Settlement‐Time Predictions in Preloading

Proper planning of preloading requires time predictions that cannot be obtained reliably from laboratory odometer tests. Time forecasts should be based on field permeability tests or test fills. The settlement versus log time curve of preloading can assume a variety of shapes, depending on the geometry and permeability of sand‐silt contained within the consolidating clay. Experience indicates that three types of curves are recurrent: (1) S‐shaped; (2) bilinear with increase in slope; and (3) linear. The first kind shows that settlement is about completed; for (2) and (3), approximate equations are proposed for predicting the settlement of the permanent structure from settlements observed during preloading. Examples are presented from two construction sites in Greece.