Abstract
In spite of the every time better understanding and knowledge of the factors that influence in the seismic behaviour of the buildings, there is a great difference at the moment between the theoretical developments that are carried out continually in the field of earthquake engineering and the concepts that are applied in the seismic design codes of many countries. This fact is reflected clearly in the very irregular seismic behaviour of the buildings during the big earthquakes occurred in the world in the last years. The earthquake design codes make exhaustive recommendations concerning the seismic loads, the simplified methods of structural analysis to be applied, to the details that should incorporate in the seismic design and construction of the structural elements and, in lesser measure, to the conceptual design of the buildings. Therefore, special attention is paid in this work to the structural ductility and its influence on the seismic vulnerability of the buildings and on their seismic damage and risk.
