Análise de edifício em alvenaria estrutural sobre fundação do tipo radier: estudo de caso de ocorrência de manifestações patológicas

Abstract

This work consists of a study case of a structural masonry building considering the soil-structure interection which has the following configuration: four standard floor and a raft foundation which presented structural problems in two walls on the ground floor. The study followed two approaches, the first: analyzing the behaviour effectiveness of the raft employed, by checking the bending moments in the raft, reinforcement used as a result of the design and the adequacy of the shear strength. The second approach is about study the walls which presented cracks, by evaluating: the normal stress in the basis and the top of the walls; the shear stresses in the basis and the top of walls, and the supportive reactions under one of the walls. In that context, it was used the equivalent frame model proposed by Nascimento Neto et al (2014), which consists of mansory and raft discretization using bars finite elements. The soil was represented by the winkler model, which uses linear and independent springs. The soil parameters used were obtained from the SPT testing results performed to the foundation design. The results showed that the foundation behaviour was quite different of a raft foundation and closer to a continuous strip footing, and also showed that the reinforcement designed in flexure were insufficient in some sections analyzed, but it does not demanded reinforcement in shear design. Moreover, were observed tension and shear stresses with intensities greater than the limits prescribed by the Brazilian standard code NBR 16868-1, which justifies the cracking accurance in those walls and indicates the need for use a construtive reinforcement to prevent ones.