soil pressure with 0.6d=w

huangyhg

soil pressure with 0.6d+w
is it required to check soil pressure for a footing using the above load combination?  i can see nothing in the ibc or asce 7 that would exmpt a check of soil bearing pressure, so my opinion is that by the code, you have to.  on the other hand, this seems overly conservative to me.  in the "old days" we only checked to make sure we had the required factor of safety against overturning or uplift.  i know that this has been discussed before.
the code we use is the 2003 ibc.  section 1805.4.1.1 states that footings shall be designed for the most unfavorable effects due to the combinations of loads specified in section 1605.3.  section 1605.3.2 does not require the 0.6 factor on d, and we could use these load combinations to design footings.  but if so, how would overturning or uplift be addressed by the code?  engineering jusgement would say that a minimum factor of safety should be 1.5.  compounding the confusion, asce 7-02 does not include the alternate basic load combinations.
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