Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Steel column flange damage repair

[Subject Prev][Subject Next][Thread Prev][Thread Next]
The process of heat straightening steel requires cheery red color (approx 1200 degrees) but going beyond is difficult when using the proper heating tips on the torches. If heating is done with a cutting tip then success is doubtful. However, we must keep in mind that the steel started its life as a liquid, a very hot liquid. Our fears are over stated!!!!
 
Back to the hydraulic jack. If the bent flange is heated to cherry red along the bend, and the jack is used a means of moving the flange inline there is little to no chance to damage the remaining portion of the member.
 

David I. Ruby, S.E.
Chair, Coalition of American Structural Engineers
President, Ruby & Associates, P.C.
30445 Northwestern Hwy., Suite 310
Farmington Hills, MI 48334-3102

Phone:            (248) 865-8855
Fax:              (248) 865-9449
Cellular:         (248) 514-2677
E-mail:           druby(--nospam--at)rubyusa.com

-----Original Message-----
From: Daniel Luna [mailto:DGXL(--nospam--at)worldnet.att.net]
Sent: Friday, December 08, 2000 2:33 PM
To: seaint(--nospam--at)seaint.org
Subject: Re: Steel column flange damage repair

I recommend using caution regarding the flame straightening process (depending on the flange thickenss-trying to straighten the thicker flanges may result in further distortion if not performed properly). The contractor should submit a procedure delineating how the straightening process will be performed. Also note the heat limitations set forth in AWS D1.1:2000, 5.26.2 (1200 degrees F) and the allowable dimensional deviations permitted by ASTM A6. A welding procedure (WPS) is required as well.
If a hydraulic jack is used for straightening and loaded against other areas of an already welded joint (i.e., the top flange) make sure to re-inspect or test those welds. Good Luck.
 
Daniel G. Luna
----- Original Message -----
Sent: Friday, December 08, 2000 2:28 PM
Subject: Steel column flange damage repair

I have a new moment frame column where the flange is bent locally inward on
one side for about 4 inch length. It appeared to have been caused during
shipping or fabrication. The fabricator erected the frame anyway and it was
not caught until I visited the site for structural observation. The damage is
located within the critical bending moment area.

I am proposing straightening the flange and adding plates on both sides of
the flange with weld all around. The fabricator suggested applying heat to
straighten the flange. The steel is ASTM A992.

Are there any concerns with the above procedure? are there other repair
schemes?

Thanks in advance.

Oshin Tosounian, S.E.
Los Angeles, CA