Abstract: To explore the influence of various working conditions on the stability of a siltstone slope in a project, through the geological investigation of this slope, the strength reduction method in MIDAS GTS NX software was employed to conduct stability evaluations for the two-dimensional slope under the un-reinforced condition and eleven reinforced conditions. By comparing the horizontal displacement, the plastic strain zone, and the stability coefficient under each working condition, the slope stability and reinforcement effect were analyzed. The results show that in the three regions of the slope top, middle, and toe, after applying a prestress of 1000kN to the anchor cable of the reinforced slope, the slope stability coefficient increases to 1.80, and the slope is in a stable state. The ground anchors in different regions of the slope have different impacts on the overall stability of the slope. The prestress of the ground anchor in the toe region is crucial. When the prestress loss of the ground anchor in the toe region is 60%, the maximum horizontal displacement of the slope increases by 146.7%, and the stability coefficient decreases by 27.8%. When considering the reinforcement of prestressed ground anchors during the service period, the ground anchors at the slope toe should be preferentially selected for reinforcement.

Key words: Siltstone Slopes, Slope Stability Coefficient, Prestress Loss of Anchor Cable, Simulation Numerical Model