I have a building with a collection of reinforced concrete shear walls that I am doing preliminary designs for. Some walls are standalone and others are built around cores, so they form C shapes and rectangles. I have grouped connecting walls together to form individual cores, where applicable.
I have assigned base reinforcement to all the walls based on code minimum reinforcement ratios for 12" walls (all walls are the same thickness). When I run the analysis, RAM is saying that some walls do not have adequate reinforcement to satisfy the minimums, despite them all having the same reinforcement and same unit areas. Am I missing something, or is RAM screwing up the area calculation for grouped walls somehow? Am I using the group function incorrectly? I have pasted some examples below. You can see for an individual 12" wall the calculated ratio is what you would get via a hand calc for #4@12"oc. However for the box shape the reinforcement ratio is much lower, and "failing", and I can't figure out where that number is coming from. I would expect these two calculations to match...right?
Any advice is appreciated.