Remedial Excavation at Shuffleton Substation
Puget Sound Energy
Renton, Washington

Frozen soil shoring was chosen as the best approach to retain soil during remediation of hydrocarbons at this active substation facility

Special Considerations

• Excavation of contaminated soil was required immediately adjacent to the existing powerhouse that was constructed in the 1920's.
• Previous attempts to excavate the loose, wet running sand resulted in the undermining of soils beneath the powerhouse foundation.
• The site also has numerous buried utilities, including a large timber tunnel that supplied water to the powerhouse.

Frozen Soil Shoring Works

• Frozen soil cut off most of the groundwater and stabilized the running sand.
• Excavation of contaminated soils was safely accomplished adjacent to the powerhouse with no loss of soil beneath its foundation.
• Utility services were maintained throughout construction activities.
• Frozen soil shoring was formed around the buried utilities, including the timber tunnel. This significantly reduced dewatering requirements at the site.
• The project was completed within budget and ontime.