08/13/2026
Throughout the bond process and in many individual conversations over the past few months, we’ve been asked the same question…
How will we build a new school on the Helena High School campus given the poor soils and groundwater issues that have plagued the site for the past 75 years? The answer is relatively straightforward, but the techniques used by the engineers and contractors are not widely known outside the construction industry. Over the last three weeks contractors have been installing over 2,800 Rammed Aggregate Piers (RAPs) to strengthen the ground under the footprint of the new school. The process works like this:
o A specialized auger (think of it like a large drill) creates a shaft down into the weak soil
o The shaft is backfilled with a special mixture of engineered aggregate
o Another specialized piece of equipment compacts the mixture into the shaft until it is forced tightly together
o The process is repeated many times to create a dense, stable base for the school’s concrete foundation and slab.
The new Helena High School site requires over 2800 RAPs to support the new school and ensure it resists settling for the life of the building.
