Philemon Drive Landslide

The Philemon Landslide failed in the spring of 2005, damaging the rear yards of four residences and destroying one home. A design-build contractor purchased three of the four properties, and retained GMU to provide geotechnical services for repair and redevelopment. GMU performed a subsurface investigation and assisted in development of repair plans for submittal to the City of Dana Point. The repair consisted of temporary horizontal drains to protect the residences during the permitting process (over the winter months) and a grading repair that included backfilling a portion of the slope with concrete slurry in lieu of the weak onsite soil. Challenges to the project included weak clay existing fill and bedrock materials, adverse geologic structure, perched water within the landslide, and existing residences at the head of the landslide. GMU worked with the City to obtain permit approval for the repair, and provided observation and testing during the repair. The project was successfully completed in 2013 and GMU received an Outstanding Project Award for the project from  CalGeo in 2014.