ADEI was brought in to stabilize the bluff. Erosion had left the coastal slope below a Rancho Palos Verdes home unstable enough to put the house at the top at risk, and a permanent structural fix had to be built from a tight bluff-top site.
The Challenge
Because the failing bluff endangered the house above, the work was deemed an emergency repair, and the California Coastal Commission granted emergency approval so construction could begin without delay.
The site itself made the job demanding. Access is limited, with little room on the residential lot to stage equipment and materials. Crews set up the drill rig at the top of the bluff and on the slope face, with the ocean directly below. The design also calls for long piles and long tiebacks, which makes each installation a significant undertaking.
ADEI’s Solution
ADEI is installing a shear pin system with a gradebeam and tiebacks to hold the bluff in place. The shear pins are drilled piles that extend through the unstable material and resist sliding along the slope. The gradebeam ties the tops of the piles together so they work as one structure, and the tiebacks anchor that structure back into the hillside.
The scope includes 17 piles and 17 tiebacks. The count may sound modest, but the length of each element, combined with the restricted access, makes this a major effort.
Project Status
Work is well underway. Twelve of the 17 piles are installed, and the tiebacks will follow once the remaining piles are in place. When complete, the system will hold the bluff in place and protect the home above.
Project Details
- Location: Rancho Palos Verdes, CA
- Services: Bluff repair, emergency slope stabilization
- Scope: 17 shear pins (piles), gradebeam, 17 tiebacks
- Status: In progress
