📖 Preorder now for early access and other cool stuff: practical.engineering/book 🌉 More stories about infrastructure: th-cam.com/play/PLTZM4MrZKfW_kLNg2HZxzCBEF-2AuR_vP.html
@@abetts123 For preschool construction books, maybe you and your child can go out to construction sites, take your some pics and make your own book. In addition, you most likely know that there are construction videos for kids. One of them is called Road Construction Ahead.
@@abetts123 It's Civil Engineering, it's already ready for kids! I KID, I KID! :P I've already preordered my copy! Really looking forward to the release! I remember growing up with the Disney Wonderful World encylopedias. It's what got me interested in Engineering at a young age. I'm sure my kids are going to love leafing through this book. :)
My sympathies to the unseen unheard people at FIGG who knew exactly what their company was doing and tried to fix things from the inside but were shouted down by varying levels of leadership. I see you.
Reminds me of an old saying: "Whenever hiring an engineer for a project, always hire the one that says it will cost the most and take the longest: they are clearly the expert."
“Stepping into a dead man’s shoes” - really hits home. I was a superintendent for a 3rd party GC on a big new home development and the developer wanted to cut costs. Fired all of us and brought his own guys on. Job went bankrupt 6 months later. Drove by it the other day and saw all the half built homes boarded up. Sort of feels like an “I told you so” moment but also sad to see. Oh well. I make more money for someone else now.
Grady is so good at explaining things adequately to the laypeople like me, while also not sounding condescending or as if he's assuming that we're idiots. THIS is how you get people interested in engineering. Thanks for another great video. 🖤
@TheWeaver You are 'spot on' about how good Grady is at this. I really enjoy the channel and look forward to receipt of my "signed book" {....certainly, "a first" for me [receiving a signed book :) ]}
He really is. I'm definitely a layperson in this and usually don't try to learn about engineering things - like physics, the maths involved just intimidate the heck out of me. But he explains so well, and doesn't need us to know the maths. His pacing is great too, which I appreciate just as much!
@@Beryllahawk It is essential to know that the cap design is capable of mathematical analysis, but the details of that analysis are of interest only to specialists. Understanding both those statements and acting accordingly is what makes this video so good.
And as an engineer, he doesn't dumb it down so much that it becomes unwatchable/uninteresting to those who do understand the issue. It's the perfect balance
I agree. But while watching the video I had the image of thousands of workers who had to go home without pay and they were all surely saying "f those engineers". 😅
Everyone is "confident in the safety and durability of the bridge as designed" until they get featured on Plainly Difficult channel because the bridge fails due to some preventable problem that was not fixed because someone wanted to save money.
We have a single tower cable stay bridge here in Toledo, Ohio and Figg Bridge Group was the engineering company on our project. 4 Iron workers were killed and 4 others injured in 2004 when the 2 million pound truss crane collapsed. I pray all the workers on the Texas project go home safe to their families when all is said and done. I love your videos, even though I usually only understand about half of what your talking about, thanks and good luck on book sales.
As a bridge engineer I had been following this story and it amazes me that the EOR is still openly fighting some of these claims, specifically the rigid footing assumption. Every structure of this size goes through extensive review and throughout the design process there are many of these "battles" over design methodology, especially around footings. However to assume the footing as rigid seems ridiculous. This rigid assumption is usually used on standard highway structure to the simplify design of footings. It is usually a good assumption because the size of the footing as compared to the design loads are low(i.e. not enough force to make the cap deform). However, this method is losing favor as better software comes into play making it easier to better model distribution of forces in pile caps. As stated in the video the footings are 18ft deep. When designing footings this deep the code recommends the strut-and-tie method which if done correctly provides a conservative (sometimes overly conservative) design. The reviewer stated they looked into STM and found the decencies even worse, which would be expected. Based on the depth vs width ratio of the footing I think the reviewers design methodology to be best. Using computer modeling that takes into consideration the cap stiffness, the pile stiffness, and the soil stiffness should give a robust economical design.
being a lay person, I would have thought anything that close to moving water would automatically discount assuming anything would be rigid? I'd also assume the ground is some sort of sandy composition in one form or another?
As a South Texan in the construction industry, thank you for this excellent explanation of the engineering issues at hand. The media, in calling this a safety issue, is making it sound like a simple case of people not wearing their steel toe boots or hi-viz vests, and not a very serious life safety issue.
I live with engineering majors at TAMUCC, and when we were talking about this situation, they were really upset about how people are underestimating what the problems could mean
nothing gets onto radio or tv or news print with out some corporation or wealthy person paying for it to be there. how much attention is dedicated is also financially driven, apple pays all the media companies a billion dollars a year NOT to put anything negative about apple into their syndications. money buys everything
@@aprilgeneric8027 somebody compiled a list of about 10 different shows on CNN and included after the intro who was sponsoring it. Pfizer. Gee I wonder why they were pushing vaccination so hard, considering we're now finding out the vaccines aren't near as effective as they initially claimed.
My dad was a Professional Engineer-probably in the top 10 of his time in Texas-and worked for a construction materials testing company right off the bridge from 1980 to the early/mid-nineties. He was a true straight shooter, and his name was respected or despised, depending on which end of his P.E. stamp you were on. We lived in Aransas Pass, so I know the old bridge and port area well. I can still see all those ships coming in (and feel that oppressive humidity!) I remember going on many a slab pour and doing load tests on various sites and remember Dad walking girders looking at bolts. He took his job very seriously, not just from a character POV, but as you said, because civilians depended on him. Sadly, the engineering gene didn't pass on to me, but the work done is till awe-inspiring to me.
@@Graham_Wideman Great suggestion! I really get into the particulars of dispute resolution. When there is money on the line, GC points at Engineer, Engineer points at GC, and Owner points at both. It’s a big game of pin the blame (and bill)
Civil Engineer here: the most mind boggling issue (to me) among the ones you mentioned is the shear transfer between the delta frame and the box girder section. I mean, that's statics + basic RC design. Big projects are both scary and fascinating. So simple of a mistake can be made when no one is *actually* checking the work without leaving their mental lane they are stuck in.
I was just looking at that, and I thought, boy if there are shear loads there is going to be a problem. And I only had one civil engineering class in college as a general engineering requirement. I’m not an expert! If it looks like a bad design to an armchair engineer like me, how could it possibly have been missed?
@@five-toedslothbear4051 even worse is I haven't even had any engineering classes yet and saw the issue pretty front and center there lol Like bro what the hell was going on to have THAT be missed if someone seriously lacking qualification can see that.
@@AllianaCordova It may have to do with how the work is organized and how communication happens and attitude. And that does not make it any less serious than what it is. But I can see how a thing like this happens within the confines of 1 organisation (the joint venture) but it still gets caught by someone else. So it's like a bad marriage, but the neighbours know everything that's going on, even though everything looks fine in family reunions. Although it's an unfortunate metaphor, I feel like it's an accurate one.
My “engineering” discipline is computer science and even I immediately wondered how they were handling shear loads when Grady showed the drawing. I was expecting him to explain how there’s this other feature for distributing the shear load and upon reviews, etc etc. nope. They just didn’t address it in the design. What?!
Grady, Your description of the assumption that the column base is rigid reminds me of an incident with a king post (mast) and boom on a tanker. The tanker was fitted with two king post and booms, located just aft of the center of the ship, and outboard so the king posts landed on deck supported by a longitudinal bulkhead and a transverse frame. The king post was not stayed, so there were no other supports. The boom was designed to pickup 15 long tons, at about a 60 foot radius. The issue remained unknown until a mate decided to expedite the rigging of the boom by leaving the boom resting in it's cradle and leaving the block hooked to a deck staple. By paying out the block while topping (lifting) the boom, the boom could be rigged faster than doing the work in two separate operations. Unfortunately, the mate got his hands confused and he topped the boom while he pulled in on the block. The ship's main deck started bending at the base of the king post. The boom started bending at the cradle. Luckily, no one was hurt. In reviewing the failure with the shipyard engineers it was determined that the engineers had assumed the deck was rigid and that all loading was from the load being lifted. Ships are large beams subject to both shear force and bending moments both when the ship is still and when it is motion. Ships both hog when the the load is concentrated more at the ends and sag when the load is concentrated in the middle. Like with the bridge, it was wrong to consider the deck as being ridgid. Ultimately the deck and underdeck structure was strengthend and pipe stays were added to better transfer load. Bob
Thanks for the info. I know nothing about physics/engineereing (aside from common sense/intuitive things you pick up from day-to-day life), but it's refreshing to see people express their genuine and (seemingly? (Not saying your wrong, I just don't have the background to evaluate any of your points)) well informed opinions.
As a Corpus native and fellow engineer, I'm very glad TXDOT is being as transparent as they are. I just a wish a solution comes soon as the current Harbor Bridge is beyond its life cycle by numerous years...will miss the view it gives to Whataburger Field when it's eventually gone though
@@derrick_builds The new bridge is built higher to allow for larger ships to pass. Keeping the old bridge would defeat the purpose of building a higher bridge.
@@man0warable the ships can all be unloaded on the East side of the bridge. Rail and road out of Ingleside, Tx. But by all means let's keep pumping money to the Port Mafia.
Currently working on a joint venture myself , Engineer on the contractor side, and seeing videos like these make me feel great about what I do. Just pre ordered my book! Grady, I wish I could make engineering as fun as you do!
The fact that TDoT is being so public with their findings and issues does a lot to shift my opinions to believe them and their claims over the contractors. The fact that they might have moved slow on stopping the project might because they wanted to have everything lined up for public release before stopping things.
...and you don't PRELIMINARILY stop a project like this. It's too big. You don't lose all those workers to other projects and then say, 'Oops, I was wrong! Go ahead!'
It's impossible to say from the outside. It could just as easily have been some political power move resulting from a disagreement amongst the interested parties. They wouldn't need to have things lined up for public release to give the people in charge of the project a heads-up, for instance.
Wow, as an ME that works on government projects, this is my worst-case nightmare scenario. I despise DB projects for this reason. I hope everyone involved can figure out how to make things work and that parties at fault are held accountable. As a PE, we need to maintain trust with the public and projects like this are a major breech of that trust.
Agree, one solution is for the Owner to perform the quality control, and the quality assurance. Current practice is to have the fox in the hen house, quality control, and have the contractor hire the quality assurance manager, the Golden Rule, the man w/the gold makes the rules.
I think this might be my favorite youtube channel of all time. I may take breaks of months, but I've been coming back here for years now and it always feels like home.
Your video is definitely making the rounds here in Corpus! The Caller-Times just posted about it and I've seen a ton of people around here saying they finally understand the problems. Also, we hadn't hit our first anniversary yet at the groundbreaking. I'm hoping the bridge is done by our 10th. Not looking good.
In my 42 years on this planet, out of the countless books i've owned in that time; yours is the very first i've ever pre-ordered, and certainly in the top 5 list of 'books i can't wait to get my sticky fingers on'. I'm very much looking forward to seeing your book and reading it with my nephew (he's 9, loves your vids, and absolutely absorbs stuff like this)
Thats crazy they didn't account for the shear on those tendons. That's almost hard to believe on a project this size that a mistake that major would make it that far.
I am doing Quality Assurance on a Design Build Project currently(and probably for the next 3-4 years), and the biggest thing you need is a good working and communicative relationship with the Owner/DOT in that area. Without that, the project, while able to still be completed, will have many issues throughout its life. If you do not have that relationship, a lot of this finger pointing and trying to avoid blame becomes a big issue. When TXDOT first found the issues, and barred the designer, the DB should have had the new engineer review his findings with TXDOT, and work out any issues before it came to this. A bad relationship will cause this standoffish attitude.
Yeah, that part is really confusing. You got put on a project where the designer got canned because they killed people and new designer is like, "Yeah, design great! Let's go!" and TxDOT says, "Okay, let's go... don't mind me over here, I'm just gonna triple-check this... hmmm.... hmmmm.... hmmmm.... Ya know, maybe we should look this over again?" "Uh... we started, you said everything was good." "No, you said everything was good. We said it was okay and we didn't want to slow things down." right.... Both seem to have made critical errors - if the design is actually deficient, and frankly it sounds like it is - then the designer messed up but TxDOT didn't do sufficient due diligence and, more importantly, didn't throw the flag on the field immediately when they suspected the issues.
Although working in a competely different field, I also find that the customer bears a lot of responsibility that they don't always rise too. It sometimes seems like a combination of being naive, disinterested and combative works against the customer in any complex project, residential or commercial.
This is VERY interesting to see: here in Germany a very similar situation occurred around 2y ago. One of two major motorway bridges to cross river Rhine in the Cologne area was found in critical condition by sudden cracks in superstructure during a routine inspection 6y ago. As result the bridge was immediately closed for any vehicle starting from light trunks onwards. Only standard cars could pass the bridge from now on. This caused and still causes major traffic congestion and major headache to many businesses in the area (Ford Germany has two production plants nearby and other large scale factories depend on this bridge too). A high prio project was started to build a new bridge next to it with a higher traffic capacity as fast as possible. After 3y of construction work the first parts of the mid part steel superstructure should be delivered from China. There were already concerns in welding quality during on site checks in China. But the parts were nevertheless shipped to Rotterdam to get offloaded to small cargo ships passing river Rhine towards construction site. But after re-checking the parts in Rotterdam finally the decision was drawn to reject ALL parts due to insufficient welding quality and the contract was cancelled. So a new contractor had to be found and negotiated which put the whole project around 2y behind schedule and tax payer has to cope a 30% increase in total cost for the project...
sourcing the project to China and then expecting quality was the first mistake and as a result the project now is delayed for years. The person responsible should be fired...
