An overview of the Central Artery/Tunnel (CA/T, Boston, MA) project and the tunnel ventilation methodologies employed to ensure public safety and to maintain acceptable internal tunnel air quality
- Bechtel/Parsons Brinckerhoff, Boston, MA (United States)
The Central Artery/Tunnel (CA/T) Project in Boston, Massachusetts is the largest highway project currently in progress in the United States. Design and construction of this project falls under the jurisdiction of the Massachusetts Highway Department with the assistance of a Management Consultant. The CA/T project consists of a three (3) mile eastward extension of I-90 East/West from its current terminus and the replacement of approximately eight (8) miles of existing I-93 North/South roadway. The CA/T Project roadways are composed of a variety of viaduct, bridge, open cut boat section, cut-and-cover tunnel, and sub-aqueous tunnel. A variety of tunnel ventilation methods are being employed to maintain a safe environment within these tunnels during normal operations and emergency situations. The automotive emissions generated within the tunnels are emitted from tunnel exit portals in the case of longitudinally and semi-transversely ventilated tunnels. The automotive emissions generated within the full transversely ventilated tunnels are emitted from exhaust stacks located at ventilation buildings. The effects of the emitted automotive exhaust components on Ambient Air Quality Standards (AAQS) have been determined in a boundary layer wind tunnel. The CA/T Project`s seven (7) ventilation buildings and eighteen (18) potential longitudinally and semi-transverse ventilated tunnel exit portals have been evaluated in boundary layer wind tunnels. The results of the extensive physical modeling testing of the CA/T Project tunnel ventilation components have allowed the Management Consultant to optimize the design of these components and to subsequently achieve significant construction cost savings while ensuring that AAQS requirements are not violated. This paper provides an overview of the CA/T Project with emphasis placed on the project tunnels and ventilation methods.
- OSTI ID:
- 351680
- Report Number(s):
- CONF-970677--
- Country of Publication:
- United States
- Language:
- English
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