Hey there and welcome to the BigAppleSchool podcast. My name is Sam.
And today we’re asking what’s the craic about construction. We’re gonna ask what it is, who designs what to build, I mean, where do those buildings come from? So we’re gonna ask questions to kinda raise awareness about bridges, coverts, buildings.
Where do they come from? How many of them have we been involved with in our lives? What kind of different types of constructions there are, I’m gonna share a little bit of knowledge about that – nothing too extreme, nothing too technical.
We’ll talk about forces, a little bit maybe about materials, about the problems with buildings and bridges. We will ask who is better – an architect or an engineer? And talk maybe a little bit about our favorite structures, bridges or buildings or whatever. So, all good?
I got a question for you Sam. You know, when you say construction, what does it actually mean? And yeah, who cares to decide what to build? What to do with it?
Okay, so a construction is of course a big industry, there’s multi facets.
So you’ve got builders, you’ve got civil engineers, you’ve got roads that need to be constructed – they aren’t just thrown down. It isn’t just one layer, there are multiple layers to them. You’ve got roads, you’ve got buildings, and of course there are buildings that are purely for living in, but there are also buildings for different purposes, for governments, for government buildings.
There are bridges, which have to be thought of carefully. There are lots of things that have to be thought of and there are lots of different elements in that. Electrical stuff, mechanical stuff, all kinds of weird and wonderful stuff that goes into that.
You know, I was in Seoul just before arriving here to Novosibirsk, and they’ve built an airport on a man-made island. And they decided to interconnect it to Seoul with a huge bridge. Now I’ve always been a big fan of, you know, long long bridges, I’ve always wanted to know the engineering that goes into those things. How do they make it stable? I mean, what goes into building a bridge?
So, way back if you like, I worked in a civil engineering office, and we were involved in roads and bridges, and worked for the government. And what I maybe didn’t realize prior to that was that it’s a team.
It’s not only civil engineers, and there’s a lot to civil engineers, figuring out the calculations and what problems it might have, and what best configurations and balancing cost and benefit – on all kinds of thoughts. I mean, years and years of work go into. But they’re not only civil engineers, but support technicians, and I was a technician on autocad, an autocad manager as well.
And they’re supported by those guys, they’re supervised, there’s finance. I mean, who finances it. It’s a big big decision and a lot of years of work go to that. And I’m sure there were quite a few years involved in that bridge that you’re speaking. Incheon bridge I think it’s called.
Incheon bridge, that’s correct.
And I looked into that a little bit, cause you spoke to me about that.
And it’s not just one bridge. I mean you can look at it – it’s several different structures involved, and there are different elements to it. And there’s, you know, there’s the bigger parts, and also there’s a road leaning up to it.
It would have, of course, been done in stages, and designed in stages. The route would’ve been planned, all sorts of things. A normal person wouldn’t realize automatically what goes into this, what stuff. It’s really…
I don’t wanna scare anyone, it’s very technical, but at the same time it’s not done by one person, it’s not like one Einstein kinda person sitting there ‘I know what this will be, I know what to do here’, it’s a group, it’s a team effort.
You know, what really surprised me about that Incheon bridge was – they’ve actually blocked the sea from… That part was where the sea used to pass, and they blocked it out. So you actually see fields and mud essentially.
I mean you see a little bit of water coming in, but it’s nothing to threaten the bridge. So, my guess is that movement of the water and the currents really threaten the integrity of the bridge. Structural integrity of it.
I would like to talk about that, cause there are weaknesses of bridges, but we’ll talk about that a little bit later.
No worries. But I mean, Sydney, obviously, has a huge bridge. Yeah, we basically call it the Sydney Harbor bridge. And it was constructed well over a hundred years ago. And when it was built, a few people died building it.
And it took many years to build it, and it was done in sections. And when it was built, it was considered a technological marvel. And some say, I’ve heard some engineers say that it cannot be replicated today. Is that true?
Well, not being super familiar with it, I think that it would depend on the materials that were used, maybe some of the methods. Sometimes some of the methods and the skills involved are lost.
Yeah. Especially with some of the, I mean, much much older style or there was some skill involved, or maybe, you know, it was some special kind of metal rather than what we tend to use nowadays is iron for different constructions – of course other materials, reinforced concrete is very popular.
Sorry, steel is popular, whereas in the past it was cast iron or a special, different types of iron. I know those materials are not used so much now. Are not used at all maybe now.
Actually, yeah. Sorry to interrupt, but Sydney Harbor bridge – look at it from the surface, it does look like cast iron. It doesn’t actually look like steel, so maybe they reinforced it over the years, with most of things, but overall it’s got this black cast iron look to it.
