Civil Engineering Reference
In-Depth Information
Figure 19.20
Equilibrium stress field for a foundation for undrained loading.
19.11 Bound solutions for the bearing capacity of a
foundation for drained loading using fans
Analyses for the bearing capacity of a simple foundation for drained loading are similar
to those for undrained loading and, as before, the best solutions are those with a slip
fan or a stress fan.
(a) Upper bound with a slip fan
Figure 19.21(a) shows a mechanism consisting of two triangular wedges and a slip fan
and Fig. 19.21(b) is the corresponding displacement diagram: these are essentially the
same as those in Fig. 19.14 and, as before, the foundation is assumed to be weightless.
Because the mechanism is not symmetric the work done by the self-weight forces do not
