Fadum's chart
Fadum's chart
(OP)
Has anyone got equations that can be used to represent Fadum's chart for influence values to determine settlement?
Fadum R E Influence values for vertical stresses in a semi-infinite solid due to surface loads - School of engineering Harvard university (1941).
Fadum R E Influence values for vertical stresses in a semi-infinite solid due to surface loads - School of engineering Harvard university (1941).





RE: Fadum's chart
Poulos and Davis is the "bible" for elastic solutions.
RE: Fadum's chart
Iσz = 1/(2π)*[arctan(m*n/sqrt(m²+n²+1)) + {m*n/sqrt(m²+n²+1)}*{1/(1+m²) + 1/(1+n²)}]
where Iσz = influence coefficient
m = B/z
n = L/z
B = half breadth of foundation
L = half length of foundation
z = depth
We use half breadth and length because we work from the centreline in both directions and then multiply by four to model the four quadrants of the foundation.
My old book assumed that we would work from charts etc rather than work it all out.