Analytical Solutions for Internal Stability of a Geosynthetic-Reinforced Soil Retaining Wall at the Limit State

Closed-form analytical solutions are presented for the critical failure plane angle and maximum total reinforcement force in a geosynthetic-reinforced soil (GRS) retaining wall, as obtained from a general force equilibrium analysis of a triangular soil wedge at the active limit state. The solutions can accommodate variable wedge geometry, pore pressure, shear strength parameters, reinforcement force inclination, surcharge stress, applied loads, and pseudostatic seismic coefficients, and include explicit consideration of reaction forces at the toe of the wall. The soil wedge and facing column are treated as a combined block with a vertical load factor to account for soil downdrag on the back of the column. Verification checks show exact agreement with existing analytical solutions for simplified conditions, including Rankine, Coulomb, and Mononobe-Okabe, and good agreement with experimental data from a large-scale GRS retaining wall test. A numerical example is provided to demonstrate the solutions, compare the results with other methods, and highlight the effects of selected variables. Capabilities and limitations of the method are discussed, and a general design approach is outlined.