Previsão e monitoramento de recalques em aterros sanitários/ estudo de casos: central de resíduos de recreio - Minas do Leão/RS e São Leopoldo/RS

Abstract

The population growth s results and their great consumption caused the increase in the generation of municipal solid waste that become an environmental problem in the final disposition of these waste, in other words, they can cause contamination of the soil, of the superficial and underground waters, when disposed improperly in the soil, as in big garbage in the open sky. Therefore, the most adequate technical, economic and environmentally safe solution is the disposal in sanitary embankments. One of the greatest problems of the landfills are the elevated values of the vertical and horizontal shifts (settlements), because the waste are more compressible and suffer time degradation and consequently may cause damage in the structural systems of the sanitary embankments (coverage and waterproofing systems, superficial drainage and effluents). This article has the objective of evaluate the settlements of two landfills with measures of shifts by superficial landmarks, verifying the efficiency of some prevision s models of settlements in landfills of municipal solid waste existing in the literature. The evaluation was made in the São Leopoldo and Minas do Leão s landfills, comparing the settlements measured with the provided and adjust the models used basing in the monitoring data already made in the landfills in a five years period. The prevision s models of settlements that were used are: Yen and Scanlon (1975), Exponential of creep of Edil et al. (1990). Bjarngard and Edgers (1990), Rheological of Gibson and Lo (1961), Gandolla et al. (1992), Hyperbolic of Ling et al. (1998), Meruelo and the observational method of Asaoka s (1978) models. The repressions observed, at Minas do Leão s landfill, varied between 0,55 to 4,0 meters, corresponding a deformation between 4 and 24% related to the initial height of the settlement. And, about the São Leopoldo s landfill, the observed settlement, in the Remedied Landfill cell, varied between 0,1 and 1,03 meters, corresponding with a deformation between 1 and 5,8% related to the initial height of the settlement. And in the Phase I Landfill, the observed settlement varied between 0,5 and 2,4 meters, corresponding with a deformation between 8 and 16,5% of the initial height of the settlement. The values found are inside of the values zone found in the literature, except the values of the deformation of the Remedied landfill which were below of the values zone of the literature. From the analysis made in this article, it was possible to verify that the most adequate models to settlement prevision in both landfills analyzed was the Hyperbolic (1998), Exponential of creep, Bjarngard and Edgers (1990), Meruelo and the Gibson and Lo (1961) models, that obtained good adherence between the values measured and provided. Stands out that the Asaoka s (1978) method is very interesting for the accompaniment of the settlement and to verify the stabilization and the forecast of the final settlement.