Outrigger — where it appears
Named by 2 essays across one field — each of them below, with the objects they name alongside it.
How a tall building stands still
A shear wall bends and a framed tube shears, and the two deflected shapes are the wrong way up for each other. Tie them together at every floor and the pair is stiffer than the sum of their stiffnesses — because near the base the wall holds the frame back and near the top the frame holds the wall.
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.
Named alongside it
The objects these essays reach for when they reach for this one.
Lateral systemCompatibilityCoreDifferential shorteningDriftIndeterminacyInteractionOptimisationOverturningPerimeter columnRedundantRotational stiffness