Thursday, September 17, 2009

RE: ASCE 31-03 part 2

Did someone say beer?

 

Can the “compression struts”, however you may model those or even finite elements, be given a failure state such as an axial strain or deflection or stress limit? Then run a case without them?  Earthquakes, unreinforced masonry, ….another beer

 

A Structural Engineer, P.C.

Glenn C. Otto, P.E.

Virginia Beach, VA

 

-----Original Message-----
From: Michelle Motchos [mailto:mmotchos@sw-sc.com]
Sent: Thursday, September 17, 2009 4:38 PM
To: seaint@seaint.org
Subject: ASCE 31-03 part 2

 

I know I must not have properly included the magic word since I did not get a single response the first time so I'll make sure to include it in this follow up:

 

For a C3 building would you typically consider removing the URM as decreasing the overall lateral capacity of the building or improving the frame's performance?

 

-BEER-

:-)

 


From: Michelle Motchos [mailto:mmotchos@sw-sc.com]
Sent: Tuesday, September 15, 2009 3:03 PM
To: seaint@seaint.org
Subject: ASCE 31-03

A potential upcoming project will require evaluation be ASCE 31-03 at both the Tier 1 and Tier 2 levels. A quick glance of the plans and it would be a "C3" concrete frame with unreinforced masonry and rigid diaphragms. There are irregularities that I believe will require the application of the Linear Dynamic Procedure during the Tier 2.  Does anyone know of a good reference for how to model and analyze this system for the evaluation? ASCE indicates they behave as a shear wall thru the development of compression struts in the wall for a period until the wall is destroyed and then it transitions to frame frame behavior but I am not sure how to capture this behavior numerically or in a 3d model for the dynamic analysis.

 

-Michelle