A portion of Highway 1 near Big Sur that was covered by a landslide reopened July 18, about two months ahead of schedule. The landslide, which hit May 2017, was caused by heavy rains and dropped about 6 million cu yd of dirt on the roadway, displacing 50 acres of road and creating 16 acres of new California coastline.
The $54-million California Dept. of Transportation project to repair the highway at a location called Mud Creek was led by San Luis Obispo, Calif.-based John Madonna Construction Co. The company's CEO, John Madonna, said his crew worked seven days a week and 12 hours a day to shave time off the job. To repair the damaged roadway, crews created a foundation with 200,000 tons of riprap to maintain the newly created land so that Highway 1 can now cross what used to be the Pacific Ocean.
"Rather than trucking or pushing millions more cubic yards of soil into the ocean, a new roadway alignment was created across the ball cap-shaped landslide," said Madonna. Crews also enhanced the upper catchment area using wire gravity walls designed by Hilfiker.
To prevent injury from falling debris, Madonna says ground-based radar systems were used to monitor and evaluate movement on the mountain 24 hours a day. Workers evaluated reports produced every morning at 5:30, before work started. "Aerial and satellite monitoring, including lidar, was used," he said. "We also used a continuously operating total robotic station to monitor dozens of prisms placed on the mountain, and drones were used to create a high-resolution 3-D graphic."
With the reopening of Highway 1, commuters can drive straight between Carmel and San Luis Obispo without hitting a roadblock at Mud Creek, which led to numerous detours and delays during the closure.