Round Building Footing

In 2019, Cunningham Backhoe Service was contracted to dig and prepare the foundation footings for a one-of-a-kind structure — the Hennessey Eagle Event Center, a 180-foot diameter monolithic dome serving as both a school gymnasium and FEMA-rated community storm shelter.

Built to withstand EF-5 tornado winds exceeding 245 mph, this facility demanded precision excavation on a massive scale.

Scope of Work

• Precision excavation for a perfectly circular 5-foot-wide footing ditch using a 30" bucket.
• Additional 18" footing excavations for smaller structural elements.
• Digging the elevator pit to specification.
• Utilizing both 18" and 30" buckets to match specific engineering requirements.

Overcoming Challenges

During the build, the project team encountered an error in the construction drawings and a miscommunication that led to the initial footings being placed a foot too high. While this required the first poured foundation to be removed, Frank responded with professionalism — returning to the site to re-dig the footings 18" deeper.

This second round required even more skill, as he had to work around portions of the previously dug area while still keeping the precision needed for the dome’s perfect circle.

Technical Approach & Tips

In his YouTube video “Mistakes Were Made” (DigginOK channel), Frank demonstrates:

• How to swing a backhoe off the ditch without damaging the edges.
• The importance of bucket size selection for different footing widths.
• Strategies for keeping a circle true over a 180-foot diameter.

Outcome & Impact

Thanks to Frank’s adaptability and experience, the re-dig went smoothly, and the Eagle Event Center now stands as both a state-of-the-art athletic facility and one of the safest public spaces in the region. His work laid the precise, stable foundation required for this FEMA-certified monolithic dome.

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