Brooklyn Navy Yard: Shallow Soil Mixing

The Challenge:
Improper backfill next to the seawall bulkhead was causing issues known as soil subsidence in a parking lot on Brooklyn Navy Yard property. The subsidence occurred on the landside of an existing sheet pile wall that served as a tieback to the bulkhead adjacent to the East River. The Navy had originally installed this tieback during their occupation of the property decades ago.

Our Approach:
The Franklin Company Contractors developed a remedial excavation and backfill program to address the subsidence issue. We removed deleterious materials from the backfill of the original tieback wall. Our team introduced flowable fill to the excavation area to create a properly compacted foundation for new subgrade material and asphalt paving.

Regulatory Compliance:
We conducted all excavation work under the Construction Activity Management Plan (CAMP) protocol due to Brooklyn Navy Yard’s historical use as a US Navy facility. This protocol minimizes hazards to surrounding people and property during excavation activities.

Complex Project Challenges:

• Tidal Constraints:
  We could only perform excavation during specific tidal periods due to groundwater conditions.
• Groundwater Management:
  Our team used frac tanks and dewatering equipment to maintain proper groundwater depth during flowable fill installation.
• Operational Continuity:
  We maintained full access and operation of an existing brick building occupied by a Brooklyn Navy Yard Development Corporation tenant throughout the project.
  
• Structural Engineering:
  We excavated to depths greater than the building’s zone of influence, which required us to drill and grout 12-inch rigid inclusions to subgrade. These inclusions provided adequate support for the building’s loading dock, as the existing historical fill proved unsuitable for structural support.
  

Successful Outcome:
Usable parking lot for current tenants of The Brooklyn Navy Yard.

Contact The Franklin Company Contractors for your petroleum construction project needs.