I’ve seen the picture, but to be honest I haven’t researched it, so I would suspect it could be, because it’s the materials that involved some skill in creating that aren’t…. It’s fallen out of fashion and use if you like. It’s not like…
It’s not say that the shape couldn’t be replicated, and the form, and how it functions couldn’t be replicated. Maybe the actual use of the materials is not…
Is different now. Okay. Yeah, but, you know, I just find that bridges are really really remarkable. And so, you know, buildings. The bridges isn’t the only thing that’s remarkable for me. I love architecture, and specially I find so much great architecture in Novosibirsk.
A lot of people don’t like it, the locals, but I love them. I love seeing it. Have you been to, you know, the buildings? What’s your thoughts on the buildings? I really love the old soviet style buildings. But I don’t know about you – what’s our opinion on buildings?
I appreciate the Novosibirsk ballet theatre building, NOVAT. And I love the dome, it’s great inside, but I like it outside maybe. It’s quite posing, nice big structure, a lovely dome. And for me that kind of form with curves and strong lines -it’s everything fantastic.
Even though, I mean, I worked in civil engineering, so it’s not.. Most of the time a civil engineer is not concerned with buildings or the outside of it too, it’s not – although a lot of civil engineers know buildings, they can’t be, so I don’t know, I haven’t had a lot of experience with architecture per se. But I appreciate good architecture.
I see. And you know, every day I go to some building and I see things I’ve never seen where I grew up. Sometimes it’s like it’s a different world. What about you? Any interesting buildings you’ve been to?
So, what I would point out is, or what I wanna say to people is that bridges and culverts are everywhere, and architecture is everywhere too, I mean, and I think that we are kinda blinded by. And especially if you’re living in a big city or a town, or even when you’re going through the countryside
you will cross a bridge or a covert, which might be buried or partly buried, or you will walk past the building and you won’t notice it. Because there’s just so much happening.
And like, back when I used to go and inspect bridges, I used to go out onto the road, and you would literally drive over 2-3-4-5 culverts or bridges without really thinking about it.
And unless you’re actually conscious of it, you’ll miss the architecture, you’ll miss the bridge, you’ll miss the culvert. And maybe you should take a little time to appreciate it.
I mean, architecture being art, and art has to be appreciated in detail. It’s all about detail. If you just have a look at one glimpse, you’re never gonna be able to appreciate an art. That’s what I believe.
I think so. But then on the flip side, the beauty is in the eye of the holder, but there are bridges, there are buildings that are function rather than beauty.
That’s true. It’s just that the architecture is a little bit different form the other arts, because it serves a practical function.
That’s right. That’s their beauty. But I’ve always wondered, you know, what kind of construction, what types are there for these bridges and buildings? How do you work into that engineering principle?
Right. This is where I hope I can educate you as best I can. So I’ll look at it from a little bit of bridge point of you, but you can relate it to architecture too. So in bridges there is a wonderful thing called an arch bridge. And it takes the form of a circle if you like, although it’s three dimensional of course.
And what it does is when the pressure is pressed down at one point, that one point starts to press into the other point. And if you like it, it supports each other, it’s got that, it’s a wonderful natural shape, this arch. And when you press it, it all kinda pushes back to at you.
And domes as well, if you’re thinking more about architecture, a dome is kind of self-supporting, because one piece of it if you look at it, if you just try to visualize one piece, one piece is pushing down on all the other pieces.
And they’re in turn kinda pushing back if you like. So it’s kind of self-supporting structure with the forces coming down, things pressing down on it, even just gravity. It’s kind of holding its own if you like. Each of the parts are working together to hold it up.
I think the Romans were one of the first people to use that.
It’s about 3000 years old maybe.
Yeah. I think so. I think they were originally taught by people ….. And I think they used, the domes and the arches, I think they used the keystone technology.
Keystone is the top middle part.
And once to have it in place is pushing down on both sides of the arch, and they’re in turn are kinda pushing back. So it’s a self supporting kind of system.
So, what happens without? If you don’t keystone?
If you take a keystone it doesn’t work.
Without the keystone it doesn’t function.
It actually doesn’t stand up.
Yeah if you take one piece out of that arch, it’ll start to collapse, it’ll start to fail.
I see. So this is where it can be quite fragile.
So if a one key structure is damaged or, you know, whatever, it can actually collapse.
What I did and what you need to do is inspect them.
I’ve seen that. I have seen it in Novosibirsk train station, the train one, the green colored one, where there was this guy, young man, with a couple of attendants from the train station inspecting everything from the dome and to the grills of the floor.
