Rigid Walls. For the case of rigid walls, which involves wall translation or rotation
“into the backfill,” the movement necessary to develop passive earth pressure behind the
wall varies from 0.020H to 0.060H for cohesionless soils, dense to loose, respectively.
Also, for stiff to soft cohesive soils, the lateral displacement will vary from 0.020H to
0.040H. It is obvious that passive earth pressures can be developed in these defined conditions.
Certainly, the best way for the designer to account for these pressures is to avoid
them wherever possible and practical, alleviating the conditions under which such pressures
develop. This brief discussion is intended only to generate an awareness in the designer
that such conditions can be created. An example would be dead-man type anchorages
tying the wall top into solid materials or outside the failure plane of the wedge, thus preventing
the movement necessary for development of the active pressure state.