Drift — where it appears
Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.
The arm that makes the columns work
The perimeter columns of a tall building are already there, already carrying gravity, and already the furthest thing from the centre. They take almost none of the overturning, because a floor slab transmits shear and not moment — and one storey-deep arm at the right height changes that by nearly a half.
Two motions with one name
A tall building's sway is two movements added. A frame racks like a stack of parallelograms, worst at the bottom; a cantilever bends about its base, worst at the top. The total at roof level says nothing about which storey is worst, and on this building it is neither.
Named alongside it
The objects these essays reach for when they reach for this one.
Lateral systemBending stiffnessCantilever actionCladdingCompatibilityCoreDeflected shapeDifferential shorteningMoment frameOptimisationOutriggerOverturning