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# Square Steel Tube Column Got Damaged

• To: <seaint(--nospam--at)seaint.org>
• Subject: Square Steel Tube Column Got Damaged
• From: Sam Chang <szchang(--nospam--at)mail.arc.nasa.gov>
• Date: Mon, 03 May 2004 22:44:34 -0700

In a tilt-up type of building that was built in 1980 in Northern California, a square tube column HSS5x5x3/16 was bumped by some vehicle that crated a permanent measurable deflection of 1.5 inches from the ceiling level to the floor.

Floor to the top of the girder is about 17 feet height.  The girder above is 5.125"by30"glu-lam girder.  This column deflects along the same direction of the glu-lam girder. The columns are spaced at 53.5 feet and girders are spaced at 22.5 feet.

(15DL+12LL)*22.5*53.5 = 18.1 kip DL + 14.5 kip LL = 32.6 kips

AISC ASD Column Table has allowable P-load capacity (L=17ft) = 47 kips which takes out about 70% of column capacity.

If I take the P-delta into consideration the M = 48.9 kip-inch:

Sxx = 5.03 in^3, Bending stress to the HHS = 9.72 ksi which takes out about 35% of pure bending capacity.

This column is not a part of lateral resisting frame.

The column was probably design as pined-pined connection.

Questions:

1. Should I consider P-delta?

2. Should it be pull (jack) back to a plumb position?