And I was like “What is he doing?” And I think that’s what he was doing – he was checking the constructional integrity of every nook and cranny of this train station.
Yeah, because you have all those little parts. I’m not quite finished yet. So beams are running from one support, so maybe it’s a pier, maybe it’s a wall. Something that’s supporting. And, of course, two things you’ve got, and you’ve got a beam running between that, then of course, it’s quite simple principle,
you put something on top of that beam and it’ll support it. Nothing drastic about that, but beams are of course very very popular constructions. Simple stuff like that. Trusses. Do you know what a truss is?
Basically it’s triangles, if you wanna boil it down. It’s triangles. So if you think of shapes, if you want to look at construction from a shape point of view, we’ve got circles, semicircles, arches, and triangles.
And they are quite similar in principle in that – if you press at one point, the other points are kinda pushed back. So it’s kind of a self supporting idea. So trusses are essentially triangles. They are often made from the steel. Or cast iron, if they’re older bridges. And so they kind of support – they’re wonderful shape to support.
And bridges are often made out of these shapes, the combinations.
Not just bridges, but you’ll see them in buildings too.
Buildings too. Okay. You know, talking about structural integrity, when I was in university learning physics, they showed us what oscillation can actually have effect on bridges, what effect oscillation can have.
And they showed us this old video, this very old film clip of a bridge. The winds got the right oscillation, and the basically it set acting what’s called torsion force in to the bridge. And eventually basically the bridge collapsed. It just collapsed.
It didn’t even seem like a high force wind. It’s isn’t a high force wing affecting it. With enough frequency and vibration they were saying these things can actually… But that’s before they figured out certain engineering principles to make it stable.
So can you run through a little bit of that? What’s that about forces that affect bridges and how do we combat these things?
So there are four main ones: compression, which is basically push, pushing down or pushing across or pushing together, whatever. So compression is a thing. And tension, which is basically bending.
If you think of a ruler and you try to bend it, unless it’s a very special ruler, it will break eventually. There is torsion which you mention, which basically twisting, and it can happen for various reasons.
It can happen because of wind, it can happen because of some other push from the side, or from above or whatever. Sheer is another thing, which is basically when you cut down or through a structure. And to add to what you said is I believe there is a Millennial bridge- it’s a foot bridge in London.
Yeah, yeah. They built it and they did a very good job in one sense, but they didn’t consider, which is probably not something that is often considered or wasn’t often considered. They didn’t consider the fact that it swayed and people started to move to the kind of rhythm of this sway.
And that had a negative effect on the bridge. And when you have to think about structures, you have to think about the wear and tear. You have to think about not only these forces, pushing, bending, twisting, cutting. All of these kind of things.
Sounds like the lord of the Rings. But you also have to think that this is happening regularly. This is happening, you have to think about the frequency of this kind of forces as well. Not just how much and how strong it might be, but the fact that it can wear down the bridge.
Is this how in English we use entropy?
So it’s the idea… Well the idea is that you have not got just a truck, or you’ve not just got people walking on that structure, but you’ve got maybe multiple. Multiple trucks or multiple people.
I mean, you’ve got books – books are very heavy, if you’re thinking of a library, so it’s necessary to think when you’re designing buildings structure – to think practically, to think what will actually happen throughout its life. What will be the worst effect?
Well I think I guessed previously – water must have the huge force of it, but I mean what are some of the other problems for bridges?
So what interested me when I started to get into inspecting bridges and learning about how they’re built and learning about negative effects – water. Something as simple as water is like a destructive force.
I mean, I guess it’s not a super surprise, but the sort of a philosophy of that idea, the simplicity of that, just something that we need every day – we need water to drink, to clean whatever, can have such a destructive force.
If you’ve got a flood, your arch bridge, if it’s flushed by a flood, and stones are removed, which can be, then it starts to lose its strength and it starts to collapse. And there are many arch bridges which have stood for years and years and years, decades, maybe hundreds of years, but a flood has come and taken parts out of it, and it’s collapsed.
I think I’ve seen a video of that. I think in Bali about 10 years ago or so – there was a big flood and you actually see tourists filming in the video. And it just comes in and it just knocks everything. It’s not even a huge flood. It’s a low level, but it just swings to the bridge and then to the village and it just wiped it clean.
And another thing is that water can carry salt and other harmful chemicals inside the structure. It can be a building, it can be a bridge. It can carry it inside it, and often in bridges and structures you have steel.
