The following table shows the computation of the values of

certain that the two methods could not have been brought

deflection and bending moment as a function of depth, using

into perfect agreement. An examination of Figure 4-27a

the above equations. The same problem was solved by

shows that is impossible to fit a straight line through the

plotted values of *E*s versus depth; therefore, *E*s = *kx *will not

computer and results from both methods are plotted in

Figure 4-28. As may be seen, the shapes of both sets of

yield a perfect solution to the problem, as demonstrated in

curves are similar, the maximum moment from the hand

Figure 4-28. However, even with imperfect fitting in

method and from computer agree fairly well, but the

Figure 4-27a and with the crude convergence shown in

computed deflection at the top of the pile is about one-half

Figure 4-27b, the computed values of maximum bending

the value from the nondimensional method. One can

moment from the hand solution and from computer agreed

conclude that a closed convergence may have yielded a

remarkably well. The effect of the axial loading on the

smaller value of the relative stiffness factor to obtain a

deflection and bending moment was investigated with the

slightly better agreement between the two methods, but it is

computer by assuming that the pile had an axial load of

0

0.0

2.43

2.29

0.0

0

17

0.2

2.11

1.99

0.198

0.499

34

0.4

1.80

1.70

0.379

0.955

50

0.6

1.50

1.41

0.532

1.341

67

0.8

1.22

1.15

0.649

1.636

84

1.0

0.962

0.91

0.727

1.832

101

1.2

0.738

0.70

0.767

1.933

118

1.4

0.544

0.51

0.772

1.945

151

1.8

0.247

0.23

0.696

1.754

210

2.5

-0.020

-0.02

0.422

1.063

252

3.0

-0.075

-0.07

0.225

0.567

294

3.5

-0.074

-0.07

0.081

0.204

336

4.0

-0.050

-0.05

0.0

0

100 kips. The results showed that the groundline deflection

results, not shown here, yielded an ultimate load of 52 kips.

increased about 0.036 inches, and the maximum bending

The deflection corresponding to that load was about

moment increased about 0.058 106 in-lb; thus, the axial

3.2 inches.

load caused an increase of only about 3 percent in the values

computed with no axial load. However, the ability to use an

(7) Apply global factor of safety (step 7). The selection

axial load in the computations becomes important when a

of the factor of safety to be used in a particular design is a

portion of a pile extends above the groundline. The

function of many parameters. In connection with a particular

computation of the buckling load can only be done properly

design, an excellent procedure is to perform computations

with a computer code.

with upper-bound and lower- bound values of the principal

factors that affect a solution. A comparison of the results

(6) Repeat solutions for loads to obtain failure moment

may suggest in a particular design that can be employed with

(step 6). As shown in the statement about the dimensions of

safety. Alternatively, the difference in the results of such

the pile, the ultimate bending moment was incremented to

computations may suggest the performance of further tests

find the lateral load *P*t that would develop that moment. The

of the soil or the performance of full-scale field tests at the

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