CONSTRUCTION OF THE NORTH DORCHESTER BAY CSO STORAGE TUNNEL IN BOSTON

This paper describes the successful management and construction of the 5.18 m (117 ft) diameter, segmentally lined, North Dorchester Bay CSO storage tunnel in Boston, MA. This 3,300 m (10,830 ft) long tunnel was mined through variable soft ground with only 6 m (20 ft) of cover, using an earth pressure balance tunnel boring machine. These extensive data collected from the projects unique automated and internet accessible geotechnical and TBM monitoring system, will be examined and used to explore the relationships between geological conditions, TBM operating parameters and measured settlements, The paper will also discuss the use of screw revolutions as an indicator of muck volume.