Night closures of freeway, Wilshire planned (updated)

The temporary center column for the Mulholland Bridge moves into place. Photo/Metro. © 2012 LACMTA

The Mulholland Bridge is at it again. The freeway-spanning overpass that brought you Carmageddon is being rebuilt after last summer’s demolition watched ‘round the world.

And that means some highly visible construction supports need to be installed starting Friday, temporarily changing the look of the bridge and requiring six nights of freeway closures (although only in one direction at a time.)

The iconic bridge with the imposing 237-foot-long central span was designed without center support columns. So, unlike the Sunset and Skirball bridges that also are being demolished and rebuilt for the project, the Mullholland Bridge requires some extra TLC, not just to tear down but also to build back up.

Workers in early February installed a temporary 64-foot-high central support structure (known in the trade as falsework) to shore up the bridge and allow for the reconstruction of the south side of the structure torn down during Carmaggedon.

More of the temporary falsework, in the form of six steel girder beams, each more than 100 feet long, will be installed starting Friday. Plywood will then be placed above the beams and used to form the roadway that will run across the bridge, which originally opened in 1960.

While all that’s going on overhead, the 405 Freeway will be closed from Getty Center Drive to the 101 Freeway so that the work can proceed safely.

The first overnight closures will affect the northbound freeway, and will take place on Friday and Saturday, March 2 and 3.

Then the same stretch will be closed in the southbound direction on the nights of Monday and Tuesday, March 5 and 6.

The work is expected to conclude with another two-night southbound closure, again on the stretch running from the 101 to Getty Center Drive, on Monday and Tuesday, March 12 and 13.

In each case, the drill is the same: some ramps will begin closing as early as 7 p.m. and some lanes will go out of commission beginning at 10 p.m. The full shutdown of freeway lanes will take place from midnight to 5 a.m.

(For updates on the closures and for detour information, check the project website or follow it on Facebook, Twitter or Nixle.)

Updated 3/2/12: Metro announced Friday that Wilshire Boulevard at Sepulveda also will be closing from 8 p.m. to 6 a.m. on a series of upcoming nights starting Monday, March 5. The closures are needed for some advance work on widening the portion of the 405 that crosses Wilshire. Details are here.

The work is all part of the massive, $1.03 billion project to construct a 10-mile northbound carpool lane on the 405, along with a series of modernizations and improvements, including “flyover ramps” at Wilshire Boulevard.

Some of the complexities of demolishing and rebuilding the Mulholland Bridge could have been avoided under a time- and money-saving plan that would have built an entirely new bridge before tearing down the old. But that idea, although popular with many on the project’s Community Advisory Council, was scuttled after some neighborhood groups filed objections.

The date for Carmageddon, The Sequel, in which the north side of the Mulholland Bridge will come down, requiring a shutdown of the entire freeway in both directions sometime this summer, has not yet been set.

Posted 2/29/12