Notes
Draft memorandum dated March 5, 2001 from Douglas Lindquist E.I.T., Barry Chen PhD P.E., and Michael Bailey P.E. of Hart Crowser Inc. to Jim Thomson P.E. of HNTB, project J-4978-30. Presents revised methods and results of liquefaction analyses for the SeaTac Third Runway embankment, based on revised probabilistic seismic hazard analysis (PSHA) and one-dimensional site response analyses for proposed embankment heights of 50 and 150 feet. Analyzes 120 borings with Standard Penetration Test (SPT) results; evaluates liquefaction potential and post-liquefaction residual shear strength at NSA Wall, West Wall, South Wall, and 2H:1V slope area. Uses cyclic stress ratio (CSR) and cyclic resistance ratio (CRR) method per Seed et al. 1985 and NCEER 1996 Workshop for 475-year return period design event. AR049946, STIA 00551.