Collection 14
- Location: Washington, DC
- Scope: Underpinning and shoring of existing structures
- General Contractor: McCullough Construction, LLC
- Engineering Consultant: GEI Consultants
- Category: Commercial
The Project
Steele Foundation provided solutions to multiple deep foundation challenges in transforming the 14th and W Street, NW city block of five structures and a parking garage into a modern, large, mixed-use property to be known as Collection 14. The developer intended to retain historic street-facing building façades (to the extent possible) to preserve the character of the neighborhood.
The project included the former headquarters of Martha’s Table in Washington, DC.
Steele Foundation’s structural shoring for the conversion required complex basement construction and lateral bracing for four existing historic structures in poor condition. This is challenging work that few firms in the region have the expertise and professional staff and craftspeople to perform.
Why Steele Foundation?
Steele Foundation was selected by the contractor because of a history of successful complex projects. Early involvement enabled Steele and the construction team to determine optimal engineering and construction approaches.
Challenges and Results
Reduced Access
● The structural shoring for the conversion to a large-scale, mixed-use property required basement construction beneath an existing historic structure to preserve the character of the façade.
● The reduced access necessitated hand-dug pits, which could have added months to the schedule. Instead, restricted-access drilling equipment installed micropiles and shoring frames within and around the structure to overcome this scheduling and budgetary challenge.
Agile Response to Project Conditions
● As the actual construction proceeded and the conditions of the soil and foundations were revealed, several design and construction plans needed to be quickly re-tooled to adapt to the realities of the project.
● This was a rapid-paced and intensely schedule-driven project involving numerous concurrent phases and contractor teams, so Steele’s extensive experience with deep foundation construction was a crucial lynchpin in maintaining the schedule.
“The support of excavation for this project presented unique challenges including suspending a one-hundred-year-old building above the mass excavation. Steele Foundation spent extensive efforts in the design phase to ensure the system was engineered properly and would allow for excavation equipment to operate below. Steele erected their systems with a high level of precision and the excavation proceeded accordingly to schedule. We are proud of our long-term relationship with Steele Foundation and have relied on their expertise on many challenging projects.”