ETABS Pier Vs. Spandrel 1

[Dzonni]

Hello, everybody! I have a question regarding the ETABS modelling of shell elements above openings in walls. To put it short: is there a rule to help me instantaneously decide whether to design the piece of the wall above the opening as spandrel or as pier? I am pretty sure that the depth to width ratio plays a key role, but i am curious as to what ratio that might be (in order not to produce great differences in the amount of reinforcement) from the standpoint of more experienced modellers. Also, if similar topic has already been discussed, please direct me towards it. Cheers!

 

[MrHershey]

Has nothing to do with ratio and everything to do with what you wish to look at.

Piers will design horizontal section cuts. So cut it through walls and it'll design vertical rebar for axial-flexure interaction and horizontal rebar for shear. Keep in mind that piers only output results at their top and at their bottom, nowhere in between.

Spandrels will design vertical section cuts. So cut it through walls and it'll design horizontal rebar for axial-flexure interaction (or often just flexural) and vertical rebar for shear. Keep in mind that spandrels only output results at their left end and at their right end, nowhere in between.

ETABS help article on pier/spandrel labeling: Pier and Spandrel Labeling and Design