![]() “Well, for every different kind of infrastructure, there’s a different answer.” “How do you prepare any one of those infrastructure elements to better withstand an earthquake?” said Boulanger. To replicate the impact of an earthquake, scientists can house a built-to-scale model of infrastructure within the centrifuge’s bucket and see how it deforms through an earthquake. ![]() The high-speed spinning and shaking thrust upon the model help mimic quaking impact on a life-size structure. Physical modeling of this sort can validate analytical software tools and improve their prediction accuracy. In this manner, Boulanger has modeled a possible solution to prevent dam failure.īeyond this, scientists can evaluate solutions to withstand earthquakes. Earthquakes can liquefy loose soil the same way wet sand temporarily weakens under your feet at the beach. Decades-old dams built on soft soils can be prone to failure during earthquakes. Boulanger’s team tested the ability of walls made of cement mixed in with soil, known as soil-cement, placed at the foot of the dam to stop it from shifting during an earthquake. By creating an experimental model and testing it with the help of the centrifuge, they were able to assess any damage in meticulous detail. Using multiple sensors, the model’s response could be matched to the computer simulation and provide finer details. Structural integrity and vulnerability inform earthquake risk and impact. Scenario studies, crafted by experts from various fields of research, can gauge the level of risk involved and help inform the public and guide policy. In a different scenario study for the New Madrid Seismic Zone that stretches across Southern and Midwestern states, a magnitude 7.7 earthquake is predicted to lead to 3,500 fatalities, 82,000 injuries and economic losses of $300 billion.Ī scenario study for a magnitude 9.0, or “the big one,” along the Cascadia Subduction Zone, is estimated to result in more than 10,000 deaths, 30,000 injuries and an economic loss of $70 billion for the states of Washington, Oregon and California. “On the West Coast, we’ve been building for earthquakes for 50 years,” said Daniel Wilson, associate director of the CGM. “ they’ve never thought earthquakes were a major hazard - they did not build the infrastructure.” Lessons from earthquakes past That helps explain why the predicted damages from an earthquake along the Cascadia Subduction Zone may be lesser than any sustained in mid-America. With California bearing witness to numerous major earthquakes over the course of its recorded history, building codes have been updated to reflect lessons learned. The 1971 San Fernando and 1994 Northridge earthquakes resulted in soft story collapses and cracking in steel-frame buildings, leading to building code revisions across cities in California. “We’ve made very specific and tangible improvements in how we design our buildings,” said Amit Kanvinde, a professor in the Department of Civil and Environmental Engineering. As a structural engineer, Kanvinde uses software to model how a building, for example, would respond to being shaken by a specific earthquake. Using OpenSees, a proprietary software, Kanvinde can model a bridge, building or other structure being shaken by ground motions. This software can predict if a building will collapse or simply suffer damage - and even characterize the damage. ![]() Changes to building standards require money and time to be implemented, and while California does a lot of things right, there’s always room for more improvements, Kanvinde said. ![]()
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