We designed a tilt-up building with metal deck for roof (no zonolite or
structural concrete fill). The building is approximately 200'x200'. Framing
consists of OWSJ supported on WF steel girders.. The girders cantilever about
4 ' over columns with drop-in beams at alternate bays.Connection is with
shear plates. Girders have full height stiffners on both side of web at
column supports and bolted with 4 bolts to the cap plate. OWSJ have slip
connection at bot. chord to allow for free deflection of the joists. The
columns are spaced at 40' on center, both direction, and are HSS 6x6x0.5 X
22' tall. The framing, including columns were designed using RAMSTEEL
programme (over kill) with eccentricites included in in both axis.This is a
VA non-essential facility in West LA. Building and is all complete and ready
for TI improvements.
SO FAR SO GOOD. We now have a Very Senior VA engineer from Washington (shall
remain name less for now) telling us that the columns should be designed per
AISC Table C-2.1 column (f) (Page 5-135) with K=2. i.e with pin at ground -
Rotation fixed and translation free at top.
We have designed the columns as pin-pin with K=1. We, very strongly, do not
agree with his assesment but because of his high position we cannot convince
VA that our design is adequate.
We thought this would make an intresting topic for discussion.
Thanks to all, in advance.