The Archive, Outside the Box

Project Details

Capabilities: Deep Foundations | Design Build | Earth Retention | Earthwork | Environmental


The Archive was an ambitious multi-family commercial project that sought to build 3-stories of below grade parking while maximizing the building footprint.  Several challenges, namely the adjacent Federal Reserve Bank, lead the ownership group to team with Bolander to find innovative solutions to make this project a reality.

Bolander proposed a multi-faceted approach that would achieve a 33-ft excavation without extending into the Federal Reserve Banks property while bringing substantial budget and schedule savings.

To maximize the building footprint, the existing bedrock was improved allowing it to be used as the below grade structural wall.  Piles used in the temporary support of this structure were engineered to become permanent structural pile providing foundational support to the post tension structure.  This approach eliminated the need to pour foundation walls, waterproof and backfill, drastically simplifying the project.

To support the excavation and adjacent buildings without conventional tieback anchors Bolander installed a slurry wall, the first of its kind in Minnesota.  The slurry wall was constructed using a combination of soil mixing, rebar reinforcement and micropile.

Archive by the Numbers:

  • 114 Drill & Set H-Pile, 50-ft
  • 17,600-SF Structural Shotcrete
  • 25,000-CY of Soil Export
  • 42,000-CY of Bedrock Excavation
  • 175-Lineal Feet of Slurry Wall, 14-ft Depth