The Phoenix Academy is a unique educational center focused on children K-8 who are a school year or more behind in reading and/or math. Demand for the academy’s approach to learning has grown so much that a two-story addition was needed to accommodate additional students and faculty. The original expansion plan called for sheet piling alongside the current foundation while the foundation for the new wing was built. Concerns regarding the noise, vibration, and relatively high costs associated with sheet pile installation led the project engineers and general contractor to approach Thrasher Commercial for a more cost-effective and low-impact solution. Timing was also a critical factor so that students were disrupted as little as possible during the project.
Thrasher Commercial was able to find a cost-effective, low-impact, and timely solution to Phoenix Academy’s problem with a combination of push piers, helical soil nails, and shotcrete. Prior to the project, soil borings were completed and it was determined that the worksite consisted primarily of Peoria Loess soil. A total of 13 Model 288 push piers were installed at intervals of 6.5 feet along an 85-foot span of the existing foundation wall. The piers were installed to a depth of 60 feet to support a design working compression load of 15 kips each. Additionally, 63 Model 150 helical soil nails were installed at a 12-degree angle to a minimum embedment length of 14 feet in a grid pattern with 4-foot spacing to support a design working tension load of 15 kips each. Two benches were required to complete the soil nail installation that was then finished with 1,020 square feet of shotcrete to a thickness of approximately six inches. All systems were installed to achieve a safety factor of at least 1.5.
The entire project was completed in just six working days and the academy was able to continue to hold classes without interruption during installation. The general contract was able to begin work ahead of schedule thanks to the speed and ease of Thrasher Commercial’s project approach.
Certified Installer: Thrasher | Commercial
General Contractor: Vrana
Project Engineers: Td2 and Alley Poyner Architects
Products Installed: (13) Foundation Supportworks (FSI) PP288 Push Piers, Installed to a Depth of 60 feet, Design Working Load of 15 kips; (63) FSI HS150 Helical Soil Nails, 8-inch-diameter helix plates, Minimum Installed Lengths of 14 feet; 1,020 square feet of FSI ShotLock Shotcrete, Installed Thickness of Approximately 6 inches