I have to agree with vossejongk: While it is not impossible to get something of quality in China you really take a big chance with such an important project on short notice. Chinese companies are famous for cutting corners to save money and anyone who blindly believes they will give everything you require for an amazing price often find they will have a big surprise which in reality should not have been such a surprise.
When will the West learn? Every steel item from China is inferior quality and inferior welding. I specifically refuse them in my spec. sheets for tenders now.
In 1979 I worked on a prestressed, post tensioned precast Bridge in Toronto. Drove over it just last week, it's still standing! One if the most interesting project I ever worked on. Great video, thanks for posting!!!
As an engineer, its the most important thing to remember the oath and what it means. The engineer is responsible for what they don't know and they are personally responsible for the safety of everyone using their design. If you don't know that its 100% safe, then you don't sign off. Management will always push for their profits, but the oath is clear. I've worked on safety critical systems and had to put my foot down; most of the time it works, once the execs were so forceful in meeting their business goals that it was clear the only option available is to get a new job. You know that management will find some other engineer to sign off on the design, but its not an excuse. Shame to all those engineers at FIGG who stayed working there and signed off on that work. At least they earned their reputation that will be stained on their Resumes for decades thanks to TDOT being transparent.
Nothing is 100% safe; engineers are responsible for providing an appropriate level of safety for the circumstances, intended use and all the conditions that can be reasonably foreseen. (Basically, not to tell you it won't break, but to tell you _when_ and _how_ it will break.) And then their job is to do this at as reasonable a cost as possible. And this is made more complex by there being no bright line in most circumstances; as you get close to the line there are reasonable arguments to be made on both sides. I'm not saying that what's going on here is anywhere near the line, though, rather than well beyond it. I am not equipped to judge that with the information I have. It does appear to me that TxDOT is doing the right thing by making all their data and analyses public; at least others who do know something about these things can look at them. All that said, I do know what you're getting at, and yes, I agree that it's up to engineers to not to sign off on things that are obviously wrong, or where they do not firmly believe, based on evidence, that the structure is suitable for purpose. I think it's one of the most admirable things about the discipline of engineering that engineers have this code to put truth before profits or anything else.
@@Curt_Sampson We seem to agree an everything except the semantics here. 100% safe is when an appropriate level of safety for the circumstances, intended use and all the conditions that can be reasonably foreseen. No one expects that bridge to function as intended for the next 500 years with zero maintenance, or to work without careful inspection should a magnitude 9 earthquake hit or to have 500 Abrams tanks roll over it in a column 6 tanks wide bumper to bumper. If the safety factor is agreed to be 1.5 and due to some supply chain disruptions the proper class of bolts for the beams will take 2 months to arrive your not allowed to use an alternate bolt that would only meet a safety threshold of 1.4. Your also not allowed to sign off on the design unless you know everything you need to know to perform all your analysis and calculations. Its the same type of rules that apply to open heart surgery, because if your oath is not followed the results are similar. An Engineer can end a lot more lives than any Doctor.
@@seangriffin7803 I see; you define 100% safety as "100% of the necessary amount of safety" rather than "perfectly safe," meaning that you could achieve "110% safety" (which would obviously mean you spent too much on safety if it cost more than "100% safety" does). That's fair enough, and leaves me in full agreement with you.
I've seen some other comments suggest that the engineers involved here are probably inexperienced and thus may not have known better. Certain assumptions were made that a more experienced engineer would know not to make. It seems like TDOT was also a bit slow in communicating their exact concerns and it's very well possible that the engineers didn't see TDOTs concerns until after they went public (management may have not have communicated the concerns to them). Of course I'm just speculating here, I just don't want to assume it was malice on the engineers part when it could have been ignorance and/or malice on managements part.
@@grn1 Engineers have a special position of public trust where ignorance is NOT better than malice. Every one of us Engineers have been there; where you think you know how to get the design completed, but your not sure and management is applying pressure to meet the schedule. We all know better -> If your not absolutely sure; you cannot sign off on it PERIOD. You may end up having to get a new job, but that's no excuse; its a core part of the job. The technical buck stops with you if you sign off. Nobody knows everything and each design can have its unique challenges; once there was a project with a twist that was new to me and despite efforts to read up and educate myself on that particular technical detail; I still didn't feel sure enough that without experience in that area that everything was as good as it needed to be. I told leadership that they needed to hire an outside specialist to perform a review of that aspect of the design. Leadership was very upset and they pushed back due to the several week delay and 6 figure cost that would add to the project. If your not up for what is required to keep the public safe, then steer your career away from positions where you need to sign off on these projects.
So. There I was, minding my own business, winding down my nightwatch shift, enjoying a few almond pancakes, casting about for something interesting to watch on YT. You know--nothing too dramatic or involved, maybe a step or two above background noise. And then....this. The saga of this bridge that I'd never heard of in Corpus Christi, TX. So much for "light" entertainment, lol. Great content, fabulously presented, as always. Thanks, and cheers from the shores of the Arctic Ocean (AK's North Slope).
Glad that someone had the guts to speak up and put it on hold. The cost to suspend construction is high, but the cost of human life, should it fail, is immeasurable.
I am an electrical engineering student and a single mom of 3. My youngest son hasn't started kindergarten yet, so he gets to come with me to classes and absolutely loves it. This week we have been discussing concrete on our walks to class and why the "dirt" is important below it and what happens for different scenarios if something isn't built right with concrete. I am super excited for your book to come out finally so he and I can read it together.
@@nixonhoover2 none thank you, and I'm paying my own way through college without grants or loans. its called working hard. I still work full time from home, attend school and I'm a mom. I have no time for self care, but it is worth it when you set high goals. While I know you commented with hate in your heart, know that not everyone makes excuses and looks for handouts. My children bring me great joy and while my ex husband is not around due to his physical abuse of us. I will not let that hold back any opportunities for my children into the future. They did not get to choose their parents and I will work twice as hard to make sure they have a life that is fully enriched and have every opportunity any other child will out of my own pocket. Just because someone had children or they have life circumstances where they find themselves as a single parent, it doesn't mean they can't work hard and they are no longer allowed to have life goals and passions. In reality, it makes those goals so much more important to achieve.
I'm not very smart, and I don't understand load capabilities, or load bearings, but it's always interesting to hear / see about the complexities of such huge projects. The depth of engineering, the depth of potential failure, and the unity of corporate and federal companies all coming together to make it possible. Thanks for this. Hopefully this gets resolved and the bridge gets completed in a relatively timely manner
it’s amazing to see how much progress has been made since this video was posted. i drive across the old harbor bridge anywhere between 2 and 7 times a week for my work and i admire how the bridge is starting to take shape
The tendons holding the box girders to the delta frames without additional reinforcement against shear loads gives the same vibes at the Kansas City Hyatt Regency walkway collapse: a small change in design completely changes the way forces are handled by something loadbearing. It's obviously not 1 to 1, but it isn't that far off imo.
My sentiments exactly. Watching the animation of delta plate shear sent chills down my back. In Corpus we might have a troubled bridge over harbor waters, instead of a bridge over troubled waiters. Neither outcome is good.
Thank you for bringing light to this situation! As a Corpus Christi resident myself, it sometimes gets confusing on what’s ACTUALLY happening with the bridge. Keep up the good work!
I'm no engineer, in fact I'm an art student, but I'd absolutely love to buy your book (i'll try saving up money.) I love watching your videos, its just so interesting and fun to listen to as someone with a fascination for architecture and bridges!!
FIGG also screwed up the new span of the Sam Houston Tollway Ship Channel Bridge here in Houston. Harris County Toll Road Authority (HCTRA) had to suspend that project to get another engineering firm to check the safety of the bridge. FIGG was terminated from that project.
Just preordered the book. I've been watching every episode for over a year now, and I can't get enough. And my kids (7 and 10) are asking better and better questions about how things work and how they're designed. They're also learning to appreciate how complicated things can be, despite appearing simple. They also love to read. :) Keep up the good work!
As a non-engineer, and certainly not qualified to speak towards problems such as this, I truly appreciate the way that you explain and illustrate what those problems might be, and their consequences if left unchecked. God Bless each and every one of the engineers and designers, and the builders that take on such tremendous responsibility as a project of this magnitude. I'm pretty confident that the insurers also spend some sleepless nights while making their commitment decisions.
Engineering disasters was a favorite show of mine for a long time. My friend was the one who videoed the collapse of Big Blue at them Miller Park. You know Norm was a QC for P&H because the moment the turn bearing bolts began to fail from load he began to film the failure at its point. It's so awesome to watch these episodes and reminds me why I originally wanted to be an architect mechanical engineer.
Congratulations on your book! In a very small way I helped a engineer friend of mine write a book about a Famous Race Car team that we both worked on and when it was completed, he took immense pride in that book and has sold well over 1000 copies and now is on his way to writing the companion / follow up book to that one. They are both books on mechanical/electrical engineering so they are not exactly light reading!
Just a note. There is a walkway on the present bridge. I ran over the bridge when I was young. It was scary because the roadway bounces up and down when trucks pass.
As a government's CO representative at one time (on much smaller contracts than anything like this), I know that any 'stop work order' is really considered a 'last resort' when it comes to govt/ contractor relations. Of course there is always room for 'honest differences of professional opinion' between the independent reviewer and the principle designer. But if the review wasn't done before this, then looks like there's plenty of blame on both sides.
As a new electrical consulting engineer, I can't believe they didn't have constant reviews. Normally there are regular deliverables for XX% design, ifc, ect. and before each deliverable there is an understanding of what needs to complete or postponed for a later deliverable. Not to mention all the internal reviews and coordination that happens between deliverables. And at the end you get to code reviews and submit for permits where the government officials get final say on if your design is acceptable or not. I can't imagine that they got a permit worthy design without a couple hundred reviews and various questions being asked along the way to the point that such a serious issue wasn't discovered earlier.
I know in my area, the DOT would have had to approve the design before it could start. I wonder if they did, and missed these issues at that time, and that is why it is such a mess.
until the latest round of Bridge collapses, FIGG was considered a top drawer bridge design firm. They had been designing bridges for almost a century, so it is entirely possible, even probable, that TXDOT just took thier statements on faith, especially if the engineers on the TXDOT side of the table were young/inexperienced. The Florida Bridge collapse was a real wake up call to the industry that something was not right at FIGG, and triggering an audit of every single project they were involved in. I can tell you from personal experience that the regional engineers for TXDOT aren't the sharpest tools in the drawer.
@@Rorschach1024 And that is working as designed, right? We don't want all the best engineers in state government, we want them out there working on the best projects, wherever they may be. So they rely on outside engineering firms to design quality work for their projects. This is my outsider understanding. They don't provide oversight in terms of "checking you did all the work right," their oversight is primarily making sure you hire licensed professionals (unless they have reason to hire an outside firm to do such a check). If that's not the way it is designed I'd be curious how the system is supposed to work.
Thank you, Grady for this series and your book. I pre-ordered, and was surprised and pleased when I got it. There is something on every page that expands my knowledge of engineering. I’ve been a fan of this kind of construction my whole long life. And on top of that, my son, also a fan bought the book for my two grandsons for Christmas! The legacy continues!
You should make a video series of the Gordie Howe project. Not only the bridge itself, but all the infrastructures tie to it is impressive in size. 2 border controls, 1 bridge, and 1 interchange in Detroit, and not to mention all the work that was done in Windsor prior, with the extention of the 401 highway.
@@damonkay4177 Nice I watch the drone footage release by the Gordie Howe International Bridge youtube channel to follow the construction, and I've seen many engineering technique in that area.
The only reason they're building the Gordie Howe is because the privately-owned Ambassador Bridge has been allowed to decay and the owners also didn't build connections between the bridge and customs according to contract. The owners also tried to seize a nearby Detroit park, arguing that they had to have the land to fulfill anti-terrorism requirements. And over in Windsor, they bought up an entire neighborhood that sits beneath the bridge rather than adequately repair the bridge, which was dropping debris on the area. It's been quite a saga.
Yes, a video about the crumbling Ambassador Bridge (through greed and neglect) and the Gordie Howe Bridge would be interesting. Despite its issues, the tunnel nearby, and the Blue Water Bridge to the north, it’s still the busiest international crossing in North America, carrying 25% of our trade with Canada.
I've been on more than one project where the contractor was under the distinct impression that design-build meant that it was up to the subs to design it as we were building it.
I am sold. I immediately ordered the book as soon as I found out about it. Glad I stuck around to the end of the video. You should promote the book more often and earlier in the video. I’ve been recommending your videos to my students for years. I can’t wait to see it. Good luck!
I rolled through Corpus several weeks ago, headed to Port Aransas, and marveled at the new bridge; well, what has been built so far. The video here does not convey just how freaking BIG the new bridge is. I appreciate the update.
If you're looking for more of these, take a look at the Pelješac Bridge which was opened in Croatia a few months back. I hope it doesn't suffer from these issues, as it is very beautiful and MUCH needed for the entire Dubrovnik region. Its total length is 2404 m. But back to yours, it is (well, should have been?) a beauty, really. There's something in cable-stayed bridges that's just breath-taking.
Last year I was driving along the coast line wishing my trip had been a few months later to use that new bridge system. Major undertaking to bypass Bosnia.
@@thomasm9552 Well, it was made by the Chinese, but as far as I can tell it looks and feels amazing. Naturally, I know nothing about construction they might have used spaghetti instead of rebar as far as I could tell I guess time will be the judge of its built quality. The EU paid for most of it so I suppose they took care of the quality part.
120% of designed tolerance. Yeah, things like that are why I’m happy enough just being a cog in the great machine of society, as I don’t have to worry about the absolute worst case possible at my job, just follow the procedures and regulations promulgated by my state’s department of ecology.
