In a story that united geologists with rare car enthusiasts last month, a massive sinkhole opened up beneath the National Corvette Museums’s Skydome, swallowing eight rare cars into its cavernous depths. Since then, the museum has worked tirelessly to recover the cars and fill in the sinkhole so that the Skydome can open anew. But how do you undo a giant sinkhole?
Well, first, engineers have to make sure the sinkhole wasn’t going to swallow up anything else — like the crane they needed to lift up the cars. As recounted in this fun, nerdy story from the magazine of the American Society of Civil Engineers, the team carefully drilled micropiles to stabilise the not-yet caved in parts of the floor.
Then they brought the cranes inside the museum. The raising of the first car took two whole days while they made sure the sinkhole didn’t start sinking again in the process. This first car — a 2009 Prototype ZR1 — was strapped in, then reinforced with secondary straps for extra caution (a theme is starting to emerge, yeah?). It was lucky enough to escape the sinkhole nearly unscathed: someone jumpstarted its battery and drove it right out of the Skydome.
The museum has since recovered five of the eight cars, including the most valuable, the millionth Corvette ever made, which was perched precariously on top of a deep crevice. Unfortunately, this one looked a little worse for the wear once it was hauled up.
Two of the cars have not been seen since the sinkhole first collapsed, possibly falling into a deep crack in the Earth. Michael Marasa, an engineer working on the site, tells Civil Engineering he’s doing everything he can do to find them. “I’ve reviewed those security camera videos six ways to Sunday, and I have an idea where I think the seventh [car] is, but I have no idea where the eighth one is. These are the pearls we are going after.”
Once the cars have all been recovered, the sinkhole will be filled in with low mobility grout, which is used to stabilise loose soil. It will then be topped off, and the Skydome will open again.
While sinkholes as dramatic and big as this one are rare, smaller ones open up all the time in people’s backyards and driveways depending on ground conditions. Plugging them in just takes some concrete and clayey sand. After an insanely deep hole swallowed an intersection in Guatemala City in 2010, engineers planned to fill it in much the same way with cement lime.
Ultimately, the sinkhole has been great publicity for the National Corvette Museum in Bowling Green, Kentucky. It’s currently enjoying a big spike in visitors, there to gawk at the sinkhole as much as the cars. [Civil Engineering]
Photos courtesy of the National Corvette Museum