EXH1288052045

This report presentsthe resultsof Hart Crowseds Beotechnicalensineering analysesand recommendationsfor Phase 5 construction of the proposed embankment to support the new Third Runway at Seattle-Tacoma International Airport (STIA), in SeaTac,Washinston. This report provides 8eotechnical recommendations for desiBnand construction for the Phase 5 work, indudin8 embankment construction,subsrade improvements, constructionof Pond "A" for temporary erosion and sediment control (TESC),aswell as modificationsto Ponds D and F. Hart Crowser's 8eotechnical recommendations are based on resultsof subsurfaceexplorations and teststhat are presented in a companion report "Subsurface Conditions Data Report, Phase5 Filland Subsrade Improvement" (Hart Crowser 2001 b). SUMMARY This section presentsa summaryof the major observationsand recommendations presented in thisreport. At the end of the summary isa description of how this report isorsanized. The remainder of thisreport presents important information that supportsand expands on thissummary, and the entire report should be reviewed and considered asa whole. Site Preparation .- Site preparation recommendations for the Phase 5 embankment are the same as previouslyrecommended and implemented for prior Third Runway fill construction. Site preparation includes installationof TESC;abandonment of existin8 undersround utilitiesby fillin8 pipes with concrete; removal of surficial vesetation; proof rolling to discloseany soft or loose zones unsuitable to support the embankment; and removal of topsoil in a strip 50 feet wide alon8 the toe of the new fill. HartCrows= Pase 1 4978-28 Septlmlber26, 2001 AR 052049 o. Subgrade Improvement / Phase5 fill construction will extend over areas identified as weflands: which include but are not limited to drainage swales created by erosion. Observations indicate these areas range from…

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PSCAA Advisory Council Meeting Agenda
Add to CalendarMWednesday Mar 11, 9:00am - 11:35am
1904 3rd Avenue, Suite 105, Seattle, WA 98101
Call to order – Roll Call – Quorum Established – Land Acknowledgement We would like to acknowledge that our Agency operates in four present-day counties, which are the traditional lands of the Coast Salish people, past and present. This acknowledgement does not take the place of authentic relationships with indigenous communities in our jurisdiction and [...]