San Diego, CA, March 26, 2007 -- Sixth-grade students from Carmel Del Mar Elementary School shrieked with unabashed amazement about 2 p.m. Tuesday at a UC San Diego earthquake-safety research complex eight miles east of campus. All but one of the seven-story buildings constructed by 20 teams of students in their classrooms toppled during Tuesday’s quake test, with K’NEX rods, connectors, and building parts scattered across the surface of UCSD’s largest shake table.
The noisy learning experience was part of a unique earthquake-safety competition organized by Philip Yu, a graduate student in the Jacobs School of Engineering’s structural engineering department, and involved more than 1,100 fifth- and sixth-grade students from schools in Escondido and Del Mar. UCSD faculty also helped, as did scientists with the National Science Foundation, the federal agency that funded the construction of the shake facility at the Englekirk Structural Engineering Center.
Participating students were required to present carefully documented project descriptions at each day’s competition. Their buildings, about the size of bird cages, were judged on the basis of cost, with each plastic part carrying a price tag, with the maximum possible cost of a building set at $1.5 million. Aesthetics and how well the plastic creations withstood powerful jolts were also part of each team’s overall score.
Yu, who also is past president of the UCSD student chapter of the Society of Civil and Structural Engineers, recruited fellow graduate students to serve as competition judges. They carefully evaluated the design of each K’NEX building and asked each team of budding engineers about strike-slip faults and other geological features involved in earthquakes.
“We try to make all the learning that takes place in the classroom relevant to kids, but often they ask, ‘Why do we need to understand earthquakes?’ ” said Linda Dugger, a science teacher at Carmel Del Mar. “This is a realistic project that puts all of that into perspective.” Sixth-graders Christopher Phan, Calvin Kim, and Ryan Doriguzzi cheered wildly as Tuesday’s shake ended. Their building was the only one left standing.
The happy sixth-graders’ structure was a combination of engineering and art. They placed diagonal braces at strategic locations in the building and topped the structure with a serpentine arrangement of K’NEX connectors. The aesthetic flourish added additional cost to the building, but the students thought it was well worth it in another way. “In ancient China, dragons gave you good luck,” said a smiling Phan after the Tuesday shake.
Earthquake-safety researchers at UCSD are interested in many of the same criteria that the students were required to consider in designing their project. Last year, UCSD researchers built a much larger version of the students’ K’NEX models: a seven-story building section. They tested a new theory that mid-rise, steel-reinforced concrete apartments, condominiums and hotels can be built to survive powerful earthquakes with less steel reinforcement than currently required by California building codes. The goal of an industry-sponsored testing was to optimize the balance between strength and flexibility, two key parameters of design that affect the performance of buildings during earthquakes.
Those tests on the 25-foot-by-40-foot shake table were funded by California contractors. One of the contractors’ colleagues, Robert Englekirk, also is UCSD adjunct professor of engineering. Englekirk has championed the development of more suitable building codes in Southern California, and he has used full-scale building tests at the center he helped found as a way to change the codes.
Some of the 1,100 students participating in the quake competition also mentioned the balance between strength and flexibility as part of their designs. When asked why his team used diagonal braces in their design, Carmel Del Mar sixth-grader David Leonard used his index finger to demonstrate that an angled building brace actually supports vertical and horizontal forces. He said a vertical brace would more easily snap during a quake. “It’s just sort of common sense,” he said.
All of the students involved in last week’s competition were born after the 1994 Northridge earthquake, whose ground motions were duplicated during the school competition. Northridge resulted in about 60 deaths, more than 7,000 injured, 20,000 homeless, and more than 40,000 buildings damaged in Los Angeles, Ventura, Orange, and San Bernardino Counties. The death toll and roughly $40 billion in property damage prompted the call for more scientific testing of buildings and other structures.
After the tests, many of the students talked about the human toll as if their plastic models had been real buildings. That’s just the kind of relevance that the participating schools had hoped to achieve.
“Hopefully, these will be future engineers and, obviously, future home buyers, or builders themselves,” said Dugger, the science teacher. “Now they understand what goes into providing an opportunity to design a plan that would be selected to be purchased and built.”