Slope Stability Analysis Method Based on Known Seepage Lines

The seepage field is a prerequisite for solving effective stress and conducting stability analysis, but solving saturated and unsaturated seepage fields is relatively complex, and the calculated results usually have significant discrepancies from the measured results on engineering sites. Therefore, a slope stability analysis method based on the known seepage lines is proposed. The specific steps are as follows: first, determine the pore pressure distribution within the slope based on the known seepage line; then, apply the unified effective stress equation for saturated and unsaturated soils to solve the slope's effective stress field; finally, perform the slope stability analysis using the finite-element limit equilibrium method. The stability of a dam was analyzed using both the new method and the stability analysis method based on fluid–solid coupling. The results show that when the seepage line is relatively gentle, with the angle between the exit point and the horizontal direction being less than 10°, the sliding-in and sliding-out ranges of the slip surface calculated by both methods are basically consistent. The relative error in the factor of safety is about 2.3%, and the accuracy meets the engineering requirements. Finally, the slope stability analysis method based on known seepage lines is applied to a certain tailings dam project. The influence of seepage line variations on the stability of the tailings dam is analyzed, yielding satisfactory results and demonstrating the advantages of the seepage line-based stability analysis method in rock and soil slope engineering.