Civil Engineering Reference
In-Depth Information
Figure 21.19
Stability numbers for drained loading. (After Bishop and Morgenstern, 1960.)
21.10 Behaviour of simple excavations
All the features of slope stability described in the previous section can be observed by
digging a hole in the beach. What you will see is illustrated in Fig. 21.20. In the dry
sand at the surface the slope angle is
φ
c
. In the unsaturated sand above the water table
the pore pressures are negative and it is possible to excavate a vertical cut BC. The cut
Figure 21.20
Stability of a simple excavation.
