Can engineers PROTECT old bridges before the BIG EARTHQUAKE hits?
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- čas přidán 6. 06. 2019
- California gets big earthquakes. What keeps the next BIG ONE from shaking apart more bridges on our freeways?
Jerry De Santos, a supervising bridge engineer for the California Department of Transportation (Caltrans), explains lessons engineers learned from major earthquakes in 1971, 1986, 1989, and 1994. These lessons help California (and the world) build better bridges now.
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Sources:
California Retrofitting Program
www.dot.ca.gov/hq/paffairs/abo...
Oregon Retrofitting Program
ftp://ftp.odot.state.or.us/bridge/15_BR_DSGN_CONF_PDF/Session%201/1B_ODOTBrConf_2015_Johnson_Future_SeismicRetrofit.pdf
Washington State Retrofitting Program
www.wsdot.wa.gov/eesc/bridge/... - Auta a dopravní prostředky
He's like a youtube Bill Nye for roads
So many CZcamsrs like this who would have fit right in on educational television programming.
@@Strideo1 well, isn't it great that they actually have a way of sharing their knowledge with the world instead of hoping they get picked up by an international studio run by billionaire penny counters?
@@EMETRL Absolutely.
FR
Rob boi the new bill nye
5:41 911, what's your emergency?
There is a man, playing on the highway with scissors and Play-Doh.
I lost it at "the SECOND time i was a B student".
Haha, yeah, huh? I was like, "OHH!" Haha!
I felt personally attacked by that one :)
Imagine driving around and seeing a random guy in a reflective vest playing with play-doh in the middle of the road 😂
Around 5:30 I think it looks like he's in a parking lot, lol.
Love these videos
Same
Oh what’s up claw boss, never knew I would see you here, love your school bus vids
Oh hi clawBoss
As a Californian, I remember visiting Texas and thinking "wow those lines of skinny bridge pillars are gonna fold like a house of cards in the slightest shake" 🃏
Lived in California 33 years of my life and never knew most of this!! Great video, thanks!
GREAT video, Rob! I love the element of including an interview. This was fascinating.
So when is CalTrans going to just hire you as their Social Media guru? 😉
rob for caltrans reporter
6:46. “Dramatization: Professional driver on a closed course”. Hahahaha! Your videos are educational and fun. Great job. Thanks.
I lived in Southern California back in 1970-1971. I was in the 1971 Sylmar Quake. I had just driven the I-5 between Los Alamitos and Bakersfield the night before the Earthquake. Many of the structures I had driven over the night before had failed in the quake. I was then stationed at Pt. Mugu and when I drove through the area of I-5 almost ALL of the freeway overpasses had structural damage. From that point on, I was never comfortable stopping under an overpass. When the 1994 Northridge quake occurred and I saw the pictures of the Newhall interchange, I noticed that it failed in almost the same way it did in 1971.
Jerry De Santos was incredible to listen to. Your explanations similarly supported his words very well. I enjoyed this a lot :)
Hi Rob! As a happy Southern Californian, I really enjoy your videos. You have educated me in a very fun way! Keep the fun info coming!!
This is only the beginning. It seems like you're taking this very seriously and playing the long game. Keep it up and amazing things will happen! I hope next year you can upload more frequently and maybe branch out to other transportation-related topics.
This video was awesome. I saw many of those concrete supports and wondered what and why.
Hats off to Jerry DeSantos for the great engineering explanation.
Great video! Just wanted to point out that Oregon ALSO has a program going on to retrofit its bridges, so you shouldn't be quite as worried. Since the 2009 report you mentioned in your video, Oregon has been retrofitting or replacing its bridges based on simulations they ran for a 9.0 Cascadia Subduction Zone earthquake. By 2014, they had addressed (retrofitted or replaced) 355 bridges statewide under this program, with 800 left to go. From what I've gathered from the 2019 Bridge Condition Report, another 4 have been fixed and 26 funded, leaving 153 bridges left in Phase 1 of the program.
This is such a good video! I love how well you illustrated your points. The guitar example was amazing👍
Didn't realize those columns were just to catch the overpass when it collapsed.
I am in support of anti-human-flattening columns
You make a seemingly boring topic seem very interesting, nice work. Keep it up!
This was great editing and even better interview. He looked so excited. Thank you
In Arkansas, we use steel, concrete and rebar on our bridges and overpasses because we're mostly subject to freeze / that cycles, high winds and tornadoes and the most destructive earthquake in history happened near our northeast border with Missouri, so we have to prepare for the next big one as well
YEEEEESS, been waiting for a new video forever. You're channels gonna grow massively soon, keep up the great content
That overpass is one of my favorite seismic retrofit projects.
You can always tell when a CZcamsr really cares about their videos, and I can tell that this guy really fuckin loves roads
Its criminal how little Attention you get. You put so much work into these, and have such good energy.
I'm a huge roads nerd, I'm so excited I found your channel, I think I partly got so interested in road design because I live in Oregon after moving from California when I was a child and the roads here are terrible. That said, I love driving so much so I've spent a lot of time on our crappy roads and terrifyingly unsafe bridges since I was a teen 😅🛣️🌉
It works as long as it's built as designed. The I-880/I-80 interchange was not updated after a design modification years before the 1989 quake in CA.
