North River Canal LLC Development – Salem MA

NRCClient: North River Canal, LLC
282 Bennington Street
East Boston, MA
Completion Date: 2005
Total Project Value: $25,000

Relevant Project Features:

  • Geotechnical Investigation
  • Settlement Analyses Report
  • Foundation Alternative Evaluation

RT Group, Inc. (RTG) was retained by Fairbanks Engineering Corporation (FEC) to complete a subsurface investigation and evaluate foundation alternatives for this challenging geotechnical engineering project. The project included a circa 1900 4-story tannery building (see Photo above) that the Owner wished to evaluate for re-use as part of a proposed 4-story condominium project. The existing building had settled over 12 inches at some locations and the first step was to determine why this settlement had occurred and what the potential ramifications for the proposed development were.

NRA geotechnical investigation was completed by FEC and RTG and about 10 to 12 feet of fiberous peat was discovered about 10 feet below the floor slab of the building (see Spilt Spoon Photo). In addition, although the investigation revealed that the existing building was supported by timber piles (at the perimeter and column locations), the existing timber piles were small in diameter (about 6 to 8 inches) and relatively short (only about 10- to 15-feet-long). Through analyses, RTG was able to demonstrate that not only was the foundation system inadequate to support the existing building, as evidenced by the amount of settlement observed, it was woefully inadequate to support the proposed building.

As part of this Project, RTG was retained to present its findings to the local Historical Society and help persuade them that it was uneconomical and impractical to salvage and re-use the existing foundation (it would have cost over $1,000,000.00 more to save and underpin the existing foundation versus constructing a new pile supported foundation). Following the Historical Society meeting(s), the Owner was given permission to demolish the entire building and proceed with his plans to support the proposed building on a new pile supported foundation. RTG was subsequently retained by FEC and the Owner to complete the necessary investigations to finalize design for this new foundation system.