RAM SS - Foundation [FAQ]

CanmatfoundationsbedesignedinRAMFoundation?

MatfoundationscannotbedesignedinRAMFoundation.MatfoundationsmodeledinRAMStructuralSystemcanbeimportedintoRAMConceptforanalysisanddesign.

SeethefollowingwebpageformoreonimportingRAMStructuralSystemmodelsintoRAMConcept:

RAMConcept-RAMStructuralSystemIntegration

How is 1/3 overstress accounted for?

The allowable soil stress assigned to the footing is constant for all combinations. So, there is no good way to accommodate 1/3 allowable overstress in the design if it pertains to some, but not all of the load combinations. 

We suggest incorporating the equivalent allowable overstress into the soil combos, by using reduced load factors on the combos with short duration loads.

Alternatively, the model could be designed twice; once with only gravity combos and a lowered allowable soil stress, once using gravity and lateral combos with the higher allowable.

How is uplift and overturning design done for spread footings?

See this blog post for details: Spread Footing Overturning and Uplift Checks in RAM Foundation

Why does the required area of steel increase when I use larger diameter bars?

In small foundations, the longitudinal bars are only partially developed at the critical moment location. When the program reports the area of steel required it is increasing the value reported by dividing by the percentage of full development. With smaller bars the development length is shorter so less net area of steel is commonly required.

This check can be circumvented by assigning the bars to be hooked (Assign - Geometry command)

The same rule also affects continuous footings in the transverse direction.

See Also

Structural Product TechNotes And FAQs

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