Helical Pile Deep Foundation Support for Mayo Clinic Expansion in Phoenix, AZ
Challenge
As part of a major expansion project at the Mayo Clinic Hospital in Phoenix, Arizona, engineers faced a complex deep foundation challenge involving the construction of an elevated walkway within a confined courtyard surrounded by existing hospital structures. The expansion required structural support for multiple heavily loaded column locations while working within extremely limited access conditions that prevented the use of large traditional construction equipment.
In addition to the logistical constraints, subsurface soil conditions presented further complications. Geotechnical analysis revealed layers of clay fill and loose to medium dense sands over deeper stiff clay soils, creating concerns about long-term load-bearing performance for the new structure. The project required a deep foundation solution capable of supporting significant compression and tension loads while minimizing disruption to ongoing hospital operations.
The restricted work environment, demanding structural loads, and variable soil conditions made traditional foundation systems impractical for the project. A specialized deep foundation approach was necessary to provide reliable structural support within the confined construction area.
Solution
To address the site limitations and structural demands, the project team selected a helical pile foundation system as the most efficient and cost-effective deep foundation solution for the Mayo Clinic expansion. Helical piles provided the ability to install deep foundation support in tight-access conditions while delivering the required compression and tension capacities for the elevated walkway structure.
Arizona Foundation Solutions coordinated specialized installation logistics to safely move compact equipment and hydraulic drive systems through hospital access corridors during off-hours, allowing work to proceed without major disruption to hospital operations. Multiple helical pile configurations and pile cap layouts were engineered to accommodate varying structural loads across the project.
After preliminary load testing confirmed the design capacities, the installation team successfully installed dozens of helical piles to torque-correlated capacities exceeding required service loads. Additional pile reinforcements and retrofit helical pile systems were later incorporated at several locations after updated structural loading requirements were identified during construction.
The completed deep foundation system provided reliable long-term structural support for the hospital expansion while overcoming the project’s difficult access conditions and challenging soil profile. By utilizing advanced helical pile technology and carefully coordinated installation procedures, the project was completed efficiently, safely, and with minimal disruption to the surrounding medical facility.
