Compressibilidade de solos utilizados como liners em aterros sanitários

Abstract

Sanitary landfills are one of the most used forms of final disposal of Urban Solid Waste in Brazil. With the globalization process and increase in consumption, the need to have sanitary landfills with more efficiency and longer useful life has increased. The base layers, also called liners, are essential structures for the operation of landfills, since their purpose is to avoid contamination of the soil and groundwater. Several materials are used in the formation of liners, and one of these materials is the mixture of natural soil from the landfill site and bentonite, and the main function of the addition of bentonite is to reduce the permeability of the layer. As it is a material composed, basically, of clay-minerals and presents a great plasticity, it is necessary to study the process of densification of these mixtures, since this mechanism causes settlements, which can mechanically destabilize the waste cells. Thus, the present study aimed to analyze the compressibility of soil mixtures used as a liner in a sanitary landfill located in Campina Grande - PB. The methodology of this research initially consisted of carrying out the geotechnical characterization of mixtures with contents of 5, 15 and 25% of bentonite. To determine the compressibility, edometric compression tests were performed on a deformed sample. The results of this research showed that the addition of bentonite influences the soil consolidation process, but in a non-linear way. It was observed that the 15% sample presents greater vertical displacements to the detriment of the others analyzed, thus, the 25% sample presented itself as the most viable to avoid greater instabilities in the structure.