Glad I"m not the only one confused by that part. ... Is just a script error? Or is it one of those cases where an industry-standard usage doesn't match with the conventional, everyday usage?
While your classes were a the lamp for infrastructure, the Florida university bridge collapse was the lamp that told the TEXDOTs engineers where to look for potential failures. Like pointing out the crooked tile in a bathroom, you can never un-see a simple design choice that makes sense at the time but you always regret once you see it.
One of the most important lessons learned is that the owner must insist on an independent design review for each phase of a contract before one yard of concrete is placed. The very nature of DB projects is such that the designer is reporting to and being paid by the contractor who wants to get it done as quickly and cheaply as possible. You can't really blame the DB team either. After all, they're in business to make money. However, this is not necessarily in the best interest of the owner. It is therefore incumbent on the owner to have hands-on involvement in the project from day one to keep everyone honest. I know this all too well. I used to work for a state agency that built a large bridge using DB. We regularly went round and round with both the contractor and designer that tried to skirt around our requirements and water down their own proposal. We rejected work on more than one occasion and it often got ugly, but it was worth it. The final product was good.
The design authority on the bridge was originally delegated by the owner to the designer/builder. As you point out, this is never an ideal situation. A very high profile example of delegated authority going badly wrong is the Being 737 MAX project.
I'm fairly certain that the Millennium Tower in San Francisco was also a DB project. A 58 story, poured in place building (dense concrete), built on bay fill. There is testimony that a soils engineer was never retained! What could possibly go wrong?! They saved $4 million by not driving the piles down to bedrock. That probably doesn't cover A month's legal fees on the retrofit currently, much less the construction costs! From what I've experienced in the industry, design build on large complex projects, inherently creates a conflict in interest! Not very "efficient" in the long run.
They are bridges for cryin out loud, to stand the test of time and environmental strain there needs to be built in design criteria which mostly is there because of previous events. If it’s not right it,s not worth a penny
John Roebling had 7 civil engineering consultants review his Brooklyn Bridge design. This was a Design-Build project. I go over the history of this bridge in my TH-cam Video if you're interested. th-cam.com/video/N-GrjJwWqhc/w-d-xo.html In the Future of these Design-Build projects, you would think that the highway departments would have an independent design team review the DB design. You see this in the northeast when a Structural Value Engineer reviews the design of highways, bridges, and water treatment plants.
You should do a series on an interesting project from each state. Most states don't have the budgets of a CA, TX, NY, or FL, but I have to imagine there is still some interesting work being undertaken in all of them.
Good Catch TXDot! After Harvey nobody is gonna take chances in that Area! When the NTSB bans a Engineering Company, there’s a Darn Good Reason for It! Was wondering why this was taking so long every time I take a long weekend in Port Aransas!
Good point, small correction: NTSB has no enforcement authority. The ban was from the Federal Highway Administration. I only mention it because we should have more agencies like the NTSB -- their ENTIRE job is based around post-accident truth -- if the people who make the rules also get to investigate themselves, they are unlikely to find anything wrong with themselves. Government works better when we have investigators who don't work for the people being investigated. State and federal level. That's why air safety has improved and if you want to see improvements in other government agencies, it's a really good model. (Cops investigating cops? Profit-based hospitals investigating complaints about their screw-ups? Military Commanders investigating accusations they allow abuse and hazing? etc. etc.)
Hello. I'm not a Engineer but I really appreciate the way you explain things it makes it easier to understand, it's just unbelievable how much math goes into a project like building a bridge, or understanding the ground under it, I have seen lots of your videos and they help me understand how things can go wrong if everything is not taken into account, I once build a porch onto the front of my house, everyone said I over did it , but I just did not want anyone to feel like they mite get hurt , so I put a lot of thought into it, and to this day it has stood up with on problem and with lots of people on it Thanks for all the information on your videos
Huge fan Grady. Love all your videos. As a contractor I really appreciate the level of depth but succinctness that you do in your work. We’ll be getting a copy of your book for our kids for sure. We home school and this will be a fun primer for the kidlets to wet their appetite on. Blessings!
probably not. It's called "safety factor" or "factor of safety". Elevators are NEVER to be loaded more than 10% of their rated capacity, because of the assumptions necessary. Peak forces can be higher than assumed. Putting a megaproject like this at a safety factor of 5 (meaning that the bridge is never to be loaded more than 20% capacity) is completely normal and reasonable. It sounds ridiculous at first, but the whole world is designed this way, and I'm very happy it is.
I was wondering about that too, it might actually be 20% though. With structures like this is quite possible the safety factor would be well over 4 meaning any component hitting over 20% of design load would be considered overloaded. I have a feeling that a retrofit to stiffen that pretty immense pad at those loadings is going to be a veritable jungle of steel work going about a third of the way up the pillars.
I was a bit baffled as well, not necessarily due to the safety factor of five, but the sentence afterwards ["In other words, they would fail" - as I thought at first "the bridge would catastrophically fail" (-> 120%), not "it would fail to meet specifications in terms of exceeding the allowed load percentage" (-> 20%) ], but then again, my english isn't that good, especially when it comes to technical speech/terms.
@@prmperop That's not how we do Structural Engineering. Our capacity calculations (AASHTO & LRFD) have safety factors *BAKED IN* they are not added after the fact. Thus 20% of capacity means 20% of the *FACTORED* capacity. In order to be in trouble he would have to mean *20% OVER* capacity. It's up to engineering judgement, but on a new build, even WITH the safety factor baked in, I don't like to exceed 85%-90%.
@@zyeborm Retrofit would probably just consist of tying into and thickening the concrete pad to get adequate stiffness. Once it's sufficiently rigid the original calculations are valid.
Great review. Ignoring the stiffness of concrete is understandable if you are building the foundations of a house. I wouldn't have imagined any design team on a project this big would just assume infinite stiffness.
There are some things that are ignored in the calculations - like the connecting plates in the I-35W bridge in Minneapolis. That design was reviewed again and again every time modifications were made to the bridge - later with the benefit of computers - but the plates were always ignored as they weren't supposed to ever be the weakest link. Turns out they were because someone in the 60s messed up the calculation and they were only half the thickness they were supposed to be.
Disclaimer: I'm not an engineer, and my expertise in this area is best described as knowing my limits. that said, the engineering involved in building a small thing is much simpler than the engineering involved in building a gigantic thing. part of this is because at small scales, things get inherently overbuilt just to make them large enough to fasten.
You certainly shouldn't, considering all of the design tools that have become available since my engineering career started in the 1980s. Problem is, on a DB job, the contractor is the boss, and the pressure to cut costs is on the designer who no longer reports to the owner.
Its a very common assumption for your typical DOT interstate bridge (spans under 200ft, prestress bulbs or plate girders). Bringing in a footer's flexibility into the calculations would add unnecessary complications into design without having any consequential outcome in design. All this said, a ginormous segmental cable stay bridge is not a typical structure by any stretch. The rigid footer assumption shouldn't have gone past preliminary design efforts.
I was driving down 183 in Austin, TX this evening; something I've done countless times before, and always taken for granted. But this time, for the first time, I noticed (and marveled at) the gentle curve, both vertically and from left to right of the suspended highway; the fact that it *_is_* suspended; and the simple fact that it hasn't fallen down under the gazillions of vehicles that use it. And I found myself grateful to the teams of engineers, their well-nigh miraculous collaboration, and the overall technical excellence that it represents. And I noticed all this directly because of Grady's videos. Awesome stuff. All hail Grady and his _Practical Engineering._
This is an AMAZING video...our local media has completely failed to plainly explain this project and it's issues like you did with this video. Thank you for your analysis....I too am a S. TX resident and cross the Harbor Bridge multiple times per week. Growing up here I remember hearing older generations talk about the construction of the current bridge and even know a few people (2 to be exact) who refuse to cross it due to rumors about the current bridges construction.
If you know reporters you will learn with certain exceptions they really are what they call them in the UK...newsreaders. The copy that they read is not vetted by any expert because that would take time which equals money . News is a business so whatever the subject be very careful about your sources. Fools believe anything presented to them as we see in today's voting public .
Congratulations for the book release and a happy new year! I have been studying house constructing for four months (90 % on the site, theory lessons via Teams) and find this channel as well as Your book very interesting and revelational even! I will order a copy once I get the official coursebooks done, most likely that way I get the most our of the effort You have put into it. Keep up, good work and greetings from Finland ✌😎
I'm glad there is somebody willing to discuss this issue in far greater depth than we get from the news media. I'm eager to see updates as this situation is eventually resolved.
One of our professors @TAMUK was on the team that determined the faults in design and listed 5 main concerns that were brought up in TXDOTs letter. Neat
Hi Grady, I am in my home office right now designing wood residential homes. My daughter is with me and I printed a few plans for her to color on. She asked me if when she grows up, if she can be an engineer too, and if girls can be engineers. I told her of course and that I have many friends in engineering school that were girls and are now engineers. I told her I'd buy her first engineering book and preordered two copies of your upcoming release. We are very excited and I wanted to share that story with you. Wishing you the best! Thanks.
I enjoy videos about current engineering projects as well as the past. The videos you do are concise and entertaining. I have taken vacations to see bridges, dams, and other great projects. The men and women that designed and build these great structures should be remembered.
Probably not the video's intended result, but such engineering design responsibility sounds absolutely terrifying to me. How can these people even sleep at night short of not even being capable of feeling anxiety.
I didn't do so well in my structural analysis class and that was definitely part of what led me to endeavor never to be a structural P.E. that can stamp structural plans. It's one thing to design a sewer or sidewalk. It's another to basically sign your life away on your confidence in calculations to determine how thick a certain structural member ought to be.
I feel this. Even being the one in charge of building something off of another engineers drawings, you have to make sure everything is being done correctly and nothing is missed or else it can be a huge danger. I only build patio covers and have done some very unique ones (very tall or over two-story decks) and I have got anxiety before just trying to make sure everything is done right for the safety of my coworker who walks the roof and anyone in the future who uses it. Lol
Can you talk sometime about the move from suspension bridges to cable-stayed bridges? It is plain that engineers think of the latter as preferable to the former and have done since the late 20th century but they were somehow considered impossible before that. Was it improvements in metallurgy or in understanding concrete or some other factor or factors that drove this chaneover?
This is just my wild guess, but it might be that it's case by case. And one big factor might be the environment, like in this case, salt water proximity. Also, the improvement in concrete technology from the 18/1900s might have enabled the new building techniques used today. Because, in my view, steel construction was more widespread because of machine construction. So that would help accelerate the development of steel technology faster than concrete. And so civil engineering and mechanical engineering were doing a piggy back on each other with steel technology development at that time. But this is just an idea. And this means I'm tottaly down for that video!
I think the longest spans these days are still suspension, but cable stay grew into a niche economically for those medium-long spans. It's probably more that suspension got more expensive and no longer became the most economical option unless you REALLY need a long span. All the work required to run the main cables in a suspension bridge takes time and money.
@@davidmarshall2399 ... I think suspension bridges align forces better, all the weight goes up and hangs in the main cable nicely.... cable stayed using a tower then cables goin off at sharp cables is pulling harder and weird angles..... But we know how to make and test steel and concrete now better, we aren't afraid of adding forces for fear of weakness in material.... With reliable materials the designers can skip less stressful option for easier to make... Maybe...
@@alexwilliamrussell that's the design side and I don't disagree. But the work involved in actually getting a suspension bridge up is a lot more involved. The whole thing is waiting for the main cables to be run before you can do a single bit of deck. With a cable stay you at least have two work fronts on each pier from the moment the towers are done, so lots of places to get things moving. The equipment to wind the main suspension cables must be intricate as well. Cable stay you just get shorter lengths of standard stuff and connect it up.
Cable stayed bridges are self-anchoring, meaning you can build a cable stayed bridge, and all you need is one tower in the middle. Suspension bridges need significant foundations for the cables on either end, which are extremely expensive and limit its use. When you need just one or more than two towers, cable stayed bridges thus are preferable to conventional suspension bridges. Like with the bridge in this video you can also incorporate cable stayed elements into a regular bridge, whilst a suspension bridge would've required San Francisco Bay Bridge style concrete anchors on either end. Suspension bridges are still being built if you've got convenient places for the cable foundations and a span that wouldn't be possible with a cable stayed design.
11:18 This "experimental" 1.33 overstress rate on the post-tensioning seems like a major flaw on it's own. Why would a design rely on rates that aren't even supported by code?
@@urieaaron someone correct me if im wrong, but overstress is a condition that is designed for so that even if you overstress the cables (or they shorten due to weather, or the bridge is loaded beyond the expected loadings etc) you are not going to have a sudden failure of the connections, anchor points or sudden crushing of the concrete (brittle failure). This means the cable is "the weakest link in a strong chain" and if it were to exceed its capacity it would fail in a controllable manner which can be observed during routine inspections and corrected (e.g. cracking) as opposed to sudden catostrophic failure.
In the end codes are made to simplify the designing process. They include lots of excess safety factors which could be neglected if reasoning is good enough. For example in post tensioning there is margin of error for the post tensioning jack force. So using better calibrated jacks could be good reason for overtensioning as you know the actual end tensioning force with greater accuracy.
@@zyeborm yes I would say ventilation inside really would be the major issue. Typically, the lights and ventilation are provided temporarily for construction; during service, only some people like maintenance guys will access this part occassionally, so theres no need for permanent light/ventilation. Also important to note that there are narrow passages on some sections and lots of wire and other electrical components for streetlights, cctv, etc
Such a great presentation. I'm retired now but did 12 years of bridge work. We have a cable stay bridge here in Boston. My friends daughter calls it the hammock bridge. I can't get that out of my head every time I see it😆
Grats on your new book Grady! Thanks for all the well made and informative documentaries you produce. I love watching your channel. I'm an IT Engineer myself, but even though I don't work in the same industry, I support clients that do work in construction, and it's always fascinating to learn about the world they work in.
