Concrete steps toward building state’s second busiest interchange
Anyone who’s driven on the north side of town has probably noticed the ongoing construction of the Centennial Bowl.
You can’t miss the $47 million project, with the numerous daily detours, a small army of construction workers swarming the work site and towering cranes swinging into action on a daily basis.
But what does it take to hoist those ridiculously huge slabs of concrete 60 feet above ground, ultimately creating a 2,500-foot-long flyover bridge linking the westbound 215 Beltway to southbound U.S. Highway 95?
Graham from North Las Vegas said he drives past the construction site twice a day and wanted to know.
“I’ll willingly own up to being the only dummy in town if somebody will explain to me how they get the concrete up there,” Graham wrote in an email earlier this month.
No need going to such extremes, Graham. It’s a great question, so I asked Tony Illia from the Nevada Department of Transportation to guide us through the lengthy process.
Crews at the Centennial Bowl site are using enough concrete to build a 120-mile sidewalk that could run from Las Vegas to St. George, Utah, Illia said. That’s a whopping 5.2 million pounds of concrete just to build the flyover, not including the supporting columns.
The flyover is being crafted in three separate segments with each measuring roughly 860 feet that range from 1.68 million pounds to nearly 1.83 million pounds.
Building each segment is a lot like baking a cake, Illia said. An 860-foot-long tub girder serves as the cake pan, getting attached to the bridge. Much like batter, the wet concrete is poured into the girder from a 120-foot-tall telescoping boom that’s attached to a pair of pump trucks parked at ground level.
High above, workers shape the gloppy mixture around a set of steel rods known as rebar that will help reinforce the new flyover bridge, Illia said. Once the mixture has hardened, the girder — or cake pan — is removed, and slips forward until the next segment is ready to be formed.
“Once it begins, it requires a steady uninterrupted stream of trucks making continuous deliveries with drivers, pump machine operators and concrete laborers working together nonstop in a marathon session that can last 16 hours or more,” Illia said.
When completed in early 2017, the Centennial Bowl is expected to become the second-busiest freeway exchange in Nevada, coming in after the Spaghetti Bowl crossing of U.S. Highway 95 and Interstate 15 in downtown Las Vegas.
PRECHECK OFFICES
A temporary PreCheck enrollment center is opening in Las Vegas for just one week to help handle the increased demand for expedited airport security screening.
About 1,000 appointments are available from Aug.9-13 at temporary office inside the DoubleTree Hilton Hotel, 7250 Pollock Drive, said Charlie Carroll, a senior vice-president for MorphoTrust USA, the company contracted by the Transportation Security Administration to process applications. Travelers pay $85 to register for the speedy screening. In return, they’re assigned a “known traveler” number that lets them jump into a shorter security line for the next five years.
Walk-ins will not be accepted at the temporary office. Appointments can be made at identogo.com/tsaprechecktour.
However, appointments and walk-ins are accepted at the three permanent TSA PreCheck registration offices at: McCarran International Airport’s Terminal 1; EMSI, 2080 E. Flamingo Road, Suite 302, in Las Vegas, and an H&R Block office at 2801 N. Green Valley Parkway in Henderson.
FAULTY SIGNALS
Ed from Las Vegas wanted to know where he could report problems with traffic signals. That would fall under the “Seeing Orange” campaign by the Regional Transportation Commission of Southern Nevada, where residents can ask questions about construction projects and traffic signal problems.
To speak with an operator, call 702-928-2663 from 7:30 a.m. to 6 p.m. Monday through Thursday, or leave a voicemail message the rest of the time. You can also lodge complaints at seeingorangenv.com.
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