Assessment on Suitability of CD Waste as Infill for Construction of Slopes

Alternative materials and methods for improving the ground have always been a subject of study. The viability of construction and demolition waste (CD waste) as slope infill is examined in this research. To investigate its suitability for construction of slopes, a three-layered slope infill is considered. Parameters studied in the present study include thickness of CD waste layer and slope angles. CD waste is used in the middle layer and its thickness is varied from 0 to 7 m in increments of 1 m. The bottom layer thickness is kept constant at 7 m, whereas the top layer depth is varied such that the total height of embankment is 17 m. The SLOPE/W module of GEOSTUDIO is used to perform a slope stability analysis, and the factor of safety is calculated for various embankment sections. Limit equilibrium analysis is carried out for three different slope angles; viz., 30°, 45° and 60°. From the analysis, it is observed that angle of friction of infill is critical as far as stability of slope is considered. According to study, 17–25% of the thickness of an embankment can be replaced with cohesionless CD waste without compromising on factor of safety.