@lambert,
1) It's clear that the things you're asking have nothing to do with the posted worksheet. I think you should post your question in the "Problem" room.
2) Section 5.9.3 of PCI Design Handbook 7th ed. might give you some idea. Also section 13.8 of Prestressed Concrete by Prof.Naaman (2004) should help clarify the differences between RC and PC long columns' stiffness. Note that the book is based on ACI 2002 provisions, which were revised a lot on 2008, eg. the slenderness limit of 100 for 2nd order analysis being removed.
1) It's clear that the things you're asking have nothing to do with the posted worksheet. I think you should post your question in the "Problem" room.
2) Section 5.9.3 of PCI Design Handbook 7th ed. might give you some idea. Also section 13.8 of Prestressed Concrete by Prof.Naaman (2004) should help clarify the differences between RC and PC long columns' stiffness. Note that the book is based on ACI 2002 provisions, which were revised a lot on 2008, eg. the slenderness limit of 100 for 2nd order analysis being removed.