2013 Practical Considerations for Direct Shear Testing of Mine Spoils

Civil engineering laboratories use the direct shear test to provide shear strength parameters for soils under drained conditions. Standard shear boxes are of suitable capacity in terms of dimensions and load to provide reliable data for the majority of soils for civil engineering applications. However, the reliability of this data becomes questionable when extended to the field of mine engineering where materials differ from traditional soils, and stresses may be much greater than those commonly encountered in civil engineering. When performing direct shear tests on mine spoil, geotechnical practitioners and laboratory technicians may be uninformed of the limitations of standard equipment and/or the consequences of applying unrepresentative data to geotechnical models. The purpose of this paper is to outline considerations for using standard laboratory equipment to derive shear strength parameters for coal measures spoil.