Passive earth pressure under various modes of wall movements by numerical approach

In this paper, numerical computations using FLAC code (Fast Lagrangian Analyses of Continua) are carried out to evaluate the passive earth pressure magnitude and distribution against a retaining wall subjected to different wall movement modes: translation (T) mode, rotation about bottom (RB) mode and rotation about top (RT) mode. In agreement with classical solutions, the results indicate that in T mode, passive earth pressure distribution is substantially hydrostatic with depth for all wall displacement stages. However, when the mode of rotation either RT or RB is considered, a clear non-linear distribution highly affected by wall displacement magnitude is noticed. For RT mode, due to arching effect, the increase of the earth pressure behind the lower half of the wall is more pronounced with wall displacement affecting hardly the centroid of the passive load distribution located bellow the common one-third of the wall height. In RB mode, as the wall rotation progresses, the passive earth pressure mobilized in upper part of the wall increases and its distribution gradually changes from nonlinear to linear distribution. Compared with previous experimental results available in literature, mobilized passive earth pressure in RB and RT modes needs more displacement than T mode.