You can find much in Meyerhof's 1976 Terzaghi lecture paper (ASCE Journal), which also contains several references to other sources.
However, bearing capacity of a footing does not exist. It is a left-over fallacy from the days when we had a concept and a formula and all we needed to do was to find the soil values to use with the formula. It is a source of bewilderment to me every time I meet someone who believes that a movement of 5% to 10% of the diameter is what is needed to mobilize the bearing capacity and that this is reflected in the bearing capacity formula (using phi or SPT, or whatever pleases him) without his ever stopping to consider that the 5% or 10% corresponds to movements of several inches to even feet, while designing a structure with a settlement tolerance smaller than an inch! The governing for a foundation design is settlement and the more a footing is loaded, the larger the settlement. Failure does not show in the load-movement curve and does not occur and factor-of-safety has nothing to do with limiting settlement (Loading a footing very quickly, if pore pressures are generated, can trigger a failure of a sort. However, this scenario is not covered by any simple bearing capacity theory).
To temper your belief in that SPT values can directly be related to "bearing capacity" I suggest you read a short paper of mine summarizing a lecture I gave to a DFI conference a few years ago. You can download a copy from the web site
www.UnisoftLtd.com. The paper is called "219 Delusion of Bearing Capacity.pdf". Have fun! And, start designing using settlement analysis.
While you are moving into the 21st Century, quit believing that you can get anything reliable from cranking SPT N-index values into formulae (if that is what you're doing) and start using CPTU and careful sampling and lab testing results.
Bengt H. Fellenius
