Slope Stabilization & Reconstruction Project Summary – San Clemente, CA
This project involved the comprehensive stabilization and reconstruction of a failed coastal slope in San Clemente, performed under highly sensitive conditions to protect both critical infrastructure and a historic landmark, Casa Romantica Cultural Center and Gardens.
The scope included the design and installation of a multi-tiered earth retention system consisting of three levels of post-tensioned tiebacks, drilled and anchored into competent material to provide long-term global stability. Each level was structurally integrated with reinforced concrete grade beams, forming a continuous load-distribution system across the slope face.
A key challenge of the project was maintaining uninterrupted operations and safety for the active rail corridor located at the base of the slope. All work was carefully sequenced and coordinated to minimize risk to rail operations, including controlled excavation phases, vibration monitoring, and implementation of protective measures to prevent impacts to the track system.
Simultaneously, construction activities were performed with strict controls to safeguard the adjacent historic structure at Casa Romantica. This included real-time monitoring, limited vibration methods, and engineered construction sequencing to ensure the integrity of the structure and surrounding grounds throughout the duration of the work.
The earthwork component consisted of the removal and replacement of approximately 22,000 cubic yards of unsuitable soils. Excavation was performed in controlled, staged lifts to maintain interim slope stability while facilitating tieback installation.
A critical element of the reconstruction was the over-excavation and rebuilding of the slope keyway, extending into competent material. The keyway was reconstructed using engineered fill, placed and compacted to specification to restore basal stability and provide a reliable foundation for the rebuilt embankment.
Through the integration of deep anchoring systems, structural grade beams, and large-scale soil remediation, the project delivered a durable, long-term stabilization solution—successfully protecting active rail infrastructure and preserving a historically significant coastal asset.
