A new study of high-sensitivity gravimeter and seismometer data—recorded just before and during the magnitude-9.0 earthquake on March 11, 2011, in Tohoku-Oki, Japan—describes a promising new data collection and analysis methodology that could give authorities time to issue advance warnings and secure vulnerable systems before earthquakes strike.
Structural engineer Cary Kopczynski once penned a prediction: “There may come a day in the not-too-distant future when concrete building structures will commonly be reinforced with a combination of steel fibers and steel reinforcing bar.
Since Los Angeles joined San Francisco Bay Area cities last October in tightening seismic standards for non-ductile concrete buildings and multi-family, wood-frame structures with parking underneath (ENR 11/9/15 p. 16),
seismic retrofit work in those cities has been booming.
In the next 30 years, California has a 99.7% chance of a magnitude-6.7 or higher earthquake, and the Pacific Northwest has a 10% chance of a magnitude-8 to -9 mega-thrust Cascadia subduction-zone quake, says the National Aeronautics and Space Administration.
After several minor-to-moderate earthquakes shook the U.S. interior in 2011, a number of reports suggested a link between hydraulic fracturing—a technique used to extract natural gas from shale-gas deposits—and increased seismic activity in areas typically not prone to such events.
Mitsui Inc., one of Japan’s largest construction firms and also one of its major nuclear fuel traders, is investigating the feasibility of building biomass power generators to help dispose of debris from the March 11 earthquake and tsunami as well as help recycle waste from the reconstruction effort.
Because it can moderate the damaging effects of earthquakes, base-isolation is a technique used primarily in seismically active regions. ENR takes a look at some of the largest applications of base-isolation technologies in the world.