LRFD 2003 - Analysis of Spread Foundations
introduces two types of design coefficients - coefficients modifying the load magnitude (Load factors) and coefficients reducing the soil resistance (Resistance factors).
Only partial factors are used to multiply the self weight of spread foundation and the weight of soil above the footing (overburden). Individual components of load must be pre-multiplied by the corresponding partial factors - the program does not further modify the input load.
When performing the final verification the overall resistance of the structure against failure is multiplied by the corresponding resistance factor.
Analysis based on LRFD 2003 - input of partial factors for foundations