The Conradi Building, constructed on the Florida State University (FSU) campus in the 1950s, needed to be demolished as part of the University’s strategic plan. The building was adjacent to a major thoroughfare which required one basement wall of the three-story building to remain as a retaining wall in order to prevent the soil behind the wall from moving and causing damage to the street above.
To permanently stabilize the wall, and therefore prevent damage to the street, helical anchors and earth anchors were selected. These anchors were selected because they could be installed under the roadway without inhibiting traffic flow and because they needed to be installed inside the basement before demolition could begin.
A Bobcat 323 capable of passing through openings as small as 39 inches wide was chosen for its maneuverability through the building and down to the basement. The Bobcat 323 was also fitted for an emissions scrubber to allow for safe operation of the equipment inside the basement.
Three (3) Geo-Lock Wall Anchors were chosen to stabilize three of the wall columns in the area where the roadway did not run parallel with the wall. Geo-Locks were used in this area because they only require a 1-inch hole drilled to allow the rod to pass through. Each anchor was attached to the existing wall with a 12”x28” wall plate and a 26”x26” earth anchor plate.
Twenty-four (24) Model 150 (1.5-inch) square shaft helical anchors with an 8”-10” double-helix lead section were installed with anchor lengths of 25 feet. Each anchor was installed to support an allowable capacity of 12 kips (FOS>2). Each anchor was attached to the existing wall with a 12”x28” wall plate. Installation of the 24 anchors took approximately three days to complete.