Limit Equilibrium and Stress–Strain Analysis of Stabilized Homogeneous Earth Dams under Drained and Undrained States

This study investigates the stability of a cement‑stabilized homogeneous earth dam under drained (steadystate seepage) and undrained (rapid drawdown) conditions. Laboratory tests on high‑plasticity clays treated with 2.5–10% Ordinary Portland Cement provided input parameters for numerical modeling using Bishop’s Simplified Method and finite element analysis in PLAXIS 2D. Results show that cement stabilization significantly improves soil performance, with 5–7.5% cement content optimally enhancing shear strength, dry density, and reducing permeability. Factors of safety increased under both drained and undrained conditions, demonstrating that cement stabilization combined with effective drainage offers a cost‑efficient solution for safe dam construction in Nigeria.