When designing a footing in RAM Foundations for uplift due to a steel brace frame we have adjusted to uplift Safety Factor to 1.0
Moments on the footing due to shear loads have not been included because it has been determined that the soil will be able to adequately support the lateral force from the column. A surcharge load has been added to account for the dead load of the slab on grade and soils above the footing. When modifying a footing size and running the check in View/Update with a footing that is smaller in size than what was designed by RAM Foundations the design fails and says "Uplift on compete footing." However, when reading the design results for the footing run the results list the footing Uplift Safety Factor as 2.0 (see below).
Is there other areas where to modify the Safety Factor? Is the Safety factor being over written because of other settings that have been included?
The error message may be associated with a load combination other than #320, which is governing the uplift and overturning checks. To test, uncheck all service load combinations besides #320 and see if the report outputs the same error.
If questions remain, please share your model using our Secure File Upload and post the file name here after it is uploaded.
The issue was still present after removing all other service load combinations. I have uploaded the file to the Secure File Upload, it is named CCC - Little Rock
The "Uplift on Complete Footing" error is associated with a concrete load combination and is produced because the option marked in the image below is checked.
Even if that option is unchecked, Service Load Combination #320 would have an Overturning SF of 1.3 in the minor direction and would produce a "Excessive Moment in Positive Minor Direction" error since it is less than 1.5.
Hi Karl,
I am researching overturning FS in RAM Foundation in this forum. Does the design error "Excessive Moment in Minor or Major Direction" result with a factor of safety FS less than 1 or 1.5? I see you noted 1.5 above.
In addition, I have the following questions.
1. Is that 1.0 the default FS against overturning RAM Foundation?
2. is there a way to allow FS against overturning less than 1.0 in RAM Foundation?
Thanks,
Check this: https://communities.bentley.com/other/old_site_member_blogs/bentley_employees/b/josh_taylors_blog/posts/spread-footing-overturning-and-uplift-checks-in-ram-foundation
The user can specify an uplift safety factor, but for spread footing overturning we are using 1.0. We can't evaluate something with a FS < 1.
Thank you Seth.
Follow-up question. If I uncheck include self-weight in checking soil stress, does the program still consider the self-weight for the uplift check?
I want to exclude self-weight in the bearing check and include the self-weight in the uplift check. Is this possible? thanks.