Either inside or outside, and it can carry it in it, and of course it’ll have, it’ll start to rust either inside our outside of a bridge or a structure. And that, of course, rust is generally thought of as bad, and it is bad.
So water carries up too, and it can be dripping through cracks. It might be a very slow process. It can also be water plus cold plus a cycle of wet and dry, wet and dry. Or cold and hot, cold and hot.
So the elements, if you like, it can be freezing as well if you got water that goes into a crack, and when it freezes, it expands, and that of course is gonna expand that crack. So you’re gonna… Water alone can destroy a structure if you just leave it alone.
Water alone can do it. I mean, it’s not gonna happen overnight, but if you leave it long enough without maintenance, without any attention, water alone could get into areas, cracks and any kind of area and it will destroy the bridge. It has that potential.
Over time. Okay, so let’s say the San Francisco Golden Gate bridge – even if there’s no current. Basically if you leave it long enough without maintenance, it will, no matter what the scale is..
What water, and if it’s salt water, or sea water, or whatever – especially if you got a bold, it’ll get into there because of the difference, it’s not a uniform structure, it’s not a uniform shape. Water will start to sit in certain areas and it will rust. And that’s where rust most often affects the most.
Well there are some of the other forces…
Wind can often… Especially if it’s a very big, very tall structure, wind can… You have to absolutely think of that. If this is smaller bridge or a smaller building, you know how to think of it as much. But if you’re starting to build big, your South Korean bridge or the airport, you really have to think about wind.
What happens at times, interestingly, as well, is f you’ve got a bridge, especially if it’s a little bridge, and it’s maybe an older bridge, cause generally newer bridges are built a bit taller and it’s thought of. But there are quite a lot of arches and lower bridges which are hit by lorries and trucks.
And you’ve got impact to think of. For your Korean bridge, they have thought of it being hit by ships.
So you have to think of that.
Yes, cause this is trading nation.
And they had to… By the way if you’re talking about a big bridge like that, they have to think about a channel to allow the ships through – they have to…
You have to think about the width, you have to think about the height. And they have also thought about impact, cause they’re ship. Even if.. You don’t assume that the person in charge of ship is sensible, even though 99% of them absolutely are.
You assume that it’s going to be hit, and you have to think what will happen, what is gonna happen to this bridge if it does hit, how can I stop that from happening? Cause I don’t want my bridge to fall down. Or my building, or whatever.
Well, one think I noticed in Sydney Harbor – we always have big cruise ships, they’re all Asian cruise ships and whatnot, a massive! I think one of these may be like a kilometer long, I think. And basically they’re always docked in Sydney Harbor to have passengers,
cause Australians are huge huge travelers on those cruise ships, right? And basically they’re always under the Sydney Harbor bridge – and I kinda always think as they go by, I see one under it, I’m thinking ‘will it hit the bridge?’ It never quite hits the bridge, right?
Cause there’s the safety margin that is always considered. A part of me thinks ‘These things are massive’. If they hit the Sydney Harbor bridge, a bridge as big as Sydney Harbor bridge is, I can tell there’s gonna be fatalities no matter what.
Well, it should have been thought of. And I assume that it has been thought of, in case of… With some of the older bridges, well, it’s because some of the older bridges – life has changed and trucks and lorries have got bigger. Traffic is bigger.
But as long as a newer bridge have been thought of – what height do we need to make it? And as long as those boats and ships that are going under it don’t change, the newer bridge will be suitable for it.
I see. And you know, I mean, basically, the question I’ve always had is, you know, the architect. There’s an architect who chose it up in my knowledge, basically my common day knowledge is that the architect draws up the plan, makes it esthetically pleasing and functionally viable, but then there’s engineer.
I don’t know what he does. What’s the difference and what’s the distinction between those two?
So, there’s a joke among engineers and maybe it’s not very fair, but there’s a joke that the architect designs something, you know, draws it up, does the sketch, gives it to engineer and after he’s picked himself up from the floor after laughing.
He starts to tell the architect what he can actually do. What he can actually give them. And I think it’s unfair because that is an engineer joke, not an architect. But basically it explains what the two are. So an engineer is a practical kind of guy, and he thinks about the calculations,
about the forces coming down and what is needed to push up against those forces. How to balance the forces so that the structure stays standing. And he is a very practical person, but unfortunately, and it’s not always true,
unfortunately an engineer doesn’t care much, often doesn’t care much about how it looks. And that’s not true for every engineer, it’s not true for every project, in fact many projects look fantastic.
But often an engineer is compelled to think about practicalities, about cost, and isn’t too concerned about the esthetics. And that’s not to say that it’s completely out of his mind, but it’s often not the focus and not the priority.
