Volume 6 – Geotechnical Manual, Site Investigation and Engineering ...

Chapter 9 FOUNDATION ENGINEERING
Notes:
1. For free-head short piles in granular soils
2.
H u = 0.5 DL3 K p s '
e 1 +L
1+ sin '
Where K p = Rankine’s coefficient of passive pressure =
1- sin '
D = width of the pile
Ø’ = angle of shearing resistance of soil
s = effective unit weight of soil
3. For fixed-head short piles in granular soils
4. H u = 1.5 DL 2 K P ρ C ’
The above equation is valid only when the maximum bending moment, M max
develops at the pile head is less than the ultimate moment of resistance, M u , of the
pile at this point. The bending moment is given by M max = DL 3 K P ρ C ’
5. P L is the concentrated horizontal force at pile tip due to passive soil resistance.
Figure 9.9 Ultimate Lateral Resistance of Short Piles in Granular Soils (Broms, 1914a)
9-34 March 2009