I think it is imperative to first determine if the cross-beam to main-beam connection is a moment-(resisting-)connection. I am not sure if the cross beams are (or need to be) moment-connected to the main beams.
In the given case, beams 6,11,16,... 8,13,18... appear to be cross beams that carry local floor loads. It is not generally necessary to make them moment connected. Usually they are welded to a pair of angles, which will fit to some pre-drilled holes on the web of the main beams for ease of erection. Individual beams can be transported in different trucks. If this is the case, the connection is usually considered a pinned connection.
The following is what they look like: Typical Steel Connections
(scroll to about 1/3 down the page and look for beam-to-beam connections)
If they are "welded" to the main beams and are expected to transmit moments, they would likely look like these, and obviously cost more in fabrication: Moment resisting connections
(scroll to the last fifth of the page to see beam-to-beam connections).
There is also a complication with perpendicular beam-to-beam moment connections in the sense that the beam-depths are usually different. In this case, the main beams are likely to be deeper than the cross beams. So again, moment connections are not usually called for. In any event, if beam 6 is moment connected to beams 1 and 27, the latter will provide very little torsional resistance, so I doubt if it is worthwhile to have them moment-connected.
One more reason that the cross beams are not moment-connected to the main ones would be if all these beams are welded in the shop, it would become a single piece that may not be transportable by trucks to the building site using highways. On the other hand, welding in the field would create extra quality assurance expenses, x-ray inspection, etc.