It's amazing how much research and effort you put into these videos! Do you have any merch to help support the channel?
Yea where do I get my road guy rob hat, orange vest and sun glasses
Interesting topic on bridges and highway!
i swear this guy always shoots videos or gets clips from my area its kinda cool
As a Southern Californian who lives in the Inland Empire, I'm familiar with each of the freeway intersections and bridge supports shown in your video. I used to travel daily through the ones in San Bernardino and Corona and recognized many of the elements used in the construction. Almost anything dealing with design and construction is of interest to me so I found this video informative and interesting. I've watched our freeways being built and then strengthened after the earthquakes we've had and I learned a lot from you so thank you.
That is genuinely insane. Digging a deep deep hole, so you can have the shortest column match the tallest
Some difficult concepts are clearly explained and illustrated here. Good work!
I lived in LA during the Northridge quake and remember it well (freaking horrifying!) I distinctly remember for years afterwards noticing all sorts of weird things being done to freeway bridges.
I consider myself a fan and an amateur expert on bridges... But I my after watching this video and playing this phone game called "build a bridge" that I really understood the concept and all th secrets to building Bridges....BEST VIDEO EVER!!
Why does this video only have 82k views??? Why does Road Guy Rob have only 76k subscribers???!!! I’m so confused!! I’m learning so much from this content!!
It's cool to see how we're continuing to refine the science of building good infrastructure.
4:20 I got so happy for a second to hear my home province getting mentioned only to realize this is Ontario, CA and not Ontario, Canada.
Jerry likes his job he enjoyed talking about bridges.. thanx for the video
Underrated channel.
Great video! Informative, engaging, and with fantastic delivery. Keep it up!
Rob looking fresh with the new haircut
Such good editing, examples and info! I’ve never been more interested in such a mundane topic. Extremely engaging Road guy Rob.
Thank you making these videos. They are so well done and very informative. I can only imagine how much time and research you have to put together. Again, thank you.
I love that Rob took the time to go and talk to somebody actually in charge of these bridges.
In my country, Spain, the fact of a public technician explaining his work in youtube is incredible. The channel is awesome, but that is more outstanding for me.
This was a great and informative video, I'll be looking at bridges and supports a little differently now! I'm a little sad the bridge damages from the November 30th earthquake in Anchorage were not mentioned. I understand if that's a little too far away from your home base of SoCal though.
2:44 that word has a whole different meaning now
That’s what I thought too lmao
I grew up in the inland empire and saw the retrofitting taking place in the 90's until now. Awesome videos!
Love the thoroughness. so many channels do just read wikipedia articles. *cough* megaprojects *cough*
Great material. Cheers from the UK.
I think this video would be good in schools.
I love this channel. PLEASE MAKE MORE VIDEOS!
Hats are literal magic for this dude. Puts one on and looks 15 years younger. This was the first day he realized it.
Such excellent explanations! I wish you would do a show on the stresses and fixes for northeastern and upper Midwest bridges. Primarily road salt and scour under river piers during high water and flood events, see the collapse of I-90 NYS Thruway into the schoharie river in the late 1980’s.
Awesome- Love the new block of concrete tech!
Great video, Rob!
These type of research videos are great
Great Playlist
Very interesting topic!
Another great vid
Dude I hope your channel grows huge.
Great video.
I grew up terrified of bridges and overpasses. Took forever not to have an anxiety attack
Very interesting.
Of course, money is always an issue. It's not an endless supply, so, it's still important to properly plan for and budget for bridge modifications.
Great Videos. Love them. As semi driver myself I’ve wondered about a lot of the things you cover. Now I have the answers.
I thought ALL bridge heights had to be clearly marked. In Illinois very few are.
And I feel semis should stay in the far left lane. Out of the way from the people entering and leaving the highway.
Kudos to CALTRANS! (and of course to Rob for making these videos!)
Love this channel 👍
12:20 you laugh, but my field has the exact opposite problem - people keep talking about how to get a car to steer itself and recognize signs, meanwhile we've had a solution to that problem for years, it's called a train with electric signalling.
I love that he used a Hank Phillippi Ryan book in his demonstration. She's very well known in Greater Boston, as she's been an investigative reporter for WHDH-TV for years. I didn't even know she was an author.
I love this channel!
You are such a nerd, dude, but it's awesome! Great videos, and I love the way you seem to really enjoy making them!
California at least knows what they're doing. I actually feel pretty good driving across CA bridges knowing that smart people and proper funding are doing a lot behind the scenes. It could always be better, but we are getting there bit by bit.
Our capital city Wellington has an elevated motorway that crosses a fault, and they have put large catcher platforms on the columns so if the bridge falls off the column it will land on these catcher platforms. I don't know if I would trust the columns themselves but it will deal with at least anything but the most severe earthquakes.