Oh this will be fun to watch. I moved from Corpus after a decade in 2015.... Seen the construction a few time since when visiting my parents. Good to see the port growing.
I'm a seaman bringing cement from Vietnam to Corpus Christi, proud to be a small nut in this giant mechanism. Btw, we modified our main mast on board to be collapsable to be able to pass under the Harbour bridge. Thanks for a great content!
Great video! I've been over the existing bridge many times and the view is spectacular. TxDot must have had good reasons to suspend work. I used to play tennis with a local TxDot engineer....very sharp guy. Sadly it is us (Texas residents) that get to foot the bill for this mess.
It is a true joy to watch your videos. Your concise, simplified explanations open up worlds of enjoyment to those of us who reveled in our 'tinker toys' those many years ago. Much obliged, Grady.
Here in Ohio, we had a cable stay bridge (it's built now) that had an accident where the gantry crane fell (pretty much same one as in this video), killing 3 (maybe more, been a while) The lawsuits and finger pointing were out of control.
@@anthonylozano8035 No, it happened in Toledo OH, bridge crossing the Maumee River. If I recall the report, the company that ran the construction, they cut corners when securing the gantry to each pylon. They used far fewer connections than required and forced the workers to do this to get ahead of schedule so they could get bonus money. I don't know why the unionized workers didn't tell them to pound sand but it ended up costing people their lives.
"Dead man's shoes" is right. What a cluster. How in the world did this project get greenlit with all of supposed issues that should have been foreseen based on paper? (And to be in anyway associated with that failed crosswalk in Fl is telling) This is one of my favorite videos you've done. I look forward to an update. Thanks Practical Engineer!
First this project was well underway when the FIU bridge collapsed, second the inherent problem with design-build projects are the state does not have their own engineer peer review the structural engineering. With design-build the engineer works for the contractor, the contractor wants to make as much money on the project as possible and therefore puts tight restraints on "excess" design costs, or the engineering firm bids low to get the job and has to cut costs to maximize profits. Both are to blame in this situation, The new engineer and the contractor assumed TexDOT was having a knee jerk reaction to the FIU collapse, assumed the Figg engineering was on point and resubmitted Figg's design. But TexDOT was on the ball by not revealing their findings first, they let the contractor and new engineer expose their game.
@@truracer20 When CDOT did its first design build (TREX) a rebuild of a dozen plus miles of old interstate and new light rail through Denver, CDOT had a consultant work out with them the scope, cost, required methods of independent QC,QA, and review, and CDOT review, dispute resolution processes and the DB selection process. This all took perhaps 2 years before they even asked for proposals.
Congrats on the Book, quite scary though that even today a bridge like this can be half done and not engineered correctly before it is even approved to be built.
Thank you for this very informative presentation. I grew up near Corpus Christi and remember being amazed at the "new" Harbor Bridge during the mid-60s. Before that, there was a drawbridge. Can you imagine?
Correction for you: the Harbor Bridge does have pedestrian access. The times I have visited Corpus Christi I saw runners and some walkers making their way across the bridge in the protected pedestrians side walk.
@@x--. there are concrete barriers between the road and the sidewalk. The sidewalk isn't very broad so it's enough for folks to be in single file. Its like 1.5 persons wide. So it's not a great pedestrian passing, but it's there. That's all I was trying to get across.
My wife is a civil engineer and I greatly admire the field of engineering and those who practice it. I'm sure she will enjoy your book and appreciate what you do!!
Hey Grady. I would invite you to visit Hampton Roads to view the expansion of the Hampton Roads Bridge Tunnel, the most expensive road project in Virginia history. My sons and I enjoy the travel on the preexisting bridge tunnel in full view of the incredibly rapid progress and marvels of engineering of the new span. Thanks always for the excellent content!
As someone who lives in Newport News, I'm super excited to watch the ongoing work. The only thing I wish is that they had included a rail line on the new tunnel work.
Totally unrelated to bridges, your comment got me thinking about tunnels. Those are another, almost completely opposite-of-bridges kind of engineering marvel. I'd love to see a video or two about some of the big highway tunnels out there. The Eisenhower Tunnel near Keystone / Vail is the nearest one to me and at over a mile and a half long it's a journey to drive through it. So Grady, if you wanna visit Colorado for a video on the Eisenhower Tunnel (and some skiing) let me know, you can crash at my place :)
My experience with design builds has been that the contractor's consultant does most of the design during the bidding process so by the time contract is awarded by the owner and the design gets reviewed, there's little room for change. This can result in plan errors being propagated throughout the entire project and not being caught.
It seems natural to happen in regular conditions. But when your project was so faulty that collapsed during building, and killed people, you should be in prison, not building a bigger time bomb. And this new project should be under fierce screening. And by the way, diagonal bridge? I understand that surroundings matters, and that the place was not clear fields, but a city, but still it looks so counterintuitive.
Thank you for making these videos! They are informative as hell and shed light on the big money and big problems that can be spent and experienced in these massive public works projects. Grady, could you please look into the I-5 convergence around Tacoma, Washington. They might finally be finishing it, but that project has been running since I was a kid. It was another massive project that always ran into problems and I think it would be a perfect video like this that explains the project in a pragmatic way that multiple generations of politicians lacked the capacity to do. If you don't want to or can't, I understand, and am happy that you've started opening my eyes to the massive scale and fuc... complexity of projects like these.
As someone with more than a touch of acrophobia, I would rather go through a TSA checkpoint, twice, to fly over the river than cross the bridge. I KNOW it's irrational, and I still feel that way.
@@MonkeyJedi99 I've met people with acrophobia severe enough to affect their normal functioning to the point they weren't able to work in buildings higher than a few stories. Sorry to hear man!
Unfortunately, I doubt many people will be making use of a path that requires them to go miles out of their way (because of the curve radius needed for 80mph travel) and puts them 5 feet away from vehicles traveling 80mph. That's 80dbA, about the same as using a power drill the whole time.
As much of a bummer it is when these disruptions happen, safety of course is paramount and needs to be of the utmost concern before, during, and after construction.
The only cable-stayed bridge I'm familiar with is the Leonard P. Zakim Bridge in Boston, an absolutely beautiful structure well-known as the subject of dramatic photography and other visual art. They really are impressive! I hope this bridge does finish and the people of Corpus Christi can enjoy it for decades to come.
Cable stayed bridges are actually pretty common and are the hot design these days. The Brooklyn Bridge is actually a cable stayed bridge. One of the best modern examples is the Millau Viaduct in France which is actually seven cable stayed bridges crossing the Tarn River valley.
It really is. We go to the Aquarium fairly often and the Harbor Bridge makes me so nervous that I’m getting tempted to go out to Mustang Island, take the ferry back to the mainland, and then come around through Aransas Pass to Portland and then to North Beach. It’d take an hour or more, but I’d avoid that dang bridge. There used to be a lift bridge on Navigation Blvd farther back in the port. I used to take that bridge because I could get across it so fast. So even though it was old and looked scary, I didn’t have to be on it long and it was only a couple feet above the water. But they tore in down ages ago, and now the Harbor Bridge is the only reasonable way across.
Lay person here. I'm just thankful that they did the reviews of the design and identified the flaws. I'm sure there was a sinking feeling when they realized everything had to stop, but made the right call. Though i always wonder when work/design is handed off to new firms, how do the new firms not be influenced by the hidden assumptions that the present design can bias them with. Great video
I moved out of Corpus Christi about year ago and It has been little frustrating to watch the construction. The approach spans and attaching roads have been a huge mess especially around 8 or 5 oclock. Gotta say though this bridge is huge compared to he old Habor bridge
I'm pausing at 8:21 to ask a question in regards to FIGG screwing up so colossally over several projects. How does a company get to be large enough to win bids for these projects without an apparent modicum of understanding of the laws, regs, responsibilities, and tiers of accountability associated with projects of such scale? It just doesn't make sense because if someone works their whole life to build a company from scratch, or buys/merges with one already in existence, wouldn't it be in everyone's best interest to cross every T and dot every I? Or am I just so far disconnected from what it takes to run a company that vast, that I'm missing something fundamental?
Welcome to Texas! Well, maybe not just Texas. I think the takeaway is that even if a company gets in too deep, it's rational-appearing to keep fighting due to the sunk-cost fallacy.
My assumption is that they got big and won bids on projects by making appropriate simplifications on smaller projects, where the simplifications and assumptions were within acceptable parameters. But they didn’t change that strategy when they started bidding on larger projects where seemingly small simplifications can add up to a significant impact.
They don't. I suspect their troubles are just another case of success having many fathers, but failure being an orphan. Someone had to hold the bag and it was them, whether or not that's where all of the blame deserves to go. That said... When your construction project falls down and kills people, I imagine the rest of your customers get pretty creative looking for ways to get out of their contracts. I would.
The regulations have got so big trying to cover the corner cases, complicating the formulations expecting the computer to do the calcs but not transparent to the engineer. There is No ONE or even TWO or three persons can capture all requirements in their head, leading to confusion amongst the contractors.
Hm, my hometown Hamburg/Germany just decided to build a similar bridge to replace a cable bridge built in the 70s which is already larger then the bridge planned in corpus Christi. The new bridge will allow for a passage of more then 100m below to enable the largest container ships to pass through. I hope that will turn out better, but I also have trust in German engineering (mostly).
📖 Preorder now for early access and other cool stuff: practical.engineering/book
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Congratulations on your book, well done sir.
Do you have a kids book version? My kids LOVE construction (preschool level)
@@abetts123 For preschool construction books, maybe you and your child can go out to construction sites, take your some pics and make your own book.
In addition, you most likely know that there are construction videos for kids. One of them is called Road Construction Ahead.
@@abetts123 It's Civil Engineering, it's already ready for kids!
I KID, I KID! :P
I've already preordered my copy! Really looking forward to the release! I remember growing up with the Disney Wonderful World encylopedias. It's what got me interested in Engineering at a young age. I'm sure my kids are going to love leafing through this book. :)
Can they add more pilings and some type of additional cap and connect them in?
My sympathies to the unseen unheard people at FIGG who knew exactly what their company was doing and tried to fix things from the inside but were shouted down by varying levels of leadership. I see you.
Figging execs
Happens more often than you think
they tried to figgs it
After 8 years in the army, I learned that higher leadership loves to figg things up.
Yuppp
Reminds me of an old saying: "Whenever hiring an engineer for a project, always hire the one that says it will cost the most and take the longest: they are clearly the expert."
Everyone knows you bid a job low with short lead time to land the job and then hit them with change notices after the fact lol
@@MeltingRubberZ28 RFI after RFI 😂
"We can't afford to hire the cheapest engineer".
my dad had a version of that on construction bidding summed up with taking the middle bid...
Fax
“Stepping into a dead man’s shoes” - really hits home. I was a superintendent for a 3rd party GC on a big new home development and the developer wanted to cut costs. Fired all of us and brought his own guys on. Job went bankrupt 6 months later. Drove by it the other day and saw all the half built homes boarded up. Sort of feels like an “I told you so” moment but also sad to see. Oh well. I make more money for someone else now.
Never a good position to be in as a super, been there.
Grady is so good at explaining things adequately to the laypeople like me, while also not sounding condescending or as if he's assuming that we're idiots. THIS is how you get people interested in engineering. Thanks for another great video. 🖤
@TheWeaver You are 'spot on' about how good Grady is at this. I really enjoy the channel and look forward to receipt of my "signed book" {....certainly, "a first" for me [receiving a signed book :) ]}
He really is. I'm definitely a layperson in this and usually don't try to learn about engineering things - like physics, the maths involved just intimidate the heck out of me. But he explains so well, and doesn't need us to know the maths. His pacing is great too, which I appreciate just as much!
@@Beryllahawk It is essential to know that the cap design is capable of mathematical analysis, but the details of that analysis are of interest only to specialists. Understanding both those statements and acting accordingly is what makes this video so good.
And as an engineer, he doesn't dumb it down so much that it becomes unwatchable/uninteresting to those who do understand the issue. It's the perfect balance
I agree. But while watching the video I had the image of thousands of workers who had to go home without pay and they were all surely saying "f those engineers". 😅
Everyone is "confident in the safety and durability of the bridge as designed" until they get featured on Plainly Difficult channel because the bridge fails due to some preventable problem that was not fixed because someone wanted to save money.
Glad someone respond fast enough here
Eyyy, another Plainly Difficult fan. Let's hope this bridge never ends up there!
I find Brick Immortar far more comprehensive, but Plainly Difficult is good for an overview.
Everybody is trusting the bridge until Roz says an exact date and approximate time
That's the way these things often seem to go.
We have a single tower cable stay bridge here in Toledo, Ohio and Figg Bridge Group was the engineering company on our project. 4 Iron workers were killed and 4 others injured in 2004 when the 2 million pound truss crane collapsed. I pray all the workers on the Texas project go home safe to their families when all is said and done. I love your videos, even though I usually only understand about half of what your talking about, thanks and good luck on book sales.
