Pile Design and Construction Practice, Fifth edition

Pile compresses elastically

relative to fill and

negative skin friction

is eliminated

Original surface of fill

Peak

W

0.IH

H

W

Length of shaft over

which calculated

yielding of pile toe

exceeds settlement

of fill

Yielding of pile

under combined

dragdown load

and applied load W

Yielding of pile due

to dragdown load

Compressible

bearing stratum

Residual

value

No load

on pile

(a) (b) (c)

Residual value of negative

skin friction

Peak value of negative

skin friction

Negative skin

friction reducing

Pile moves down

relative to fill

causing fill to

act in support

of pile

Peak value

Reduces

to zero

Fill settling

under

own

weight

Residual

Figure 4.40 Distribution of negative skin friction on piles terminated in compressible stratum (a) No
load on pile head (b) Compressive load on pile head (c) Design curve for loaded pile.

0

10

20

30

40

50

60

0 0.1 0.2 0.3

Skin friction factor, b

Depth of penetration (m)

0.4 0.5 0.6

Figure 4.39Negative skin friction factors for piles driven into soft to firm clays (after Meyerhof(4.37)).