Influência dos efeitos globais de segunda ordem em manifestações patológicas em um edifício de concreto

Structural accidents of high-rise buildings due to instability has occurred with some frequency in Brazil. Generally, building instability implies in a series of pathologies in structural and non-structural elements. The Brazilian code regulation suggests two simplified procedures, named as instability parameter α and γz coefficient. In terms of design, the main difference between such simplified procedures is that, differently from the instability parameter α, the γz coefficient can be used to estimate the second order effects and it is applied to buildings that do not present double symmetry. In the light of the foregoing, this paper addresses to the evolution process of pathological manifestations due to structural instability in an actual high-rise building. As soon as the building was occupied, cracks nucleated and propagated in few days. The observed cracking pattern indicated that the building could break in two pieces as a way to compensate the second order effects. Thereby, the structural instability and its consequences were evaluated by means of a commercial design computer software