They messed up the bridge there because of falling ice from the cables killing ppl on the road. It’s crazy
You're talking about *
As a bridge engineer I had been following this story and it amazes me that the EOR is still openly fighting some of these claims, specifically the rigid footing assumption. Every structure of this size goes through extensive review and throughout the design process there are many of these "battles" over design methodology, especially around footings. However to assume the footing as rigid seems ridiculous. This rigid assumption is usually used on standard highway structure to the simplify design of footings. It is usually a good assumption because the size of the footing as compared to the design loads are low(i.e. not enough force to make the cap deform). However, this method is losing favor as better software comes into play making it easier to better model distribution of forces in pile caps. As stated in the video the footings are 18ft deep. When designing footings this deep the code recommends the strut-and-tie method which if done correctly provides a conservative (sometimes overly conservative) design. The reviewer stated they looked into STM and found the decencies even worse, which would be expected. Based on the depth vs width ratio of the footing I think the reviewers design methodology to be best. Using computer modeling that takes into consideration the cap stiffness, the pile stiffness, and the soil stiffness should give a robust economical design.
How much money do they lose if the EOR admits fault?
@@x--. The answer will best be expressed in scientific notation, as in 1X10^9.
@@x--. How many lives do they lose if an unsound premise persists?
being a lay person, I would have thought anything that close to moving water would automatically discount assuming anything would be rigid? I'd also assume the ground is some sort of sandy composition in one form or another?
@@ersu.t its not about the ground being rigid, its whether the concrete slab at the top of the grid of piles is rigid.
As a South Texan in the construction industry, thank you for this excellent explanation of the engineering issues at hand. The media, in calling this a safety issue, is making it sound like a simple case of people not wearing their steel toe boots or hi-viz vests, and not a very serious life safety issue.
I live with engineering majors at TAMUCC, and when we were talking about this situation, they were really upset about how people are underestimating what the problems could mean
Not to mention the Total Disruption of Shipping Traffic if the Main Span Drops into the Shipping Channel. (erp)
nothing gets onto radio or tv or news print with out some corporation or wealthy person paying for it to be there. how much attention is dedicated is also financially driven, apple pays all the media companies a billion dollars a year NOT to put anything negative about apple into their syndications. money buys everything
@@aprilgeneric8027 somebody compiled a list of about 10 different shows on CNN and included after the intro who was sponsoring it. Pfizer. Gee I wonder why they were pushing vaccination so hard, considering we're now finding out the vaccines aren't near as effective as they initially claimed.
Lol @ blaming the "media"... Even IF they told you the truth, you say they're lying.. Texans deserves the rip off as you guys hate oversight...
My dad was a Professional Engineer-probably in the top 10 of his time in Texas-and worked for a construction materials testing company right off the bridge from 1980 to the early/mid-nineties. He was a true straight shooter, and his name was respected or despised, depending on which end of his P.E. stamp you were on. We lived in Aransas Pass, so I know the old bridge and port area well. I can still see all those ships coming in (and feel that oppressive humidity!) I remember going on many a slab pour and doing load tests on various sites and remember Dad walking girders looking at bolts. He took his job very seriously, not just from a character POV, but as you said, because civilians depended on him. Sadly, the engineering gene didn't pass on to me, but the work done is till awe-inspiring to me.
As a construction management professional, I absolutely love this kind of content. I haven’t found it anywhere else on TH-cam
Jimmy -- you might like the channel Building Integrity.
@@Graham_Wideman Great suggestion! I really get into the particulars of dispute resolution. When there is money on the line, GC points at Engineer, Engineer points at GC, and Owner points at both. It’s a big game of pin the blame (and bill)
As someone who also works in this industry, I am very glad I’m not a PM on this job
@@loganlm10 you and me both. I kept thinking that while I was watching the video.
@@jimmybonse7151 right lmao, I’m stressed out just thinking about the meetings these guys are having internally 😅
Civil Engineer here: the most mind boggling issue (to me) among the ones you mentioned is the shear transfer between the delta frame and the box girder section. I mean, that's statics + basic RC design. Big projects are both scary and fascinating. So simple of a mistake can be made when no one is *actually* checking the work without leaving their mental lane they are stuck in.
I was just looking at that, and I thought, boy if there are shear loads there is going to be a problem. And I only had one civil engineering class in college as a general engineering requirement. I’m not an expert! If it looks like a bad design to an armchair engineer like me, how could it possibly have been missed?
@@five-toedslothbear4051 even worse is I haven't even had any engineering classes yet and saw the issue pretty front and center there lol
Like bro what the hell was going on to have THAT be missed if someone seriously lacking qualification can see that.
@@AllianaCordova It may have to do with how the work is organized and how communication happens and attitude.
And that does not make it any less serious than what it is.
But I can see how a thing like this happens within the confines of 1 organisation (the joint venture) but it still gets caught by someone else.
So it's like a bad marriage, but the neighbours know everything that's going on, even though everything looks fine in family reunions. Although it's an unfortunate metaphor, I feel like it's an accurate one.
My “engineering” discipline is computer science and even I immediately wondered how they were handling shear loads when Grady showed the drawing. I was expecting him to explain how there’s this other feature for distributing the shear load and upon reviews, etc etc. nope. They just didn’t address it in the design. What?!
Yes!! That is asinine that something like that could be missed or worse, argued that the design is fine.
Did everyone also notice how Grady its trying so hard to contain his excitement as he talks about his new book. The book looks amazing!!
It's an amazing book.
Grady,
Your description of the assumption that the column base is rigid reminds me of an incident with a king post (mast) and boom on a tanker. The tanker was fitted with two king post and booms, located just aft of the center of the ship, and outboard so the king posts landed on deck supported by a longitudinal bulkhead and a transverse frame. The king post was not stayed, so there were no other supports. The boom was designed to pickup 15 long tons, at about a 60 foot radius.
The issue remained unknown until a mate decided to expedite the rigging of the boom by leaving the boom resting in it's cradle and leaving the block hooked to a deck staple. By paying out the block while topping (lifting) the boom, the boom could be rigged faster than doing the work in two separate operations. Unfortunately, the mate got his hands confused and he topped the boom while he pulled in on the block. The ship's main deck started bending at the base of the king post. The boom started bending at the cradle. Luckily, no one was hurt.
In reviewing the failure with the shipyard engineers it was determined that the engineers had assumed the deck was rigid and that all loading was from the load being lifted. Ships are large beams subject to both shear force and bending moments both when the ship is still and when it is motion. Ships both hog when the the load is concentrated more at the ends and sag when the load is concentrated in the middle. Like with the bridge, it was wrong to consider the deck as being ridgid.
Ultimately the deck and underdeck structure was strengthend and pipe stays were added to better transfer load.
Bob
Thanks for the info. I know nothing about physics/engineereing (aside from common sense/intuitive things you pick up from day-to-day life), but it's refreshing to see people express their genuine and (seemingly? (Not saying your wrong, I just don't have the background to evaluate any of your points)) well informed opinions.
As a Corpus native and fellow engineer, I'm very glad TXDOT is being as transparent as they are. I just a wish a solution comes soon as the current Harbor Bridge is beyond its life cycle by numerous years...will miss the view it gives to Whataburger Field when it's eventually gone though
The old bridge is here to stay. TXDOT will keep painting it and we will keep using it.
It just wouldn't be Corpus without the harbor bridge!
you know they released it publicly so some politician couldnt circumvent safety and push for it to go ahead because of The All Mighty $
@@derrick_builds The new bridge is built higher to allow for larger ships to pass. Keeping the old bridge would defeat the purpose of building a higher bridge.
@@man0warable the ships can all be unloaded on the East side of the bridge. Rail and road out of Ingleside, Tx. But by all means let's keep pumping money to the Port Mafia.
Currently working on a joint venture myself , Engineer on the contractor side, and seeing videos like these make me feel great about what I do. Just pre ordered my book! Grady, I wish I could make engineering as fun as you do!
The fact that TDoT is being so public with their findings and issues does a lot to shift my opinions to believe them and their claims over the contractors. The fact that they might have moved slow on stopping the project might because they wanted to have everything lined up for public release before stopping things.
...and you don't PRELIMINARILY stop a project like this. It's too big. You don't lose all those workers to other projects and then say, 'Oops, I was wrong! Go ahead!'
Txdot is still evil but even they can be right sometimes
It's impossible to say from the outside. It could just as easily have been some political power move resulting from a disagreement amongst the interested parties.
They wouldn't need to have things lined up for public release to give the people in charge of the project a heads-up, for instance.
Maybe. If those in TDoT
didn't benefit by the switch.
Then again, if they cost the builders tens of millions when a "heads up" would have had them reallocate resources earlier, who pays?
Wow, as an ME that works on government projects, this is my worst-case nightmare scenario. I despise DB projects for this reason. I hope everyone involved can figure out how to make things work and that parties at fault are held accountable. As a PE, we need to maintain trust with the public and projects like this are a major breech of that trust.
DB contracts seem like someone didn’t like competition and thought everyone should sing kum ba ya and work together.
@@JayVal90 I think you don't know what you're talking about and are adding a philosophical angle to an issue that isn't accurate
@@ClosestToTheSun Found the DB contractor
*breach
Breech is something else
Agree, one solution is for the Owner to perform the quality control, and the quality assurance. Current practice is to have the fox in the hen house, quality control, and have the contractor hire the quality assurance manager, the Golden Rule, the man w/the gold makes the rules.
I think this might be my favorite youtube channel of all time. I may take breaks of months, but I've been coming back here for years now and it always feels like home.
Your video is definitely making the rounds here in Corpus! The Caller-Times just posted about it and I've seen a ton of people around here saying they finally understand the problems.
Also, we hadn't hit our first anniversary yet at the groundbreaking. I'm hoping the bridge is done by our 10th. Not looking good.
I talked with that reporter today
1:10
8:25 relevant section
In my 42 years on this planet, out of the countless books i've owned in that time; yours is the very first i've ever pre-ordered, and certainly in the top 5 list of 'books i can't wait to get my sticky fingers on'.
I'm very much looking forward to seeing your book and reading it with my nephew (he's 9, loves your vids, and absolutely absorbs stuff like this)
Thats crazy they didn't account for the shear on those tendons. That's almost hard to believe on a project this size that a mistake that major would make it that far.
I am doing Quality Assurance on a Design Build Project currently(and probably for the next 3-4 years), and the biggest thing you need is a good working and communicative relationship with the Owner/DOT in that area. Without that, the project, while able to still be completed, will have many issues throughout its life. If you do not have that relationship, a lot of this finger pointing and trying to avoid blame becomes a big issue.
When TXDOT first found the issues, and barred the designer, the DB should have had the new engineer review his findings with TXDOT, and work out any issues before it came to this. A bad relationship will cause this standoffish attitude.
Yeah, that part is really confusing. You got put on a project where the designer got canned because they killed people and new designer is like, "Yeah, design great! Let's go!" and TxDOT says, "Okay, let's go... don't mind me over here, I'm just gonna triple-check this... hmmm.... hmmmm.... hmmmm.... Ya know, maybe we should look this over again?"
"Uh... we started, you said everything was good."
"No, you said everything was good. We said it was okay and we didn't want to slow things down."
right.... Both seem to have made critical errors - if the design is actually deficient, and frankly it sounds like it is - then the designer messed up but TxDOT didn't do sufficient due diligence and, more importantly, didn't throw the flag on the field immediately when they suspected the issues.
Amen. I work in a DOT with several DB groups. The working relationships with the groups make such a difference.
It's honestly astonishing, to me, that TXDOT allowed the work to resume without confirmation that the issues had been addressed.
Although working in a competely different field, I also find that the customer bears a lot of responsibility that they don't always rise too. It sometimes seems like a combination of being naive, disinterested and combative works against the customer in any complex project, residential or commercial.
@mia This is some BS link to a craft project, don't waste your time people.
This is VERY interesting to see: here in Germany a very similar situation occurred around 2y ago. One of two major motorway bridges to cross river Rhine in the Cologne area was found in critical condition by sudden cracks in superstructure during a routine inspection 6y ago. As result the bridge was immediately closed for any vehicle starting from light trunks onwards. Only standard cars could pass the bridge from now on. This caused and still causes major traffic congestion and major headache to many businesses in the area (Ford Germany has two production plants nearby and other large scale factories depend on this bridge too). A high prio project was started to build a new bridge next to it with a higher traffic capacity as fast as possible. After 3y of construction work the first parts of the mid part steel superstructure should be delivered from China. There were already concerns in welding quality during on site checks in China. But the parts were nevertheless shipped to Rotterdam to get offloaded to small cargo ships passing river Rhine towards construction site. But after re-checking the parts in Rotterdam finally the decision was drawn to reject ALL parts due to insufficient welding quality and the contract was cancelled. So a new contractor had to be found and negotiated which put the whole project around 2y behind schedule and tax payer has to cope a 30% increase in total cost for the project...
sourcing the project to China and then expecting quality was the first mistake and as a result the project now is delayed for years. The person responsible should be fired...
I have to agree with vossejongk: While it is not impossible to get something of quality in China you really take a big chance with such an important project on short notice. Chinese companies are famous for cutting corners to save money and anyone who blindly believes they will give everything you require for an amazing price often find they will have a big surprise which in reality should not have been such a surprise.
Don't worry, you're not going to have any fuel to run any cars soon anyway.
So you are saying they need welders in Germany?
I'm ready .
When will the West learn? Every steel item from China is inferior quality and inferior welding. I specifically refuse them in my spec. sheets for tenders now.
In 1979 I worked on a prestressed, post tensioned precast Bridge in Toronto. Drove over it just last week, it's still standing! One if the most interesting project I ever worked on. Great video, thanks for posting!!!
As an engineer, its the most important thing to remember the oath and what it means. The engineer is responsible for what they don't know and they are personally responsible for the safety of everyone using their design. If you don't know that its 100% safe, then you don't sign off. Management will always push for their profits, but the oath is clear. I've worked on safety critical systems and had to put my foot down; most of the time it works, once the execs were so forceful in meeting their business goals that it was clear the only option available is to get a new job. You know that management will find some other engineer to sign off on the design, but its not an excuse.
