Pile Design and Construction Practice, Fifth edition

Zmax 23/6.5 3.5,

x (m) Z x/R Mm Mh

00 1.00 10.9 0 0 10.9
0.5 0.08 0.98 10.7 0.10 0.3 11.0
1.0 1.15 0.97 10.6 0.15 0.4 11.0
1.5 0.23 0.95 10.4 0.20 0.5 10.9
2.0 0.31 0.94 10.2 0.27 0.7 10.9
4.0 0.62 0.85 9.3 0.40 1.1 10.4
8.0 1.23 0.55 6.0 0.45 1.2 7.2

The maximum bending moment of 11.0 MNm provides a safety factor of 15.4/11.0 1.4
against yielding of the steel.
From equation 8.3, the kinetic energy absorption value of the pile for horizontal
movement at the stage of soil rupture at sea-bed level:

In a similar manner to that set out above, it is possible to obtain pile head deflections and
bending moments for various stages of horizontal loading up to the stage of yielding of the
steel and hence to draw curves of deflection and energy absorption against horizontal load.
The deflection of the pile at sea-bed level caused by a lateral force of 421 kN applied at
the sea bed can be calculated using Randolph’s curves (Section 6.3.8).
Effective Young’s modulus of equivalent solid section pile:

An average constant soil modulus of 3.3 MN/m^2 from Figure 8.19b was used to calculate
pile deflections and bending moments. For undrained loading take Poisson’s ratio vu 0.5.

Shear modulus

G*

Critical length

In Figure 6.36a,

At 0.5 m below sea bed

z/lc 0.5/22.9 0.02 m

yr 0 Gc

H 0 

Ep

Gc

(^1)  7
y0.651.5
0.421 

34.2 103

1.5 

(^1)  7
9.7y
Homogeneity factor 1
lc 2 0.6534.2^10
3
1.5 
(^2)  7
22.9 m
1.1(10.750.5) 1.5 MNm^2
Gc 3.3
2(10.5)
1.1 MNm^2
Ep 4 ^2 ^10
(^5) 0.024
0.65^4
34.2 103 MNm^2
12  421 1 3631 000 287 kJ
MNm) 2.74Mh (MNm)( (MNm)
MA 10.9Mm MB 0.4216.5Mh M MAMB
430 Piling for marine structures