Due to the heavy foundation loads, the project included installing Grip-Tite's Heavy Duty Retrofit Brackets and utilizing lead sections with 10", 12" and 14" helices on all of the helical piles. Galvanized material was selected due to the presence of high groundwater levels and organic soils. The helical piles were installed to ultimate capacities on the order of 76 kips and terminated within the glacial till soils near depths of 30 to 55 feet below bottom of footings.
Preparing the footings included core-drilling through 18 to 24 inch thick footings in order to place the retrofit bracket beneath the foundation walls. In addition, installing the floor-slab piers included working in limited space around office desks, interior walls and built-in drafting tables.
The building was lifted to near vertical all at once, which took a huge effort by the Grip-Tite team.
American Engineering Testing, Inc. provided continuous observation and testing throughout the entire project.