No. 7 Subway (Flushing) Line Extension CM Services

New York Metropolitan Transportation Authority (MTACC)

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Construction Inspection and Management Services:

Once completed, the No. 7 Subway (Flushing) Line Extension will extend service beyond its current end point at Times Square West along 41st Street and south along 11th Avenue, terminating in the vicinity of 25th Street / 11th Avenue. The extension will include twin running tunnels with five cross passages, a 34th Street station cavern, three shafts, and numerous ancillary structures.

Gall Zeidler Consultants (GZ) provided construction management services for the MTA’s No. 7 Subway (Flushing) Line Extension. These services included design review and construction inspection safety and quality management related to the underground aspects of the work, Sequential Excavation Method (SEM) using drill-and-blast for excavation / Tunnel Boring Machine (TBM) tunnel excavation and support, instrumentation and monitoring, waterproofing, and installation of electrical and mechanical systems.

LOCATION:
New York, New York
DATE:
2007 – Present
STRUCTURE:
Running Tunnels, Cross Passages, Station Cavern, Shafts, Ancillary Tunnels and Structures
LENGTH:
Approximately 1.5 miles (2.4 kilometers) Running Tunnels
CROSS-SECTION:
3,700 square feet (344 square meters) Station Cavern
GEOLOGY:
Fill, Alluvial and Glacial Sediments, Weathered and Hard Rock (Manhattan Schist); Groundwater Table is Approximately 20 feet (6 meters) Below the Surface
COST:
Approximately $2.1 Billion
CLIENT:
Hill International - Lemley - Liro - Frankfurt Daniel (JV)
OWNER:
Metropolitan Transportation Authority Capital Construction (MTACC)