63rd Street Tunnel Connection
Long Island City, New York, USA
| Client | MTA-NYCT |
| Industries | Transportation |
| Services | Geotechnical Engineering, Tunnelling |
Assignment
The 63rd Street Line to Queens Boulevard Line (QBL) Tunnel Connection Project was a complex undertaking that involved constructing two ventilation structures, removing and reconstructing an inverted sewer siphon, and extending/transitioning two existing subway tracks underneath elevated and buried subway structures.
Our Role
The site was in a highly urbanized, congested region of Queens, 600 feet from an inactive hazardous waste site. Given site constraints and environmental concerns, the project's principal challenges were to perform all work while maintaining operational service on the QBL and Astoria Lines and to prevent adverse impacts to adjacent contaminated properties.
To satisfy project challenges, we incorporated a variety of specialty geotechnical engineering and construction techniques including:
- Soil and rock tunneling Underpinning of elevated Astoria Line structure
- Pin-pile, H-pile and caisson support of QBL structure
- Open and braced cut-and-cover excavations
- Jet-grout and concrete diaphragm (e.g., slurry) walls for excavation support and groundwater cut-off
- Soil and rock anchors
- Controlled rock blasting
- Construction dewatering
- Instrumentation and monitoring of adjacent structures and groundwater levels for control of construction activities