ACTIVE PRESSURE DISTRIBUTION FOR WALLS RETAINING COHESIONLESS SOILS

Abstract

Classical earth pressure theories of Coulomb and Rankine for static case and of Mononobe-Okabe for dynamic case consider only force equilibrium condition and neglect moment equilibrium condition. Hence they fail to predict pressure distribution. The method proposed by Prakash and Basavanna can predict static and dynamic active pressure distribution but the assumptions involved do not appear to be reasonable. Since laboratory investigations indicate a non-linear pressure variation wLth depth even for static case and especially for dynamic case, there is need for development of a better method for this purpose,. The numerical method proposed by Joshi and Prajapati (1982) computes distribution of soil reaction for Mononobe-Okabe rupture wedge by considering equilibrium of discrete wedges. The tangent, of the orientation of earth forces with horizontal at vertical interfaces within the rupture wedge is assumed to vary proportionally to distance of the inter- f ace from the upper end of rupture surface. With this the point of action of soil reaction is obtained which is useful in computing point of action of earth force using moment equilibrium condition. This method has been adopted for this investigation. The results are presented in terms of dimen-sionless factors.