Why Bridges Don't Sink

⚡I have more than 20 videos about soil! youtube.com/playlist?list=PLTZM4MrZKfW-A419dqGZVtw… 🌌Get Nebula using my link for 40% off an annual subscription: go.nebula.tv/Practical-Engineering

“skin friction” and “shaft resistance” did give me a giggle, I have to admit….

H Beams look exactly like I Beams, but H Beams have the same thickness in the flange and web, and are commonly used in vertical orientations where the loads are applied parallel to the beam length. The thicker web of an H Beam makes them more resistant to twisting. Whereas I-beams are typically horizontal, have thinner webs, because they are designed to only handle loads perpendicular to the length (top in compression, bottom in tension)

I didn't know I wanted to know about piles until now!

Broken bridges annoy me. I just can't get over them

Bridges don't sink because they know how to swim

"imagine pouring a smoothie at the bottom of a pool. Let me show you what I mean" I cannot understate my disappointment that there wasn't a smash cut to Grady pouring a smoothie at the bottom of a pool XD

Bridges don't sink because engineers secretly put thousands of pool noodles in the support columns.

grady the only guy who can get me to watch a 17 minute video about bridge foundations

I love the thought that Grady set up the hammer and nail demonstration, failed, and just ran with it

3:34 I once saw a construction site where piles were driven into the ground. There was a peat layer between two layers of sand. It took the machine a good amount of effort to drive the first four meters or so. Then it sank by itself until about four meters left. Those last few meters took a lot of effort again. Watching this for a morning gave a lot of insight into how the peat was undulating on the bottom more than on the top.

Grady, i was a concrete pump operator for several years and worked on many bridges. On company used a basketball to plug their tremme pipe to get concrete under the water in the casings. As the casings filled, one guy would climb down to recover the ball. I did have one critique about the concrete underwater as we use admixtures of bentonite and silica fume to make concrete "water proof" so that it doesn't dissipate underwater.

Somewhere in the Port of Tacoma's archives are books and books of my beats-per-foot logs that give an idea of the relative skin friction for each of thousands of piles supporting the then-new pier. That was my big engineering internship - counting and recording pile-driver hammer blows all day long. Things I learned that Summer: there's such a thing as "waterproof paper" - the pencil would still write on it, even when the clipboard was out in the rain! And pre-stressed concrete is pretty cool!

Your second channel, Impractical Engineering, should have a video on why bridges sink

Your overall production quality is excellent in nearly every aspect. Animations, voice level and quality, music.. not too loud, well chosen stock footage, editing….. etc. etc… Very impressive.

"The purpose of a foundation is to not move" Grady spittin' the hard truths we all need to hear.

My favorite story about the Coronado bridge you show in the thumbnail is how it got its iconic shape, because it wasn't designed that way originally... The story goes that at the time it was being built there were substantial federal subsidies for bridges over a certain length, but the original plan for a straight bridge from downtown San Diego to Coronado wasn't quite long enough to qualify, so the city just tacked a bit of a curve and hump onto the design to JUST meet the funding requirements, and by accident ended up with an iconic piece of infrastructure. X)

Amsterdam is build on wooden poles. A lot of older houses in the Netherlands are build like that. Due to groundwater depletion the foundations of those houses are now having problems because the poles that stayed wet and therefor didn’t rot now do (rot)

My 11 year old son loves your channel. A kid can learn a lot from watching your videos.

There were Neolithic pile dwellings built on Lake Zurich in Switzerland around 4000-7000 years ago (now part of a UNESCO world heritage site). my grandfather had a (presumably 19th century) painting showing the remains of the piles sticking out above the water. Since then, the water level has risen and the piles are all underwater.