field welded moment connections-ibc

huangyhg

field welded moment connections-ibc
could someone explain their understanding of the construction requirements of a field welded moment connection for a omf in seismic site class d between a beam flange and column flange?  specifically, how are the welds supposed to be run out/ground off at their ends to eliminate stress risers.  also, i have been told that the bottom backer bar has to be removed, the weld back gouged and a 5/16 fillet placed over the original weld.  is this requirement only for a omf? only in class d? why is the bottom weld different then the top weld?
any thoughts would be appreciated.
jtpe:
with regards to the run-off tabs, please refer to fema 353, 4.2.
the 5/16" fillet is the reinforcing fillet weld noted in d1.1, figure 3.4 (tc-u4a-gf), note 7.
i recommend getting your hands on copies of fema 350 - 353.