Pile Design and Construction Practice, Fifth edition

If equation 6.5 is adapted to a pile with an enlarged base the weight of the pile is taken in
conjunction with the weight of the soil when calculating W.
It will be noted that for deeply embedded plates or pile enlargements, Hdoes not extend
up to ground level and its value can be obtained from tests made by Meyerhof which gave
the following results:

The shape factor sfor deep foundations (including piles) is equal to 1mH/B, where m
depends on the angle of shearing resistance of the soil. Meyerhof’s values of mand the
maximum permissible values of the shape factor are as follows:

The value of Qucalculated from equation 6.5 must not exceed the combined resistance of
the enlarged base (considered as a buried deep foundation) and the pile shaft friction. These
components are calculated as described in Chapter 4.

 20  25  30  35  40  45  48 

m 0.05 0.1 0.15 0.25 0.35 0.50 0.60

max.s 1.12 1.30 1.60 2.25 3.45 5.50 7.60

 20  25  30  35  40  45  48 

H/B 2.534579 11

314 Piles to resist uplift and lateral loading

Ku

f

01020304050

0.6

0.8

1.0

B

Anchor plate

c

Qu

Po

D

H

Soil cylinder of

weight W resisting

uplift by anchor plate

W

Figure 6.9Uplift of circular plate in partly clayey (c) or sandy (c 0) soil (after Meyerhof and

Adams(6.2)).