ETABS Load Combinations Input

[Trenno]

For equivalent static earthquake analysis, I require at least 72 unique load combinations.

I have the basic load patterns as follows:

EQX1 = X dir
EQX2 = X dir + e
EQX3 = Y dir - e

EQY1 = Y dir
EQY2 =Y dir + e
EQY3 = Y dir - e

Example combination = G + 0.3Q + EXQ1 + 0.3EXY1. Each EQ load can act in either a positive or negative direction. The number of required combinations quickly adds up.

Anyway, is there a quick way to set these combinations up?

What happens when you tick all three (X, X+e, X-e) in a single load pattern? Does it envelope them?

Reason I don't use the auto load combination function is that it names each combination with a generic UDWall#. Which isn't helpful when reviewing what is the governing case. In this instance, I also need to add an out of balance basement soil load to each of the EQ and wind cases.

Any help is much appreciated.

 

[Ahmad Alhamad]

you can use response spectrum instead of static EQ, so you can make EQ directions without increase the load patterns or combinations.
if you want to use static EQ, i dont think that even you tick all three directions in single load pattern the program can envelope them. You can do it either entering all combinations manually or making several static EQ load patterns to include all direction.