01-03-2011, 07:12 AM
1) Are your columns in grid ? or randomly placed?
2) And if the loadings of each column is relatively similar?
Manual calculations is easier if both your answer to above are 'yes'.
Else, your have to have considerable understanding about flat slab, As the mat foundation is somewhat similar to flat slab, concept-wise.
Let me pass you some tips for the thickness estimations.
You have to determine a size which pass the punching shear for all the columns (presumably you have the same thickness through out).
2) And if the loadings of each column is relatively similar?
Manual calculations is easier if both your answer to above are 'yes'.
Else, your have to have considerable understanding about flat slab, As the mat foundation is somewhat similar to flat slab, concept-wise.
Let me pass you some tips for the thickness estimations.
You have to determine a size which pass the punching shear for all the columns (presumably you have the same thickness through out).