ASCE 31-03: Evaluating Cantilever Columns - CALIFORNIA

[Durango1]

Hello Everyone,
I am totally new to Eng-Tips, so forgive me if I am repeating the thread (I couldn't find anything on this though).

I am evaluating 2 different buildings, one has reinforced cantilevered concrete columns and the other has cantilevered steel columns as the LFRS. The buildings have alot of issues and the aim is to demonstrate that the buildings are not safe. However, one of the criteria of the program that I am dealing with is that it has to be analyzed using ASCE 31-03.

The problem with ASCE 31-03 is that it does not include Cantilevered Column (steel/concrete) systems, which means there are no set ways of doing quick checks (Tier 1) for issues such as shear stress etc. I am pretty much stuck at calculating the Pseudo-lateral force (which I have calculated). But I can't seem to figure out as to where I can fit in cantilevered columns in the checklists in ASCE 31.

I am wondering if anyone else has had to analyze a building with cantilevered columns as the LFRS under ASCE 31.

Thanks!

 

[TehMightyEngineer]

I've never used ASCE 31 but you might have to go back to ASCE 7, ACI 318, and AISC 341 and run a full engineered analysis.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

http://www.americanconcrete.com

 

[sandman21]

Cantilever Steel or Concrete would be a subsection of S1 and C1. Hopefully that helps.

 

[Durango1]

Thanks Sandman. That is true, it is a subset, however, C1 & S1 are all frame systems. That is, beam stiffness plays a role in lateral resistance, as the connections are assumed moment connections. Hence, the formulas that are provided pretty much apply to frame systems, rather than an "inverted pendulum". At this point, I am just thinking about a hybrid approach, where I'll use whatever I can from ASCE 31 and figure out the rest based on structural analysis formulas.