There is an A/D Parameter, under the "Footing" tab to consider effective footing dimensions in analysis of a spread footing. This appears to calculate the effective footing assuming the footing is bearing on soil (as opposed to rock). Is there a way to trick the program to analyze the effective footing while bearing on rock? Thanks.
Generally the program computes the maximum soil pressure.
In the footing TAB there is an option to input the "User Specified Maximum Soil reaction" .
I hope this option helps.