Comment by ZeroGravitas
1 day ago
Building to protect occupants and building to make the structure salvageable afterwards may be two different goals. Think crumple zones in cars.
1 day ago
Building to protect occupants and building to make the structure salvageable afterwards may be two different goals. Think crumple zones in cars.
This is not a good analogy.
Crumple zones in cars exist under the assumption that they will not be occupied by humans. In a house, on the other hand, any place could have a person inside of it during an earthquake, meaning that basically the entire house would need to stand to avoid any human being hurt.
I'm not an architect and don't live in an earthquake zone, but I was under the impression that wooden homes flex in earthquakes and if and when they do fall on you, do less damage than concrete homes which are stiff up until a point and then crack and fall.
So the human surviving may come at the cost of more houses collapsing.
Can personally confirm. Wooden houses do flex and often survive unscathed. The only major damage is usually due to any masonry attached to the house (see: chimney) or the house moving off of the foundation (see: before ties were in the building code).
It absolutely happens in steel and concrete construction in earthquake loading, when loading past the smaller earthquakes.
Plastic/non-linear deformation is intended in shear panels of steel connections and the core of well confined concrete beams/columns. The idea is to provide a lot of energy damping due to the nonlinear nature of the f*D hysteresis curve. This works long enough for the earthquake to go away and the people to get out of the building, at which point, you need a new building but hopefully no one has died.
Nice point. Still, in wast majority of cases, house keeps standing -> habitant survival chance goes up.
Cars being on the move, makes that distinction much much more relevant
For inhabitant survival a sifficient goal is something like “remains structurally intact for ~30 minutes after the end of the earthquake”. Which is significantly leas than is required for staying habitable
Makes sense.
I was fixating on the opposition of goals in the car (if car doesn’t bend/deform, then death risk increases).
Where is the crumple zone in the burned out buildings in California?
Evacuation. Hardly anyone died in these fires.
That's traffic lights, not crumple zones.