Seismic vulnerability of earth buildings in seismic areas. A case study in Bucaramanga city (Colombia)

The city of Bucaramanga is located in the northeast of Colombia in a high seismic hazard zone of the country, where low-height constructions predominate. Approximately 11% of these buildings were made of earth seventy years ago and some of them are more than one hundred years old. Due the existence of these earth buildings, their seismic vulnerability, and the high hazard zone, Bucaramanga is expected to be submitted to a relatively high seismic risk. Consequently, the impact of earthquakes on these buildings must be a subject of research in order to come up with results that could be associated with rational formulation of contingency and mitigation strategies. For this purpose, an effective three-step procedure has been developed: a) Inventory of the earth buildings in Bucaramanga, b) Identification of the characteristics with the greatest influence on the seismic vulnerability of earth buildings, and c) Assessment of the structural behavior and seismic vulnerability of earth buildings. The seismic vulnerability of these buildings was evaluated by estimating the damage they would suffer due to earthquakes with different maximum acceleration values. Finally these results have been used to develop earthquake damage scenarios in Bucaramanga.