Toe buttressing procedure to stabilize slide zones for dragline stripping operations

CIM Bulletin, Vol. 82, No. 925, 1989

Farrukh Z. Khan, Terracon Geotechnique Ltd., and Dennis Nikols, TransAlta Utilities Corporation

Highvale Mine, located at Wabamun, Alberta, produces thermal coal for TransAlta's Keephills and Sundance generating plants. Overburden stripping in the mine is conducted by draglines which normally operate on top of the overburden bench. In certain areas of the mine, however, these overburden benches are susceptible to slope failure. In these areas, due to safety considerations, the draglines are utilized in the less productive chop-cutting mode, supplemented by mobile equipment where the bench height exceeds the dragline chop-cutting limit. This paper proposes maintaining the draglines in their normal digging mode through areas of unstable or failed overburden, by utilizing a dragline carried toe buttress to ensure adequate bench stability. The data requirements and methods of slope analysis to design a toe buttress across an unstable high-wall area are examined in rigorous detail.
Keywords: Open pit mining, Dragline stripping operations, Mining operations, Slope stability, Rock mechanics, Toe buttressing