Poppy Trail Landslide Rolling Hills

The Poppy Trail Landslide failed in 2005, resulting in closure of a residential access road to multiple homes, and damage to one outbuilding. GMU was retained to provide geotechnical investigation and design services to repair the landslide and reconstruct two residential building pads. The project presented significant challenges, including steep terrain, complex geologic conditions, adjacent properties with multiple structures and improvements, and time constraints to repair the road and provide permanent access for the residents. GMU conducted a geotechnical investigation to evaluate the complex geologic structure and failure mechanism, and prepared a repair design that included removal and reconstruction of the slope using standard grading methods, geo-reinforcement (both global and surficial), and a complex subsurface drainage system. GMU was retained to provide both observation and testing during construction, as well as construction management advisor services. Challenges during construction included sequenced grading to remove the landslide debris, narrow slot excavations using low-vibratory equipment to minimize movement of the landslide during removal, limited area to stockpile materials during removal, development of a monitoring program along adjacent property lines, and constant communication with the project team, the governing agencies, and the residents. GMU worked closely with the contractor and civil engineer during construction to solve problems quickly and meet scheduling deadlines. The project was completed successfully in 2012.