California Polytechnic State University’s (Cal Poly) Fremont Hall dormitory, which was built in the late 1950s, was impacted by a slow-moving landslide and was immediately evacuated. Now, with the completion of a project that stabilized and restored the slope and surrounding hillside, the dorm is renovated and safely occupied after three years of vacancy.

The landslide occurred during February 2017 due to a record-breaking rainy season and impacted the back wall of the dorm. During the following spring and summer, Cal Poly Facilities began installing drainage improvements while preparing for full mitigation. This included drainage features to divert surface and subsurface water away from the landslide zone and winterizing the slide area for the following rainy season.

Cal Poly selected Cannon to provide survey and general civil engineering services for stabilization and restoration of the unstable slope. Cannon’s 2017 work included winterization plans for erosion control, upslope surfaces, and subsurface drainage improvements; as well as topographic survey; surface monitoring; and construction staking. In 2022, Cannon provided topographic surveys of the hillside and a larger zone to study a potential deep-seated landslide. Cannon also provided grading and drainage plans for the slope, subsurface drains, and dorm courtyard improvements.

Construction began in August 2021 and was completed July of 2022. Several tie-back walls were also installed, including a tie-back soldier pile wall. The exposed surfaces were finished with a simulated sandstone bedrock. After the work was completed, a post-construction monitoring system was installed to track tie-back performance and hillside movement for long-term management of the landslide.

To read Cal Poly’s article on the completed project, follow this link.