Volume 32, Issue 6 (November 2004)
Cone Resistance of Compacted Ash Fill
Coal ash is a granular byproduct of the combustion of coal in coal-fired thermal power plants. The compacted ash is frequently used as a structural fill material. Standard geotechnical investigation methods used for natural soils have revealed inconsistencies when extended to ash fills. The characterization of ash shows morphological dissimilarity with natural soils. It is observed that several groupings of in situ density and stress level lead to similar penetration resistance in coal ash. Thus, the correlations reliable for soils may have questionable interpretations of blow count or measured cone resistance in coal ash. The static cone penetration test results analyzed at various combinations of stress level and relative density indicated the need for a new scheme for interpretation of behavior of ash fills on the basis of relative dilatancy of the ash. The resistance to penetration of the standard cone was interpreted at varying depths on ash fill compacted at varying relative densities. Correlations are suggested to estimate bearing capacity and settlement characteristics of coal ash on the basis of cone penetration test results for direct geotechnical design.