Project Case Studies

The Northeast Boundary Tunnel (NEBT) is a reinforced concrete sewer tunnel (7m diameter, 15-48m deep), that will increase the capacity of the existing sewer system in Washington DC’s North East District.

Maxwell GeoSystems is providing its industry leading MisssionOS cloud-data platform, to meet the client’s needs for real-time feedback of ground deformation in conjunction with shaft construction & key TBM operation parameters.

Due to the sensitivity of surrounding infrastructure, the client relies on MissionOS ’s real-time alarm notification system to alert key parties of potential unwanted settlements.

Addtional key features implemented on this job include proximity functions to relate ground deformation to TBM operations, prediction models to estimate final settlement, and TBM parameter alarms.

The NEBT is the largest component of the Clean Rivers Project in Washington DC (USA) and will be built using the TBM “Chris” (92m in length).

The tunnel project faces a number of challenges including heavy clay and water bearing clayey sands at water pressures up to 3bar, a challenging alignment with 15 curves, and a complex work environment for shaft construction with small shaft sites combined with urban residential neighbourhoods and a high traffic corridor.

Parties afiliated with the Project: Designer: Brierley Associates; TBM Supplier: Herrenknecht; Slurry Walls, Jet Grout, Secant Piles, Solider Piles: Treviicos; Segmental Tunnel Liner Supplier: ConSeg JV; Muck Hauling: Bulldog; Construction; Instrumentation: Entech; Traffic Engineering & Instrumentation Installation: EBA; Construction Manager: EPC Consultants; DC Clean Rivers Program Manager: McMillan Jacobs and Greeley & Hansen.