Waterfront Tunnel - Alexandria Virginia
GEO's Trevor Brown, Geoffrey Hawkins, and Jake Paris in front of the Herrenknecht TBM recently delivered to AlexRenew, Alexandria Virginia's water treatment service. The TBM was named for Hazel Johnson, one of America’s leading pioneers for environmental justice. Photo by Hristo Dobrev, GEO's project manager.
Hazel next to the launch shaft. After launching, Hazel will excavate the 2-mile long Waterfront Tunnel at an average depth of 100 feet. The tunnel will capture and transport combined sewage to the AlexRenew facility where it will be purified and returned to the Potomac River.
AlexRenew has provided pre-construction surveys to owners and residents as part of its community outreach. GEO will be monitoring for potential movement of road surfaces, underground utilities, and structures along the path of the tunnel boring machine. Map and conceptional drawing of instrumentation courtesy of AlexRenew.
GEO will install up to 10 AMTS systems for measuring structural monitoring points ( 136 L-Bar Prisms) and ground monitoring points (87 Road Prisms). Other instrumentation includes 12 RVM vibration monitors, 46 borehole extensometers, tiltmeters, utility monitoring points, piezometers, and strain gauges (for shaft SOE).