Implementation of novel subsurface deformation sensing device for open pit slope stability monitoring - the Networked Smart Markers system

摘要

Comprehensive and rigorous surface and subsurface monitoring to determine slopedisplacement in open pit mining is one of the most important means of assessing overall slopeperformance. The monitoring campaigns are aimed towards achieving and maintaining safeoperating conditions, providing advance notice of zones of potentially unstable ground,providing geotechnical information for analysing any slope instability mechanism thatdevelops, designing appropriate remedial action plans, and assessing the performance of theimplemented slope design.Today's surface displacement monitoring instruments are sophisticated; they includeautomated wireline extensometers, universal EDM total stations, 3D digital photogrammetryand laser scanning, and ground-based and satellite-based radar. Together, they can provide areal-time 3D record of any surface movements that may be taking place around the walls ofthe pit. However, in-ground displacement monitoring instruments are less sophisticated.Typically, they include shear strips and/or time domain reflectometers (TDRs),extensometers, and inclinometers placed in boreholes to locate or examine the propagationof subsurface movement after evidence of subsurface deformation has been detected at thesurface. Less regularly, they are placed where it is anticipated that movement may not bedetected by surface instruments. Rarely, if ever, are they able to detect in real time subsurfacedeformation as it develops and propagates to the surface.This paper describes the first steps in the implementation of the novel Networked SmartMarkers (NSM) technology for subsurface deformation monitoring in large open pits. A casestudy of the trial installation at an open pit mine in Chile shows the importance of a welldesignedinstallation, resulting in a robust and successful installation. This procedure wouldlead towards a more comprehensive monitoring campaign with further development of theNSM platform for multi-sensor, multi-variable monitoring.