Stability Of Slopes Of Municipal Solid Waste Landfills With Co-disposal Of Biosolids
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M. Chopra, D. Reinhart, M. Vajirkar & B. Koodhathinkal
This paper deals with the impact of the addition of biosolids on the geotechnical properties of class I landfills with Municipal Solid Waste (MSW). The properties are estimated from a field exploration program using the Cone Penetration Test (CPT). The geotechnical shear strength parameters (angle of internal friction and cohesion) of MSW and biosolids mixture are estimated by correlation with the CPT results. These parameters are then used to study the impact of the addition of biosolids on the stability of the slope of the landfill. The slope stability analysis is conducted on various landfill models using the software SLOPE/W. The waste is assumed to act similar to a cohesionless soil. Based on the field explorations, the angle of internal friction was found to be about 29°. Previous research indicated that the most suitable approach to introducing biosolids into the landfill was in the form of trenches. From the slope stability analysis, it was found that the factor of safety reduces significantly with the introduction of biosolids due to a reduction in the shear strength and with increase in the overall moisture content. Keywords: landfills, biosolids, slope stability analysis, cone penetrometer. 1 Introduction Landfills are well engineered facilities that are used for disposal of Municipal Solid Waste (MSW) and are located, designed, monitored, operated and financed to ensure compliance with federal regulations. Disposal of water treatment facility sludge and wastewater treatment facility biosolids presents significant challenges to facility operators, as this practice often violates loading of metals and exceeds the allowable levels of pathogens for land application. Thus,
landfills, biosolids, slope stability analysis, cone penetrometer.