Another night of bridge demolition

It ain’t over yet.

Demolition work on the Sunset Bridge over the 405 Freeway, set to wrap up this morning, will now extend into a seventh night.

That bit of bad news is actually good news, project managers say.

The extra night is needed because the contractor accomplished more than was initially expected during the past six nights of demolition. Workers have already started dismantling the bridge’s two center support columns—work that originally had been expected to take place a month from now. Tonight’s work is intended to finish demolition of the bridge’s second support column. The extra night now will mean one less night later.

Unlike the previous six nights, tonight’s work will require a series of intermittent freeway closures and some lane reductions, but no full shutdowns. Sunset Boulevard, however, will be completely closed beginning at 9 p.m., with an expected reopening by 6 a.m.

Demolition work on the bridge’s south side began last week.

The demolition process has played out like a surreal nocturnal ballet. Hoe rams—moving like huge, animatronic dinosaurs crossed with Woody Woodpecker on steroids—could be seen battering the 54-year-old bridge. Concrete chunks fell onto the freeway below, padded each night with 15 truckloads of dirt to help muffle the noise. The fallen debris was instantly whisked away by supporting players in the form of a couple of front end loaders. A trio of construction workers wielding acetylene torches sent showers of sparks cascading as they cut tangled ribbons of rebar exposed by the demolition work. The entire work area has been cocooned with thousands of square feet of sound blankets.

Techniques and procedures to keep the noise down have evolved with each passing night.

“You know, we’ve not been stagnant,” said Mark Van Gessel, Metro’s manager for the Sunset segment of the project. “We’ve tried to improve every night.”

Adding a degree of difficulty to the demolition mission is the need to tear down the bridge while simultaneously protecting a vital, 34-inch water line that provides water to much of the Westside of Los Angeles.

When demolition of the south side of the bridge is complete, 10 months of reconstruction lie ahead, and then it all begins again on the north side.

The completed bridge will be wider and will have up-to-date seismic reinforcement.

Two more bridges over the 405—at Skirball Center and Mulholland drives—also will be demolished and rebuilt in coming months as part of the project to add a 10-mile northbound carpool lane to the freeway, along with other improvements.

All photos by Metro.

For a look back at the Sunset Bridge in its earliest days, click here.

Posted 7/29/10