A new slice method for seismic stability analysis of reinforced retaining walls

According to the retaining wall that reinforced by extensible reinforcements such as geogrids and geotextiles, a new slice analysis methodology was developed to analyze its internal stability under horizontal and vertical seismic loads. The slide failure wedge of the reinforced retaning wall was divided into a number of soil slices parrallel to the reinforcements. Based on the single line shape assumption for the critical slip surface of the wall, the equilibrium equations for horizontal forces, vertical forces and moments of each soil slice were established. And then, the recurrence formulas for horizontal and vertical inter-slice forces, reinforcement tensile forces were derived consequently, in which the relationship between the inter-slice forces and the safety factor FS of the wall was included. The safety factor FS and the vertical bearing capacity q(mar) at the wall top were obtained by solving those recurrence formulas. This proposed slice method was applied to analyze the seismic stability of two reinforced retaining walls whose height was 5m and 10m respectively, and the results were compared with those of some conventional approaches such as strength reduction method and FLA3D. The results show that: this method is simple, practical and good precision in calculation, so it can be used in actual seismic stability design of reinforced walls; the simplifed critcal slip surface is more feasible and convenient for engineering application than the log-spiral failure surface.