Notes
GeoSyntec Consultants letter dated 22 June 2001, authored by Patrick C. Lucia Ph.D. P.E. G.E. and Edward Kavazanjian Jr. Ph.D. P.E. G.E., submitted to U.S. Army Corps of Engineers Regulatory Branch (Muffy Walker/Gail Terzi) and Washington State Department of Ecology Shorelands and Environmental Assistance Program (Ann Kenny), on behalf of the Airport Communities Coalition (ACC). Responds to Port Of Seattle’s April 30, 2001 reply to GeoSyntec’s February 16, 2001 letter regarding the West Mechanically Stabilized Earth (MSE) Wall and embankment fill for the Third Runway Expansion Project at Seattle-Tacoma International Airport. Key concerns: insufficient laboratory strength testing of foundation soils, underestimated extent of liquefiable material, incorrect seismic stability analyses, inadequate documentation for regulatory decision, and unconservative use of shear strength at 20% strain vs. 10% strain. Addresses Comments 1B, 2, 3, and 4 on MSE wall size, cone penetration test correlations, and static/seismic factor of safety. Administrative Record number AR021830.