STAAD FOUNDATION ADVANCED (DESIGN OF COMBINED FOOTING)

Question

Good day Engineers!!! Can anyone help me solve this problem that I encountered in my program? Thanks!!! Footing Design.sfa 
 
 16:24:17 [ERROR] UNABLE TO DETERMINE A SUITABLE WIDTH FOR THE GIVEN LOADING. LAST WIDTH TRIED = 3.609 FT 
 16:39:30 [ERROR] UNABLE TO DETERMINE A SUITABLE LENGTH FOR THE GIVEN LOADING. LAST LENGTH TRIED = 23.130 FT 16:44:15 [ERROR] THE BAR SIZE CAN NOT BE SELECTED. PLEASE CHECK THE MAXIMUM AND MINIMUM BAR SIZES INDICATED, LOAD CASE = 109 
 17:20:25 [ERROR] UNABLE TO DETERMINE A SUITABLE WIDTH FOR THE GIVEN LOADING. LAST WIDTH TRIED = 4.101 FT

Kris Sathia · Answer

By primary, I presume you are referring to pure component load cases. It doesn't make sense to design for such load cases. Designing for a load case that represents just wind, or pure seismic means you will have a lot of de-stabilizing effect due to lateral loads, and no stabilizing effect from the vertical loads to accompany that. If you do this, you may end up with much larger foundation sizes than warranted, or a failure when there shouldn't be one. 
 It makes sense to solve just for the load combinations since they represent the simultaneous action of gravity with live, gravity with wind, gravity with seismic, etc. 
 This principle applies to all types of foundations - isolated footings, pilecaps, mats, etc.

Kris Sathia · Answer

In the current version of SFA - 9.4.0.20 - this model runs successfully. See the attached output. 
 In older versions, if the maximum size limit was reached on any of the 3 dimensions - length, width or thickness, the program would stop iterations. In the current version, if the limit is reached on any of those three, the program will perform another trial by increasing the size of those sides which have not reached their limit. 
 PDF

Kris Sathia · Answer

If you want the footing to be designed for just load cases 10 to 79, you need to 
 a) Edit the job and remove load cases 1 to 9 frrom the list of "Selected Load Cases". 
 b) Load cases 10 to 37 should have their type changed from Primary to Ultimate. 
 c) Load cases 38 to 79 should have their type changed from Primary to Service. 
 For (b) and (c), see this 
 https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/39223/applying-load-case-types-to-load-cases-or-combinations-in-batches

STAAD FOUNDATION ADVANCED (DESIGN OF COMBINED FOOTING)

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