Ralph Demarco Park in Queens, NY is a public park that runs along the East River and is maintained by New York City Department of Parks and Recreation (DPR). The shoreline stabilization obtained federal disaster recovery funding by the Federal Emergency Management Agency (FEMA) to rehabilitate the shoreline due to damages from Superstorm Sandy. GZA was retained to restore the riprap revetment, vegetated slope, walkways and handrails, and adjacent upland lawn. The proposed rehabilitation design project required approval from FEMA to receive federal disaster recovery funding and compliance with applicable FEMA regulations and technical guidance.
Challenge
GZA engaged the services of a drilling sub-contractor and mobilized to the site to perform four exploratory borings along the shoreline park. Two borings were performed in the upland park area from a truck mounted drill rig, and two borings were performed in the river from a barge mounted drill rig. The in-water borings needed to be performed from a lift barge due to the high current velocities encountered on this portion of the East River. The program made allowances for a variety of sampling and in situ testing procedures due to the site location and potential for organic river deposits. The samples collected were analyzed by a soil testing laboratory for sample classification.
Solution
GZA developed conceptual design alternatives for shoreline stabilization at the site. Geotechnical analyses include slope stability analysis using the SLOPE/W computer program and riprap sizing based on USACE approved methodologies. The key design parameter is wave height at the site, which was analyzed for the effects of wind speed, fetch, and shore slope. The potential for wave action from ship passage in the nearby navigational channel was also evaluated. The revetment design and opinion of probable costs were provided to enable procurement of the contractor by the DPR.
GZA provided permitting services on behalf of New York City Department of Parks & Recreation for the construction of the shoreline rehabilitation. This includes processing and obtaining Small Business Services (SBS) permit, U.S. Army Corps of Engineers (USACE) Nationwide Permit #3 (Maintenance) and the following New York State Department of Environmental Conservation (NYSDEC) permit programs: Excavation and Fill in Navigable Waters, 401 Water Quality Certification and Tidal Wetlands.
Benefit
GZA performed construction administration services to achieve quality assurance and permit compliance. GZA reviewed contractor submittals and RFIs, attended project progress meetings, completed a site visit to the quarry for the project, evaluated the stones onsite to be salvaged, resolved any deficiencies or issues by the contractor observed onsite, verification of the construction work per the approved contract documents and ensured all construction activities adhered to the permit requirements and complied with FEMA funding requirements.
