Why are we using rammed aggregate piers?

Included in the Montana Heritage Center foundation are 763 rammed aggregate piers. Rammed aggregate piers are typically installed in grid patterns aligned underneath future footing and slab-on-grade locations. These piers reinforce the soil to limit any future settling of the building. Onsite you will see heavy equipment drilling holes, filling & compacting them with gravel, and then hauling off the dirt spoils. Different parts of the foundation require piers with different diameters and different depths, depending on the structural calculations. The complete installation of the 763 piers will take approximately 2.5 weeks. The process does have some noise, and we appreciate everyone’s patience while we get these piers in place so that Montana’s Museum is ready for footings.