Monitoring the Deformations in an Open Pit Lignite Mine Slopes by Geodetic Methods and Mathematical Analyses

Slope sliding and landslides occurring on the open pit benches can lead to consequences such as the loss of life as well as the economic loss and deterioration of the stove geometry. Safe geotechnical designs, supports, rock fall prevention systems and monitoring the deformations occurring on the slopes are among the most familiar precautions which must be taken to prevent these consequences. This study is performed in Muğla Province Yatağan District Eskihisar lignite open pit mine which was in the management of TKİ-GELİ (Turkish Coal Enterprises-South Aegean Lignite Management) in 2011. As a result of investigations and preliminary assessments at the mine regions which have instability problems were identified at the western side of the mine. Then, it is decided to monitor these regions which could have instability problems. Measurement stations were set up on the tension cracks which are the signs of a probable instability problem at the western slopes and slope movements were monitored periodically for 216 days by geodetic measurement methods. As a result of the obtained data deformation movements were evaluated and it was determined that the movement was continuing in a moderate velocity trend. A mathematical model was developed related to these movements. It was seen that there is a good correlation between the results of the model and the in-situ data. It will be possible to predict future deformation rates and velocities on the slopes of this location with this model.