×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Fadum's chart

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).

RE: Fadum's chart

Normally, I would say Poulos and Davis' book of Elastic Solutions for Soil and Rock Mechanics without looking - but I looked it up this time and they only give the chart.  However, they give formulas by Holl (1940), Giroud (1970) - although they do not give the individual formulas of a number of 'constants' required - and Harr (1966) which does give the formulations for vertical displacement at depth z under the corner of a rectangle (Section 3.4 of Poulos and Davis, pp 54 to 58.  Giroud (1969) also gives values for horizontal displacements.
  Poulos and Davis is the "bible" for elastic solutions.

RE: Fadum's chart

(OP)
Thanks for your help BigH.  Page 54 of Poulos gives the formulae as you say:
z = 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.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources