COMPARATIVE-ANALYSIS OF TOPPLING BEHAVIOR AT CHUQUICAMATA OPEN-PIT MINE, CHILE

Reliable and economically efficient mining of the Chuquicamata pit, Ch ile, is already subject to a great number of complex operational deman ds, among which the geomechanical issues are currently an important fa ctor and will be even more relevant as the pit expands and deepens. To address these demands a team was assembled to collect geomechanical i nformation and perform numerical analysis. The west wall is the larges t and flattest of all the design sectors in the pit. This fact and a g eological structure that permitted two-dimensional analysis were the m ain reasons for initiating rigorous geomechanical studies of that wall . The behaviour of the wall is controlled mainly by a set ef steeply d ipping joints within the slope and a weak zone that extends vertically near the pit bottom. Together, these features lead to large toppling displacements in the upper portions of the west wall. Both continuum a nd discontinuum methods of analysis are candidates for representing th e observed behaviour. An account is presented of the development of th e conceptual model of behaviour, the calibration of the numerical mode ls and the favourable comparison with the measured behaviour that was obtained with both analytical methods.