Don't Rebuild on China Quake Faults, Experts Warn
Kevin Holden Platt in Beijing
for National Geographic News
|June 17, 2008|
Rebuilding should be banned along the tectonic faults that caused the massive May 12 earthquake, two scientists say.
The researchers had pinpointed China's Sichuan Province as a seismic hazard in a study released in 2007, ten months before the quake hit.
Fissures that cut through the Earth's crust where the Sichuan Basin collides with the eastern edge of the Tibetan Plateau could still give rise to a future seismic shock, according to Mike Ellis of the British Geological Survey.
"These faults remain active," said Ellis, co-author of the 2007 study that appeared in the journal Tectonics.
(Read more about plate tectonics.)
"There should be a no-building zone that envelopes the length of the active faults," Ellis told National Geographic News.
"Schools and hospitals should not be built within a critical distance of the faults, nor should any high-density population building be placed in a landslide hazard zone."
Alex Densmore of the Institute of Hazard and Risk Research at Durham University, who also co-authored the 2007 study, agreed that a buffer zone should border these faults, which stretch for about 150 miles (250 kilometers).
"If you put a building across a fault, it is literally going to be split in half," Ellis said.
The idea is not new: A buffer zone was created after the San Fernando earthquake in California in the 1970s, he said.
In China countless homes and schools constructed of unreinforced brick or concrete crumbled like sand castles during the quake, which killed about 70,000 people.
(Related story: "China Quake Delivered Seismic One-Two Punch" [May 15, 2008].)
Higher building standards and a buffer zone along the faults "could help cut the number of deaths during an earthquake by one or two orders of magnitude," Densmore said. "Instead of tens of thousands of people dying, maybe thousands or hundreds will die."
Recalling travels in Sichuan in recent years, Densmore said, "The rate of building in the area was astonishing.
"Development in the region has progressed farther and farther back into the mountains, toward the epicenter [of the May 12 quake]."
Five million people have become refugees since their homes were leveled, and the Chinese leadership and foreign aid groups are now scrambling to assemble temporary "tent cities" (see photo).
But the real challenge is to construct cottages, schools, hospitals, and communities reinforced to withstand any future temblor, experts say.
"With the exception of [quake-triggered] tsunamis, earthquakes do not kill people. Buildings kill people," said Guido Cervone of the Center for Earth Observing and Space Research at George Mason University in Virginia.
Architecture for Quake-Prone Areas
Scientists and building designers have made steady advances in creating seismically sound architecture, Cervone said.
The new China Central Television (CCTV) complex being built in Beijing by the Dutch architecture firm OMA, for instance, has been designed, reinforced, and tested to survive powerful earthquakes, said OMA architect Ole Scheeren.
The building's frame has already withstood hundreds of "extreme events" in intense experiments conducted by China's leading engineers, he said.
Improving the earthquake resistance of rural Chinese housing doesn't require such advanced technology, though.
Svetlana Brzev co-founded a Web project called the World Housing Encyclopedia (WHE), which shares information on how to create quake-resistant structures.
"A confined brick masonry earthquake-resistant house," said one WHE pamphlet, "is designed and constructed so that its walls are able to resist earthquakes. Its plan view must be simple and symmetrical. Its bearing walls must be well constructed and must always be confined by reinforced concrete columns and beams."
"Adobe and other forms of unreinforced masonry construction are proven 'serial killers' in many earthquakes worldwide," said Brzev, also an engineer at the British Columbia Institute of Technology in Canada.
"Unreinforced masonry seems to be a culprit in the earthquake-affected area in China," Brzev added.
Sudhir Jain, a professor at the Indian Institute of Technology in Kanpur, said WHE's simple manuals on reinforcing a building's beams and columns with steel designed to bend during a seismic shock could be popularized across China.
Architects inside China have begun calling for a system of checks and balances to prevent local officials, government-appointed builders, and inspectors from siphoning funds out of public construction projects, especially schools and hospitals.
Jiang Jun, founder of the architecture magazine Urban China, said, "China's Ministry of Construction is now carrying out a massive investigation into the public buildings that collapsed during the Sichuan earthquake and is drafting measures to prevent any more disasters in the future."
The government is expected to pass stricter laws on earthquake-resistant construction, approve a corps of independent engineers to inspect buildings nationwide, and begin retrofitting unsafe schools across China, he said.
As the superproject to rebuild Sichuan is launched, Jiang added, "China is likely to welcome the globe's leading earthquake engineers to help."
During a rare roundtable discussion on the earthquake and its destruction of haphazardly built schools, architect Liang Jingyu said the public and the media could help in the effort.
"The press needs complete freedom to investigate this earthquake and all public building projects in the future."
Even before that, earthquake experts and builders across China and worldwide could start meeting in cyberspace to create a safer future for Sichuan, Liang said.
His studio is helping set up a wiki platform that Chinese architects and international earthquake engineers can use to bounce ideas, blueprints, and technologies around the planet.
Worth the Cost
The extra expense of designing buildings to absorb seismic shocks seems cost-effective, experts say. For instance, adding counter-quake protections makes the cost of building a school only slightly higher.
Brian Tucker is the president and founder of GeoHazards International, an organization that works with locals around the world to devise or improve building codes.
"In polls conducted across the world, people say they are willing to spend more to make sure schools are safe for kids during earthquakes," Tucker said.
One of the group's main goals is to help international earthquake experts and architects transfer newer technologies to the rest of the world.
The group might join a China-based reconstruction project now being considered by the Organisation for Economic Co-operation and Development, which promotes democracy and market-based economies.
One aim, Tucker said, would be "helping China to design and build structures that absolutely must remain standing after an earthquake, like hospitals and schools."
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