Displacement flexibility number for multipropped retaining wall design

The results from 30 nonlinear finite-element analyses of undrained deep excavation in stiff clay are used to support the use of a new displacement flexibility number in multipropped retaining wall design. The analyses address the effects of different initial stress regimes and various values of prop stiffness for the internal supports to the excavation. It is demonstrated that this flexibility number defines support systems that will displace to the same maximum lateral wall deflection and will result in the same profiles of vertical and horizontal ground surface displacement behind the wall. It is concluded that, as it is these movements that must be controlled to limit the damage to adjacent buildings, structures, and services, the new flexibility number gives the engineer more confidence in assessing possible support strategies to a given problem at a given site.