In April of 2011, a landslide damaged a 200-foot portion of California State Route 1—a historic part of our state’s transportation infrastructure—along the steep cliffs between Bixby Bridge and Rocky Creek Bridge, south of Monterey and Carmel-by-the-Sea.
The hillside was stabilized right away using a soil nail wall, but the highway had to be reduced to one lane with signal-controlled traffic through the area. The Rocky Creek Viaduct, a 600-foot bridge structure, is being constructed to completely replace the roadway adjacent to the repaired slope. Creating a bridge here means future landslides won’t affect the Viaduct area—any slide material will pass between the bridge and the hillside, keeping motorists safe and preventing further expensive damage to this stretch of road.
In order to ensure that motorists were still able to use this portion of Highway 1—a concern both for the locals who travel by car to get to work, school, and home, and for the many tourists who frequent this scenic coastal highway—the project is being constructed in two stages. By focusing on one part at a time, the roadway can be kept open for those who need it.
Rocky Creek Viaduct Technical Details
The technical details of this California transportation infrastructure are as follows: The viaduct foundations consists of pile supported abutments at each end of the bridge, and seven 5’-6” diameter cast-in-drilled hole (CIDH) steel cased concrete piers placed 60’ into the steep slope. A continuous 36’ wide reinforced concrete roadway was constructed over 48 precast/prestressed concrete girders that span between large concrete caps at each pier. A 600’ long retaining wall consisting of 76 steel soldier piles embedded in the rocky slope was built with timber lagging between piles to support the steep cliffs above the new structure.
MNS Engineers is providing Construction Management services for this Caltrans project.