Shame to all those engineers at FIGG who stayed working there and signed off on that work. At least they earned their reputation that will be stained on their Resumes for decades thanks to TDOT being transparent.
Nothing is 100% safe; engineers are responsible for providing an appropriate level of safety for the circumstances, intended use and all the conditions that can be reasonably foreseen. (Basically, not to tell you it won't break, but to tell you _when_ and _how_ it will break.) And then their job is to do this at as reasonable a cost as possible.
And this is made more complex by there being no bright line in most circumstances; as you get close to the line there are reasonable arguments to be made on both sides.
I'm not saying that what's going on here is anywhere near the line, though, rather than well beyond it. I am not equipped to judge that with the information I have. It does appear to me that TxDOT is doing the right thing by making all their data and analyses public; at least others who do know something about these things can look at them.
All that said, I do know what you're getting at, and yes, I agree that it's up to engineers to not to sign off on things that are obviously wrong, or where they do not firmly believe, based on evidence, that the structure is suitable for purpose. I think it's one of the most admirable things about the discipline of engineering that engineers have this code to put truth before profits or anything else.
@@Curt_Sampson We seem to agree an everything except the semantics here. 100% safe is when an appropriate level of safety for the circumstances, intended use and all the conditions that can be reasonably foreseen.
No one expects that bridge to function as intended for the next 500 years with zero maintenance, or to work without careful inspection should a magnitude 9 earthquake hit or to have 500 Abrams tanks roll over it in a column 6 tanks wide bumper to bumper.
If the safety factor is agreed to be 1.5 and due to some supply chain disruptions the proper class of bolts for the beams will take 2 months to arrive your not allowed to use an alternate bolt that would only meet a safety threshold of 1.4. Your also not allowed to sign off on the design unless you know everything you need to know to perform all your analysis and calculations.
Its the same type of rules that apply to open heart surgery, because if your oath is not followed the results are similar. An Engineer can end a lot more lives than any Doctor.
@@seangriffin7803 I see; you define 100% safety as "100% of the necessary amount of safety" rather than "perfectly safe," meaning that you could achieve "110% safety" (which would obviously mean you spent too much on safety if it cost more than "100% safety" does). That's fair enough, and leaves me in full agreement with you.
I've seen some other comments suggest that the engineers involved here are probably inexperienced and thus may not have known better. Certain assumptions were made that a more experienced engineer would know not to make. It seems like TDOT was also a bit slow in communicating their exact concerns and it's very well possible that the engineers didn't see TDOTs concerns until after they went public (management may have not have communicated the concerns to them). Of course I'm just speculating here, I just don't want to assume it was malice on the engineers part when it could have been ignorance and/or malice on managements part.
@@grn1 Engineers have a special position of public trust where ignorance is NOT better than malice. Every one of us Engineers have been there; where you think you know how to get the design completed, but your not sure and management is applying pressure to meet the schedule.
We all know better -> If your not absolutely sure; you cannot sign off on it PERIOD. You may end up having to get a new job, but that's no excuse; its a core part of the job. The technical buck stops with you if you sign off.
Nobody knows everything and each design can have its unique challenges; once there was a project with a twist that was new to me and despite efforts to read up and educate myself on that particular technical detail; I still didn't feel sure enough that without experience in that area that everything was as good as it needed to be. I told leadership that they needed to hire an outside specialist to perform a review of that aspect of the design. Leadership was very upset and they pushed back due to the several week delay and 6 figure cost that would add to the project.
If your not up for what is required to keep the public safe, then steer your career away from positions where you need to sign off on these projects.
So. There I was, minding my own business, winding down my nightwatch shift, enjoying a few almond pancakes, casting about for something interesting to watch on YT. You know--nothing too dramatic or involved, maybe a step or two above background noise. And then....this. The saga of this bridge that I'd never heard of in Corpus Christi, TX. So much for "light" entertainment, lol. Great content, fabulously presented, as always. Thanks, and cheers from the shores of the Arctic Ocean (AK's North Slope).
And surprisingly not the tragic ending one
Glad that someone had the guts to speak up and put it on hold. The cost to suspend construction is high, but the cost of human life, should it fail, is immeasurable.
I am an electrical engineering student and a single mom of 3. My youngest son hasn't started kindergarten yet, so he gets to come with me to classes and absolutely loves it. This week we have been discussing concrete on our walks to class and why the "dirt" is important below it and what happens for different scenarios if something isn't built right with concrete. I am super excited for your book to come out finally so he and I can read it together.
How nuch in welfare benefits do you consume?
@@nixonhoover2 none thank you, and I'm paying my own way through college without grants or loans. its called working hard. I still work full time from home, attend school and I'm a mom. I have no time for self care, but it is worth it when you set high goals. While I know you commented with hate in your heart, know that not everyone makes excuses and looks for handouts. My children bring me great joy and while my ex husband is not around due to his physical abuse of us. I will not let that hold back any opportunities for my children into the future. They did not get to choose their parents and I will work twice as hard to make sure they have a life that is fully enriched and have every opportunity any other child will out of my own pocket. Just because someone had children or they have life circumstances where they find themselves as a single parent, it doesn't mean they can't work hard and they are no longer allowed to have life goals and passions. In reality, it makes those goals so much more important to achieve.
@@nixonhoover2 If you dont like helping the less fortunate with your taxes you could always stop paying them.
@@nixonhoover2 So much assumption.
Bravo for educating your child about the world around them. Whether they go into engineering or not!
I'm not very smart, and I don't understand load capabilities, or load bearings, but it's always interesting to hear / see about the complexities of such huge projects. The depth of engineering, the depth of potential failure, and the unity of corporate and federal companies all coming together to make it possible. Thanks for this. Hopefully this gets resolved and the bridge gets completed in a relatively timely manner
Not very smart yet use precise vocabulary related to engineering . I am a gambler and bet you are smart at allot of things.
Same
it’s amazing to see how much progress has been made since this video was posted. i drive across the old harbor bridge anywhere between 2 and 7 times a week for my work and i admire how the bridge is starting to take shape
а как давно он строится?
@@homuchoghoma6789 since like 2016 if i remember correctly
@@jacobmoney02 Такой мост за 1 миллиард возможно без заморозки за 5 лет построить. Вот пример вантового моста в 1 миллиард долларов.
The tendons holding the box girders to the delta frames without additional reinforcement against shear loads gives the same vibes at the Kansas City Hyatt Regency walkway collapse: a small change in design completely changes the way forces are handled by something loadbearing. It's obviously not 1 to 1, but it isn't that far off imo.
My sentiments exactly. Watching the animation of delta plate shear sent chills down my back. In Corpus we might have a troubled bridge over harbor waters, instead of a bridge over troubled waiters. Neither outcome is good.
Thank you for bringing light to this situation! As a Corpus Christi resident myself, it sometimes gets confusing on what’s ACTUALLY happening with the bridge. Keep up the good work!
Same
I'm no engineer, in fact I'm an art student, but I'd absolutely love to buy your book (i'll try saving up money.) I love watching your videos, its just so interesting and fun to listen to as someone with a fascination for architecture and bridges!!
th-cam.com/video/SOMT7Detuwc/w-d-xo.html
FIGG also screwed up the new span of the Sam Houston Tollway Ship Channel Bridge here in Houston. Harris County Toll Road Authority (HCTRA) had to suspend that project to get another engineering firm to check the safety of the bridge. FIGG was terminated from that project.
Just preordered the book. I've been watching every episode for over a year now, and I can't get enough. And my kids (7 and 10) are asking better and better questions about how things work and how they're designed. They're also learning to appreciate how complicated things can be, despite appearing simple. They also love to read. :)
Keep up the good work!
As a non-engineer, and certainly not qualified to speak towards problems such as this, I truly appreciate the way that you explain and illustrate what those problems might be, and their consequences if left unchecked. God Bless each and every one of the engineers and designers, and the builders that take on such tremendous responsibility as a project of this magnitude. I'm pretty confident that the insurers also spend some sleepless nights while making their commitment decisions.
Engineering disasters was a favorite show of mine for a long time. My friend was the one who videoed the collapse of Big Blue at them Miller Park. You know Norm was a QC for P&H because the moment the turn bearing bolts began to fail from load he began to film the failure at its point.
It's so awesome to watch these episodes and reminds me why I originally wanted to be an architect mechanical engineer.
My mind is boggled now considering what goes into these gigantic projects.
Congratulations on your book! In a very small way I helped a engineer friend of mine write a book about a Famous Race Car team that we both worked on and when it was completed, he took immense pride in that book and has sold well over 1000 copies and now is on his way to writing the companion / follow up book to that one. They are both books on mechanical/electrical engineering so they are not exactly light reading!
Just a note. There is a walkway on the present bridge. I ran over the bridge when I was young. It was scary because the roadway bounces up and down when trucks pass.
Walked it too. Got dirt sticking to me from the vehicles.
I was gonna say this, I always thought I remembered seeing a walkway/bike path on the side of it
yeppppp
As a government's CO representative at one time (on much smaller contracts than anything like this), I know that any 'stop work order' is really considered a 'last resort' when it comes to govt/ contractor relations.
Of course there is always room for 'honest differences of professional opinion' between the independent reviewer and the principle designer. But if the review wasn't done before this, then looks like there's plenty of blame on both sides.
As a new electrical consulting engineer, I can't believe they didn't have constant reviews. Normally there are regular deliverables for XX% design, ifc, ect. and before each deliverable there is an understanding of what needs to complete or postponed for a later deliverable. Not to mention all the internal reviews and coordination that happens between deliverables. And at the end you get to code reviews and submit for permits where the government officials get final say on if your design is acceptable or not.
I can't imagine that they got a permit worthy design without a couple hundred reviews and various questions being asked along the way to the point that such a serious issue wasn't discovered earlier.
Issues like the one involving the Delta frame tie in would not seem to qualify as a simple difference of opinion, it's an oversight.
I know in my area, the DOT would have had to approve the design before it could start. I wonder if they did, and missed these issues at that time, and that is why it is such a mess.
until the latest round of Bridge collapses, FIGG was considered a top drawer bridge design firm. They had been designing bridges for almost a century, so it is entirely possible, even probable, that TXDOT just took thier statements on faith, especially if the engineers on the TXDOT side of the table were young/inexperienced. The Florida Bridge collapse was a real wake up call to the industry that something was not right at FIGG, and triggering an audit of every single project they were involved in. I can tell you from personal experience that the regional engineers for TXDOT aren't the sharpest tools in the drawer.
@@Rorschach1024 And that is working as designed, right? We don't want all the best engineers in state government, we want them out there working on the best projects, wherever they may be. So they rely on outside engineering firms to design quality work for their projects.
This is my outsider understanding. They don't provide oversight in terms of "checking you did all the work right," their oversight is primarily making sure you hire licensed professionals (unless they have reason to hire an outside firm to do such a check).
If that's not the way it is designed I'd be curious how the system is supposed to work.
Thank you, Grady for this series and your book. I pre-ordered, and was surprised and pleased when I got it. There is something on every page that expands my knowledge of engineering. I’ve been a fan of this kind of construction my whole long life. And on top of that, my son, also a fan bought the book for my two grandsons for Christmas! The legacy continues!
You should make a video series of the Gordie Howe project. Not only the bridge itself, but all the infrastructures tie to it is impressive in size. 2 border controls, 1 bridge, and 1 interchange in Detroit, and not to mention all the work that was done in Windsor prior, with the extention of the 401 highway.
He should. I’m working on this project now near the 401 connection
@@damonkay4177 Nice I watch the drone footage release by the Gordie Howe International Bridge youtube channel to follow the construction, and I've seen many engineering technique in that area.
@@remitheriault7268 funny enough they’re actually flying the drone right now.
The only reason they're building the Gordie Howe is because the privately-owned Ambassador Bridge has been allowed to decay and the owners also didn't build connections between the bridge and customs according to contract.
The owners also tried to seize a nearby Detroit park, arguing that they had to have the land to fulfill anti-terrorism requirements. And over in Windsor, they bought up an entire neighborhood that sits beneath the bridge rather than adequately repair the bridge, which was dropping debris on the area.
It's been quite a saga.
Yes, a video about the crumbling Ambassador Bridge (through greed and neglect) and the Gordie Howe Bridge would be interesting. Despite its issues, the tunnel nearby, and the Blue Water Bridge to the north, it’s still the busiest international crossing in North America, carrying 25% of our trade with Canada.
I've been on more than one project where the contractor was under the distinct impression that design-build meant that it was up to the subs to design it as we were building it.
lol
So it's the equivalent of agile in it project ? :D
@@startide 😂They would've been so happy if they knew about that back then.
😂😂. As a welder, we say, "beat it to fit, paint it to match." Same principle I think.
@@quietobserver4636 “grinder and paint make me the welder I ain’t” 😮
I am sold. I immediately ordered the book as soon as I found out about it. Glad I stuck around to the end of the video. You should promote the book more often and earlier in the video. I’ve been recommending your videos to my students for years. I can’t wait to see it. Good luck!
I rolled through Corpus several weeks ago, headed to Port Aransas, and marveled at the new bridge; well, what has been built so far. The video here does not convey just how freaking BIG the new bridge is. I appreciate the update.
If you're looking for more of these, take a look at the Pelješac Bridge which was opened in Croatia a few months back. I hope it doesn't suffer from these issues, as it is very beautiful and MUCH needed for the entire Dubrovnik region. Its total length is 2404 m.
