Seismic rotational stability analysis of reinforced soil retaining walls

Abstract

Reinforced soil retaining walls have been widely constructed all over the world. Although the limit equilibrium (LE) method is common practice in design, a growing body of experimental and analytical evidence has demonstrated that it could lead to overly conservative (and hence, uneconomical) design. In this paper, a kinematic limit analysis method, combined with a pseudo-dynamic method of analysis, is developed for rotational stability analysis of reinforced soil retaining walls based on the log-spiral failure mechanism. The proposed analysis method is validated against the results from different pseudo-static methods. However, the rotational stability and the corresponding yield acceleration coefficients from the proposed method are shown to vary with time, and with factors such as the backfill shear modulus and the frequency of ground motion. Parametric analyses are also conducted to study the influences that pseudo-dynamic analysis parameters, reinforcement properties, wall height, and soil strength have on rotational stability and failure geometry of reinforced soil retaining walls. Results indicate that optimum value of ultimate reinforcement strength is greater when the reinforcement is more widely spaced. Additionally, the cross-sectional area of the rotational failure mass is smaller for walls with lower-strength reinforcement and larger vertical spacing.