Reinforce concrete column under biaxial bending

[mohamadh95]

I've made a program with Mathematica that will compute the load along with the moments sustained by a concrete column given the stress block area and orientation(in other word the neutral axis center location and the angle it makes with the horizontal). However I am facing an issue with setting the upper limit for the distance of the neutral axis to the top left corner as shown in the attached picture. I would like if anyone could help me.

 

[paisiello2]

Are you breaking the section down into layers?

 

[pongo38]

Please clarify your question.