But back to yours, it is (well, should have been?) a beauty, really. There's something in cable-stayed bridges that's just breath-taking.
Last year I was driving along the coast line wishing my trip had been a few months later to use that new bridge system. Major undertaking to bypass Bosnia.
Hopefully it's not another "tofu-dreg project" from the Chinese.
@@thomasm9552 Well, it was made by the Chinese, but as far as I can tell it looks and feels amazing. Naturally, I know nothing about construction they might have used spaghetti instead of rebar as far as I could tell I guess time will be the judge of its built quality. The EU paid for most of it so I suppose they took care of the quality part.
12:44 20% of their capacity? or 120%? If 20% is right is that because of a huge required safety margin/factor?
120% of designed tolerance. Yeah, things like that are why I’m happy enough just being a cog in the great machine of society, as I don’t have to worry about the absolute worst case possible at my job, just follow the procedures and regulations promulgated by my state’s department of ecology.
Glad I"m not the only one confused by that part. ... Is just a script error? Or is it one of those cases where an industry-standard usage doesn't match with the conventional, everyday usage?
While your classes were a the lamp for infrastructure, the Florida university bridge collapse was the lamp that told the TEXDOTs engineers where to look for potential failures. Like pointing out the crooked tile in a bathroom, you can never un-see a simple design choice that makes sense at the time but you always regret once you see it.
One of the most important lessons learned is that the owner must insist on an independent design review for each phase of a contract before one yard of concrete is placed. The very nature of DB projects is such that the designer is reporting to and being paid by the contractor who wants to get it done as quickly and cheaply as possible. You can't really blame the DB team either. After all, they're in business to make money. However, this is not necessarily in the best interest of the owner. It is therefore incumbent on the owner to have hands-on involvement in the project from day one to keep everyone honest. I know this all too well. I used to work for a state agency that built a large bridge using DB. We regularly went round and round with both the contractor and designer that tried to skirt around our requirements and water down their own proposal. We rejected work on more than one occasion and it often got ugly, but it was worth it. The final product was good.
The design authority on the bridge was originally delegated by the owner to the designer/builder. As you point out, this is never an ideal situation. A very high profile example of delegated authority going badly wrong is the Being 737 MAX project.
I'm fairly certain that the Millennium Tower in San Francisco was also a DB project. A 58 story, poured in place building (dense concrete), built on bay fill. There is testimony that a soils engineer was never retained! What could possibly go wrong?!
They saved $4 million by not driving the piles down to bedrock. That probably doesn't cover A month's legal fees on the retrofit currently, much less the construction costs!
From what I've experienced in the industry, design build on large complex projects, inherently creates a conflict in interest! Not very "efficient" in the long run.
They are bridges for cryin out loud, to stand the test of time and environmental strain there needs to be built in design criteria which mostly is there because of previous events. If it’s not right it,s not worth a penny
John Roebling had 7 civil engineering consultants review his Brooklyn Bridge design. This was a Design-Build project. I go over the history of this bridge in my TH-cam Video if you're interested. th-cam.com/video/N-GrjJwWqhc/w-d-xo.html In the Future of these Design-Build projects, you would think that the highway departments would have an independent design team review the DB design. You see this in the northeast when a Structural Value Engineer reviews the design of highways, bridges, and water treatment plants.
@@michaelshettig7805 Yes. Independent review early in the design, and independent design check prior to construction.
You should do a series on an interesting project from each state.
Most states don't have the budgets of a CA, TX, NY, or FL, but I have to imagine there is still some interesting work being undertaken in all of them.
Good Catch TXDot! After Harvey nobody is gonna take chances in that Area! When the NTSB bans a Engineering Company, there’s a Darn Good Reason for It! Was wondering why this was taking so long every time I take a long weekend in Port Aransas!
Good point, small correction: NTSB has no enforcement authority. The ban was from the Federal Highway Administration.
I only mention it because we should have more agencies like the NTSB -- their ENTIRE job is based around post-accident truth -- if the people who make the rules also get to investigate themselves, they are unlikely to find anything wrong with themselves.
Government works better when we have investigators who don't work for the people being investigated. State and federal level.
That's why air safety has improved and if you want to see improvements in other government agencies, it's a really good model. (Cops investigating cops? Profit-based hospitals investigating complaints about their screw-ups? Military Commanders investigating accusations they allow abuse and hazing? etc. etc.)
Hello. I'm not a Engineer but I really appreciate the way you explain things it makes it easier to understand, it's just unbelievable how much math goes into a project like building a bridge, or understanding the ground under it, I have seen lots of your videos and they help me understand how things can go wrong if everything is not taken into account,
I once build a porch onto the front of my house, everyone said I over did it , but I just did not want anyone to feel like they mite get hurt , so I put a lot of thought into it, and to this day it has stood up with on problem and with lots of people on it
Thanks for all the information on your videos
Figuring out the soil engineering and earth work is arguably the harder part, because nature tends to throw curveballs at you.
Huge fan Grady. Love all your videos. As a contractor I really appreciate the level of depth but succinctness that you do in your work. We’ll be getting a copy of your book for our kids for sure. We home school and this will be a fun primer for the kidlets to wet their appetite on. Blessings!
Grady, at 12:46 did you mean "loads of more than 20% *above* their capacity", rather than "of their capacity"?
probably not. It's called "safety factor" or "factor of safety". Elevators are NEVER to be loaded more than 10% of their rated capacity, because of the assumptions necessary. Peak forces can be higher than assumed.
Putting a megaproject like this at a safety factor of 5 (meaning that the bridge is never to be loaded more than 20% capacity) is completely normal and reasonable. It sounds ridiculous at first, but the whole world is designed this way, and I'm very happy it is.
I was wondering about that too, it might actually be 20% though. With structures like this is quite possible the safety factor would be well over 4 meaning any component hitting over 20% of design load would be considered overloaded.
I have a feeling that a retrofit to stiffen that pretty immense pad at those loadings is going to be a veritable jungle of steel work going about a third of the way up the pillars.
I was a bit baffled as well, not necessarily due to the safety factor of five, but the sentence afterwards ["In other words, they would fail" - as I thought at first "the bridge would catastrophically fail" (-> 120%), not "it would fail to meet specifications in terms of exceeding the allowed load percentage" (-> 20%) ], but then again, my english isn't that good, especially when it comes to technical speech/terms.
@@prmperop That's not how we do Structural Engineering.
Our capacity calculations (AASHTO & LRFD) have safety factors *BAKED IN* they are not added after the fact.
Thus 20% of capacity means 20% of the *FACTORED* capacity. In order to be in trouble he would have to mean *20% OVER* capacity.
It's up to engineering judgement, but on a new build, even WITH the safety factor baked in, I don't like to exceed 85%-90%.
@@zyeborm Retrofit would probably just consist of tying into and thickening the concrete pad to get adequate stiffness.
Once it's sufficiently rigid the original calculations are valid.
Great review. Ignoring the stiffness of concrete is understandable if you are building the foundations of a house. I wouldn't have imagined any design team on a project this big would just assume infinite stiffness.
There are some things that are ignored in the calculations - like the connecting plates in the I-35W bridge in Minneapolis. That design was reviewed again and again every time modifications were made to the bridge - later with the benefit of computers - but the plates were always ignored as they weren't supposed to ever be the weakest link. Turns out they were because someone in the 60s messed up the calculation and they were only half the thickness they were supposed to be.
Disclaimer: I'm not an engineer, and my expertise in this area is best described as knowing my limits. that said, the engineering involved in building a small thing is much simpler than the engineering involved in building a gigantic thing. part of this is because at small scales, things get inherently overbuilt just to make them large enough to fasten.
You certainly shouldn't, considering all of the design tools that have become available since my engineering career started in the 1980s. Problem is, on a DB job, the contractor is the boss, and the pressure to cut costs is on the designer who no longer reports to the owner.
A prudent design approach is also to model the pile cap is either infinitely rigid or flexible so that both outcomes are captured
Its a very common assumption for your typical DOT interstate bridge (spans under 200ft, prestress bulbs or plate girders). Bringing in a footer's flexibility into the calculations would add unnecessary complications into design without having any consequential outcome in design. All this said, a ginormous segmental cable stay bridge is not a typical structure by any stretch. The rigid footer assumption shouldn't have gone past preliminary design efforts.
I was driving down 183 in Austin, TX this evening; something I've done countless times before, and always taken for granted. But this time, for the first time, I noticed (and marveled at) the gentle curve, both vertically and from left to right of the suspended highway; the fact that it *_is_* suspended; and the simple fact that it hasn't fallen down under the gazillions of vehicles that use it. And I found myself grateful to the teams of engineers, their well-nigh miraculous collaboration, and the overall technical excellence that it represents. And I noticed all this directly because of Grady's videos. Awesome stuff. All hail Grady and his _Practical Engineering._
“So in 2011, over a decade ago now…”
Holy smokes time flies.
i know right!
And burning money makes such smoke...
This is an AMAZING video...our local media has completely failed to plainly explain this project and it's issues like you did with this video. Thank you for your analysis....I too am a S. TX resident and cross the Harbor Bridge multiple times per week. Growing up here I remember hearing older generations talk about the construction of the current bridge and even know a few people (2 to be exact) who refuse to cross it due to rumors about the current bridges construction.
If you know reporters you will learn with certain exceptions they really are what they call them in the UK...newsreaders. The copy that they read is not vetted by any expert because that would take time which equals money . News is a business so whatever the subject be very careful about your sources. Fools believe anything presented to them as we see in today's voting public .
Congratulations for the book release and a happy new year! I have been studying house constructing for four months (90 % on the site, theory lessons via Teams) and find this channel as well as Your book very interesting and revelational even! I will order a copy once I get the official coursebooks done, most likely that way I get the most our of the effort You have put into it.
Keep up, good work and greetings from Finland ✌😎
I'm glad there is somebody willing to discuss this issue in far greater depth than we get from the news media. I'm eager to see updates as this situation is eventually resolved.
One of our professors @TAMUK was on the team that determined the faults in design and listed 5 main concerns that were brought up in TXDOTs letter. Neat
Hi Grady,
I am in my home office right now designing wood residential homes. My daughter is with me and I printed a few plans for her to color on. She asked me if when she grows up, if she can be an engineer too, and if girls can be engineers. I told her of course and that I have many friends in engineering school that were girls and are now engineers. I told her I'd buy her first engineering book and preordered two copies of your upcoming release. We are very excited and I wanted to share that story with you. Wishing you the best! Thanks.
@22_45sig I am a structural engineer, so only framing as it relates to structural (wood, steel, masonry etc.)
I enjoy videos about current engineering projects as well as the past. The videos you do are concise and entertaining. I have taken vacations to see bridges, dams, and other great projects. The men and women that designed and build these great structures should be remembered.
#1 in the How To & Home Improvements category on Amazon. Congrats on your book’s success Grady!
I appreciate how fair and balanced this video is and as always enjoyed the excellent engendering explanations.
Probably not the video's intended result, but such engineering design responsibility sounds absolutely terrifying to me. How can these people even sleep at night short of not even being capable of feeling anxiety.
i would say usually the engineers present problems and those in charge ignore them
That's where my depressive brain goes every time lol. The responsibility is terrifying!
I didn't do so well in my structural analysis class and that was definitely part of what led me to endeavor never to be a structural P.E. that can stamp structural plans. It's one thing to design a sewer or sidewalk. It's another to basically sign your life away on your confidence in calculations to determine how thick a certain structural member ought to be.
Hello, fellow solid-color-profile-pic-haver! You're making me want to change my display name to ☆.
I feel this. Even being the one in charge of building something off of another engineers drawings, you have to make sure everything is being done correctly and nothing is missed or else it can be a huge danger. I only build patio covers and have done some very unique ones (very tall or over two-story decks) and I have got anxiety before just trying to make sure everything is done right for the safety of my coworker who walks the roof and anyone in the future who uses it. Lol
Can you talk sometime about the move from suspension bridges to cable-stayed bridges? It is plain that engineers think of the latter as preferable to the former and have done since the late 20th century but they were somehow considered impossible before that. Was it improvements in metallurgy or in understanding concrete or some other factor or factors that drove this chaneover?
This is just my wild guess, but it might be that it's case by case. And one big factor might be the environment, like in this case, salt water proximity.
Also, the improvement in concrete technology from the 18/1900s might have enabled the new building techniques used today.
Because, in my view, steel construction was more widespread because of machine construction. So that would help accelerate the development of steel technology faster than concrete. And so civil engineering and mechanical engineering were doing a piggy back on each other with steel technology development at that time.
But this is just an idea. And this means I'm tottaly down for that video!
I think the longest spans these days are still suspension, but cable stay grew into a niche economically for those medium-long spans. It's probably more that suspension got more expensive and no longer became the most economical option unless you REALLY need a long span. All the work required to run the main cables in a suspension bridge takes time and money.
@@davidmarshall2399 ... I think suspension bridges align forces better, all the weight goes up and hangs in the main cable nicely.... cable stayed using a tower then cables goin off at sharp cables is pulling harder and weird angles..... But we know how to make and test steel and concrete now better, we aren't afraid of adding forces for fear of weakness in material.... With reliable materials the designers can skip less stressful option for easier to make... Maybe...
@@alexwilliamrussell that's the design side and I don't disagree. But the work involved in actually getting a suspension bridge up is a lot more involved. The whole thing is waiting for the main cables to be run before you can do a single bit of deck. With a cable stay you at least have two work fronts on each pier from the moment the towers are done, so lots of places to get things moving.
The equipment to wind the main suspension cables must be intricate as well. Cable stay you just get shorter lengths of standard stuff and connect it up.
