| Earthquake Proof House - Science Insider
Reported November 2007
BACKGROUND: In natural disasters such as earthquakes or hurricanes, the biggest danger doesn’t come directly from the shaking or the winds, but from debris. In both cases, broken glass becomes deadly shrapnel. Architectural engineers at Pennsylvania State University are investigating the behavior of glass and walls during earthquakes to come up with better strategies for building windows and walls able to withstand earthquakes and other natural disasters.
WINDOW TREATMENT: During an earthquake, a building’s frame or skeleton will sway with the tremors. The frames that hold the glass window planes in place change shape as they shift along their joints. Yet the glass remains rigid. Pressure builds on the corners of the glass, and chips and cracks begin to form. The Penn State researchers built a model wall and window frame and used an actuator to simulate the effects of an earthquake, noting points of failure. They concluded that if the corners of a sheet of glass are rounded, and the edges processed, this shifts the point of stress concentration so the window frame can move without breaking the glass.
OFF THE WALLR: The engineers have devised another system to help prevent the collapse of certain types of walls during an earthquake. Usually masonry infill walls are used in conjunction with beams and columns to form the structure’s “skeleton,” thereby bearing the weight. But an earthquake gives rise to the same kinds of stresses exhibited by glass window panes. A potential solution is to add steel reinforcement into the infill wall and tie the wall to the building’s frame. Another solution is to add a gap between the walls and the frame. This prevents interactions during earthquakes, although one would sacrifice some of the stiffening power added by infill walls. The Penn State team opted for middle ground: instead of isolating the walls completely, they used a hockey-puck-like fuse to connect the wall to the frame, providing support, but also serving as a buffer during seismic events.
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The American Geophysical Union, the American Society of Civil Engineers, the Institute of Electrical and Electronics Engineers, Inc., the Incorporated Research Institutions for Seismology and, the Materials Research Society contributed to the information contained in the TV portion of this report.
If you would like more information, please contact:
Ali M. Memari, Ph.D., P.E., Associate Professory
The Pennsylvania State University
(814) 865-3367
amm@engr.psu.edu
Institute of Electrical and Electronics Engineers, Inc.
IEEE-USA
Washington, DC 20036-5104
(202) 785-0017
http://www.ieee.org
ieeeusa@ieee.org
The American Society of Civil Engineers
Reston, VA 20191-4400
(703) 295-6404
http://www.asce.org
American Geophysical Union
Washington, DC 20009-1277
1 (800) 966-2481
http://www.agu.org
Incorporated Research Institutions for Seismology,
Taber, Education & Outreach
Program Manager
Washington, DC 20005
(202) 682-2220
taber@iris.edu
Materials Research Society
Warrendale, PA 15086-7573
(724) 779-3003
webmaster@mrs.org
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