I-405/SR-522 Stormwater Detention Vault
Washington State Department of Transportation
Woodinville, Washington

• The goal on this project was to provide a dry environment for the construction of this 100-foot by 30-foot by 30-foot deep storm water detention facility.

• The 20-foot deep excavation was made in wet sand, silt, and peat located near a creek.

• We constructed a 4-foot thick frozen soil shoring wall around the excavation and completely cut off ground water. This eliminated the need for an expensive concrete seal and dewatering.

• One side of the frozen soil shoring capably supported fully-loaded dump trucks within 2-feet of the wall, with no lateral movements.

• Our frozen soil shoring allowed the contractor to work in a dry hole during the two months the excavation was open.