Notes
Hart Crowser geotechnical summary report (project 4978-06) prepared for the Port of Seattle for presentation to the U.S. Army Corps of Engineers, November 2, 2001. Covers Third Runway embankment construction at Seattle-Tacoma International Airport: 17,000,000 cubic yards compacted earth fill, maximum fill thickness 165 feet, 2H:1V side slopes, three Mechanically Stabilized Earth (MSE) retaining walls with exposed face heights 50–135 feet above ground, steel strip reinforcement, reinforced concrete facing. Addresses subgrade improvement for liquefiable soils 15–20 feet below ground, stone column field tests (SPT and CPT data, 100+ stone columns, four test patterns), removal and replacement with compacted structural fill selected over stone columns, granular backfill compacted to 95% modified Proctor (ASTM D 1557). Discusses Miller Creek, adjacent tributary wetlands, groundwater seepage, FAA P-152 compaction specifications, HNTB Corporation, Parametrix involvement, and wall/slope alternatives evaluation (Embankment Station 174+00 to 186+00). AR 018323.