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'.

The 5 Cases
To determine which case is best suited to the loading condition under consideration refer to Highter and Anders Two-way Eccenticities. or if you know the case simply scroll down or click on one of the links below.

Case 1 Case 2 Case 3 Case 4 Case 5

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

• A' = effective area of foundation, ft² or m²
• B = width of foundation, ft or m
• B' = effective width of foundation, ft or m
• L = length of foundation, ft or m
• L' = effective length of foundation, ft or m
• R = radius of foundation, ft or m
• e_b = eccentricity of load from centreline of width, ft or m
• e_L = eccentricity of load from centreline of length, ft or m
• e_R = eccentricity of load from centre of foundation, ft or m