sp Column Fixity condition and general fundamentals

[ATHS]

I am unclear on which options to choose for design of a pier column. The pier column will be between a pier cap and drilled shaft. The length of column is about 26 ft. My understanding is it will be a sway frame in y axis for sure but not 100% clear on x axis (y being the axis parallel to bridge a x being perpendicular to bridge). In addition, I am not clear on the end conditions to choose. End conditions has always caused me problem. Some explanation on end condition of the pier column would be greatly appreciated.

 

[BridgeSmith]

We usually run an analysis on the drilled shafts (Allpile or Lpile) to find the depth to fixity, and then take the length from the pier cap to the fixity of the drilled shaft as the column length with it fully fixed at the bottom.