Temperature load on finite elements

Dear Mr./Mrs;

need your support to get an answer about the application of temperature loads:

1- when can we use the axial elongation?

2- when can we use the top and bottom option?

3- when can we use a combination between the above?

4- if I have large underground tank with 230 m length and I need to apply the temperature loads, which of the above option can I use?

5- which result can I depend on special for the foundation elements and walls. because if I did not apply the axial elongation, I did not get any axial force or membrane stress on the foundation mat.