Heartland Coop Bin Expansion
Geopier Rammed Aggregate Pier® elements provided a safe and cost-effective solution, saving the owner time and money. Shoring was not required adjacent to the existing structures.
- Owner: Heartland Coop
- Millwright: Mid States Millwright
- General Contractor: Beers Construction
Construction consisted of three grain bins with diameters of 78 feet and 84 feet eave heights for an existing facility in Dallas Center, IA. All the bins were set on ring foundations with above grade tunnels.
Soil conditions consisted of up to 6 feet of lean clay fill underlain by 7 to 14 feet of medium stiff to very stiff lean to fat clay overlying stiff glacial till.
Rammed Aggregate Pier® (RAP) elements were recommended by the geotechnical engineer to improve bearing conditions and reduce total and differential settlement. The Geopier GP3® system was used to install 24-inch diameter elements to provide an allowable bearing capacity of 4,700 psf.
A total of 905 RAP elements were installed in two phases to a depth of about 13 feet to support the three grain bins. Construction of these Geopier elements took place over 13 days. The designed total allowable settlement was 4 inches and allowable differential settlement was 1.5 inches. A modulus test was performed to confirm the RAP soil reinforcement design.