Cable stayed bridges are self-anchoring, meaning you can build a cable stayed bridge, and all you need is one tower in the middle. Suspension bridges need significant foundations for the cables on either end, which are extremely expensive and limit its use. When you need just one or more than two towers, cable stayed bridges thus are preferable to conventional suspension bridges. Like with the bridge in this video you can also incorporate cable stayed elements into a regular bridge, whilst a suspension bridge would've required San Francisco Bay Bridge style concrete anchors on either end. Suspension bridges are still being built if you've got convenient places for the cable foundations and a span that wouldn't be possible with a cable stayed design.
This is scary, but it’s good that they realized that, and even better that they stopped construction instead of hiding it
11:18 This "experimental" 1.33 overstress rate on the post-tensioning seems like a major flaw on it's own. Why would a design rely on rates that aren't even supported by code?
What does that mean? Do you have any context to this?
@@urieaaron He gave a time stamp, it's right there on the screen.
@@urieaaron At a guess this refers to the safety factor, and is the ratio of component rated stress to maximum design stress.
@@urieaaron someone correct me if im wrong, but overstress is a condition that is designed for so that even if you overstress the cables (or they shorten due to weather, or the bridge is loaded beyond the expected loadings etc) you are not going to have a sudden failure of the connections, anchor points or sudden crushing of the concrete (brittle failure).
This means the cable is "the weakest link in a strong chain" and if it were to exceed its capacity it would fail in a controllable manner which can be observed during routine inspections and corrected (e.g. cracking) as opposed to sudden catostrophic failure.
In the end codes are made to simplify the designing process. They include lots of excess safety factors which could be neglected if reasoning is good enough. For example in post tensioning there is margin of error for the post tensioning jack force. So using better calibrated jacks could be good reason for overtensioning as you know the actual end tensioning force with greater accuracy.
9:26 as someone who previously worked inside a box girder, I can confirm this. also a great shelter when it rains above
How nice would it be to have installed lights and power in it though. Bonus points if they include provisions for some serious fans.
@@zyeborm yes I would say ventilation inside really would be the major issue. Typically, the lights and ventilation are provided temporarily for construction; during service, only some people like maintenance guys will access this part occassionally, so theres no need for permanent light/ventilation.
Also important to note that there are narrow passages on some sections and lots of wire and other electrical components for streetlights, cctv, etc
Such a great presentation. I'm retired now but did 12 years of bridge work. We have a cable stay bridge here in Boston. My friends daughter calls it the hammock bridge. I can't get that out of my head every time I see it😆
Grats on your new book Grady! Thanks for all the well made and informative documentaries you produce. I love watching your channel. I'm an IT Engineer myself, but even though I don't work in the same industry, I support clients that do work in construction, and it's always fascinating to learn about the world they work in.
Oh this will be fun to watch. I moved from Corpus after a decade in 2015.... Seen the construction a few time since when visiting my parents. Good to see the port growing.
I guess you think it's fun to see your tax dollars wasted! Lol
I'm a seaman bringing cement from Vietnam to Corpus Christi, proud to be a small nut in this giant mechanism. Btw, we modified our main mast on board to be collapsable to be able to pass under the Harbour bridge. Thanks for a great content!
Hehe, he said seaman
Small world, I haul cement out of the port to the concrete plants
"Exceedingly deficient to resist design loadings" Damnation-by-underestimation at its finest.
Great video! I've been over the existing bridge many times and the view is spectacular. TxDot must have had good reasons to suspend work. I used to play tennis with a local TxDot engineer....very sharp guy. Sadly it is us (Texas residents) that get to foot the bill for this mess.
It is a true joy to watch your videos. Your concise, simplified explanations open up worlds of enjoyment to those of us who reveled in our 'tinker toys' those many years ago. Much obliged, Grady.
Here in Ohio, we had a cable stay bridge (it's built now) that had an accident where the gantry crane fell (pretty much same one as in this video), killing 3 (maybe more, been a while)
The lawsuits and finger pointing were out of control.
No one ever wants to be the one to take the blame.
Is this the Ohio river bridge between Ohio and Kentucky?
An accident where the gantry crane? How horrible!
I think you a part of a sentence there.
@@anthonylozano8035 The I-280 bridge over the Maumee River in Toledo. Veterans Memorial Skyway Bridge.
@@anthonylozano8035 No, it happened in Toledo OH, bridge crossing the Maumee River.
If I recall the report, the company that ran the construction, they cut corners when securing the gantry to each pylon. They used far fewer connections than required and forced the workers to do this to get ahead of schedule so they could get bonus money.
I don't know why the unionized workers didn't tell them to pound sand but it ended up costing people their lives.
"Dead man's shoes" is right. What a cluster. How in the world did this project get greenlit with all of supposed issues that should have been foreseen based on paper? (And to be in anyway associated with that failed crosswalk in Fl is telling) This is one of my favorite videos you've done. I look forward to an update. Thanks Practical Engineer!
First this project was well underway when the FIU bridge collapsed, second the inherent problem with design-build projects are the state does not have their own engineer peer review the structural engineering.
With design-build the engineer works for the contractor, the contractor wants to make as much money on the project as possible and therefore puts tight restraints on "excess" design costs, or the engineering firm bids low to get the job and has to cut costs to maximize profits. Both are to blame in this situation, The new engineer and the contractor assumed TexDOT was having a knee jerk reaction to the FIU collapse, assumed the Figg engineering was on point and resubmitted Figg's design. But TexDOT was on the ball by not revealing their findings first, they let the contractor and new engineer expose their game.
@@truracer20 When CDOT did its first design build (TREX) a rebuild of a dozen plus miles of old interstate and new light rail through Denver, CDOT had a consultant work out with them the scope, cost, required methods of independent QC,QA, and review, and CDOT review, dispute resolution processes and the DB selection process. This all took perhaps 2 years before they even asked for proposals.
Congrats on the Book, quite scary though that even today a bridge like this can be half done and not engineered correctly before it is even approved to be built.
I work in IT at an ACE firm and videos like this help me understand what our engineers have to go through. As usual Grady, Bravo Zulu!
Really appreciate the direct and concise way you explain these engineering issues. Excellent and informative videos.
Grady I love what you do. Just bought your book. Will be a good resource for my ARE exams.
Thank you for this very informative presentation. I grew up near Corpus Christi and remember being amazed at the "new" Harbor Bridge during the mid-60s. Before that, there was a drawbridge. Can you imagine?
Correction for you: the Harbor Bridge does have pedestrian access. The times I have visited Corpus Christi I saw runners and some walkers making their way across the bridge in the protected pedestrians side walk.
I wouldn't recommend it though lol
How separated is it?
@@x--. there are concrete barriers between the road and the sidewalk. The sidewalk isn't very broad so it's enough for folks to be in single file. Its like 1.5 persons wide. So it's not a great pedestrian passing, but it's there. That's all I was trying to get across.
@@John-cz7mp Thanks.
My wife is a civil engineer and I greatly admire the field of engineering and those who practice it. I'm sure she will enjoy your book and appreciate what you do!!
Hey Grady. I would invite you to visit Hampton Roads to view the expansion of the Hampton Roads Bridge Tunnel, the most expensive road project in Virginia history. My sons and I enjoy the travel on the preexisting bridge tunnel in full view of the incredibly rapid progress and marvels of engineering of the new span.
Thanks always for the excellent content!
As someone who lives in Newport News, I'm super excited to watch the ongoing work. The only thing I wish is that they had included a rail line on the new tunnel work.
I've been hoping he would analyze the HRBT project!
Totally unrelated to bridges, your comment got me thinking about tunnels. Those are another, almost completely opposite-of-bridges kind of engineering marvel. I'd love to see a video or two about some of the big highway tunnels out there. The Eisenhower Tunnel near Keystone / Vail is the nearest one to me and at over a mile and a half long it's a journey to drive through it.
So Grady, if you wanna visit Colorado for a video on the Eisenhower Tunnel (and some skiing) let me know, you can crash at my place :)
My experience with design builds has been that the contractor's consultant does most of the design during the bidding process so by the time contract is awarded by the owner and the design gets reviewed, there's little room for change. This can result in plan errors being propagated throughout the entire project and not being caught.
It seems natural to happen in regular conditions. But when your project was so faulty that collapsed during building, and killed people, you should be in prison, not building a bigger time bomb. And this new project should be under fierce screening.
And by the way, diagonal bridge? I understand that surroundings matters, and that the place was not clear fields, but a city, but still it looks so counterintuitive.
Thank you for making these videos! They are informative as hell and shed light on the big money and big problems that can be spent and experienced in these massive public works projects.
Grady, could you please look into the I-5 convergence around Tacoma, Washington. They might finally be finishing it, but that project has been running since I was a kid.
It was another massive project that always ran into problems and I think it would be a perfect video like this that explains the project in a pragmatic way that multiple generations of politicians lacked the capacity to do.
If you don't want to or can't, I understand, and am happy that you've started opening my eyes to the massive scale and fuc... complexity of projects like these.
It's good to see that walking and biking is also going to be accommodated (if they manage to solve the issues).
As someone with more than a touch of acrophobia, I would rather go through a TSA checkpoint, twice, to fly over the river than cross the bridge.
I KNOW it's irrational, and I still feel that way.
@@MonkeyJedi99 I've met people with acrophobia severe enough to affect their normal functioning to the point they weren't able to work in buildings higher than a few stories. Sorry to hear man!
sadly it's still just a shared use path while cars get 3 lanes..
@@swedneck sure. But a shared use path is a very good start.
Unfortunately, I doubt many people will be making use of a path that requires them to go miles out of their way (because of the curve radius needed for 80mph travel) and puts them 5 feet away from vehicles traveling 80mph. That's 80dbA, about the same as using a power drill the whole time.
As much of a bummer it is when these disruptions happen, safety of course is paramount and needs to be of the utmost concern before, during, and after construction.
One of the channel patrons is Waffles the Dog. It's so nice when dogs can appreciate good engineering content.
The only cable-stayed bridge I'm familiar with is the Leonard P. Zakim Bridge in Boston, an absolutely beautiful structure well-known as the subject of dramatic photography and other visual art. They really are impressive! I hope this bridge does finish and the people of Corpus Christi can enjoy it for decades to come.
The Fred Hartman bridge in Houston is also a cable-stayed bridge, which crosses the Houston ship channel
Cable stayed bridges are actually pretty common and are the hot design these days. The Brooklyn Bridge is actually a cable stayed bridge. One of the best modern examples is the Millau Viaduct in France which is actually seven cable stayed bridges crossing the Tarn River valley.
The Queensferry Crossing across the River Forth near Edinburgh, Scotland is also a really nice example of a cable-stayed bridge.
The current/old Harbor Bridge is looking pretty dang scary nowadays. Always nerve racking looking at the amount of rust when driving across
Golden gate Bridge in San Francisco scared the hell out of me 😂
It really is. We go to the Aquarium fairly often and the Harbor Bridge makes me so nervous that I’m getting tempted to go out to Mustang Island, take the ferry back to the mainland, and then come around through Aransas Pass to Portland and then to North Beach.
It’d take an hour or more, but I’d avoid that dang bridge.
There used to be a lift bridge on Navigation Blvd farther back in the port. I used to take that bridge because I could get across it so fast. So even though it was old and looked scary, I didn’t have to be on it long and it was only a couple feet above the water.
But they tore in down ages ago, and now the Harbor Bridge is the only reasonable way across.
Lay person here. I'm just thankful that they did the reviews of the design and identified the flaws. I'm sure there was a sinking feeling when they realized everything had to stop, but made the right call.
Though i always wonder when work/design is handed off to new firms, how do the new firms not be influenced by the hidden assumptions that the present design can bias them with.
Great video
I moved out of Corpus Christi about year ago and It has been little frustrating to watch the construction. The approach spans and attaching roads have been a huge mess especially around 8 or 5 oclock. Gotta say though this bridge is huge compared to he old Habor bridge
I'm pausing at 8:21 to ask a question in regards to FIGG screwing up so colossally over several projects.
How does a company get to be large enough to win bids for these projects without an apparent modicum of understanding of the laws, regs, responsibilities, and tiers of accountability associated with projects of such scale? It just doesn't make sense because if someone works their whole life to build a company from scratch, or buys/merges with one already in existence, wouldn't it be in everyone's best interest to cross every T and dot every I? Or am I just so far disconnected from what it takes to run a company that vast, that I'm missing something fundamental?
Welcome to Texas!
Well, maybe not just Texas. I think the takeaway is that even if a company gets in too deep, it's rational-appearing to keep fighting due to the sunk-cost fallacy.
Because the people who are supposed to scrutinize the company are working with the company to benefit themselves.
My assumption is that they got big and won bids on projects by making appropriate simplifications on smaller projects, where the simplifications and assumptions were within acceptable parameters. But they didn’t change that strategy when they started bidding on larger projects where seemingly small simplifications can add up to a significant impact.
They don't. I suspect their troubles are just another case of success having many fathers, but failure being an orphan. Someone had to hold the bag and it was them, whether or not that's where all of the blame deserves to go.
That said... When your construction project falls down and kills people, I imagine the rest of your customers get pretty creative looking for ways to get out of their contracts. I would.
The regulations have got so big trying to cover the corner cases, complicating the formulations expecting the computer to do the calcs but not transparent to the engineer. There is No ONE or even TWO or three persons can capture all requirements in their head, leading to confusion amongst the contractors.
Hm, my hometown Hamburg/Germany just decided to build a similar bridge to replace a cable bridge built in the 70s which is already larger then the bridge planned in corpus Christi. The new bridge will allow for a passage of more then 100m below to enable the largest container ships to pass through. I hope that will turn out better, but I also have trust in German engineering (mostly).