A researcher from the University of California, San Diego checks monitoring equipment in front of a six-story building that is undergoing a series of earthquake tests on a giant shake table, to see how the steel frame structure would fare in a major temblor, in San Diego Wednesday, June 15, 2016.
加州 圣迭戈 大学的一个研究团队，对一栋6层的建筑在振动台上进行了一系列的地震测试。在世界最大的室外振动台。
SAN DIEGO (AP) — California researchers plan to rock and rattle a six-story steel-frame building on the world’s largest shake table to see if the structure can withstand the force equal to a 6.7-magnitude earthquake.
Engineers at the University of California, San Diego, hope the experiment Wednesday will help them determine whether steel frames are a better option than wood frames for tall buildings in earthquake-prone areas.
The construction industry is interested in building tall, steel-frame residential buildings because they are cheaper, faster and more durable than wood-frame buildings.
Wood frames are also known to collapse as well as catch fire during major earthquakes.
The six-story building was built in a week and will undergo a simulation of the Northridge quake, which caused significant damage to the Los Angeles area in 1994.
SAN DIEGO (AP) — Researchers at the University of California, San Diego rocked and rattled a six-story steel frame building on a giant shake table Wednesday to see how the structure would withstand major earthquakes.
The towering building jolted, shuddered and let out a hollow, grinding sound but remained standing as drones peeked in its windows. The water heaters and at least some of the flat-screen TVs seemed to remain in place, though researchers still need to review the drone footage to see exactly how the building fared inside and out.
The event was a simulation of the 6.7-magnitude Northridge quake. That temblor caused heavy damage to the Los Angeles area in 1994.
The test is part of a $1. 5 million, three-week series of tests aimed at determining whether the lightweight steel structure is a better option than wood frame structures for tall, residential buildings in earthquake-prone areas like California.
The six-story structure built in about a week and designed to replicate a multi-family residential building is the tallest building of its kind to ever undergo such tests. It is equipped with appliances, such as water heaters and stoves, which could potentially ignite a fire during an earthquake.
“What we are doing is the equivalent of giving the building an EKG to see how it performs after an earthquake and a post-earthquake fire,” UC San Diego structural engineering professor Tara Hutchinson said.
Over the next few weeks, the building will undergo more intense simulated quakes, including California’s 7.2-magnitude Cape Mendocino earthquake in 1992 and the 8.8-magnitude temblor in Maule, Chile in 2010.
Later, researchers from Worcester Polytechnic Institute will set rooms on fire to test the frame’s resistance.
Hard-hatted scientists, engineers, earthquake safety experts and news media witnessed the tests Wednesday. Small drones flew in and around the building to map the structure and assess damage. More than 250 sensors, more than 40 video cameras, and a GPS system were also in the building, gathering data. Some sensors are sensitive enough to detect movements caused by the wind.
Researchers also want to know whether drones equipped with heat-detection cameras could be used to find survivors and assess damage after earthquakes and the fires that often follow the temblors.
As part of the tests, researchers will ignite pans of heptane, a liquid fuel, in eight rooms on the second and sixth floors to achieve temperatures as high as 1,000 degrees Celsius — almost 2,000 degrees Fahrenheit. Using temperature probes and video cameras, the researchers will assess how damage from the simulated earthquakes affects the fire protection systems.
The engineers expect the building to fare well in all the tests, in part because the structure is lighter than a concrete building of the same height, making it more flexible and easier to move with the shaking rather than resist it.
The project is supported by a coalition of government agencies, foundations and industry partners including tAt the end of the testing, the building will be put to its biggest test — a simulated earthquake that is stronger than what the structure was designed to withstand.
The largest building of this construction type tested before on the giant shake table was a two-story residential structure in 2013.he U.S. Department of Housing and Urban Development, the California Seismic Safety Commission and partners from the steel industry and insurance companies.
Copyright 2016 The Associated Press.