Net uplift on shear wall 1

[DNBINC]

I am trying to figure out some calculations but I have run into a problem on the shear walls on a flexible diaphragm. In reviewing this engineers work he came up with the following values. Total shear panel length=13.5' panel length=6' Vasd=75.6 wall hieght=8' Motm=3628.8 uniform load=300lbs Mresist'g.=2160 asd net uplift=108 He has the the formula net uplift=motm-.9Mr/L in the column for net uplift. However, when I plug in the numbers I do not come up with the 108. Can anyone help to show me how he came up with this number? He also has the shear panel marked for 4x4 posts. This is in California if that makes a difference.

 

[haynewp]

It looks like he didn't include the 0.9 factor, if you leave it out you get 108.

 

[DNBINC]

Do you know what the .9 factor is for? This is for LA County. I really appreciate your help I poured over this for a whole day. I appreciate your help.

 

[DNBINC]

Also he has holdown type=HD2A allowable tension=1166 then the last column has s.f.=10.8 I know you divde the 1166 by 108 to get 10.8 but what does the number 10.8 represent?

 

[UcfSE]

What kind of application is this? Are you in charge of the engineer (a co-worker) whom you are reviewing? Where these calculations submitted to you as shop drawings or something similar?

 

[DNBINC]

This is for residential wood construction. These were jsut some old calculations that I am using to further my understanding of wood construction. Removing the .9 factor worked on the first one but on the next it didn't work out
total panel length=10' panel length=10' Vasd=229.5 wall hieght 8' Motm=18360 Mr=4000 net uplift=951

 

[UcfSE]

Design Of Wood Structures, ASD Fifth Edition by Donald Breyer is an excellent reference if you want to learn more about wood construction. The NDS package you get when you order there publication comes with several supplement, all with some very good information as well. You can probably get both the book and the NDS for less than $200. If you search through the fora you'll find also that some members have posted some very good links to free information on the net.