The Dorchester Avenue bridge, located between Von Hillern and Kemp Streets Boston, MA and carries vehicles, pedestrians, and bicyclists over the Red Line, the Commuter Rail Old Colony Lines, and the Cabot Yard maintenance track. Originally constructed in 1925, it is being replaced due to its structural integrity, ensure reliable MBTA service and to reduce future maintenance costs.
GTR was retained by the General Contractor to design and implement a Geotechnical Instrumentation Monitoring program to monitor deformation of and vibration levels at adjacent structures. GTR collaborated with project stakeholders to implement a comprehensive site-specific program to monitor critical infrastructure during construction, including the existing MBTA and MBCR railroad tracks, existing Dorchester Ave. bridge, I-93 Bridge Abutment; adjacent retaining walls, utilities, private residences and the MBTA Red Line Subway tunnel portal. The scope of instrumentation included robotic total stations (AMTS) to monitor remotely the deformation of all structures, and automated seismographs to monitor vibration levels. GTR also monitored an existing inclinometer behind the existing bin wall on Von Hillern St. All data was reported to our project specific web-based instrumentation website for real-time reporting to the project team.
Additionally, GTR provided contractor support services related to the proposed driven pile deep foundation system for the new bridge, and for the new permanent soil nail wall along Von Hillern Street. Specifically GTR performed wave equation analyses to estimate pile lengths and size pile driving equipment, and executed dynamic pile testing to evaluate site-specific pile capacity. GTR then furnished and installed embedded strain gages for long term monitoring of select soil nails in the bin retaining wall.
