Steel-Framed Floor Vibration - Consideration of Corridor Location

[abusementpark]

I'm working on a multi-story steel-framed building and vibrations are of significant concern. I am using AISC Design Guide 11 (2nd Edition) and FloorVibe. In addition to the typical acceleration limit criteria for occupant comfort (Chapter 4), a generic velocity limit criteria for sensitive equipment (Chapter 6) is required in some locations. We are in the preliminary stages and considering grid layouts. In chapter 6, it specifically states that it is advantageous to locate gridlines along corridors. I can clearly see the benefit of this in the Chapter 6 procedure. If the sensitive equipment and corridor are in separate bays, then you don't have to consider the effect of fast walking on the equipment. However, for the Chapter 4 acceleration criteria, there does not seem to be any way to account for the corridor being completely separate from the bay under consideration.

Basically, what I am finding is that if I align the gridlines at the corridor walls, it really helps me for the Chapter 6 criteria, but actually hurts me in Chapter 4, because the corridor span is so short that it reduces the effect floor width. Any ideas? This doesn't make sense to me. I am wondering if having a continuous full-height corridor wall along the girders would be just cause for using full 5% damping, considering a higher effective MOI of the girder than actual (similar to the 2.5 increase recommended for exterior walls with cladding), or both.

 

[structSU10]

Its tough during preliminary design, but it may warrant and FEA model to verify the condition.

Without digging back into the design guide to confirm what chapter is what, is it reasonable to use the mode shape modifier assuming the walker is at midspan of the girder at the edge of the corridor?