I thought concrete buildings without steel frames came down instantly in earthquakes. What am I missing?
Concrete buildings without sufficient bracing at the corners where supporting beams meet floors fail pretty much instantly in earthquakes for sure, but if you put bracing supports in at the corners then that makes them much, much stronger. You’re probably thinking that concrete buildings just collapse from your experience of post-earthquake film footage from countries with poor governance where building firms can cheap out on the construction (lets save 15% of our material costs by skipping the bracing!) and their buildings inevitably collapse when the next earthquake comes along.
Concrete buildings without sufficient bracing at the corners where supporting beams meet floors fail pretty much instantly in earthquakes for sure, but if you put bracing supports in at the corners then that makes them much, much stronger. You’re probably thinking that concrete buildings just collapse from your experience of post-earthquake film footage from countries with poor governance where building firms can cheap out on the construction (lets save 15% of our material costs by skipping the bracing!) and their buildings inevitably collapse when the next earthquake comes along.