Description of Work:
Geo-Solutions installed a slurry wall through and under a new embankment dam. The slurry wall was part of a larger reservoir project to create municipal water storage for the City of Golden Colorado. The dam encloses a former gravel pit.
The slurry wall is a total of approximately 125,000 vertical square feet, with depths varying from 40 to 85 feet. The total length of wall is approximately 2,100 feet. The wall is keyed 8 feet into the underlying silt aquaclude. Geo-Solutions created backfill with trench spoils along with dry bentonite at a rate of 2% to achieve permeability in the range of 1×10-8 to 1×10-9 cm/sec. This low permeability will help to meet the State of Colorado Engineer’s Office requirements for leakage in this type of water storage system.
The key challenges on the project were coordination with the other contractors on the site, meeting the schedule deadlines, and working in some very narrow areas. There were also two utility crossings which the slurry wall had to be installed under and around without damage.