difference between actual & design axial load in ETABS

[ibrahemnasr]

hi every body
i have question regarding the design of concrete columns using ETABS

1- For the load combination containing the response spectrum load case , ETABS design for another axial load different from the actual axial load from the same combination

(the Actual analysis axial load = 345 KN , The program design for 226 KN )

but for other load combinations containing dead or live loads , the program design for the actual axial load

i search alot for the reason , i think this is because reducing live load or LLRF but i turn them off and nothing happen

 

[asixth]

Has it something to do with the case combinations for the paticular design code?

Might have something to do with the overstrength factor were the actual force is 345kN but because of energy absorption you only need to design of 226kN.

 

[ibrahemnasr]

I use ACI in design , overstrength factor 1.25
may be because energy dissipation but is this behaviour of design (reducing axial load due to energy dissipation )adopted by ACI code?
How can i control this condition in ETABS?