On July 10, 2006, a section of suspending ceiling panels in Boston’s I-90 Eastbound Connector Tunnel collapsed onto live traffic tragically killing a local woman. The Connector Tunnel is part of Boston’s “Big Dig” tunnel network, formerly known as the Central Artery/Third Harbor Tunnel (CA/T) project, which was being operated and maintained by the Massachusetts Turnpike Authority. Following the collapse, then Governor Romney took control of the investigation ordering the Executive Office of Transportation (EOT) to perform and oversee an independent evaluation of the tunnel’s condition.
On July 25, 2006, DTC was hired by the EOT under the direction of the Massachusetts Highway Department (MHD) to perform emergency safety inspections of the CA/T tunnel system. Work began immediately, when DTC mobilized staff the next evening to inspect anchorage systems for two large air-circulatory jet fans located in Ramp F, one of the connector tunnels.
Since that initial assignment, work continued at a brisk pace where DTC conducted in-depth inspections on miles of other CA/T connector and main line tunnel sections, including the I-90 Westbound Connector Tunnel, Ramp B, Ramp L, Ramps D & DN, and Ramp RT.
The inspections originally focused on the ceiling panel anchorage support systems and quickly developed into the full inspection and assessment of all of the tunnel elements including the development, with EOT/MHD, of inspection procedures and specific inspection report forms to be used by all consultants. The Inspected items included ceiling panel hanger units, roof slabs, roadways and safety walk areas, tunnel finishes and false walls, slurry walls, wall and roadway plenums, and utilities.
Immediately following each inspection, DTC prepared report summaries and deficiency reports with recommendations for each deficient item. DTC is in the process of preparing formal inspection reports.