Earth pressures and stability of retaining walls - The Mechanics of Soils and Foundations - page 384

Figure 24.8 Effects of water on retaining walls.

P /7 (because there are seven equipotential drops in the flownet) and the size of the
last element

δ s can be determined by measurement from a scaled diagram.

24.7 Calculation of earth pressures - drained loading
As a retaining wall moves the horizontal stresses change, as illustrated in Fig. 24.2,
and when they reach the limiting active or passive pressures the soil has reached its
critical state. The active and passive pressures can be calculated using upper and lower
bound and limit equilibrium methods and, as always, it is necessary to distinguish
between drained and undrained loading.