Alternative Evaluation
Risk assessment and three-dimensional finite analysis to evaluate a value engineered alternative
This project involved the construction of a passageway for the northbound barrel of the new Central Artery-Tunnel project beneath the Massachusetts Bay Transportation Authority’s (MBTA) South Station, which serves the Red Line subway. The work also involved a 110-ft deep excavation immediately adjacent to Amtrak’s South Station terminus. The contract method consisted of the construction of structural slurry walls down the outer limits of the work perpendicular and beneath the MBTA station.
The construction of the I-90 interchange for the Central Artery Tunnel (CA/T) in Boston involved deep excavations, cut and cover tunneling, pipe-jacking through frozen ground, and soil mix techniques for ground improvement, all taking place adjacent to and under seven (7) Massachusetts Bay Transportation Authority (MBTA) and Amtrak tracks leading to Boston’s South Station. Geocomp was responsible for all of the geotechnical monitoring work which included piezometers, observation wells, extensometers, and inclinometers in ground and support-of-excavation walls, as well as structural monitoring including tilt, crack gages and horizontal column deformation in nearby structures.