M D Bolton, W Powrie, I F Symons. This paper was first published in GE’s January 1990 edition
A method is set out by which designers can check both the safety and serviceability of relatively stiff reinforced concrete retaining walls constructed insitu in overconsolidated clay.
Conventional design calculations are of the limit equilibrium type, being based on the assumption of ‘fixed-earth’ or ‘freeearth’ support conditions illustrated in Figure 1. Current guidance in CIRIA Report 104 (Padfield and Mair 1984)is that the fixed earth support calculation is relevant only to unpropped walls and that free earth support conditions are more realistic for stiff propped walls which approach a failure condition by rotation about the prop position. A lumped factor of safety is used in conjunction with limiting ‘active’ and ‘passive’ earth pressures. The resulting design depends not only on the magnitude of the factor of safety adopted but also on the particular way in which it is introduced into the calculations. No explicit information is provided on the likely displacements in service.