UTArlington - The University of Texas at Arlington Magazine

Building to Survive Earth’s Killer Crust

Earthquakes can’t be stopped or predicted, but they can be understood. Research by UT Arlington scientists and engineers shows promise in mitigating the types of disasters that recently devastated Japan and Haiti.

On a pleas­ant March after­noon ear­lier this year, Paul Hayashi and his dog were tak­ing one of their twice-daily strolls along red brick foot­paths in a pic­turesque neigh­bor­hood park in Katori, Chiba Pre­fec­ture, Japan. Dr. Hayashi, an eco­nom­ics pro­fes­sor emer­i­tus who retired in 2002 after 35 years at UT Arling­ton, returned to his native Japan in 2004 with his wife.

That lit­tle park is a haven of seren­ity undis­turbed by Tokyo’s mas­sive Narita Inter­na­tional Air­port nearby and the crush of a pop­u­la­tion exceed­ing 30 mil­lion in Greater Tokyo on the island of Hon­shu. But at 2:46 p.m. March 11, 2011, as Hayashi and his dog ambled toward a rose gar­den, the land sud­denly pitched and rolled in vio­lent undu­la­tions that lasted about 10 sec­onds. They had to sit down on the heav­ing ground.

“I could not stand still,” he says.

Hayashi instantly rec­og­nized an earth­quake. He grew up with quakes and after­shocks. Japan annu­ally endures 1,500 quakes of vary­ing inten­sity, the seis­mic con­se­quence of Earth’s colos­sal, unpre­dictable tec­tonic mess.

Like an eggshell bro­ken into jagged pieces, Earth’s crust com­prises 15 major slabs of rock 50–250 miles thick. These tec­tonic plates float in all direc­tions at up to 20 cen­time­ters a year, col­lid­ing with and side­swip­ing and over­lap­ping each other. In time, their stressed bound­aries can rup­ture, releas­ing pent-up energy.

On March 11 off Honshu’s north­east coast, extra­or­di­nary stress had built up in a fault where the vast Pacific plate slides beneath the North Amer­i­can plate and Japan itself, accord­ing to a United States Geo­log­i­cal Sur­vey (USGS) analy­sis. In an instant, the fault frac­tured, thrust­ing up into the sea 130 feet along an area 190 miles long and cre­at­ing a monster—the fifth-largest earth­quake in recorded history.

“I could not believe I was expe­ri­enc­ing an earth­quake of that mag­ni­tude,” Hayashi says. “It was fright­en­ing. When I returned home, my wife and I talked about how bad the earth­quake was. Our dogs were so fright­ened that they refused to go to their room.”

The Hayashis soon learned that the epi­cen­ter of a mag­ni­tude 9.0 quake was just 231 miles north­east of Tokyo, where observers described high-rise build­ings sway­ing like trees in the wind.

Worse, a mas­sive quake-spawned tsunami breached sea­walls at the Fukushima Dai­ichi nuclear power plant 150 miles north of Tokyo. Inun­dated, the plant lost power, which led to a melt­down in three of its six reac­tors. The tsunami washed away tens of thou­sands of struc­tures and vir­tu­ally every­thing in its path—factories, ship­ping oper­a­tions, trans­porta­tion systems—along hun­dreds of miles of coast­line and for miles inland.

The twin dis­as­ter left 25,000 peo­ple dead or miss­ing and an offi­cial esti­mate of at least $259 bil­lion in dam­age. A cat­a­strophic blow to life and com­merce, includ­ing the auto and high-tech indus­tries, it left Japan’s econ­omy reeling.

MINIMIZING THE DESTRUCTION

There’s no stop­ping or pre­dict­ing such events. But a detailed under­stand­ing of plate tec­ton­ics and related mat­ters is emerg­ing that can help antic­i­pate them. Mean­while, earthquake-focused research explores con­struc­tion mate­ri­als and tech­niques that should vastly improve the abil­ity to with­stand a quake’s vio­lent impact. Four UT Arling­ton fac­ulty mem­bers are immersed in these labors.

