[00:00] If you go peeking underneath bridges, you're likely to find a variety of interesting structural connections like this. Can you name that infrastructure? Pause the video here if you want to make a guess. Bearings transfer loads of a bridge's superstructure to the substructure.
[00:15] They literally bear the bridge's weight. Girders can't sit directly on supports below because bridges move. The superstructure deforms and vibrates with traffic loads, expands under the glaring sun, and shrinks when it cools down.
[00:28] Without isolation from the substructure, these movements would build up stress and potentially cause structural members to fail. Most modern bridges use these elastomeric pads on their own, or inside steel pots as bearings between the super and substructures. But many older bridges
[00:44] used cool looking roller or rocker bearings to provide freedom of movement for the deck and girders. I have two sections in my new book dedicated to bridges. If you'd like to win a free copy, make a social media post about infrastructure like this one, and include the hashtag engineering
[00:59] in plain sight.