Combined Sewer Overflow Phase III – Pawtucket Tunnel
Pawtucket, RI
Founded in Pawtucket, Rhode Island in 1933, J.L. Marshall is proud to have contributed to this project which will have positive impact on the local community for generations to come. This sewage containment system is designed to hold over 58 million gallons of sewage overflow and prevent stormwater runoff from entering Narragansett Bay.
On this project, J.L. Marshall’s constructed a circular concrete tunnel lining using a collapsable hydraulic steel-ply radius form system. Work on this project was conducted inside a 2.2-mile tunnel at depths of up to 155 feet underground.
J.L. Marshall’s crew installed the upper radius hydraulic steel-ply system in 25-foot increments along the lower radius, starting from the vent shaft and working toward the main shaft. Bulkheads were scribed to fit both the steel-ply system and the excavated rock shaft. Using hydraulics, the system was lowered, raised, and extended into position for each placement.
To place concrete, the pump was stationed outside and above the tunnel at street level. Concrete was poured through ports in the form system 400 feet from the area of placement. At the conclusion of each pour, an outside circular form was created and secured against the tunnel’s rock wall to form the scribe bulkhead and complete the section.