Free-standing reinforced Beam-Column
Free-standing reinforced Beam-Column
(OP)
I am designing a free-standing beam-column that is supporting a piece of the world trade center for a memorial. It is 8" thick roughly 14.5' high. Klu/r is roughly 150. (fixed base & r=.3h) How would I go about designing this member? Should I consider it for sidesway? All beam column examples I see only have the moments applied at the tops and bottoms of the columns. My moments (lateral wind and eccentricity from the piece of steel) are not exactly at the top. Attached is a pdf of memorial.
-Robert Miller, E.I.T.
KPA Structural Engineers






RE: Free-standing reinforced Beam-Column
Essentially you need to consider initial imperfections, both in-member P-delta and structural P-Delta, better subdivide your column in segments for a more ensured consideration of P-delta effects, use a reduced stiffness, and use beam column checks from the code.
RE: Free-standing reinforced Beam-Column
It looks like perhaps one of the walls actually supports the steel and could be designed as a concrete beam/column. Simply apply your loads and check the Pu and Mu combinations of values at various heights for a rectangular column.
RE: Free-standing reinforced Beam-Column
RE: Free-standing reinforced Beam-Column
-Robert Miller, E.I.T.
KPA Structural Engineers
RE: Free-standing reinforced Beam-Column
RE: Free-standing reinforced Beam-Column
Due to their thinness I would treat them as walls and see how that works.
For this level of load I would normally ignore the axial load and check for bending only. Pdelta effects require a significant P, which you do not seem to have.
Also ensure that you have allowed for people hanging off this thing in your calculations - it will happen.