Laboratory tests for evaluation of shear strength and tensile effect generated by fibers present in Muribeca’s landfills of municipal solid waste

Abstract

Understanding the geotechnical behavior of a municipal solid waste landfill (MSW) requires the filtering of several studies. Regarding the mechanical behavior, there are several discussions about the conditions for the stability maintenance of these structures. This stability depends a priori on the resistance of the compacted material to remain itself stable in a way that it does not generate ruptures or slips. Of various materials compacted found in the MSW landfills, high percentages of fibers (such as plastic, fabric and wood) are verified, these materials have a great influence on the mechanical behavior of the structure. These fibers in turn produce in general an increase in the geotechnical parameters: cohesion (c), friction angle (ϕ) and tensile (ζ), which consequently increase the degree of stability of the landfill. In this context, the present work performed evaluations of the effect of fiber tensile and shear strength in samples of Muribeca’s MSW landfills, the analyzes were performed by laboratory tests using a specimen of aged residues collected in the field, with a deposition age of 10 years. With the collected sample, direct shear tests were performed on 3 different sample proportions of fibers: 0%, 16.17% and 32.33%, in two conditions of test: flooded and non-flooded. From the results obtained in the tensile angles (ζ) in the condition of flooded of 10.2° and 5.0°, for the percentages of 16.17% and 32.33%, respectively.