Impact of spatial variability in undrained shear strength on active lateral force in clay

This study explores the mechanism of the active lateral force (P-a) in clay when there is spatial variability in the undrained shear strength. It is shown that the effect of such spatial variability cannot be fully explained by considering the spatial averaging over a prescribed area or line only; the mechanism to seek the favorable failure path is also important. Ignoring this important mechanism is risky, rendering the P-a estimate smaller than the actual P-a value. The mechanism of seeking the favorable failure path is explored, and a probability distribution model for P-a is proposed to characterize this sophisticated mechanism. Furthermore, a simplified procedure is proposed to simulate the Pa samples without the use of the finite element method or limit equilibrium method. (C) 2014 Elsevier Ltd. All rights reserved.