Projects » North Seattle Conveyor Excavation

Projects » North Seattle Conveyor Excavation

Location: North Seattle

Size: $9.6 Million

Depth:   Over 50’

Site Restoration:  5,000 CY Imported


   Total Soil: 86,000 Cubic Yards

   Impacted Soil: 11,500 Tons

   Conveyor Moved:    86,000 CY

   Structural Excavation:  3,000 CY

   Backfill:  1,800 CY


The mass excavation consisted of utilizing a conveyor system to be set over an existing loading dock.  It also included under slab trenching for foundation drainage, and backfill between the foundation and slab on grade consisting of pea gravel, low strength CDF, and permeable cellular concrete.  The restoration scope included City of Seattle Street Improvement work with accompanying traffic control, concrete panel replacement, and sidewalk grading.  A key challenge was the building up to subgrade over the roof of the undergound facility with imported drain rock, geo-foam, and Type 17 aggregate gravel. Site drainage was installed prior to the final phases of the restoration.