Pro­fes­sor Pamela Jansma, dean of the Col­lege of Sci­ence, spe­cial­izes in neo-tectonics, exam­in­ing the move­ment of Earth’s crust to find ways of pre­dict­ing earth­quakes. Her hus­band, earth and envi­ron­men­tal sci­ences Pro­fes­sor Glen Mat­ti­oli, uses satel­lite and ter­res­trial geo­detic tech­niques to study earth­quake– and volcanic-induced ground deformation.

Shih-Ho “Simon” Chao, assis­tant pro­fes­sor in the Depart­ment of Civil Engi­neer­ing, con­cen­trates on devel­op­ing designs and con­struc­tion mate­ri­als to bet­ter with­stand vio­lent shak­ing. A native of seis­mi­cally active Tai­wan, Dr. Chao was inspired to pur­sue his Ph.D. after expe­ri­enc­ing a 7.7 quake in Tai­wan in 1999 that irrepara­bly dam­aged 10,000 build­ings, killed 3,000 peo­ple, and left more than 100,000 homeless.

He some­times part­ners with soil expert Anand Pup­pala, a dis­tin­guished teach­ing pro­fes­sor of civil engi­neer­ing. With two grants, includ­ing one from the National Sci­ence Foun­da­tion Major Research Instru­men­ta­tion pro­gram, Dr. Pup­pala is research­ing how expan­sive soils are tested and how to sim­u­late earth­quake load­ing on unsat­u­rated soils. Find­ings could lead to improved con­struc­tion practices.

He also col­lab­o­rates with Asso­ciate Pro­fes­sor Lau­re­ano Hoyos on devel­op­ing a tri­ax­ial test­ing tool to mea­sure soils’ reac­tion to seismic-type dynamic load­ing in dif­fer­ent moistures.

All work with a sense of urgency, well aware of the world­wide toll in death, destruc­tion, and eco­nomic loss. Last year alone, the USGS recorded 21,541 quakes that killed 226,729 people—the dead­liest year since 2004. This year’s Great East Japan Earth­quake drew intense inter­est from the UT Arling­ton fac­ulty members.

Chao notes that lim­ited dam­age in Tokyo reflected how Japan’s earth­quake expe­ri­ence has led to highly advanced build­ing codes and engi­neer­ing. Cal­i­for­nia, rid­dled with geo­log­i­cal faults, needs more mate­ri­als and inno­v­a­tive engi­neer­ing like Japan’s in prepa­ra­tion for “the big one” that’s expected at any time, he says.

Chao is prin­ci­pal inves­ti­ga­tor for an engi­neer­ing team that, with a $1 mil­lion, three-year NSF grant, is research­ing the earth­quake resis­tance of rein­forced con­crete build­ings and how they react in extreme con­di­tions, issues about which “there are many unknowns.”

Much of the research is under way at the Uni­ver­sity of Minnesota’s Multi-Axial Sub­assem­blage Test­ing Lab­o­ra­tory, where the effects of an earth­quake can be sim­u­lated. There, researchers can shake rein­forced con­crete beams until they collapse.

The work exam­ines a building’s sur­viv­abil­ity when high-performance steel fibers replace most con­ven­tional rebar in con­crete. In related work with a $600,000 NSF grant, Chao is look­ing for designs in steel trusses that will make them prac­ti­cal for build­ings con­structed in earthquake-prone locales. He hopes to pro­vide engi­neers, archi­tects, and oth­ers in related indus­tries with new approaches to the seis­mic design of structures.

“New tech­nolo­gies, design meth­ods, and mate­ri­als could min­i­mize the losses in life and prop­erty,” he says.

MAXIMIZING SURVIVABILITY

That’s an essen­tial step toward society’s abil­ity to sur­vive earth­quakes, Mat­ti­oli says. “It’s not the ground shak­ing that kills peo­ple. It’s the falling objects” as build­ings, bridges, dams, and other struc­tures collapse.

“Sur­viv­ing earth­quakes is related to vul­ner­a­bil­ity and is largely a socioeconomic/political issue. But since most of the world’s pop­u­la­tion lives very close to major con­ver­gent or strike-slip bound­aries capa­ble of gen­er­at­ing mag­ni­tude 8.0 events, and most of the world’s pop­u­la­tion is poor, the expo­sure to earth­quake haz­ard is increas­ing and there­fore so is the risk.”

That sketches con­di­tions in much of the Caribbean, where Drs. Mat­ti­oli and Jansma have long focused their research. Their urgency increased after the 7.0 earth­quake that rocked Haiti in Jan­u­ary 2010.

