STRUCTURAL ENGINEERING AND SAFE CONSTRUCTIONS IN SEISMIC AREAS

Earthquakes have always been a danger that builders of all ages have had to deal with. Numerous solutions have been explored to create buildings capable of resisting earthquakes, from ancient times to modern seismic engineering which today can benefit from the systematization of scientific knowledge, technological innovations, and direct observations of the consequences of earthquakes on buildings. The current approach to seismic design commonly requires buildings to be designed to survive earthquakes, ensuring people can exit the building. It is therefore normal for buildings to be heavily damaged during earthquakes and that their recovery can be extremely expensive and often not convenient. There are alternative approaches to seismic design capable of guaranteeing negligible damage and their use must be evaluated considering the costs of construction and for repairing damage due to earthquakes, as part of a life cycle analysis of the building. Seismic action is a dynamic horizontal action that produces an oscillating motion of the building. Hence, the rules of static design for actions that always act downwards are no longer useful and the design approach must be based on the analysis and evaluation of three fundamental parameters: mass, period, and dissipation. This chapter proposes a discussion of the role of these three parameters, illustrating in a simple way methods and tools currently available to guarantee the safety of buildings in seismic areas, with specific interest for existing buildings in general and for buildings with historical and monumental value in particular.