This paper deals with the monitoring and assessment of structural performance of reinforced concrete residential buildings damaged during the lifetime by several important natural disasters such as earthquakes. The problem belongs to the risk management of built environment areas subjected to various natural catastrophes. In our work, we present a methodology based on modeling, simulation and nonlinear analysis applied on two classes of existing buildings located in the damaged infrastructure of earthquake sensitive cities. The decisions for risk mitigation taking into account the real seismic vulnerability of structures are based on GIS (Geographical Information Systems) mapping, and application of some artificial intelligence techniques. Finally, our paper discusses a new methodology for awareness and mitigation of seismic effects in case of future events in dense urban areas based on a case study for Iasi city, Romania.