01 Jul 97
Figure 1-4. Drilled shaft details (1 in. = 25.4 mm)
length/diameter ratios less than 10. The selected shaft dimension
within 0.5 inch of displacement, while end bearing may not be fully mobilize
should minimize the volume of concrete required and maximie
until displacements ex eed 10 to 20 percent of the base diameter or underream for
constuction efficiency. T e lateral load capacity of driven piles may be
drilledshafts, unless the tip is supported by stiff clay, dense sand, or rock. Figure
1-5 illustrates an example of the vertical axial load displacement behavior oa
single pile or drilled shaf. The load-displacement behavior and displacements that
correspond to ultimateload are site specific and depend on the results of analyses.
These analyses are given in Chapter 3.
(3) Lateral loads. Lateral load capacity of a pile or drilled shaft is directly
related to the diameter, thus increasing the diameter increases the load-carryin
capacity. For a drilled shaft that sustains no axial load, the cost of constructio
may be optimized by theselection of rigid shaftswithout underreams and with