Rendering of Planned Passageway
Rendering of Planned Passageway Break-in to Exisiting Line
Owner
Washington Metropolitan Area Transit Authority [WMATA]
Client
Washington Metropolitan Area Transit Authority
Cost
$8 million USD
Timeframe
August 2018
— September 2018
Services performed
Dr. Sauer & Partners provided construction methodologies for the proposed passageway, including considerations of instrumentation & monitoring, breaking in and out of the platforms through existing station structures, preliminary FE calculations, risk management, and cost assessment.
Description
In order to relieve capacity constraints and increase passenger safety during peak travel periods at Gallery Place – Chinatown Station, WMATA considered the construction of a new diagonal passageway connecting the platform level of the Red Line with the mezzanine level above the Green and Yellow Line. The proposed passageway provided improved passenger movement through the station to alleviate platform overcrowding. Additionally, the passageway also included emergency egress to the street via a stairway and a hatch opening at the sidewalk along G Street NW.
Geology
Fill, alluvium, and Pleistocene terrace deposits of sand with silt and gravels.
Location
Washington DC, USA
Highlights
- Dense, urban environment.
- Break-In into existing, live operating subway lines.
- Challenging soil and ground water conditions, which require ground treatment prior tunnelling.