Single Angle Compression
Single Angle Compression
(OP)
I am working on an existing structure with some single angle columns, built in 1955, and am working to make it meet the 2003 IBC code requirements. I am aware of the method used in the 1989 ASD specification and the article from 1991 AISC Engineering Journal showing how to calculate the compressive capacity of angles that are loaded at the legs. Using this method it shows the angles are seriously overstressed, although they have been in use for 50 years with no problems. A coworker commented and said the AISC ASD method for calculating capacity is a very conservative method. He mentioned that ASCE has a design guide for transmission towers that lists ASD capacity tables or a less conservative method for single angles in compression. Has anyone used this and does anyone know which publication this is?
Thanks.
Thanks.






RE: Single Angle Compression
RE: Single Angle Compression
RE: Single Angle Compression
- One thing I just realized is that I applied the entire axial load at an eccentricity, and I should have only applied the incremental load at an eccentricity and the rest of the load should be concentric. That will change things quite a bit....
RE: Single Angle Compression
Assuming there are 13 floors supported by this angle (160 feet @ 12 feet per floor), there is a DL of 50 psf and a LL of 70 psf (office), and the tributary area is 10 feet by 20 feet (edge column in small bay spacing?), the loading is around 310 kips.
Am I missing something here?
RE: Single Angle Compression
RE: Single Angle Compression
Well re-running the #'s it almost works according to the 13th ed AISC manual, but not according to the 9th ed. And the 13th edition is not accepted in the 2003 IBC.