Great video
Can you explain more the part where all the bridge supports are the same size? that give the bridge a way higher amplitude response at its very sharp resonance frequency, intuitively (and lowers it), having varying support lengths spreads the response spectrum out and the global amplitude response is smaller since only a few support can resonate at a time.
Not a mech/civil engineer so this is based just on some reasoning.
If the bridge is tuned to resonate at a specific frequency then the structure designed against this as a worst case. In addition, the whole bridge will move as one unit. The advantage is you can plan for this directly.
Having many column and deck sizes means one may get "unlucky" and resonate or move more than the others, or have a large displacement from one section to the next. This can cause just one section to fall in isolation.
The goal is to have the whole bridge standing at the end, because even one section falling would be catastrophic. This can be achieved *economically* through designing the failure point at a known case, instead of spreading them out to many complex interactions.
Hey I live in that area. I drive that freeway in the intro all the time.
I love your humor!
@Rob somewhere between the infrastructure, play-doh, and twizzlers, you've won my heart.
10:42 you show Boston as an example of cities that do not have earthquakes yet Boston had one in 1755 and it was quite a tremblor!
I expect concrete bridges didn't exist 1755.
well, hopefully any new tremblor won't notice all the steel and concrete bridges that have been built since.
That particular interchange in San Bernardino actually has the San Jacinto Fault running right through it. It would be nice if we would put something in cars that would alert drivers to the fact that an earthquake is occurring and perhaps allow them to get off bridges and pull over safely, kind of like they have in Japan, although I realize that the warning wouldn't be as easy to give drivers before the shaking starts since most of the dangerous faults are on land.
On a side note, there's a lovely bike path that goes under that interchange and out to the beach and I recommend anyone who bicycles in the area to try it out because it's really peaceful since it follows the river and only occasionally passes under roads and into civilization.
We rarely if at all get earthquakes in Arizona that are even noticeable. I wonder how much this changes the engineering of our overpasses compared to California. Especially since all our overpasses are fairly new compared to theirs...
Great Video! I don't understand how some people gave this a thumbs down??? lol
I live by the New Madrid fault and I get the same irrational fear under and on top of bridges and overpasses. The DOTs here (Memphis and suburbs) have done a ton of retrofitting though with cabling and abutments similar to shown here.
I can tell you first hand that automatic braking works to a point. Smashed my brand new car a few years ago into a person who ran a stop sign exiting a parking lot. She was at fault as I crashed into her totaling both cars. The car did brake but not fast enough. Naturally, she has insufficient insurance resulting in my carrier picking up the slack. My premiums went up as a result.
Get Jerry an office!
Rob, with the carpool ramp shown in 2:10 to 2:15, I notice that the RL on the road surface gradually decreases, while the ground is presumably flat. Is the basic approach for designing the pillars the same? Same pillar length with the pipe sleeves, and just that the depth of the pillars from the ground made different in accordance to how high off the ground the pavement is?
I do wonder what the necessity of earthquake oriented design for cities like St Louis near the New Madrid Seismic Zone is. Like we don't get significant earthquakes often, but in the event of a severe one from New Madrid, it would be brutal
The problem with the area near the east coast is that the continental crust is much more dense than the crust on the west coast, due to being much older. So basically even weak earthquakes can be felt over very large distances. An earthquake can happen almost anywhere and cause damage many many miles away.
On the west coast it's the opposite. There are stronger earthquakes more often, but the crust is not as dense, so they are only majorly felt in the local vicinity, and not across the entire state.
I wonder. what about the bridges in OC near Irvine and Rancho Santa Margarita? those are so long tilts
I was wondering how those cables on the overpasses in Memphis works. Both Memphis and St. Louis both have seismic retrofits on their bridges due to the New Madrid Fault nearby that has been historically known to have produced the more powerful earthquake in mainland US history.
God, I could never. Imagine having to account for so many variables and peoples' lives depend on it
Excellent video. Little blown out on that interview but forgiven ... until you can afford a camera team and concrete.
I can't believe I just found this channel
You don't link your twitter in the description dude. Nice video!
Fixed that! Thanks
This is why the Alaskan Way Viaduct in Seattle was replaced after the 2001 Nisqually Earthquake.
Since CA is more prone to shaking, the freeway should be replaced.
PUT "bridge crossing arms on freeway, that fall blocking passage under bridges in event of a "quake"
and also arms stopping cars from entering said bridge at same time🤔(so when quake hits, no cars shall be on or under bridge
This is great! I totally get it! But, are they going to retrofit all of the bridges in California like this?
Have other earthquake prone states figured this out???
"... But they're notttttt" 😎
A decade since the Oregon statement has passed. How many of the 1600 bridges are now made safe for earthquakes in Oregon?
It is kind of funny that Oregon (like most states on the Westcoast) want to create safe spaces for students, but not for drivers!
I was driving through Illinois the other day and I saw a few rural interstate overpasses with no central supports. I'm not going to ask how they'd fare in an earthquake because I know they'd probably slide off of one of the abutments. But how are these safe when supporting several hundred tons of traffic at a given moment?
Howzabout the details on the shear walls retrofitted between bents?