Stability Analysis of Tailrace Outlet Slope at Right Bank of Kala Hydropower Station

The tailrace outlet slope located on the right bank of the Kala hydropower station represents a typical bedding slope characterized by a moderate to large dip angle. The excavation at the toe of the slope create favourable conditions for rock mass deformation and failure. In order to evaluate the slope’s stability, a thorough investigation and analysis of the engineering geological conditions are conducted. Additionally, the stress-strain characteristics resulting from the slope excavation are simulated utilizing the discrete element software 3DEC. Finally, the strength reduction method is used to evaluate the safety factor of the slope. The research results show that the stability of the slope is notably influenced by the presence of medium and large dip structural planes, the cutting excavation at slope toe can lead to deformation and localized block instability. The implementation of the system pre-stressed cables effectively increases the safety factor of the slope and ensures the stability of the tailrace outlet slope. These findings will provide valuable references for the design of similar rock slopes.