Model Tests of Seismic Stability of Several Types of Soil Retaining Walls - Reinforced Soil Engineering: Advances in Research and Practice - page 319

Figure 7 Progressive formation of multiple failure planes predicted by considering
effects of strain localization in backfill. (After Koseki et al., 1998b.)
shaking tests (Koseki et al., 1998a). This factor is not considered in the current
seismic design practice. This behavior suggests that the horizontally placed short
reinforcement layers cannot effectively resist such simple shear deformation of
the reinforced backfill. A modification of the design procedure is being attempted
to evaluate the residual deformation of the wall due to this simple shear
deformation of the reinforced backfill (Horii et al., 1998).
It should be noted that the two failure planes observed in the unreinforced
backfill of the reinforced soil wall types 1 and 2, as shown in Fig. 6d and e, were
Figure 8 Two-wedge failure mechanism assumed in current seismic design of
reinforced soil retaining walls with rigid full-height facing. (After Horii et al., 1994.)