TagMechanically Stabilized Earth(42)

Memorandum dated December 20, 2001 from Michael Bailey, P.E. and Reda A. Mikhail, P.E. of Hart Crowser, Inc. to Jim Thomson, P.E. of HNTB Corporation regarding AR053223, project 4798-40. Analyzes sensitivity of MSE (Mechanically Stabilized Earth) wall design to variations in soil shear modulus under dynamic/seismic loading for the Third Runway Project at Sea-Tac Airport,

Hart Crowser, Inc. geotechnical summary report prepared for the Port of Seattle for presentation to the U.S. Army Corps of Engineers (Seattle District), dated November 2, 2001, project number 4978-06. Covers design of the Third Runway embankment and three mechanically stabilized earth (MSE) retaining walls (50–135 feet height) at Seattle-Tacoma International Airport (STIA). Addresses 17,000,000

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

This 2001 declaration from civil and environmental engineer Dr. Patrick Lucia, filed with Washington's Pollution Control Hearings Board, supports the Airport Communities Coalition's motion to halt construction of a proposed Third Runway at Seattle-Tacoma International Airport. Dr. Lucia, a principal with GeoSyntec Consultants, outlines his review of geotechnical and seismic concerns related to the runway's embankment fill and MSE retaining walls. The declaration references multiple technical letters submitted to the Washington State Department of Ecology and the U.S. Army Corps of Engineers raising safety and environmental questions about the project.

In August 2001, GeoSyntec Consultants submitted technical comments to the U.S. Army Corps of Engineers and Washington State Department of Ecology raising serious concerns about the geotechnical safety analyses for the proposed Third Runway expansion at Seattle-Tacoma International Airport. The firm identified multiple flaws in the design work performed by the Port of Seattle's consultants, including underestimation of earthquake risk, incorrect seismic stability analyses, and overestimation of post-earthquake soil stability. GeoSyntec concluded that the Port's consultants had not adequately demonstrated that the embankment fill and retaining wall structures would perform safely under anticipated seismic loads over the facility's lifetime.

GeoSyntec Consultants, hired by the Airport Communities Coalition, wrote to the U.S. Army Corps of Engineers and Washington State Department of Ecology in June 2001 raising serious technical concerns about the proposed Third Runway Expansion at Seattle-Tacoma International Airport. The letter challenges the Port of Seattle's geotechnical analysis for the West Mechanically Stabilized Earth (MSE) Wall, arguing that soil strength testing was insufficient, the extent of liquefiable material may have been underestimated, and seismic stability analyses were being performed incorrectly. GeoSyntec concluded that the Port had not yet demonstrated the wall could be safely and economically constructed to withstand potential seismic loads without unacceptable deformation.

FAA Northwest Mountain Region letter dated June 19, 2001, from FAA to Ms. Muffy Walker, U.S. Army Corps of Engineers Regulatory Branch Seattle District Office, following up on May 31, 2001 letter. Addresses three issues raised in April 30, 2001 Memorandum for the Record regarding the Port of Seattle third runway at Seattle-Tacoma International Airport

Memorandum for Record (MFR) dated 24 April 2001 from CENWS-OD-RG summarizing telephone conversations with Elizabeth Leavitt and Jim Kelley (Port of Seattle consultants) on 9-10 April 2001 regarding the Army Corps of Engineers’ review of the Port’s draft responses to letters from Azous and Sheldon concerning the Third Runway project at Sea-Tac Airport. Corps comments

Memorandum from Michael Bailey, P.E., Hart Crowser, Inc. to Jim Thomson, P.E., HNTB Corporation, dated March 26, 2001, documenting post-earthquake reconnaissance at the Sea-Tac Airport (STIA) Third Runway Project site (project J-4978-06) following the February 28, 2001, Nisqually earthquake. Two reconnaissance visits on March 1 and March 2, 2001 by Hart Crowser engineers Doug Lindquist

Hart Crowser memorandum (J-4978-19) from Michael Bailey, P.E., to Port Of Seattle attn. Michael J. Cheyne, CC HNTB attn. Jim Thomson, P.E., dated March 26, 2001, summarizing MSE (Mechanically Stabilized Earth) wall performance during the February 28 Nisqually earthquake. Discusses two MSE walls identified by Helsell Fetterman (Eglick & Stock 3/20/01) and GeoSyntec (3/15/01) as