allowable high rise building drif
 

allowable high rise building drift
hello
i want to ask about the allowable high rise building drift
if (steel or concrete building)
all of us know the allowable story drift shown in table 12.12-1 (asce7-05),but i ask about the drift for the whole building
for example building with height 150 meter
what is the allowable building drift?
we use aci and ubc
i wish to find aswer with refrence in code
many thanks
check out our whitepaper library.
building drift should be as the story drift in seismic.
usually story drift is more critical, if the building pass in it , will pass also in building drift
the case is the same for wind loads.
heard that the empire state building sways about 18 inches = but no references for substantiation
that's crazy....the empire state building is a steel frame encased in concrete. this concrete encasement increases the stiffness by almost 4 times. i would love to see some proof of that.
i would believe that the empire state building could sway that much (under high wind loads). it has fmc for the lateral system (with masonry infill - even though the masonry wasn't designed as part of the lateral system, i am sure it is taking some of the lateral loading and, as a result, reducing drift somewhat) and h/500 drift on a 500' tall building is 12".
not surprising at all.
i also can easily believe 18" sway on the empire state building.
18" over a height of 1250' is h/833. very stiff. or, looked at another way that is a average story-to-story drift of only 1/8" per floor. much, much better than a lot of modern buildings.