A 6-m-high retaining wall having a cross section as indicated by Figure 25 is to be designed to support a backfill consisting of predominantly coarse-grained soil, containing some silt but no clay. The surface of the retained soil has a slope of 3 horizontal to 1 vertical. Using the Terzaghi-Peck charts, determine the magnitude of Ph and Pv that can be assumed for designing the wall. Provide a sketch of the wall, indicating the magnitude and location of these two forces.