] [Thread] [Date] [Author]

["Sprague, Harold O." <SpragueHO(--nospam--at)bv.com>]

David,

I am a little confused.  Are you using Chapter 7 of FEMA 273?  

If not, check it out.  

If you are, please give a better description of the issue?

Regards,
Harold Sprague



> -----Original Message-----
> From:	merrick group [SMTP:merrickgroup(--nospam--at)compuserve.com]
> Sent:	Friday, January 21, 2000 1:04 PM
> To:	Seaint
> Subject:	(E) Masonry with steel upgrade
> 
> I have an older building that has masonry 
> steel ratios of .0008, .0009 and a total of 
> .0017. I need .0007 min and a total of .002. 
> 
> How can I get this total ratio up? 
> 
> Can I allow the total number to be rounded 
> up to 0.002? The code suggests a significant 
> figure of one. I jokingly consider using the 
> CMD97 program that allows the ratio. 
> 
> Shear capacities are from 1.5 times to 4 times 
> that needed. Recall that the seismic-force-
> amplification-factor is 3.8. It would seem that 
> adding extra reinforcement is unreasonable 
> for capacity to demand ratio that is more than 
> 3.8. 
> 
> Without any good recommendations, I am 
> adding some steel pilasters that can carry the 
> tributary lateral loads out of the wall's plane. 
> I will consider the pilaster as equivalent to a 
> vertical bar of steel, at that location, to 
> increase the effective steel ratio. The walls 
> already have masonry pilasters every 14 feet.
> 
> Less than minimum steel has been considered 
> as having an equivalent ductility of masonry 
> with no steel. How silly. I am request that the 
> Seismic-rulers-of-the-code to consider a 
> reduced minimum steel ratio that is 
> dependent on an application of an adjustable 
> seismic-force-amplification-factor. 
> 
> David Merrick, SE
> Merrickgroup(--nospam--at)compuserve.com
> 
> 
>