MHT Cargo Facility

Manchester, New Hampshire

Geopier Rammed Aggregate Pier® Elements Installed to Support 64,000 sf Warehouse

  • Owner: Aero Manchester III, LLC
  • General Contractor: Whiting-Turner Contracting Co
  • Geotechnical Engineer: John Turner Consulting, Inc.
  • Structural Engineer: Foley-Buhl Roberts & Associates, Inc.
Client's Challenge

Total foundation settlement of +/-2 inches was estimated for unimproved ground conditions for the proposed 64,000 sf warehouse at the Manchester Boston Regional Airport. Geopier® elements were selected for ground improvement to reduce total foundation settlement to less than 1 inch, supporting the new warehouse foundations and slab on grade. The airport was an active airport, and therefore maintaining the construction schedule was a key driver for this project. 

Subsurface Conditions

Soil conditions consisted of a shallow granular fill layer underlain by very loose to loose native sand. Groundwater was present at about 10 feet below grade. 

Geopier® Solution

Geopier X1® Rammed Aggregate Pier® (RAP) elements were selected for supporting new foundations and slabs due to the effectiveness of the elements for improving ground conditions, as well as their ability to be installed rapidly. A total of 657 RAP elements were installed to an average depth of about 10 feet. Production rates of more than 150 elements/day were achieved. With average element spacings of about 8 feet, these production rates resulted in completion of up to nearly 10,000 square feet of building area in a day’s work. Ground improvement was completed ahead of schedule.