Helical Piles Support Mt. Vernon, Illinois Hospital

A Mt. Vernon, IL hospital planned a second level for their existing one-story building. A team of contractors determined the second-story addition would overload four existing column locations supporting the hospital. To support the additional loading, they proposed the installation of new columns next to the existing columns. The hospital needed to remain operational during the entire renovation, and access and allowable working space was limited inside the building, creating a challenge.

Given their ability to be installed within the confined space of the existing building using relatively small equipment, helical piles were selected to support the proposed columns. The helical piles were installed with a high-flow skid steer, which could be driven through standard double doors and over temporary bridging that spanned excavations within the tight working conditions. Scrubber attachments were used to mitigate exhaust fumes within the building.

Hollow round shaft helical piles with a triple-helix lead section were selected to support design working loads up to 50 kips per pile. A kip is a unit of measurement equivalent to 1,000 pounds of force, so these helical piles are sure to provide the necessary support for the hospital. Two column locations required a pair of helical piles to support a service load of 100 kips, and four helical piles were installed at each of the remaining two-column locations to support a service load of 200 kips.

The piles were installed to achieve ultimate capacities of at least twice the design working loads. The installed helical piles were fitted with new construction caps and cast within the individual column footings. The helical piles were installed with a high-flow skid steer, which could be driven through standard double doors and over temporary bridging that spanned excavations within the tight working conditions. Scrubber attachments were used to mitigate exhaust fumes within the building. The helical pile installation was completed in just two days.