Settlement and Bearing Capacity Mitigations for Organic Marine Deposits for an Offshore Wind Port

The existing State Pier in New London, CT, is being improved for staging, marshaling, and storage of offshore wind components. Site conditions and structural loading demand imposed unique geotechnical challenges. One geotechnical challenge involved potential reuse and long-term settlement remediation of the organic dredge spoil using ground improvement. An alternative approach involved using borrowed granular material and disposal of the dredge spoil off-site. A second challenge involved foundation treatment for the large diameter, heavily loaded “spudcans” supporting jack-up vessels for load-in and out. Alternatives considered included removal of the organic soil and replacing with a thick stone pad, ground improvement, and pile foundations. This paper provides insights into the challenges in port developments, where soft marine deposits and heavy structural loading often co-exist. Early engagement among the owner, developer, design team, and construction administration team were crucial. A collaborative geotechnical peer review approach was utilized and proved to be effective.