Built at the Aberdeen Log Yard site in Grays Harbor County, the project's design-build team was challenged with building a casting basin that was larger than three football fields, on soft and liquefiable soil, and ten feet below the adjacent Chehalis River.

Shannon & Wilson provided geotechnical and hydrogeologic services to support the pontoon casting basin during design and construction. We worked closely with the design-build team to provide an integrated design and construction approach.

For the project, we:

• Characterized subsurface soil conditions using soil borings and cone penetration tests
• Analyzed slope stability considering static, seismic, rapid drawdown cases
• Recommended axial and lateral resistance for 130-foot long driven 18- and 24-inch pile foundations
• Performed a design and production-phase test pile program with dynamic pile tests
• Developed strong ground motion time histories for the design ground motion
• Modeled the two-dimensional dynamic soil-structure interaction of the basin slopes and base
• Evaluated the influence of cutoff wall depth and dewatering well spacing, depth and configuration using a numerical groundwater model
• Conducted an on-site pumping test and infiltration test to calibrate the numerical groundwater model