New England East-West Solution (NEEWS) is comprised of multiple related high voltage electric transmission projects designed to provide stronger interconnections across Massachusetts, Rhode Island and Connecticut and allow more power to be moved between east and west in New England. National Grid is responsible for the design and construction of those portions of NEEWS, which are located in southeast Massachusetts and Rhode Island. These NEEWS projects include the Rhode Island Reliability Project, the eastern leg of the Interstate Reliability Project, and Berry Street Substation.
GZA was retained by Power Engineers, Inc., Owner’s Engineer to National Grid, to provide geotechnical services in support of the design, procurement and construction for these projects. Combined, these projects include over 100 circuit miles of new 115kV and 345 kV above-ground transmission located on over 60 miles of right-of-way; 6 substation expansions and/or upgrades and one new green field substation (Berry Street) with interconnections. Construction is completed for Berry Street Substation and Rhode Island Reliability Project, and nearly complete for Interstate Reliability Project.
GZA provided geotechnical engineering services during design and construction of these projects beginning in 2007 and will continue through the Summer of 2015. GZA’s field activities, including subcontractors, have compiled nearly 3,000 man-days to-date and resulted in zero lost time safety incidents.
GZA’s Geotechnical Investigation studies for the planning and design phases of the Rhode Island Reliability, Interstate Reliability, and Berry Street Substation projects culminated in 19 Geotechnical Engineering Reports. GZA’s design support services included:
• Desktop research of surficial and subsurface conditions at proposed exploration and structure locations.
• Coordination and oversight of 360 test borings located in energized right-of-way and active substations
• Managing productivity and coordinating up to six test boring teams operating concurrently
• Supplemental explorations to assess shallow bedrock conditions
• Foundation design support to address seismic issues and dynamic bus structure loading
GZA provided geotechnical engineering services during the foundation and civil construction of the Berry Street Substation, the Rhode Island Reliability Project, and the Interstate Reliability Project which consists of over 1,500 new transmission structure and substation foundations and includes caissons up to 11 feet in diameter and over 60 feet deep. Utilizing findings and reports from our geotechnical exploration program, GZA engineers provided quality control observation, covering up to 20 concurrent foundation and civil contractors operating concurrently. GZA also provided as-requested value engineering support, technical response to abutter inquiries, vibration monitoring, and recommendation for mitigating subsurface conditions that proved difficult for caisson construction, including caving soils, boulders, and pinnacled hard rock.