Marlborough, MA
Massachusetts Water Resource Authority, Walnut Hill Treatment Plant, Cosgrove Intake Pipeline
Scope/Solutions
The Cosgrove Intake pipeline, a 144 in. dia. prestressed concrete cylinder pipe (PCCP), at MWRA’s Walnut Hill Water Treatment Plant Project was completed in early 2004 as a part of the water supply system for the City of Boston. Less than a year after construction of the pipeline, a large leak of approximately 700 gpm developed near a deep manhole chamber in a section of the pipeline with multiple elbows. SGH provided emergency response and evaluated the risk of failure resulting from the leak, inspected the pipeline to determine the cause of the leak, and developed a repair scheme.
For this project, SGH:
- Performed internal inspection of the leaking pipe using a diver during a brief shutdown while the line was in operation
- Evaluated the structural safety due to the combined effects of internal pressure, dead loads, prestress, and hydraulic pressure-induced thrust at elbows
- Internally inspected and measured all harnessed joints to determine if any joints opened more than the design limits, inspected the pipeline for visible signs of anomalies, and externally inspected the leaking joint
- Designed repairs that included welding of the leaking joint and soil grouting.
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Project Summary
2004
Completion Date
Solutions
Repair & Rehabilitation
Services
Structures | Advanced Analysis
Markets
Infrastructure & Transportation
Client(s)
Barletta Heavy Division
Specialized Capabilities
Repair & Strengthening | Buried Infrastructure | Failure Analysis
Key team members
Additional Projects
Northeast
Tuskegee Airmen (formerly 100th Street) Bus Depot
The contractor attempted to repair the 280,000 sq ft of elevated decks and ramps, but subsequent cracking, including some through the previous repairs, raised concern about the service life of the depot. SGH investigated the cause of cracking in the concrete slabs.
Northeast
MBTA Bus Repair Garage
The building includes three garage bays, offices, and locker facilities for the bus operators and repair staff. When an elevated concrete floor slab in one of the bays failed under the weight of a bus wheel, the MBTA retained SGH to investigate.