Highway 1 closed near Big Sur due to rockslide. What are crews doing to reopen road?
Days after a rockslide closed Highway 1 near Big Sur, Caltrans crews are working to remove a large rock outcropping and stabilize the cliff below it, the state road agency said Friday.
Caltrans expects that the All-American Highway will remain closed at least until Nov. 3.
The rock became a threat after the slope holding it sent dirt and smaller rocks onto Highway 1 near Salmon Creek on Wednesday morning. In response, Caltrans closed the road from Ragged Point in San Luis Obispo County to Gorda in Monterey County.
According to Caltrans, crews will work seven days a week during daylight hours, including over the Halloween holiday weekend, to repair the highway as long as site conditions are safe for workers.
The threat of the outcropping and possible further instability of the slope have made clearing the rockslide about two miles north of Ragged Point a more complex challenge, Caltrans spokesman Kevin Drabinski wrote Friday via email.
“The major concern is the instability” of the outcrop, he wrote. “It is difficult to estimate its size.”
Caltrans authorized a $500,000 emergency contract Wednesday morning with Papich Construction of Arroyo Grande for work to clear the slide.
Drabinski wrote that Papich and Caltrans workers were “on site within hours” to begin “their assessment in earnest.”
“The plan is to bring the outcrop down with excavators providing the force from up top and to the side,” he explained. “To that end, crews have hauled in roughly 2,000 cubic yards of dirt from Paul’s Slide to create an access ramp, so that excavators are to the side and not directly below the outcrop when it comes down.”
Paul’s Slide is about 20 miles north of the slide area.
Drabinski wrote that the ramp will allow the excavators to safely “be above and to the side of the outcrop.”
“It’s too early to speculate on how crews will dispose of the outcrop,” he added. “We will know more when it has been brought down to the roadway.”
Then additional studies of the slope can help engineers calculate if protective features need to be installed on or below the slope.
A confluence of possible contributors to Wednesday’s rockslide.
A quick but intense rainstorm swept through the Central Coast on Sunday night through Monday, dropping more than 5.5 inches of rain in one San Luis Obispo County area. In addition, a small flurry of earthquakes struck near San Simeon on Monday, the largest of which measured magnitude 4.7.
“Our geotechnical teams say we may never know the precise reason this rockslide became active – to what extent the rain or earthquake might have been factors,” Drabinski wrote, adding that “the location of this rockslide has not been considered especially geologically active in the past.”
It’s also not known if incoming storms will cause additional problems.
The closure area extends from just past the border between San Luis Obispo and Monterey counties to Gorda about 10 miles north.
Despite a brief power outage on Wednesday, the Ragged Point Inn remained open and busy. So have other Gorda area businesses, including the Whalewatcher’s Cafe and Gorda Springs Resort, where some of the road workers are staying.
Drivers are notified of the closure, which affects both lanes, at several locations along the highway, including a sign just north of the entrance to Hearst Castle, which is closed due to damage to an access road from a January storm.
Caltrans District 5 spokesman Jim Shivers said Wednesday that Highway 46 West and Highway 101 are detours for travelers heading north and Highway 68 and Highway 101 are options for those going southbound.
Updates will be provided as details about progress on the project become available.
For the latest information about the closures and conditions on Central Coast highways, call Caltrans District 5 Public Affairs at 805-549-3318 or go to dot.ca.gov/caltrans-near-me/district-5.
This story was originally published October 29, 2021 at 11:05 AM.
