McFadden Avenue bridge demolition over 405 partially done, with more on the way

The first step in demolishing and replacing the McFadden Avenue bridge over the 405 Freeway in Huntington Beach and Westminster was done overnight Saturday, with Part 2 scheduled for next weekend.

Workers closed the 405 in both directions between Beach Boulevard and Bolsa Avenue as they tore down the side of the bridge over the southbound freeway.

The process will repeated with another full freeway closure on the same stretch from about 11 p.m. Saturday to 7 a.m. Sunday as the other half of the bridge is razed.

While the freeway is shut down, drivers heading north exit at Beach Boulevard, while those traveling south are detoured at Bolsa Avenue/Goldenwest Street.

The bridge will be out of service for about a year as it is replaced. It’s the first of more than 18 bridges that will be replaced, widened or built as part of a $1.9-billion project to expand a 16-mile portion of the 405 between the 73 Freeway in Costa Mesa and the 605 Freeway near Rossmoor, according to the Orange County Transportation Authority.

Once rebuilt, the McFadden bridge will include two lanes, a sidewalk and a bike lane in each direction. The bridge currently has one lane in each direction and a sidewalk on its north side.

To prepare the freeway for the bridge demolition, crews coat the lanes with dirt — perhaps 2 feet deep in some places — to provide a buffer between the roadway and the heavy equipment and falling debris.

With the padding in place, workers using excavator breakers, basically hydraulic hammers — chip away at the concrete bridge. There are no wrecking balls or explosions. The debris is hauled away for disposal.

McFadden is one of only a handful of freeway bridges that will have to be closed to traffic during the 405 project. Most — including the Slater Avenue bridge in Fountain Valley, which OCTA also expects to start work on this year — will remain open to some extent.

When the overall 405 project is finished in 2023, both directions of the freeway between the 73 and the 605 will have an additional general-purpose lane and a new “express” toll lane, officials say. The existing carpool lane in both directions will be converted to an express lane.

For more information about the project, visit octa.net/405improvement.