Murray Combined Sewer Overflow Project

CLIENT King County Department of Natural Resources

Location Seattle, WA

The Murray Combined Sewer Overflow project included construction of a 96-foot diameter, 45-foot deep storage tank using secant piles for excavation support.

The project was constructed through potentially liquefiable soils, and a combination of glacially over-consolidated, very dense saturated sand, silt and gravel, and hard clay, with artesian conditions present at the site.

As geotechnical and environmental consultant, Shannon & Wilson developed and coordinated the field and laboratory testing program, which included collecting and reviewing existing data; preparing an exploration plan; coordinating borings and geoprobes; selecting well and piezometer locations; and selecting samples for pertinent testing.  We also provided recommendations for the various project elements including slope stability, groundwater control and dewatering design; excavation and shoring for structures; ground movement, settlement, and vibration considerations; foundations; seismic design; and geotechnical instrumentation.

Shannon & Wilson provided input to the geotechnical portions of the plans and specifications, assisted King County with the review of submittals, requests for information, and made periodic visits to observe geotechnical construction.


Michael Kucker
Vice President, Underground Services Deputy Director

David Ward
Vice President

Paul Van Horne

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