lb. per sq. ft. The true value is possibly between these two extremes.
Fig. 25.
Recurring again to earth pressures, the discussion pertaining to [Fig. 24] suggests the following modification of the graphical method of [Fig. 11] to adapt it to finding the pressures of coherent earth against retaining walls, for the case supposed above. In [Fig. 25], let
be the inner face of a retaining board or wall, which is backed by earth with a horizontal surface
. The vertical height of the wall is 10 ft. and the physical constants are assumed as follows:
