Last year, Steve Burrows CBE (Principle at the engineering consulting firm Arup) spent several weeks in Egypt studying the pyramids through the eyes of a modern day structural engineer. The result, which was presented in a documentary for the Discovery … Continue reading →
This is an unofficial transcript meant for reference. Accuracy is not guaranteed.
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But then that structural engineer brain kicks in every time you look at something you think festival. How did they do that? Then? I start thinking. How would I do that in a recent article and design intelligence he took those questions head on, as if a client gave him a brief to build something like the great pyramid. Today we get these incredible challenges, were you doing something? That's never been before. So. One of the incredible facts for me was that the great pyramid status, the tallest building in the world for some fisheries and as someone who, in the present day, is higher to engineer seemingly impossible structures, see brows thinks that the engineers of twenty hundred BC, really knew what was possible and made most of the major decisions, as at present, they engineer would so some of the things they knew where the if they built on the gaze of plotter, they could put stones that to a certain pressure and the ground didn't collapse beneath it. You can look it up
pyramids and see the previous mistakes that were made and they got to know what the ground capacity was, and I think that determine the size of the great pyramid, because if you can build the tallest building in the world, how tall do you want it to be? Do you want it a mile or just a bit taller than the last told us building. You ve gotta make a decision, and I think the decision was made for them by the quality of the ground that they were building up, so that was number one. Secondly, they had to build a in the faroes lifetime. I'm pretty sure that somebody. A contractor said you know. With the best will in the world, we can only lay. This number stands a day. I can only assemble this many men. And assembling men through city the right wording here, because- and I totally missed this historical revision, but the consensus now is that it was a rather privileged well tree at a class of Egyptians that built the pyramids.
Slaves that blew my mind says be the mill is going to be passed, twenty thousand men can only lit lay this many times a day and the fairy typically lives. Thirty, five is so you know that many many times that many stands times thirty five years means it's gonna, be this high, so the ground can only hold so much mass without buckling. The workers can only built so much an affair with lifetime and, finally, the material had to be delivered to the site in time to build the thing, and I would think, depending on whether quarry was relative to the actual sites which was chosen for its known ground, bearing capacity and also heighten visibility above Cairo, they also figured out that they could only get so many stones that they only had so much material off the quality at the quarry. Fifty
Those things that these practical engineering considerations determine the size, the pyramid, its height, the number of stones and, ultimately, while we all marvel at thousands of years later, it wasn't so much mistakes, us just practical necessity. Another practical consideration that led to the pyramids. Longevity is cereal chemistry. There are other ancient buildings that are not held up as well as the pyramid. The buildings are saw had lasted thousands of years and they haven't all perform perfectly well, sir. It was pretty clear to me that the Egyptians had a pretty good understanding of the material they were. They were working with, but it wasn't a hundred percent perfect. For example, the first large mud brick stretches. I look that had massive vertical cracks. In the end, it was very clear to me that they were thermal cracks. What has happened is that they were used to building walls, but when a walls turns a corner, that point becomes very stiff
because the temperature is very hugely between day and night. These materials, these walls expand and contract from when it contracts masonry will always break next to the stiff point. So every time there was a corner found a huge vertical crack, so they clearly didn't understand the thermal performance of mud bricks and not pro is exacerbated by the fact that they laid these might bricks on a mortar, bad. So the effect we have two materials for building, so they dues mud, brick and Malta, and by putting these different Mattel, together, they thermally move at different amounts and they had cracked. So somebody must have said well. If we only use one material laid, the bricks dry would they have performed better, and the answer is yes and the pyramids are ignored
clever. So there is only one materials used that means that the pyramids they never got very hard in the dying very cold at night, but the material throughout the pyramid is consistent, and so it didn't crack because they move together, they effectively breeze and because they breathed to account for the changes in temperature, their able to last a long time without cracking and break So this prompted brows to think about modern buildings, where we put so many materials to gather all the time. Steel and glass and aluminium and concrete and semen tissues, materials and the board and aside walking round modern buildings and looking at where all the cracks where every crack is the joint between different materials, and I started to think. Maybe we could think about this alone, but more and if we did, we can actually make buildings last longer just by thinking harder about
Joints which presently we solve by putting you, know Dewey material in the joint to try and take up that feel movement. But if we just detailing bats, are in the first place, they would last longer and I think the longer buildings lost the most sustainable AR for the longer that life in the last Mateo. To use in the long run. Germany is probably the most basic rules to sustainability in the pyramids. Are the poster children for lunch every time? In addition, a chemistry adhering to basic, prince
buzz of physics keeps your building around for millennia, with little or no maintenance. A pyramid is a nice stable shape and I think they will have learnt a lot, but it is as simple as the way I was thinking about if they had a bucket of some from. I put it on the floor than it actually naturally makes a pyramid shaped so intuitively. They know that that is a stable thing to do, but actually one of the interesting things is that they gradient of the sides of the pyramid is not determined like sand by its natural angle of repose. You can actually make it whatever you want to make it, but you can see from the prior pyramids from step pyramid and the bent pyramid the pyramids that preceded the great pyramid that they were sort of going a little bit steeper, but they never never really got above fifty degrees, because I think somebody felt up as a sort of a maximum mango about which we should never exceed
so again empirically derive knowledge sets the agenda. If you put these things together, how much stone you can get the bearing pressure that you can put on the ground and the angle you know it determines the height of the building. On a pretty sure, the simple mathematics and the work between the architect engineering contractor gave a practical So what could be built this exercise and using engineering principles to augment the archaeological data may give us an insight into why the great pyramid is both the oldest and the largest permanent of Giza, because people probably thought it was the limit of everything it's the biggest bearing capacity it's a steep as they can go and it's as many stones ass can be laid in a lifetime? You can't do any bigger than their here. Is the speed of light if you like, for building parents.
I know it's no revelation that the pyramids and well designed on hunting Eddie it. Let learning about these practical considerations from steel brows just made me appreciate their majesty in a new way. These structures are not other worldly. You don't need to come up with crazy theories to explain. They are the product of small architects and designers and engineers and skilled workers who apply dollars that was gained over. I'm in passed down over generations and through that perfectly understandable and reputable process. They discovered their limit, but don't get me wrong. I don't ever want to see the tallest building we could possibly build, but Might like to see the one design, not enough durability and flexibility to last for four thousand years Ninety nine percent invisible was produced by me, roman Mars, with support from lunar, making indifference with creativity, it's a project
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Transcript generated on 2020-02-15.