Janbu, Bjerrum and Kjaernsli's chart reinterpreted

Abstract

The chart developed by Janbu, Bjerrum and Kjaernsli for estimating average elastic settlement of embedded foundations is examined to determine whether improvements can be made in the light of modern capabilities for stress analysis. The parameter describing the effect of a finite layer can be evaluated more accurately from recent results such as those of Giroud. The parameter describing the effect of embedment was originally taken precisely from Fox's work, but finite element analyses indicate that Fox's correction substantially overestimates the effect of embedment. A better estimate can be made by using Burland's correction or, more simply, by ignoring the effects of embedment altogether.