Work continues to stabilize Highway 1 in Big Sur along the California coast, where a section of the lane along the cliff collapsed into the Pacific Ocean on March 30 after a rain storm . Engineers are discussing a permanent solution, with a viaduct as the likely solution.
The famous stretch of Pacific Coast Highway has been closed to all convoy traffic in the Rocky Creek area, about 13 miles south of Carmel-by-the-Sea. Caltrans contracted Teichert Construction for the temporary stabilization, which involves drilling, installing and grouting vertical rock studs through the southbound lane pavement adjacent to the existing west edge of the roadway. Once the horizontal reinforcing studs are also in place, crews will install reinforced shotcrete on the vertical face of the repair to help stabilize the roadway.
The temporary fix is budgeted at $9.4 million and Caltrans expects to be completed by Memorial Day, which will open the freeway to alternating one-way traffic using a 24/7 signalized traffic control .
“The big milestone is that we’ll be able to open to anyone 24 hours a day,” says Kevin Drabinski, Caltrans District 5 spokesman. The current twice-daily convoys are limited to essential workers and residents, making the coast south of Rocky Creek inaccessible to tourists.
The estimated price of the permanent repair is $17.3 million, bringing the total cost of the highway reconstruction to $26.7 million.
Viaduct a possibility
Engineers have begun meeting to discuss the permanent solution. “A viaduct is the [solution] that would seem like a good fit at this point, but we haven’t made a final decision on that,” Drabinski says.
Other possibilities include building a bridge or wall, but after a similar slide in the Rocky Creek area closed Highway 1 in March 2011, the state opted for a viaduct. Construction on the $11 million project did not begin until September 2012 and was completed in November 2013.
“Maybe we can get some ideas from this [project]” says Drabinski. “In this case, there was a little more room to work with, a little more of a flat area inside as opposed to the steeper slope” at the site of the current slide,” he adds . “We have to see, given these specific safety concerns, what would work.”
With the Rocky Creek exit, Highway 1 in Big Sur is now closed at four points, dealing a blow to tourism. Caltrans is still working to clear the massive Paul’s Slide in southern Monterey County, which has cut off northbound access to Big Sur from San Luis Obispo County since January 2023.
Another landslide, which took place in May 2017, was also caused by heavy rains. It dropped about 6 million cubic yards of soil onto the road, displacing 50 acres of road and creating 16 acres of new California coastline. A $54 million repair job, involving 200,000 tons of riprap, reopened the highway the following year.
In 2021, the rains faded in Highway section 150 feet long, requiring 11.5 million dollars emergency repair contract. This repair meant improved filling and a new sewer drainage system.
Geological instability
Continued geological instability has led to speculation as to whether road repairs are an exercise in futility. But Drabinski notes that there are thousands of residents, businesses and schools that depend on the road. In addition, Caltrans is making “advances in engineering, so that we have more knowledge about the kinds of responses we can give to coastal challenges.
“There’s a healthy body of knowledge and history about working on the coast and what might happen in specific locations that you can use to your advantage and allow you to better prepare before winter,” adds Drabinski. “It allows you to better respond to these events.”
