Active lateral pressure to rigid retaining walls in the presence of an adjacent rock mass

If there is not adequate space for development of failure wedge behind a retaining wall, the conventional methods of determining the active earth pressure cannot be used. In such cases, the wall design procedure changes due to the change in the distribution of the soil stress in the active state and the variations of the magnitude and the position of the resultant force acting on the wall. In the present study, finite element method was employed to analyze the lateral earth pressure behind a wall, considering the limitation on the backfill width. A rock mass with an unlimited width was considered behind the limited backfill. In the analyses, the effects of various strength parameters of the backfill behind the wall and the rock mass behind the backfill were taken into account. Besides, different wall geometries and backfill dimensions were analyzed. The obtained results show that the earth pressure due to the limited backfill is considerably smaller than the lateral pressure resulting from Coulomb’s method with an infinite backfill width. Also, the position of the active resultant earth force is higher than one-third of the wall height.