Page 17 - Unit2.docx

E.A = k.U ……………………………………………3.2

……………………………………………3.3

where:

P = vertical load component

k = material constant

U = displacement

E = elastic module of pile material

A = cross-sectional area of pile

© It's Engg. Life

Figure 3-2 load on single pile

The length L should not necessarily be equal to the actual length of the pile. In a group
of piles, If all piles are of the same material, have same cross-sectional area and equal
length L , then the value of k is the same for all piles in the group.

Let us assume that the vertical load on the pile group results in vertical, lateral and
torsion movements. Further, let us assume that for each pile in the group, these
movements are small and are caused by the component of the vertical load experienced
by the pile. The formulae in the forthcoming sections which are used in the calculation of
pile loads, are based on these assumptions.

3.2 Pile foundations: vertical piles only

Here the pile cap is causing the vertical compression U, whose magnitude is equal for all
members of the group. If Q (the vertical force acting on the pile group) is applied at the