Agriculture
Middle school science adventures
Cleaning Up Fish Farms
Earth-Friendly Fabrics
Amphibians
Salamanders
Tree Frogs
Newts
Animals
A Whale's Amazing Tooth
Insects Take a Breather
Spotting the World's Leggiest Animal
Behavior
Hitting the redo button on evolution
Surprise Visitor
Storing Memories before Bedtime
Birds
Turkeys
Doves
Storks
Chemistry and Materials
When frog gender flips
Watching out for vultures
The memory of a material
Computers
A Classroom of the Mind
The Earth-bound asteroid scientists saw coming
Earth from the inside out
Dinosaurs and Fossils
Dino Takeout for Mammals
An Ancient Feathered Biplane
South America's sticky tar pits
E Learning Jamaica
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Earth
Science loses out when ice caps melt
Petrified Lightning
On the Trail of America's Next Top Scientists
Environment
Eating Up Foul Sewage Smells
A Stormy History
The Best Defense Is a Good Snow Fence
Finding the Past
Settling the Americas
Words of the Distant Past
Ancient Cave Behavior
Fish
Swordfish
Catfish
Pygmy Sharks
Food and Nutrition
Strong Bones for Life
How Super Are Superfruits?
The Essence of Celery
GSAT English Rules
Adjectives and Adverbs
Pronouns
Finding Subjects and Verbs
GSAT Exam Preparation Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
How are students placed after passing the GSAT exam
March 21-22, 2013: Over 43,000 students will take the GSAT Exam
GSAT Exams Jamaica Scholarships
GSAT Exam Preparation
GSAT Scholarship
Results of GSAT are in schools this week
GSAT Mathematics
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
42,000 students will sit for the GSAT Exam in two weeks
GSAT Mathematics Quiz, Teaching Math, teaching anxiety
Human Body
A Sour Taste in Your Mouth
Cell Phone Tattlers
Speedy Gene Gives Runners a Boost
Invertebrates
Scallops
Camel Spiders
Sea Urchin
Mammals
Marmots
Antelope
Deers
Parents
Raise a Lifelong Reader by Reading Aloud
How children learn
Choosing a Preschool: What to Consider
Physics
Dreams of Floating in Space
Road Bumps
Electric Backpack
Plants
Pumping Up Poison Ivy
Seeds of the Future
Stalking Plants by Scent
Reptiles
Boa Constrictors
Reptiles
Crocodiles
Space and Astronomy
A Galaxy Far, Far, Far Away
Planet Hunters Nab Three More
A Very Distant Planet Says "Cheese"
Technology and Engineering
Sugar Power for Cell Phones
Bionic Bacteria
Squeezing Oil from Old Wells
The Parts of Speech
What is a Noun
Pronouns
Adjectives and Adverbs
Transportation
Ready, unplug, drive
Revving Up Green Machines
Flying the Hyper Skies
Weather
A Change in Climate
Weekend Weather Really Is Different
Either Martians or Mars has gas
Add your Article

Rocking the House

Imagine what it might be like if you were in your bedroom during an earthquake. Your bed shakes. Books and stuffed animals tumble from shelves. Your computer monitor skitters across your desk and crashes to the floor. The walls creak and groan as they flex. In a very big earthquake, your whole house could collapse. To get a better idea of what might happen to an ordinary house during an earthquake, engineers did an experiment—a big one. In one corner of a building the size of an airplane hangar, they built a townhouse. Then, they shook the house with the force of a large earthquake. The house, a full-scale model of an 1,800-square-foot townhouse like many found in California, is the largest wooden structure ever tested in a simulated earthquake, says Andre Filiatrault. He's a civil engineer at the State University of New York at Buffalo, where the test was conducted last November. So, why did researchers spend several weeks building a full-size townhouse, and then try to destroy it in seconds? First, tests of small models often don't provide accurate answers because the models are stiffer than full-size structures. Second, the researchers wanted to see how the townhouse moved and flexed as it experienced the strong vibrations. "Scientists don't really understand how wood-frame buildings perform in an earthquake," says Filiatrault. Usually, researchers get to look at buildings only after an earthquake has knocked them down, he notes. Finally, the researchers wanted to see what happened to furniture and other bulky items inside the home while the simulated earthquake rocked the house. With the help of Filiatrault's wife and children, the engineers decorated the house. They put dishes, silverware, a flower arrangement, and a pitcher of water on the dining room table. They furnished one bedroom like a college dorm room, one like a master bedroom, and one like a child's room. They even put a car in the garage. Then, during the test, they watched the action through eight webcams that they'd placed at various points throughout the house. Model home The townhouse tested in Buffalo, like 90 percent of the houses and apartment buildings built in the United States, has a wooden frame. This means the skeleton inside the walls of the building is made of lumber, usually a type of board called a two-by-four. The test home's inside walls were covered with drywall, and its outside walls were covered with large sheets of chipped wood that was glued together. The outside surfaces were coated with three layers of stucco, and then painted. The house even had windows and sliding-glass patio doors. The researchers installed hundreds of sensors in the home, including 75 sensors to monitor the accelerations caused by the shaking and 125 to measure how far various parts of the structure moved back and forth. The test home didn't have plumbing or very much electrical wiring, says John van de Lindt, a civil engineer at Colorado State University in Fort Collins. However, these items don't add much structural strength to a house, so the simulated earthquake test should provide accurate results, he notes. Test quake The model townhouse rested on a concrete slab that was bolted to two platforms called shake tables. Computer-controlled equipment moved the tables back and forth. Before the scientists conducted the big earthquake simulation, they did dozens of small tests. They did some of the tests after the wooden skeleton was built, and others after the sheets of drywall had been attached. Yet other tests were done after the stucco had been added. By comparing the results of these tests, engineers can figure out which individual parts of a home make it strong, van de Lindt explains. In the big test, the researchers simulated ground motions recorded during a magnitude-6.7 earthquake that struck Northridge, Calif., in January 1994. That quake, or temblor, killed 57 people. Sixteen of them died in a single, wood-frame apartment building. The earthquake caused about $10 billion in damage. Despite the intense shaking during the test, the model house didn't collapse. The windows didn't even break. But furnishings were tossed about, drywall cracked, and stucco fractured. (To see webcam videos of the shaking, go to nees.buffalo.edu/projects/NEESWood/video.asp . For more details, go to www.sciencenews.org/articles/20061223/bob11.asp and nees.buffalo.edu/projects/NEESWood/ .) The researchers made several important findings. Early analyses show that drywall on the inside surfaces of outside walls adds to a house's strength. The tests also settled a long-standing debate about whether stucco can provide structural support for a building. The answer is yes, says Filiatrault. What's next? For the next 2 years, Filiatrault, van de Lindt, and the other members of their team will use the data they gathered during their tests to improve computer programs that engineers use to design and analyze wooden structures. They'll also use information that they discovered when they disassembled the house after the tests. They know now, for example, which pieces of wood crack and where they break apart. In 2009, the engineers will put their new computer software to the test. That's when they'll design, construct, and test a six-story wood-frame building in Japan, on the world's largest shake table. Beyond improving design-and-analysis techniques, the test results may help engineers when they update building codes. A building code provides rules that builders must follow when putting up a house. The result could be safer houses. "More than 100,000 people lost their lives in earthquakes in the 20th century," Filiatrault says. "Maybe this test will save some lives in the future."

Rocking the House
Rocking the House








Designed and Powered by HBJamaica.com™