Seismic stability of retaining walls with surcharge

The use of pseudo-static methods for the computation of soil thrust acting on retaining walls under seismic condition is well established in the desig n of such structures. Although different methods, based on the limited disp lacement concept, have been developed in the last 20 years, the most common design method is still the method derived from the theory developed by Mon onobe and Okabe. However, the Mononobe-Okabe method presents a basic shortc oming: the solution is based on the limit equilibrium of the soil wedge wit hout taking into account the presence of the wall. In the paper a new solut ion based on the pseudo-static equilibrium of the soil-wall system is prese nted. The developed solution takes into account the effect of the presence of the wall and it is applied to soil-wall systems with surcharged backfill s. Formulas are provided to calculate directly the yield acceleration and t he inclination of the failure surface. The effect of the intensity of the s urcharge and of its distance from the wall is investigated and the results are compared to those obtained in the case of soil-wall systems without sur charge. (C) 2001 Published by Elsevier Science Ltd.