How, and how fast, is Caltrans rebuilding the damaged 10 Freeway?

While the lanes of the fire-scarred 10 Freeway opened in time for the Thanksgiving holiday, there are weeks, perhaps months, of repair work ahead on the busy stretch of roadway that serves 300,000 vehicles.

As you speed by, however, you probably won’t feel any impact, according to Caltrans officials. While there is a lot of work left to do — the damaged columns holding up the overpass to the east of Alameda Street may need different levels of repair — much of the work will take place in evenings and on weekends.

Last week, officials were talking weeks — maybe even months —  before the lanes, scorched by an intense Nov. 11 pallet fire, might reopen.

Early this week, U.S. Sen. Alex Padilla estimated that the cost would be about $3 million, but later Gov. Gavin Newsom suggested the price tag would be “in the low millions.” Both have echoed that the federal government is footing the bill, tapping Federal Highway Administration “quick release” emergency funding, on the heels of Newsom’s emergency declaration.

Although the work will continue for months, many motorists were happy to see more closed ramps being reopened, as drivers faced the pre-Thanksgiving commute and holiday traffic.

“Engineers developed a plan to reinforce the bridge with temporary shoring to distribute load capacity on the bridge safely,” Caltrans spokesperson Eric Menjivar explained. “Once structural engineers certified that the loading and bracing met safety standards, I-10 was allowed to reopen to motorists.”

Caltrans emergency contractors have already cleared hazardous material and debris from the repair site ahead of schedule. And crews toiled 24 hours a day to temporarily shore up or reinforce the damaged overpass columns with more than 100 tons of steel beams and 12-by-12-inch heavy wooden posts stretching over a mile, Menjivar said. Newsom praised workers for putting in 10,000 hours of labor to open the freeway in eight days.

That’s a lot of work. But there is much work left to be done. Here’s a brisk overview of what’s ahead.

Here’s how the repair crews are moving forward:

• At this point, Caltrans has not released a precise timetable for repairs. While the inflow and outflow of traffic has largely returned to normal, Lawrence Street will remain closed between 14th Street and 10th Street for the duration of the repairs. Caltrans officials cautioned that until the work complete and safety inspections confirmed, the area is still a construction zone.
• The goal: Complete repairs, with permanent shoring complete to assure the lanes can hold up long-term to the weight of cars and trucks. Temporary shoring has been done in the meantime.
• Other occasional closures will be necessary in the weeks ahead to allow crews to work specific areas. but officials have not released a schedule of any sort.
• In the meantime Caltrans has confirmed that it has conducted an analysis to determine the amount of concrete affected by the fires and used that to inform the retrofit and repair strategy.
• Samples of concrete rebar and structural steel were taken from various parts of the freeway structure to assess the depth of damage.
• Possible damage to the rebar, which is used to reinforce the concrete, is still being assessed officials said.

Here’s a look at the freeway structure’s anatomy:

• Rebar extends from the foundation of the freeway, into the column, tying them together so that they act as one.
• Columns are made of concrete and are reinforced with steel rebar that runs the length and circumference of the structure.
• The column’s foundation extends deep into the ground.
• Cross beams span the width of the freeway and are anchored by rebar to the columns beneath the freeway.

Meanwhile, it’s unclear how the fire started, though Cal Fire, which is leading the multi-agency investigation, has declared it the result of arson. On Saturday, Cal Fire released photos and a description of a person of interest in connection with the fire. They urge the public to provide leads or tips, which can be sent anonymously to the Cal Fire Arson Hotline at 1-800-468-4408 or arsonbomb@fire.ca.gov.

The results of the investigation have not yet be released but are expected in the days ahead.

Source: Orange County Register