CMU load bearing walls not part of the SFRS
CMU load bearing walls not part of the SFRS
(OP)
Hi,
Have a typical 6 story reinforced concrete block building. Numbers of shear walls spanning across the building width and stair wells at ends and elevator shaft in the middle. I have one line of shear walls that I would like to remove from the SFRS as it stops at the second floor for a large open area on the ground floor. Construction is hollow core floor slabs and load bearing masonry shear walls. Can anybody direct me to some details that would remove the wall from the SFRS while having it remain as a structural load bearing wall? Thanks.
Have a typical 6 story reinforced concrete block building. Numbers of shear walls spanning across the building width and stair wells at ends and elevator shaft in the middle. I have one line of shear walls that I would like to remove from the SFRS as it stops at the second floor for a large open area on the ground floor. Construction is hollow core floor slabs and load bearing masonry shear walls. Can anybody direct me to some details that would remove the wall from the SFRS while having it remain as a structural load bearing wall? Thanks.






RE: CMU load bearing walls not part of the SFRS
RE: CMU load bearing walls not part of the SFRS
Are you trying to exclude it so that you don't create a soft story condition?
RE: CMU load bearing walls not part of the SFRS
Perhaps you could replace the offending wall with a steel beam and column system that would not attract lateral load. If masonry is a must for non-structural reasons, you might be able to infill the steel frames with block but leave suitable gaps between the block and the surrounding steel beams and columns.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: CMU load bearing walls not part of the SFRS
There may be some blind spots I'm not thinking about in this. Just thinking out loud here...
Check out infinity systems and similar folks. They typically do the whole building, but they could probably branch out.
RE: CMU load bearing walls not part of the SFRS
As a side bar the Sa(0.2) values for the site in time have decreased as such, 0.400 (2005), 0.359 (2010) and will be 0.263 in 2017. So if the building was being designed next year the IeFaSa(0.2) would be less than 0.35 which would put the building seismically in a whole different place with un-reinforced masonry possible! Go figure.
Jayrod12 I've always found it difficult/complex/detailed to drag loads in a HC concrete diaphragm floor system where the Architect is using the u/s of the slab as the finished ceiling. The slabs do not have a 2" topping only a Gypcrete self leveling topping and the trades, once you ask them to do much more than install the HC slabs....well, take a lot of reviewing to keep on track.