How Do Skyscrapers Resist Strong Winds?

Tall buildings are designed to sway slightly rather than stay perfectly rigid, but too much movement would make occupants feel sick. Engineers use strong concrete cores, steel frames and outrigger trusses to stiffen towers. Shapes that taper, twist or have notched corners break up vortices, the swirling eddies that can push a building side to side. Some towers add a tuned mass damper, a heavy weight that moves opposite to the sway and absorbs energy. Designs are tested on scale models in wind tunnels before construction.