moment bolted joint N-M interaction in EC3-1-8

[skjoex]

Hi,

according to ec3-1-8 it is possible to ignore an axial force influence in the moment bolted joint if this force is less than 5 percent of tension resistance of the beam. If this value is higher the interaction between bending moment and axial force must be taken into account - generally speaking. My question is: is this really unavoidable ?

I mean generally we consider that the higher row of bolts carry a bending moment only, the lower one carry the shear force only. If there is higher level of shear and lower level of bending moment it is possible to consider for higher row interaction of bending moment and shear and for lower row shear only... If there is an axial force interaction of bending moment and axial force must be calculated.

Can I avoid calculation of N-M interaction with placement of an additional bolt row to the center line of the beam ? I mean the scheme where the higher bolt row carry bending moment only, the center one axial force only and the lower one shear force only ?

ps. sorry for my poor english

Lubo