Freddie Mac – McLean, VA

Freddie Mac Ground Shoring FM8

Project Description

Subsurface Construction installed the first driven soil nail wall is allowed in Fairfax County, VA.  L.F. Jennings (G.C.) selected Subsurface Construction to design and install the ground shoring system for the Freddie Mac Expansion project in McLean, VA.  Fairfax County has a shoring geotechnical review board with strict guidelines for allowable soil properties used in shoring design. We were informed by the project geotechnical engineer that the review board never allows soil properties other than those stipulated by the board.

T.J. Ju, P.E., Chief Design Engineer at Subsurface, made a compelling argument by presenting verifiable historical data and research results to the review board and convinced them to allow alternative soil properties that more closely matched the existing subgrade conditions found on site.

In conjunction with this data, Subsurface developed a program to verify the assumed properties by testing the soil at every lift and sending data to the client.  As a result, we were able to utilize our Driven Soil Nail System, developed by our company, which saved the owner time and money.  By working in close conjunction with the grading contractor, we installed as much as 1,300 sq. ft. of shoring in a single day, and completed the shoring installation 2 weeks ahead of schedule.

Innovation is a hallmark of our company and we are pleased to be a part of this progression for soil nail wall design in Fairfax County, Virginia.

  • Use of research and field measurements to obtain more accurate soil properties.
  • 13,000 sf Driven Soil Nail Wall
  • 1,700 sf Soldier Pile Wall
  • Completed 2 weeks ahead of schedule
  • LF Jennings
  • Freddie Mac
  • Fairfax County Shoring Geotechnical Review Board

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