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Roger Weller, geology instructor
by Matthew Stanley
Earthquakes are incredibly destructive forces of nature with the
ability to cause large loss of life and cost billions of dollars in repairs.
With such a destructive force always looming underground it is natural that
engineers are working to find ways to minimize damages and to keep these
buildings standing. One of the methods that these engineers test how a
structure will hold up is to use a device called a shake table. The shake table
is capable of simulating ground movements produced by earthquakes so that the
engineers can see what would occur if the structure was put under the stress of
Photo courtesy of https://www.asme.org/engineering
With the shake table engineers have found a way to make building more resistant to earthquakes. This is by using a self-centering system which means that the building is loose with open joints which cause it to sway during a quake and once the quake is over post-tensioning steel straightens the building back to its usual shape. This system was put to the test over a week, where it was tested against earthquakes of increasing intensity with the last test matching the motion of the 1995 Kobe earthquake which killed over 5,500 people and caused around $200 billion worth of damage. This test was a success especially for the fact that it withstood all the simulated quakes over the week.
Other ways that
buildings can be made more resistant to quakes is the shape that they are
built. Certain structural shapes are better suited to the shaking caused by
earthquakes such as a pyramid shape. This is used for many different
structures, primarily towers but shaping the building this way not only helps in
the case of an earthquake, but also helps with winds that can cause some
pressure on taller structures.
Photo courtesy of wikipedia.org
These methods as well as many other methods are all used to minimalize loss of life and damage caused. Though there will almost always be loss thanks to these engineers and their work earthquakes will not cause as much destruction as they normally can.