Highter and Anders - Effective Area Method (two-way eccentricity)
Foundation Eccentricities
There are cases encountered frequently where foundations are subjected to moments as well as vertical loads. Because the distribution on the soil is no longer uniform, using Highter and Anders effective area method can account for the differences in pressure beneath the foundation under consideration. The effective lengths can then be used with Meyerhoff's general bearing capacity equation and the ultimate load the foundation can sustain can be found using the effective values of A', L' and B'.
Two-way eccentricity case identification
The 5 Cases
Case 1
Case 2
Case 3
Case 4
Case 5
Equivalent two-way eccentricity case identification
Notation and Units
Metric and Imperial Units
The above formulas may be used with both imperial and metric units. As with all calculations care must be taken to keep consistent units throughout with examples of units which should be adopted listed below:
Notation
- B = width of foundation, ft or m
- L = length of foundation, ft or m
- eb = eccentricity or effective eccentricity of load, ft or m