Seismic Stability Analysis of Embankment Supported by Geosynthetic‐Encased Stone Column Composite Foundations

Geosynthetic‐encased stone columns (GESCs) can effectively improve the performance of the foundation in seismic zones to enhance the safety and stability of superstructures. This study establishes a comprehensive probabilistic framework to quantify the seismic instability probability ( PI ) of embankments supported by GESC composite foundations. The parameterized seismic stability functions are derived from the logistic regression and seismic stability model. Key parameters include column diameter ( D c ), tensile strength ( T ), area replacement ratio ( m ), strength parameters of column ( φ c and c c ), surrounding soil ( φ s and c s ), and embankment ( φ em and c em ), and slope ratio ( H em /L slope ). Results indicate that the reinforcement effect of geosynthetic reflects on increasing cohesion related to D c and T . Reduced column diameters (e.g., decreasing D c by 0.504 m) combined with high‐strength geosynthetic (e.g., increasing T by 33.73 kN/m) optimize seismic resilience for a 0.1 rise in k h . m reduces PI with a regression coefficient of −39.303, making it 18.9 times more influential on system performance than embankment geometry. Enhancing c em improves stability 5.2 times more effectively per unit change than optimizing φ em . Embankment performance governs system behavior compared to the strength parameters of the surrounding soil and column under low‐ m conditions (e.g., ≤ 5%).