Maria-Angeliki Raptaki, "Slope stability impacts in a pit lake due to changes at the water level", Diploma Work, School of Mineral Resources Engineering, Technical University of Crete, Chania, Greece, 2023
https://doi.org/10.26233/heallink.tuc.98194
The lake formation is the most common way of rehabilitating lignite mine excavations after the end of mining. These pit lakes are usually aesthetically attractive and are mainly used for recreational purposes.This thesis aims to investigate the slope stability in a pit lake due to changes of water level. The case of the Most pit lake (in Czech Republic) was used to study the behavior of the slopes in relation to water level alteration.The stability of lake's slope was investigated in three locations, following different water level changes. In these scenarios, the Van Genuchten model was taken into consideration to assess the effect of suction on permeability of the strata in the unsaturated zone. Also, the Mohr - Coulomb elastoplastic model was used to evaluate their geotechnical behavior.Initially, the pore water pressure and the impact of suction in the unsaturated zone were estimated using the finite element software SEEP/W. Then, the limit equilibrium method (Morgenstern-Price method of slices) was used for slope stability analysis using SLOPE/W software.It is concluded that the slopes of the lake are stable. However, the safety factor decreases with lowering water level of the lake. The higher the rate of lowering of the water level, the lower the safety factor of the slopes is estimated.Also, the fluctuation of the lake water level reduces the stability of the slopes; this result is not affected by the number of variations.