Amin Keshavarz

Many conventional models in slope stability analysis utilize linear failure criteria, which may not fully capture real-world conditions. Because many retaining structures and soil slopes are situated in seismically active regions; where earthquakes induce permanent displacements and complex, nonlinear behaviors that cause severe damage; evaluating their seismic and nonlinear responses is of critical importance. This study evaluates soil slope stability using a nonlinear failure criterion, employing MATLAB programming to analyze stability under both pseudo-static and pseudo-dynamic conditions. The proposed methodology utilizes the horizontal slice method. This mathematical approach enables a detailed comparative assessment of static, pseudo-static, and pseudo-dynamic states. To validate the model, the generated results are compared against existing academic literature through comprehensive visual data, including detailed charts and tables. The findings confirm that overall slope stability is heavily governed by the geometric and geotechnical parameters of the soil. Crucially, the analysis reveals that higher degrees of soil nonlinearity negatively impact the safety factor. Furthermore, the influence of seismic coefficients is particularly pronounced in the pseudo-dynamic state, where rising coefficients lead to a significant, unfavorable reduction in the slope's safety margins