earth retention groundwater control wet soil mixing Keller Robinson Landing Potomac River

Hayward Baker constructed an earth retention system adjacent to the Potomac River Sponsored

*The TRD wall was designed to function as both a permanent cut-off and temporary earth retention system.*

Robinson Landing is a $185 million, mixed-use development that covers a full city block on the Potomac River waterfront in Alexandria, VA. Despite the challenges of working on the Potomac River adjacent to historic buildings, Hayward Baker constructed a watertight TRD earth retention system on time and with minimal movement.

The project involved excavating two levels of below-grade parking for construction of a riverside, five-story above-grade condominium building. Soils across the site consisted of interbedded layers of silty sand and gravels, soft lean clay, and stiff fat clay. A “bathtub” cut-off structure was needed to ensure no impact to surrounding properties through dewatering-induced settlement or migration of contaminated groundwater. HBI had already mobilized to the site when a historic ship’s hull was detected that lay partially within the 50,000 sq. ft. footprint at 25-ft below working grade.

HBI installed an internally-braced, vertical, soil-cement TRD perimeter cut-off extending to a depth of approximately 80 ft and keyed into the underlying marine clay. The TRD wall was designed to function as both a permanent cut-off and temporary ERS and eliminated the need to design for uplift pressure or for external perimeter dewatering. Following the detection of the ship’s hull, HBI worked with the client to redesign the shoring to facilitate inspection and safe removal of the hull without impacting the project schedule.

Jon Sandberg, Senior Project Manager at Donohoe Construction Company, said, "The wall was completed within schedule...and resulted in a finished product that exceeds the design criteria and is performing admirably."

Watch the video below that demonstrates the construction of the watertight TRD earth retention system by HBI.

Source: Hayward Baker: Robinson Landing