Stevenson Elementary School Modernization, Bellevue, WA

Stevenson Elementary School Modernization

GeoDesign (now NV5) provided geotechnical services to support the replacement of Stevenson Elementary. The new school is the largest elementary school in the Bellevue School District (BSD), coming in at 106,000 SF. The two-story structure is supported by a combination of shallow foundations supported on existing soil and foundations supported on ground improved with rammed aggregate piers. These piers were used under a portion of the site to minimize earthwork excavation, backfill, and off-site disposal of unsuitable material, which resulted in a reduction in the earthwork schedule (by two months) and significant cost savings of over $100,000. Over-excavation depths varying between 4 to 16 feet were avoided through the use of the rammed aggregate piers. Construction was completed in 2018.


Bellevue, WA


Bellevue School District


Key Facts

NV5 was able to provide a reliable estimate of the depth to suitable bearing material that supported a cost comparison between standard over-excavation versus the use of ground improvement methods. The comparison showed the benefit of including a rammed aggregate pier alternative in the bid documents and ultimately saved BSD a significant amount of money.