Back-Analysis of the Bingham Canyon South Wall: A Quasi-Static Complex Slope Movement Mechanism


A 610 m (2000 foot) high portion of the South Wall of the Bingham Canyon open pit has experienced slow-moving slope deformations several times during spring melt until the movement was stabilized approximately 7 years ago. To develop and optimize life of mine (LOM) slope designs, an understanding of the mechanism(s) and associated material strength parameters, was required. A back-analysis and calibration of the strength parameters for the salient rock mass and structural features was undertaken. The back-analysis consisted of understanding the conditions and trigger for the slope movement and adjusting strength parameters to match available monitoring data (TDR cables, inclinometers, IBIS radar data, etc.). The trigger for the movement was attributed to the spring high-perched water levels in the upper part of the wall. The back-analyses was consistent with the conceptual model and indicated that the slide was composed of mixed mechanisms, namely, a structurally controlled mechanism for the upper wall and a rock mass controlled mechanism for the lower wall (toe). Today, the O-Slide instability has been fully managed by rigorous monitoring, implementation of a toe buttress, successful dewatering efforts, and unloading of the movement mass as another slice of mining advanced down the South Wall.

Meeting Name

52nd U.S. Rock Mechanics/Geomechanics Symposium (2018: Jun. 17-20, Seattle, WA)


Mining Engineering

Keywords and Phrases

Landslide; Landslides; Shear strength

Document Type

Article - Conference proceedings

Document Version


File Type





© 2018 American Rock Mechanics Association (ARMA), All rights reserved.

Publication Date

20 Jun 2018