In a warehouse in Reno, Nevada, scientists are putting the biggest seismic facility in the country through its paces. The newly-expanded lab earthquake lab uses three 50-tonne shake tables to simulate earthquakes—including the infamous 6.9 earthquake in Kobe, Japan.
A team of schools, led by University of Nevada at Reno, recently recreated intense earthquakes to test a new type of bridge construction at the lab. The idea was to design a bridge support system that was cheaper, stronger, and faster to build than a normal bridge—and more resistant to earthquakes. So this summer, the team built a 70-foot chunk of the system atop the lab's three hydraulically powered shake tables and then strapped hundreds of sensors to its tensioned concrete columns.
When everything was set up, the team put it through a battery of faux-quakes: ten in all, culminating in one designed similarly to that of the deadly Kobe quake of 1995. How did the bridge stand up? Well, it deflected a massive 12 per cent from its origin point and broke in places, but it stood standing, which is the important part. Now, they can take the sensor data and continue working on the bridge design.
One uncanny detail from the test: according to the scientists, you could actually hear the rebar moving inside the concrete during the quakes. What did it sound like? A "zip opening." [University of Nevada at Reno]