Are you ready for this?
I entered the Calgary bridge contest for a new structure linking St. Patrick’s Island to the riverbanks of the bow. My idea was a rotating bridge that would lift the connection to St. Patrick’s Island into the air in case of river flooding.
Now I can say, told you so, my idea was not so far fetched! The bridge rotates lifting the access ramp off the Island. Not the most beautiful bridge but it would have saved a lot of money in that flood.
This is the Island flooding and all the structure on the Island getting damaged…
Is this getting built? I just saw this two year old video yesterday. (Yes I’m late to the party)
What is the point of the bridges/underwater tunnels? Is a shortcut or a “just for the hell of it” project?
One of the things we may have lost is the appreciation of hard work. Here is a older but still relevant talk by Mike Rowe.
(Remember I’m a vegetarian when you hear the first part….)
Asking what an object or structure means is an intrinsic part of what designers, architects and artists do all the time. It’s not natural for engineers, though. Engineers are practical people; they build things to spec, they keep the lights on and the trains running. To be clear, this isn’t to claim that engineers have no imagination – far from it. Engineers have plenty of imagination, but it is directed very differently. Engineers solve problems; they imagine “how”. The artist, by contrast, imagines “why”; the engineer’s problem is the end product of the artistic process.
A student of mine is taking an English course where she was asked to present a paper on a controversial engineering topic. I’m not sure the rift between conventional and ABC bridge construction is vast but it is a subject that could use a bit of clarification. Try to find a paper that gives the advantages and disadvantages of each system, not easy, even on the “Google”.
The Federal Highway Administration is pushing ABC as the construction technique of the future, writing things like “conventional construction methods involve on site activities that are time consuming and weather dependent.” True, but I could as easily write, ABC projects ALWAYS cost more than conventional construction.
So to be fair lets go through some of the advantages and disadvantages of each system.
1) SPEED -Winner ABC
Gotta give ABC it’s props, it is a much faster system than conventional construction. If speed is your thing and you just have to do it in a weekend, than build an accelerated bridge.
2) Cost – Winner – Conventional Bridge Construction
I don’t care what the spin is, conventional construction is always (yes always) cheaper. Now the arguments I hear for ABC bridges being faster and cheaper than conventional are a) wait until everyone is used to the system then the costs will be competitive and b) when you include users costs then ABC bridges are cheaper.
I have not experienced the phenomenon of ABC systems becoming cheaper than conventional construction. In fact I have often seen increased costs after construction to fix the problems associated with ABC. For example, more overlays through the years because of the amount of deck joints.
As to user costs, I have to say they are the most delight works of fiction. I looked at a cost breakdown between a conventional bridge and an ABC bridge where the user costs (subtracted from the first cost) makes the ABC bridge the winner. If you want the ABC bridge to win, just make the user costs a bazillion dollars. Then the ABC bridge will always win, but how do you “prove” user costs?
Also, why is it fair that I help pay a higher first cost for a bridge 300 miles from my house, shouldn’t the benefit of a new bridge be subsided a little by the neighborhood using it?
Conventional bridge – first cost $6,000,000
ABC Bridge $8,000,000 but wait minus a bazillion in user costs = A Free Bridge! Winner ABC.
But you still have to pay the $8,000,000 first cost and you will never see a dime of the bazillion dollars in user costs. Do I have to go house to house to get it?
3) Safety – Winner ABC
I guess the shortened construction period would protect workers from exposure to long periods of crazy drivers. If you are next to crazy drivers during construction….
4) Longevity – Winner Conventional Construction
One of the drawbacks of ABC construction is typically the increase in joints throughout the structure. Joints lead to problems because water gets in them and does bad things. Conventional construction typically, usually, most often, minimizes joints and locks the structure together as one big mass. This makes it extremely strong and long lasting. I would imagine ABC bridges will get there eventually but I still think a conventional constructed bridge will last 20% longer than an ABC bridge.
(When I say this, I have to point out that lateral slide bridges are really just conventional bridges pushed into place. So these types of structures will probably last as long as conventional construction)
5) Overall – Winner – it’s a tie!
Okay, I get it, both systems have advantages and disadvantages. Of course there is a time for conventional construction and of course ABC bridges are great tools to replace structures quickly. Honestly I like ABC, I grew up in a precast plant, just use it wisely. Engineers are not stupid, we know when to use what technology, just calm down on all the cheerleading.
We get it.
few years ago, Barry LePatner, a construction attorney and nationally renowned infrastructure expert, gave a speech up in Rockland County in which he discussed the nearby Tappan Zee Bridge. Built 58 years ago, the three-mile-long span, which crosses the Hudson River from South Nyack to Tarrytown in Westchester County, is one of the region’s busiest and most vital roadways—a major passenger and trucking route connecting New York and points west to New England that allows vehicles to skirt the gridlock of the Greater New York metropolitan area.
The Tappan Zee, LePatner told the assembled crowd of New York State finance officials, is also one of the most decrepit, and potentially dangerous, bridges in the country.
I made this a while back but I think it still works…
This pretty much sums up the current environment.
The Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than average.
This bias is attributed to a metacognitive inability of the unskilled to recognize their mistakes.
Americans seem to have some disdain for cyclists.
By Steven Fleming
Why don’t more people join them?
