curvature at increasing loads. The curves calculated using this method were called
displacement in this chapter.
The experimental curvature was also determined based on a numerical differential
method. With the numerical differential method the curvature is calculated based on
displacement values for adjacent points in contrast to the curvature based on the
displacement profile which the curvature is calculated based on a fitted line through all
displacement points that can neutralized localized effects. More details on the numerical
differential method can be found in chapter 5.
The experimentally calculated M-0 curves from both methods (displacement
profile and numerical differential) for specimen SCC3 and SCG3 are presented in Figs 6-
44 and 6-45.
140
120
100
80
60
40
-B-Disp. (SCC3)
0
20 /-A-Diff. (SCC3)
0 0.0005 0.001 0.0015 0.002 0.0025
Curvature (rads/in)
Figure 6-44. Experimental M-D curves for piles SCC3
Typically the differential moment curvature curves were different than the
displacement moment curvature curves as is noted from Figs 6-44 and 6-45. The obvious
difference was the slope of the curve. The differential curves had larger slopes than the
displacement curves. For a given load the curvature calculated based on the differential