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Dear Safeians I ma working on a 22 Storey Building. we have assume a Raft foundation of 5' for it. Net bearing capacity after overburden relief is 8kip/ft2. And i am getting 10Kip/ft2 soil pressure under service loads at some locations. one of my friend said use stress averaging to minimise the values as these soil pressures are nodal results of finite elements. do somebody have any clue how to do that using safe .. or Excel. stress distribution.bmp

You should not use LRFD combinations for checking bearing capacity. Use service load combos only for bearing capacity and LRFD for moment and shear design.

As far as high-rise design goes, there is always areas of high concentration in a raft. General practice is to ignore them and focus on more general values and see if they are within the allowable limit or not. There is no guideline for stress average. People do it by using their engineering judgement.