AREMA box culvert design - load factors

[structeng24]

I'm designing a box culvert per AREMA. The group IA load combinations for concrete design include a 1.8 factor for all loads. This culvert is under very deep cover making the 1.8 earth load factor very dominant. This is much more than the aashto factor of 1.3. Has anyone ran into this and is this load combination not intended to be used as such?, thanks for any help.

 

[ztengguy]

Yes, It seems Arema is higher than Aashto. For a culvert with high cover DL usually controls.