL SIMULATION

Management of risk is the group of actions directed to face natural threats, to reduce vulnerability, to establish mitigation, to develop a prevention strategy and to assist in reconstruction when a disasters occurs. It is based on the identification of threats, vulnerabilities and the knowledge of risks that possess towns, establishments, inhabitants, taking in consideration the response capacity that they have to act about risk factors. The work presented here, exposes results of a project of investigation of the Regional Institute of Planning and Habitat (IRPHa) of the UNSJ [1], consistent in the construction of a model for evaluation of seismic vulnerability of constructions and infrastructure nets to urban scale, as well as the design of an Evaluation Methodology of the direct physical damage, as essential stage for the development of risk mitigation and emergency plans. These developments have been applied to the evaluation of seismic risk of San Juan city, county of the same name, Republic Argentina. It is located in the area of highest seismic hazard of the country and it has been shaken by five big earthquakes in the last 110 years that caused enormous damages to buildings, lifelines, routes and great loss of human lives. It has been considered the magnitude of buildings physical damage and collateral losses in terms of dead and wounded, as well as their spatial distribution, generating different scenarios that allow evaluating the consequences of different intensity (IMM) earthquakes in the analyzed territory. GIS technology (geographical information systems) has been used allowing to manage considerable volumes of information, generating its interrelation under controlled conditions, allowing the quick evaluation of different situations (i.e.: considering different IMM and characteristic of soil response or estimating the possible losses when the parameters of a phenomenon are changed). The only way to reduce urban seismic risk is starting from this knowledge and to project reduction strategies and emergency plans.