Análise dos níveis de solicitação gerados por explosivos sobre os pilares do viaduto da BR-020 em Caucaia, Ceará, aliada à verificação de segurança e dimensionamento preventivo.

Abstract

In early 2019, Ceará was the scene of a series of criminal attacks motivated by the stance taken by the state's new public security management. The city of Fortaleza was, however, the most affected, due to the occurrence of fires, shootings and even blasts. Blasts are phenomena characterized by sudden discharges of energy, released during the detonation of explosive artifacts in the form of pressure, heat and even radiation, in case of nuclear accidents. Due the recurrence of explosive events in recent years, this work was conceived with the purpose of analyzing the explosion that occurred on the BR-020 viaduct in Caucaia, Ceará, based on estimates of mass and positioning of an idealized explosive. The research studied the levels of demand generated by the explosive action, the distances required for the safety of people and buildings, in addition to proposing preventive design strategies for the viaduct pillars in question. From the analysis of the demand levels, it was possible to conclude that the critical situation is reached when the explosive is placed on the lateral slopes of the viaduct, since the demand on the deck is 5.5 times higher than that obtained for the same amount of explosive placed between the central columns. Regarding the safety of neighboring buildings, it was found that these would only suffer damage if the amount of explosives was of an order of magnitude much higher than those normally used in improvised explosions. For humans, however, it was observed that for the estimated masses of explosives, distances of approximately 10 meters could cause rupture of the eardrums, which could lead to death if this distance was less than 2.4 meters. As for design, the technical and economic feasibility of the proposed solutions was verified, given the compliance with existing technical standards in Brazil and the small increase in the overall cost of the construction, caused by the preventive implementations presented by this research.