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posted by cmn32480 on Saturday November 07 2015, @02:41PM   Printer-friendly
from the I-feel-the-earth-move-under-my-feet dept.

Arthur T Knackerbracket has found the following story:

Given the choice between safer and cheaper construction, many housing design companies in earthquake-prone developing countries see themselves forced to save on expensive construction materials and opt for the latter. EPFL structural engineers have gathered new data on how these structures respond to earthquakes, and in which circumstances they may fail.

Earthquakes almost never kill people by themselves. Instead, the high toll they take can be explained by a lack of resilient buildings and infrastructure. In Chile in 2010, many thin-walled reinforced concrete buildings were damaged in one of the strongest earthquakes ever recorded. Yet today, more and more structures with even thinner walls are being built in some Latin American countries. Recently, engineers from EPFL evaluated the stability of thin reinforced concrete walls to understand how they fail. Their findings are published in the journal Bulletin of Earthquake Engineering.

To find out how very thin-walled structures behave in an earthquake, João Almeida and Angelica Rosso, two of the study's authors, tested two 80-millimeter-thick, 2-by-2.7-meter wall segments, similar to those used in low-income housing projects in some South American countries. By clamping the wall segments to the floor of the laboratory and loading them with five actuators strong enough to slowly bend the walls back and forth in different directions, they simulated the impact of an earthquake on the structure. By slowing down the process the researchers had time to watch the damage spread and to find out how cracks propagate across the wall, ultimately destabilizing it.

"The data we gathered in our experiment is unique," says Katrin Beyer, the principal investigator of the study. "It is the first to contain detailed measurements of a so-called out-of-plane wall failure, which means that the wall structure was irreversibly deformed perpendicularly to its surface." According to Beyer, it was also the first time that displacements greater than the wall thickness itself had been observed under these conditions. By the end of the test, the wall's reinforcement bars had bent, with the concrete crumbling in one corner of the structure. Thanks to an array of sensors, cameras, and strain gauges, the researchers were able to capture and analyze every motion leading up to the collapse of the wall.


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  • (Score: 2) by Grishnakh on Sunday November 08 2015, @04:12AM

    by Grishnakh (2831) on Sunday November 08 2015, @04:12AM (#260236)

    Show me some 2000yo buildings in a place that has tectonic activity.

    I've never heard of any earthquakes near Rome.

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  • (Score: 3, Informative) by soylentsandor on Sunday November 08 2015, @10:16AM

    by soylentsandor (309) on Sunday November 08 2015, @10:16AM (#260284)

    I've never heard of any earthquakes near Rome.

    Apart from the fact that the Romans built in concrete all over their empire, the last earthquake near Rome was in 2013 [reuters.com].
    Furthermore, the wikipedia page for the Colosseum [wikipedia.org] even specifically mentions earthquake damage to it. For an example of a building with less damage to it, see the Pantheon [wikipedia.org]. It's only about 40 years younger.

  • (Score: 1) by angelosphere on Tuesday November 10 2015, @07:56PM

    by angelosphere (5088) on Tuesday November 10 2015, @07:56PM (#261405)

    Napoli? Pompeii? How many cities should I name you?
    Italy is one of the most earth quake prone zones in Europe.