1.Using the service loads, the program solves for the eccentricity by dividing total the moment by the total vertical load.
2.Using the eccentricity and the footing dimensions, the program then determines which of six categories the pressure distribution falls into. These categories are based on the extent of the pressure diagram and the location of the resultant.
3.Finally, based on the category determined above, the program applies one of six established formulas to calculate the toe and heel pressures. In this step, the program uses an effective factored vertical load of 1.4 times the service-level vertical loads. The factor of 1.4 is meant to be an approximation of a weighted average load factor for each of the contributing loads.