Kiernan overpass demolition closes Highway 99

Demolition of the Kiernan Avenue overpass closed Highway 99 Friday night and a second freeway closure was planned for Saturday night as massive machines moved in to take down the old bridge. Removal of footings will close one to two lanes each night for at least the week ahead.

The first night’s closure went as planned, with traffic diverted around the section using offramps and onramps of the diamond-shaped interchange starting at 11 p.m.

“We bring people up and push them back down. It’s pretty convenient that way,” project manager Chris Brady said Saturday. Brady is deputy director of construction/roads/bridges for Stanislaus County Public Works.

“It worked well (Friday) night. No major delays,” he said. “We lucked out with no fog.” Cleanup finished and the highway opened just after 6:30 a.m. Saturday, nearly half an hour ahead of schedule.

“This is a milestone for our project in that a second stage of new bridge construction will commence when the eastbound portion of existing bridge is removed,” Brady said.

Large machinery bringing down large chunks of the Kiernan bridge made a full closure the only safe option.

“Full freeway closures are required for this type of demolition, so work of this type is limited to Friday and Saturday nights,” Brady said. The California Department of Transportation limits closures to weekend nights to avoid disrupting weekday commutes.

A portion of the new bridge, just north of the old span and slightly higher, is being used for traffic crossing the highway heading west, toward downtown Salida. Eastbound drivers will find themselves navigating a portion of the old overpass bridge.

Workers would spend about half the time breaking up the old bridge, half the time clearing the highway for the next day’s traffic, Brady estimated, adding this type of demolition does not allow workers to clear as they go. “It’s break, break, break, break, let everything fall down and then clean it up,” he said.

“Removal of the existing bridge column and footing in the freeway median will continue as night work in the coming week, but these efforts do not require full freeway closures,” Brady said.

After all the breaking down and clearing, construction will start its next phase. When complete – slated for fall 2016 – the $44 million project will boast revamped ramps with surrounding improvements, including a pump station to carry away stormwater.

Two additional bridge lanes will ease Salida traffic and two added freeway lanes will speed travelers as far as the Pelandale Avenue interchange, which is getting a $55 million refit.

This story was originally published January 17, 2015 at 4:00 AM with the headline "Kiernan overpass demolition closes Highway 99."