English: Mexico City Earthquake, September 19, 1985. Eight-story frame structure with brick infill walls broken in two. The foundation also came off. Credit: U.S. Geological Survey Department of the Interior/USGS/I.D. Celebi Source:http://libraryphoto.cr.usgs.gov/cgi-bin/show_picture.cgi?ID=ID.%20Celebi,%20M.%2024ct (Photo credit: Wikipedia)
I always wonder how large buildings will sustain a large earthquake since both my husband and I work in high rise buildings.
I recently found an article that reviews possible scenarios with earthquakes and how various buildings will handle the stress from the shaking ground. What I discovered was interesting and a bit scary…
First, when it comes a 9.0+ earthquake many scientists really don’t know how “skyscrapers” will handle the prolonged seismic activity. For one thing, severe earthquakes are rare (thankfully) and the large earthquakes aren’t always striking urban landscapes.
Bottom line, we don’t really know.
There are some simulations that help illustrate what could possibly happen and the results were interesting. There is a theory that with a large 9.0 earthquake that tall buildings could possibly collapse since they are not designed to severely sway for up to 5 minutes. A wood-framed small home (per this research) could sustain the 9.0+ earthquake and possibly get out with broken windows and of course, damaged contents. A brick building might partially collapse under the stress.
Here is the interesting part… say if you have a 7.0 earthquake (think Haiti) – which are often times shallow with a short and abrupt land movement for up to 60 seconds… these earthquakes could slide a wood-framed home off of its foundation, the brick building could totally collapse and the “skyscraper” might have minor damage.
The article also alluded to findings after the 1985 Mexico City earthquake and in that quake (around an 8.1 on the Richter scale) the small and tall buildings survived. Buildings with 6-15 floors had a difficult time absorbing the shock waves therefore 60% of the buildings in this size range were significantly damaged or collapsed.
How a building performs is the condition of the shaking and the engineering/design of the structure.
Whatever building type that you and your family live, work, or reside in… may it always be safe.
Source:
http://www.iris.edu/hq/files/programs/education_and_outreach/retm/tm_100112_haiti/BuildingsInEQs.pdf
Related articles
- Seismic Moment: The True Cost of Earthquakes (creditloan.com)
Cascadia Earthquake 