Design guidance for CHS base. Supplementary reinforcement options.

I am currently designing a connection between a 914x20 CHS pier post and a concrete base. This is required to transfer a relatively high moment of 2,300kNm. This causes failure in concrete breakout due to the tension
applied to the anchors when considered without supplementary reinforcement.


The anchors were originally proposed to be in a circular arrangement around the CHS, would supplementary reinforcement be an option to address this failure? When selecting a circular arrangement for the anchors, the option for
supplementary reinforcement was removed from the menu. 

As per the attached, I have attempted to specify an arrangement using supplementary reinforcement for a square layout of the anchors however the utilisations are very high. Can you please advise how to optimise this design?