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Re: Story Drift: 1994 UBC vs. 1997 UBC

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bill

I think there is something wrong with the way you are trying to work your way 
backward to compare the two methods.

let me try to take a crack at it the following way. it may clarify the case a 
little bit:

assume the "calculated" displacement under 94 UBC was D94 and for 97 UBC is 
D97. To get the equivalent drift under 97 UBC the following adjustment would 
have to be made

Delta97 = .7 (Dm)R

where 
Dm = (omega)(D97)= 2(D97)    
but D97=(1.4)D94   due the strength level forces
=>    delta97= (0.7)(2)(1.4)(D94)(2.2)= 4.3(D94)

now if you divide the 97 drift limit by 4.3:

0.025/4.3 = 0.0058 ~ 0.005 So actually not much has changed.

I hope this helps

Ben Yousefi, SE
san Jose, CA