It is not for a lack of interest. Australians have already stocked their households with an average of 1.6 bikes. The reason most of those bikes gather dust in garages is that few of us are prepared to risk our lives riding near cars, as Australian traffic and planning authorities expect us to do.
Now even the US has decided to make it easier for cyclists. Will Australia ever catch up?
In-carriage cycling – mixing it with car traffic – is the primary reason our death rates per million kilometres cycled are three times higher than in the Netherlands. We may have helmets, but the Dutch have the protection that matters: barrier protection from cars.
It looks like we are headed to default. Here is some advice for the coming Zombie Apocalypse.
“1. Organize before they rise!
2. They feel no fear, why should you?
3. Use your head: cut off theirs.
4. Blades don’t need reloading.
5. Ideal protection = tight clothes, short hair.
6. Get up the staircase, then destroy it.
7. Get out of the car, get onto the bike.
8. Keep moving, keep low, keep quiet, keep alert!
9. No place is safe, only safer.
10. The zombie may be gone, but the threat lives on.”
― Max Brooks, The Zombie Survival Guide: Complete Protection from the Living Dead
Hat tip: David
A shame to lose this bridge.
The historic Glebe Island Bridge is rotting and parts of it near collapse, according to a new report, fuelling debate on whether to demolish or restore the structure.
Councils and the community say the state government should spend more than $33 million to reopen the steel swing bridge and restore a link between the inner west and the city.
Demolishing the bridge would cost about $25 million, or $15 million if abutments were retained. However that would prevent extra public foreshore space being made.
Replacement of a damaged span.
This is how the Guardian sees our recent political shenanigans.
While the government shutdown is nominally about the Republican crusade against Obamacare, the issues at stake are far bigger than one law or even one president or one Congress. In reality, the psychodrama playing out in Washington is about the future of democracy in America.
This debate is not your garden-variety political crisis. It’s the battle for the long-term viability of American democracy, and it’s a battle that the Democrats simply must win even if it means risking default.
Of course we should.
This is a bad thing for bridges throughout the states because we use steel piles everywhere. Imagine having to check all of them! On the hand I just saw a research proposal for investigating bridge piling, what good timing for that researcher…
Hat tip: David
Interesting 3D science.
Hat tip: David
The opposite side of the coin on Calatrava.
The Santiago Calatrava I collaborated with was an excellent architect and engineer who truly cared for his clients, the contractors and the city he worked in. He was extremely competent, and it was an honor to work with him.
Hat tip Laramie
A heartfelt talk about the problems of helping and failing.
David will be drawing on his work experience in Africa to speak about the transformative power of publicly admitting failure in the development aid sector which currently lacks accountability, creativity and transparency.
About half way through, YIKES!
This is a bad thing, a sinking pier on a big bridge, link here.
It seems clients are a little upset with the man.
From the New York Times.
Mr. Calatrava was paid approximately 94 million euros (about $127 million) for his work. How could that be, Mr. Blanco asks, when the opera house included 150 seats with obstructed views? Or when the science museum was initially built without fire escapes or elevators for the disabled?
“How can you make mistakes like that?” asked Mr. Blanco, a member of the small opposition United Left party here, who said millions were spent to fix such errors. “He was paid even when repairing his own mistakes.”
But in numerous interviews, other architects, academics and builders say that Mr. Calatrava is amassing an unusually long list of projects marred by cost overruns, delays and litigation. It is hard to find a Calatrava project that has not been significantly over budget. And complaints abound that he is indifferent to the needs of his clients. Just last month a Dutch councilor in Haarlemmermeer, near Amsterdam, urged his colleagues to take legal action because the three bridges the architect designed for the town cost twice the budgeted amount and then millions more in upkeep since they opened in 2004. Mr. Calatrava is already in court over a footbridge in Venice, a winery in the Álava region of Spain and a massive exhibition and conference center in Oviedo, Spain.
From the comments section, it made me laugh. Calatrava is a structural engineer.
Who is on these review committees? Shouldn’t structural engineers have enough votes to make the decision? Why do we waste taxpayer money on egomaniacs? Surely it’s possible to have beautiful designs that also work structurally.
I made a quick video on using the Power Sizing Model for my class. You use the model to estimate the cost difference between items such as compressors or motors (industrial plants and equipment). For example what is the cost of a 200hp compressor if you know the cost of a 120 hp compressor? Since the cost change is not linear you use a simple formula with a power sizing exponent found in industry tables.
Just an amazing piece of engineering, something that could capture on site 3D images for bridge folks.
Here are 10 questions and answers regarding the status of the nation’s bridges:
1.WHAT ARE THE NUMBERS?
The most recent federal National Bridge Inventory includes 607,380 bridges that are subject to uniform bridge inspection standards. Among those bridges, there were 65,605 classified as “structurally deficient” and 20,808 as “fracture critical.”
Of those, 7,795 were both. And bridges with both red flags are open in all 50 states, the District of Columbia and Puerto Rico. While such dual designation does not automatically mean double trouble, experts who pay attention to these things say the group has increased risk.
2.WHAT DO THOSE TERMS EVEN MEAN?
A bridge is “structurally deficient” when it is in need of rehabilitation or replacement because at least one major component is deemed in poor or worse condition.
A bridge is deemed “fracture critical” when it doesn’t have redundant protections and is at risk of collapse if a single, vital component fails.
Officials say that neither category is an indication of imminent collapse, but experts agree that both classifications are signs of risk.