Static and seismic stability analysis of kumtor’s tailings dam
Kumtor gold mine is situated in the Kyrgyz Republic in Central Tien Shan Mountains at the altitude of 4000 meters in permafrost area. Construction and operation of the tailings dam started in 1995. In 1999 displacement of the dam to downstream side was detected. The dam height was 20 meters. Analysis of monitored data showed that displacement took place in ice rich loamy layer in the foundation on 4 meters depth. To stop this displacement they decided to excavate loamy layer beyond downstream and change it by construction shear key made of macro fragmental soil. The depth of shear was 5 meters. Fur the more the monitoring data showed that tailings dam continue to move on underlying soils. The additional geological investigation was done. It showed that more solid soil was located on the depth from 10 to 12 meters. The methodology of displacement stoppage was the same as previous. Worked out measures to stop the tailings dam displacement was accomplished in the period from 2006 to 2010. The goal of the research is to create numerical model in FLAC codes, forecast calculation of dam stability to 2016 when the dam height would be 42.7 meters, the dam seismic stability analysis with consideration of layered foundation.