Estudo de caso de solução para fundação em solo expansível em Sousa-PB

Abstract

The laying of foundations on expansive clay soils causes numerous problems in the structure and its components. Any foundation solution is preceded by a preliminary project, where studies are done on the soil situation, study of the solutions that can be adopted and the costs involved. Inadequate or insufficient preliminary project leads to unfamiliarity of the actual soil conditions and behaviors, which results in inconsistencies in structural design and problems in structural execution. Expansive soils are especially hazardous because they are not detected through traditional drilling tests and, therefore, require additional knowledge from the designer. Expansive soils in foundations cause excessive stress, loss of stability and cracking, and the solution must be carefully adopted. The specific case to be studied in the present monograph is the foundation for the restauration and expansion of the Hospital Regional de Sousa, whose soil has expansive characteristics. This work aims to provide a theoretical background on the types of foundations and their applications, the design of reinforced concrete structures and the study of the soil, addressing their variations, classifications, characteristics and reinforcement methods. Through the study of the local soil and the degree of pathologies associated with the expansive soil in the existing structures, a foundation solution was planned by joining foundation beams and reinforced blocks. The reinforced blocks were calculated to be supported by a rocky layer below the clay layer to avoid its effects, and the foundation beams were, associated with the lattice slab, dimensioned high from the ground in order to at the same time support the walls of the building and to maintain itself sufficiently far from the effects of expansion. Soil-cement layer was also adopted between the reinforced block and the rock layer in order to reduce the depth of the block and therefore their costs. Thus, a feasible solution to expansive soils could be sought anywhere and considerably simpler than if clayey soil improvement was sought.