RST Kyrgyzstan

The Kumtor Gold Mine, operated by Cameco Corporation of Canada and jointly owned by Cameco and the government of Kyrgyzstan, is estimated to be one of the largest gold deposits in the world and the largest western-managed mine in the former Soviet Union. The mine is located in the Tien-Shan Mountain Range at an altitude of approximately 4,000 meters.

With little warning on July 8, 2002, a large scale slope failure occurred on the 200 metre high pit wall. Rigorous daily surveying of the pit did not catch any onset of movement and it was decided that more intensive slope monitoring methods were needed.

To address the problem, the Kumtor Operating Company (KOC) contracted Golder Associates Ltd. to provide an independent geotechnical assessment, and to suggest possible modes of failure. In conjunction with KOC and Golder Associates, RST Instruments Ltd. supplied Glue and Snap Inclinometer Casing, Electrolevel In-Place Inclinometers and Time Domain Reflectometry systems (TDR). These instruments were used in conjunction with Campbell Scientific Dataloggers, and FreeWave radios as a method of monitoring pit wall movement. Manual inclinometer measurements are reduced using analysis software.



	The Kumtor Gold Mine, operated by Cameco Corporation of Canada and jointly owned by Cameco and the government of Kyrgyzstan, is estimated to be one of the largest gold deposits in the world and the largest western-managed mine in the former Soviet Union. The mine is located in the Tien-Shan Mountain Range at an altitude of approximately 4,000 meters. With little warning on July 8, 2002, a large scale slope failure occurred on the 200 metre high pit wall. Rigorous daily surveying of the pit did not catch any onset of movement and it was decided that more intensive slope monitoring methods were needed. To address the problem, the Kumtor Operating Company (KOC) contracted Golder Associates Ltd. to provide an independent geotechnical assessment, and to suggest possible modes of failure. In conjunction with KOC and Golder Associates, RST Instruments Ltd. supplied Glue and Snap Inclinometer Casing, Electrolevel In-Place Inclinometers and Time Domain Reflectometry systems (TDR). These instruments were used in conjunction with Campbell Scientific Dataloggers, and FreeWave radios as a method of monitoring pit wall movement. Manual inclinometer measurements are reduced using analysis software.

	RST was responsible for the installation of the remote monitoring stations, datalogger set-up and programming, and alarm setting. Training was also provided by RST on the proper techniques for performing inclinometer surveys in inclined boreholes and inclinometer data reduction and interpretation. Due to the fact that the failure occurred within an extremely short time frame, a system was needed that could take readings often and could monitor the entire length of the borehole with sufficient accuracy. TDR was the ideal candidate, due to its ability to sense deformation in the rock mass through the deformation of a ½” coaxial cable. Additionally, core logs were studied and In-Place Inclinometers (IPI) were placed in zones of interest in the borehole. Traditionally, IPI’s are designed for placement in a vertical borehole. For this application, RST fabricated custom instruments to be used in the 25 degree (from vertical) borehole. The instruments were designed to be adjustable, allowing them to account for the spiral and variations in inclination. The IPI’s allow continuous monitoring of specific zones through their ability to be read by the datalogger.

	Campbell Scientific, data loggers were used to take measurements and relay them back, via radio, to a base station located in the mine dispatch office. From there, the base station computer could be accessed through the system network. Due to the remote nature of the installation, solar panels were used in conjunction with lead acid main batteries and lithium backup batteries. Using Campbell Scientific’s Real-Time Data Monitoring Software, a real-time monitoring program was created to monitor the instruments and have alarms should the TDR or IPI’s detect slope movement which exceeds a specified threshold value.