Terzaghi and Peck Empirical Chart. Figure 7.8 shows a chart by Terzaghi and Peck (1967) that
presents an empirical correlation between the standard penetration test Nvalue and the allowable soil
pressure (tsf) that will produce a settlement of the footing of 1.0 in. (2.5 cm). Terzaghi and Peck
(1967) developed this chart specifically for the standard penetration test (i.e., E
m
=60, and Cb
=1.0).