PPM was responsible for building a temporary coffer dam to allow repairs to the existing Hebgen Dam. This involved dewatering around the work zone to facilitate safe and efficient repairs. Our team conducted structural repairs to the existing dam infrastructure, including the installation of new structural materials and ensuring long-term durability against future stress and natural forces.
Given the project’s location in a sensitive area, PPM worked closely with environmental consultants to ensure minimal environmental impact throughout the repair process. Throughout the project, safety was the number one priority, with stringent safety protocols in place to protect workers, wildlife, and the surrounding community.
Support consisted of construction of closed cell cofferdam and tensioned rock anchors. 36-in diameter shafts installed 20-ft into bedrock at a water depth up to 35-ft. Concrete tremie seal utilized to stabilize rock between existing intake. 1,350 cubic yard tremie concrete poured in water depths up to 60-ft. Circular cells spaced 58-ft in diameter 70-ft centers using sheet pile between 80 and 85-ft.
