Question

In determining the bearing capacity of pile, empirical factor C is assumed _________ for drop hammers.
1. 0.25
2. 1.5
3. 2.5
4. 3.5

Answer 1

Correct Answer - Option 3 : 2.5

For determining the bearing capacity of piles.

The commonly used formula is

Engineering News Record Formula (ENR Formula)

\(Q_{up}=\dfrac{W.H}{S+C}\)

kN for drop and single acting steam Hammer

Factor of safety FoS = 6 has been adopted

W = Weight of Hammer (kN)

H = Height of falls of hammer (cm)

S = Penetration or set per blow (cm)

C = constant which account for elastic compresses of pile and soil (cm)

C value are following

C = 2.5 cm for drop hammer

= 0.25 cm for steam Hammer