That tem­blor, the worst in the area in 200 years, dev­as­tated the west­ern hemisphere’s poor­est coun­try and its cap­i­tal, Port-au-Prince, which was 10 miles from the epi­cen­ter in an area where the vast Caribbean and North Amer­ica plates meet. Col­laps­ing struc­tures, often built as cheaply as pos­si­ble, caused many of the esti­mated 230,000 deaths, the dis­place­ment of 1.5 mil­lion peo­ple, and an esti­mated $8 bil­lion in damage.

Much of down­town Port-au-Prince was reduced to rub­ble. Struc­tures slid down defor­ested hill­sides, crash­ing into and atop each other. An esti­mated 380,000 chil­dren were orphaned. Mat­ti­oli arrived in Haiti by Jan. 28 to gather data with a team of researchers from other universities.

“The dev­as­ta­tion and human suf­fer­ing were stag­ger­ing,” he says.

The team blogged daily about its work and the quake’s after­math. “There is no way to prop­erly describe the level of destruc­tion and havoc,” the researchers wrote. “It will be months before this city and many of those who per­ished will be dug out.”

As with Mat­ti­oli, Jansma was deeply sad­dened, but not sur­prised. She and her col­lab­o­ra­tors have worked in the north­east­ern Caribbean on active tec­ton­ics and seis­mic haz­ard for 20 years. “Hear­ing about the Haiti earth­quake really hit home. I knew imme­di­ately that the dev­as­ta­tion would be sig­nif­i­cant and traumatic.”

Just a year ear­lier, she, Mat­ti­oli, and a group of Pur­due Uni­ver­sity sci­en­tists pub­lished a paper warn­ing that Haiti faced the immi­nent threat of a strong earth­quake. Another major event is likely, she says.

They col­lab­o­rated with researchers at other uni­ver­si­ties to deter­mine what trig­gered the Jan. 12 quake. Study­ing years of data, the sci­en­tists found strong evi­dence of the cause: the rup­ture of the pre­vi­ously unmapped Léogâné fault. Their result­ing paper was pub­lished in the jour­nal Nature Geo­science.

“What has become very appar­ent as a con­se­quence of Japan and Haiti,” Jansma says, “is the increased risk that haz­ards present as the world’s pop­u­la­tion grows and that increased under­stand­ing and mon­i­tor­ing of haz­ards is essen­tial to mit­i­gate those increased risks.”

A huge step for­ward involves refin­ing the satellite-driven global posi­tion­ing sys­tem, which trans­formed the field of neo-tectonics. From space, “we can now mea­sure move­ments of Earth’s sur­face on the order of a few mil­lime­ters,” Jansma says. “This allows us to under­stand defor­ma­tion processes at a level that was not pre­vi­ously possible.”

A sig­nif­i­cant advance in such capa­bil­ity is the Con­tin­u­ously Oper­at­ing Caribbean GPS Nat­ural Haz­ards Obser­va­tional Net­work (COCONet), which cre­ates a link of global posi­tion­ing sta­tions for the inter­na­tional geo­science com­mu­nity. Data is trans­mit­ted to an archive at Boul­der, Colo.-based UNAVCO, a uni­ver­sity con­sor­tium funded by the NSF and NASA.

Mat­ti­oli is a key player in shap­ing COCONet’s circum-Caribbean oper­a­tion. He believes its prospects are excel­lent, not­ing Japan­ese sci­en­tists’ suc­cess with the 600-site GPS in their coun­try. The system’s data helped project an 8.0 quake where the March 11 mag­ni­tude 9.0 quake occurred.

A major chal­lenge is that prepa­ra­tion for such events, par­tic­u­larly in the con­struc­tion indus­try, is far from per­fect. Sur­viv­abil­ity can’t be assured. But as earth sci­en­tists and engi­neers press for­ward, they strengthen the abil­ity to con­tend with seis­mic forces.

For Hayashi and all who are vul­ner­a­ble to quakes, life goes on. He still takes his dog, Fluffy, on daily walks through the park, where dam­age was min­i­mal. The rose gar­den is still there, and the red brick footpaths.

But so are the nearby tec­tonic pow­ers that could destroy it all in seconds.

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