open web joist alternate support poin

huangyhg

open web joist alternate support point
i must provide temporary underpinning support for a group of in-place "k" type owj's so their support beam can be replaced. the mfgr. and "model" no. are unknown. is there a generic alternative support point on these owj's that i can use?
support the top flanges along a distance that includes two or three webs connections near the beam being replaced.
i have supported them at the first bottom chord panel point.  this only reverse loads the first web - but the load is quite minor.  the seond web may carry a little more than design but do it when there is no live load on the joists and you should be fine.  
mare sure that the joists are well braced - you do not want them to roll.  and give it adequate bearing area.
i have supported them at the first or second bottom chord panel points as miketheengineer has described. i indicate to the contractor the required shoring load.