A landslide in Rolling Hills Estates sent homes on the hillside down into the ravine below and left the slope and the road above it in need of permanent support. ADEI came on board after the bidding process to build the stabilization system that would hold the road and hillside in place.
The Challenge
The work took place on a hillside that had already failed, where homes had fallen into the ravine and others still stood directly above and beside the slide area. The permanent system had to stabilize the slope and support the road without putting the surrounding properties at further risk.
Utilities were a key coordination issue. The streets around the site carry existing utilities, and new utilities were also planned, including a future sewer expansion. ADEI had to lay out and install its tiebacks so that none of them would intersect the planned sewer line, coordinating the work around both what was already in the ground and what was coming next.
ADEI’s Solution
ADEI built a shear pin and tieback system with a gradebeam. The shear pins are drilled piles that extend through the slide material and resist further movement. The gradebeam connects the tops of the piles so they work together as one structure, and the tiebacks anchor that structure back into stable ground.
The tieback layout was coordinated with the existing and proposed utilities in the streets, keeping the anchors clear of the future sewer expansion.
Outcome
Road stabilization is complete. The shear pin, gradebeam, and tieback system holds the road and hillside in place, providing permanent stabilization after the landslide while leaving room for the planned utility work beneath the streets.
Project Details
- Location: Rolling Hills Estates, CA
- Services: Landslide stabilization
- Scope: Shear pins, gradebeam, tiebacks
- Status: Road stabilization complete
