karma-dharma 8

[a-rai]

I have a few questions.

Ancient Rome's population peaked at around a million people. London in the 19th century was the first city to surpass that. According to the UN's data booklet, The World's Cities in 2018, the number of cities with at least 1 million inhabitants were 548. Tokyo was the most populous with more than 37 million people.

Consider the amount of structures and infrastructure (electrical and plumbing systems, etc.) built in a relatively short period of time. What will happen when everything starts to fail? Will we try to repair what is irreparable? In that hopeless state of things, will we hop into airplanes or spaceships to move to another plot of land or planet? Will we rebuild everything in our new home? What will happen to our old one? Will it be the post-apocalyptic world portrayed in films of the past? Will it be a laboratory for military personnel to retrieve images of mushroom clouds? In the new world, will we use the same plans or make them better? Are we all Bill Murray in Groundhog Day? Are we the end product of our own creation? Did the psyche bring the cycle? Is this not the definition of insanity?

Are you ready? I'm just curious...

 

[verymadmac]

Most things can be re-lifed if there is sufficient motivation although being designed with generous margins helps, but then if it wasn't someone would have had reason to replace upgrade it already.

Since Sparweb beat me to quoting the One Horse Shay (did you first read it due to its reference in one of J. E. Gordon's books?), I will post pics from when they let the public (me included) walk through the Thames tunnel (2011). The original Thames tunnel started 1825 finished 1843, it was relined ~ 2010 (complete with historical arches and detail work left distinguishable) as part of the overground upgrades.

 

[dik]

...as the pavement condition index above illustrates, there may be a price to do that. If left too long, the cost may be prohibitive, without proper maintenance.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Sparweb]

Since Sparweb beat me to quoting the One Horse Shay (did you first read it due to its reference in one of J. E. Gordon's books?)

Correct!

 

[a-rai]

verymadmac, I take it you're a fan of post-apocalyptic films. Picture this:

A section of the NYC subway system collapses with or without a train underneath. Notified of the event, authorities scramble to stop all service, close the system and send a team of engineers to evaluate the safety conditions of the remaining tunnels scattered throughout the five boroughs. Urged to hasten their investigation, the experts haven't a clue as to how to go about assessing the structural integrity of the tubes. Meanwhile, chaos is widespread as millions of people are left without transportation. Urged further to conclude their findings, the investigators have 2 options; delay or make believe all is good at the risk of a future collapse. Needless to say, delay won't bring a risk-free conclusion.

This can happen in any one of the nearly 200 subway systems in the world, prompting other cities to do something (nothing) about it. Is this plausible or is it groundhog-wash?

 

[GregLocock]

"the experts haven't a clue as to how to go about assessing the structural integrity of the tubes" Do you know how remarkably stupid that sentence sounds?

Cheers

Greg Locock


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[a-rai]

Could you elaborate?

 

[dik]

With many types of construction, you can make periodic inspections to look for signs of distress. For some types of construction, there may be no advance warning of a potential collapse. There is a good chance the collapse may be brought about by other issues.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[a-rai]

Right, so do like the Beatles and let it be.

After introducing Holmes' poem, Gordon wrote the following:

The entire physical world is most properly regarded as a great energy system: an enormous marketplace in which one form of energy is for ever being traded for another form according to set rules and values. That which is energetically advantageous is that which will sooner or later happen. In one sense a structure is a device which exists in order to delay some event which is energetically favoured. It is energetically advantageous, for instance, for a weight to fall to the ground, for strain energy to be released - and so on. Sooner or later the weight will fall to the ground and the strain energy will be released; but it is the business of a structure to delay such events for a season, for a lifetime or for thousands of years. All structures will be broken or destroyed in the end - just as all people will die in the end. It is the purpose of medicine and engineering to postpone these occurrences for a decent interval.

Alas, the plan is Times Square becoming the Great Pyramid and vice versa and so on... Is this a photograph?

 

[dik]

but monitor as best you can... and check for other signs such as water infiltration, etc. There are often indications that things are amiss before they happen... not always, but often.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[IRstuff]

This can happen in any one of the nearly 200 subway systems in the world, prompting other cities to do something (nothing) about it. Is this plausible or is it groundhog-wash?

So, what? Did you pay extra to ensure that that house you live in will last 1000 years? Are you paying for annual inspections of your house to ensure it won't collapse while you sleep?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[GregLocock]

"the experts haven't a clue as to how to go about assessing the structural integrity of the tubes" Well, then you've got the wrong experts.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[CWB1]

Testing infrastructure is easy and common, its just not always cheap.

 

[dik]

You'd have a tough time convincing me of even that...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Just Some Nerd]

I'm having a hard time distinguishing what we're even talking about anymore...if someone could put out a clear statement to argue over that would be great.

----------------------------------------------------------------------

Why yes, I do in fact have no idea what I'm talking about

 

[phamENG]

The earth is flat.

Now...go!

 

[a-rai]

Just Some Nerd, where is engineering going in the next 5 years? We're in the 2020s. If you read my post referencing NY State's DOT, you know there are 1,126 highway bridges in NYC that are over 53 years old (76.44% of the total). In the 2000s, 77 were built. In the 2010s, 83 were built. From 2020 to 2022, 23 were built. Many new structures are replacement bridges.

A little math will do. If we build at the same rate since 2020, we'll build 77 bridges in the 2020s. This is in line with the number of bridges built in the 2000s and 2010s (more or less 80).

If we continue to build at the rate we've been building in this millennium and replace the highway bridges that are over 53 years old, we'll need 147 years to replace them all and we'd still have 347 bridges to replace which correspond to the 23.56% of bridges that were less than 53 years old when we started. At that point the first bridge we built to replace the 76.44% stock will be 147 years old.