how do architects calculate if a structure like a bridge is stable?
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Engineer here, we learned how to do this in a class called statics. Basically the study of non moving systems (ie structues like bridges and buildings). The math is surprisingly easy and it was one of my easier classes.
Fluid dynamics on the other hand still gives me nightmares…
Engineer here, we learned how to do this in a class called statics. Basically the study of non moving systems (ie structues like bridges and buildings). The math is surprisingly easy and it was one of my easier classes.
Fluid dynamics on the other hand still gives me nightmares…
The architects don’t do that, that’s for engineers. We have a few friends called equilibrium and superposition.
The architects don’t do that, that’s for engineers. We have a few friends called equilibrium and superposition.
Civil Engineer here. There are plenty of great answers here that dig into a lot of important details, but in the spirit of ELI5, I will try to do specifically that…
Different parts of a structure will be pushed or pulled or twisted in different ways depending on a bunch of different factors. This pushing, pulling, or twisting can cause things to break. An engineers job is to figure out all of the different pushes, pulls, and twists the structure will have to deal with under the most extreme cases, figure out what parts are most likely to break, and then choose the proper shapes, sizes and materials of all the parts to make sure nothing breaks under the most extreme cases.
That’s more engineering.
But from an architecture point of view; you should have a rudimentary grasp of material strengths (tensile strength of building materials) and structural strengths (like arches, load bearing pillars or pylons)
Safety factor vary by structure type, region, design methodology, etc… Most civil and structural engineers will set the limits at 4 or above for critical structures where loss of life is probable if it fails. This helps to account for conditions that go beyond the maximum loading (which is already generous), but more importantly, it allows for the non homogeneous nature of most of the materials that are used in daily construction. Steel is fairly uniform, but it’s exposure to the elements can and will degrade its section integrity over time. Reinforced concrete can have pocketed aggregate, voids, misplaced rebar, etc… Soil, even select material can vary greatly from load to load. Wood varies by direction of grain, wood type, treatment methods, and knot placement as well.
Additional factors such as historical data for wind, snow, earthquake magnitude, and other natural loads is still being developed and we don’t know the true risk factors. Items such as vehicle weights and maximum loading of trucks and rail cars has also increased greatly over the years. All of these things contribute to the need to apply generous overdesign to these types of structures.
Safety factor vary by structure type, region, design methodology, etc… Most civil and structural engineers will set the limits at 4 or above for critical structures where loss of life is probable if it fails. This helps to account for conditions that go beyond the maximum loading (which is already generous), but more importantly, it allows for the non homogeneous nature of most of the materials that are used in daily construction. Steel is fairly uniform, but it’s exposure to the elements can and will degrade its section integrity over time. Reinforced concrete can have pocketed aggregate, voids, misplaced rebar, etc… Soil, even select material can vary greatly from load to load. Wood varies by direction of grain, wood type, treatment methods, and knot placement as well.
Additional factors such as historical data for wind, snow, earthquake magnitude, and other natural loads is still being developed and we don’t know the true risk factors. Items such as vehicle weights and maximum loading of trucks and rail cars has also increased greatly over the years. All of these things contribute to the need to apply generous overdesign to these types of structures.
r/realcivilengineer would be so mad right now.
Architects don’t do the calculations, engineers do.
That’s more engineering.
But from an architecture point of view; you should have a rudimentary grasp of material strengths (tensile strength of building materials) and structural strengths (like arches, load bearing pillars or pylons)
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