The mechanical and geotechnical properties of bulk samples and samples extracted from boreholes through a sliding spoil heap at a southwestern Pennsylvania coal mine are examined. Size gradation, moisture content, density and strength are found to vary considerably within the spoil. Gradation results suggest the material type to be more important than the age of spoil in degradation. There is also evidence from analysis that the heterogeneity of spoil and its associated density and strength do not significantly affect stability results. In other words, spoils can be sufficiently heterogeneous for purposes of stability analysis; they can be considered statistically homogeneous with regard to shear strength.
Engineering Geology 12/1984; 20(4):325-341. DOI:10.1016/0013-7952(84)90060-7