For calculation of two way (punching) shear, footing self-weight is not added to axial load.
Concept of Footing punching shear criteria is column punches in the footing. Load from the column punches the column in footing. Self-weight of footing, overburden load do not participate in punching of column as it is a uniformly distributed load, thus it is not considered in design. For more information refer “Technical discussion” of footing from help Content.