We can simply define upward soil pressure. The addition of all overburden pressure from soil weight which is present above the footing as well as self-weight of the structure.
One more interesting thing is that it is also called as the ‘Allowable Bearing Capacity’ of soil.
Allowable Bearing Capacity=(Density of soil x Depth of foundation) + Self weight of foundation.
One more important note is that the distribution of allowable bearing capacity for non-cohesive soil is greater than in the middle portion.