The client who is financing the project, will make the decision – often the clients makes the decision on what he wants and how it looks. So the engineer’s more poloid to think about ‘will this work?’ and to tell the client – here are some options, and here are the cost associate, and the client often makes the decision.
And architect is often focused more on the esthetics, and that’s not to say that the architect is not practical, it’s not to say that he can’t do calculations, but often the two work together. And the architect will help more with the esthetics.
His focus will be on the esthetics. Whereas the engineer will look at the practicality, the calculations, and what can stand, what can’t stand. And how to… maybe the engineer will, the best way to explain – the engineer will try to put it to practice the vision of the architect, what he wants to see.
Because he is often employed to make something look fantastic, to make something become a kind of icon or symbol of the country or a town. Whereas the engineer is kind of ‘how can we put that vision into practice?’
So, basically, the engineer is the unsung hero. You talked about this being a team work, right?
I think this can often, especially big iconic projects – it can often be attributed solely to one person. And that’s unfair.
But they do that though. I mean I know this from, you know, a Sydney Harbor.
I think it’s a human thing to attribute everything to kinda one hero, the heroes.
The first man on the moon – Neil Armstrong. But what about the second man?
And what about the guy who piloted? He didn’t get to step on the moon, but without him…
Michael Collins. I mean….
I’ve never have heard of the guy until you told me. So I didn’t know he existed.
Kinda generic. To be honest that’s kind of generic name.
It is a very… Is there an Irish Michael Collins?
There is, yeah. A more historic figure, Michael Collins.
Now, for example, a Sydney Opera House – icon of Sydney. Everybody remembers the architect behind that. Nobody ever says anything about the engineer.
And it was a team, it wasn’t just one person. It was a team.
That’s right. What are some of your favorite structures?
Well, so… As I talk about style, I like – as far as architecture, I like older styles. I’m not a fan of a lot of glazed, you know, a lot of windows. I’m not a fan of that, and I think that it’s… I mean, it can look good, but I think it can heat a building too much as well.
I like Victorian architecture, come from the UK maybe. But it’s quite popular actually in many of the cities and I like it. This older style. And I also like gothic too. And it’s a personal thing of course, but I like these old gargoyles and thigs.
I’m a lover of Batman you might have guessed, and gothic is of course connected with that. Maybe it’s just a whole holistic thing, but I like the use of stone, and I like the use of arches I think. I think not only as an arch practical, but it is beautiful.
And what are the materials used for this roof?
Right. So talk about the materials – we mentioned the forces, about pressing forces, compression. And then then the bending forces, tension. These are the two main forces you should consider. There are others too of course.
But one material that’s quite good, that adapts to those needs is reinforced concrete. And those who don’t maybe know much about bridges and constructions will not realize that it’s not just one lump of concrete. Your walls are not just concrete, which is your cement and your stone.
It’s not just stone. It’s not just that water plus cement plus your paste. Your cement paste and the stones form it. It’s often, especially if it’s a serious building, even if it’s a wall, it will have steel inside. The steel rods.
And it’s often called rebar – it’s reinforced steel. And they have different diameters, and they’re calculated very carefully, based on what these pressing down or pushing that structure. The steel is very good at bending, it’s good in the tension.
So those rods are there to stop it from bending and in the end it will break. The concrete is excellent in pushing compression. So those two complement each other, they work together, they’re kind of a friend.
That makes sense, because I always thought that steel beams at the concrete. I thought originally because of half-life, the degradation rate of the concrete was approximately the same as the steel inside. That’s not the case. They’re complementing different types of forces.
Different forces. And it can… Back to the water – if it gets there it can rust the reinforcement unfortunately. And that would start to break the concrete. So while they’re complementing each other, they can also work against each other.
I see. So this is why the maintenance…
Maintenance, inspection. So you’ve got reinforced concrete, steel, pure steel, just, and iron we mentioned. You can have a combination of those, you can use wood, but not for serious. Sorry, stone can also be used too. But you’ve got all of those different things. There are benefits to each of them. So that was the craic about construction. Did you like that?
Thank you very much. I think I learned a lot about construction, mate.
So we talked about what kind of.. What is construction and who is involved – it’s a team, it’s not just one person. We talked about the different types of structures you might meet as you walk down the street without even thinking, without even being conscious.
We spoke a little bit about different types of structures that there are in the world. The forces that act on them. Some problems – we mentioned those. The materials as well.
And who is better, or what’s the difference between an architect and an engineer. A little bit about favorite style – just a little bit. So guys, girls, that was the craic about construction.