Precise Automated Monitoring for Deformation of Dams Using the Global Positioning System (GPS)

Sensitive deformation monitoring enhances the safety and stability of tailings facilities. Loading from hydraulically-emplaced fills can result in rapid saturation of dam embankment material and rapid loading at dam footings. Hydraulically emplaced fills are susceptible to settlement during closure and post closure, resulting in cracked caps, leakage and other complications. The timely identification of deformation associated with hydraulic fills can save lives, avert large financial liabilities and avoid severe environmental damage. Until 1999, deformation monitoring at tailings facilities could only be accomplished by periodic survey or automated sensors (tiltmeters, TOR, electrodes, etc), or both. Periodic surveys are expensive and do not provide a real-time monitoring capability, and sensors provide only rotation or inferential data. A recent development in Global Positioning System (GPS) processing software provides automated 30 monitoring for tailings dams and other large structures in real time. This processing software differs significantly from existing GPS software and represents new technology specifically designed for long-term real-time monitoring. The unique software is Windows PC based and combines sophisticated computations of raw GPS data from numerous receivers and a comprehensive automatic warning system. The resulting system solves many of the problems associated with the use of existing GPS technology for long-term deformation monitoring and provides new monitoring capabilities in a cost­effective manner.