Afton—a geotechnical pot-pourri

CIM Bulletin, Vol. 81, No. 917, 1988

D.H. STEWART and G.J. REID Afton Operating Corporation Kamloops, British Columbia

A diversity of structures and rock types in the Afton pit has resulted in the occurrence of several different types of wall failure. Delivery of ore to the mill has not been affected and safety has not been compromised thanks to effective remedial work and to a system of structural mapping, back analyses of failures, groundwater monitoring, and simple movement monitoring. Remedial measures have included artificial support, dewatering (including vacuum-assisted drainage), flattening of slopes and temporary buttressing. This paper describes six different wall failures at Afton and highlights the features of each. Examples given include rates of movement, extent and direction of movement, and piezometric responses. The practical, low-cost monitoring system was sufficient in one case to allow the prediction of date of failure.

Keywords: Open pit mining, Rock mechanics, Afton Mine, Wall failure, Safety.