Scientists gave a stadium an ultrasound to reveal its hidden flaws

At the corner of Lindsay Street and Yanceyville Avenue in Greensboro, North Carolina, a nearly 100-year old baseball stadium is crumbling.

Many of World War Memorial Stadium’s scars are obvious. Large concrete chunks have chipped away in several places. Steel support beams, now exposed to the elements, are corroding. But a new study led by Sameer Hamoush of North Carolina A&T State University finds that the stadium, home to A&T’s baseball team, is also deteriorating in ways that the eye can’t see.

Built in 1926, just a few years after the war that gave it its name, the stadium is listed on the National Register of Historic Places. So when Hamoush and his colleagues set out to test the building’s structural integrity, they had to walk a fine line: They needed to poke and prod the building enough to figure out its breaking point while making sure to not actually push it to that breaking point.

To do that, Hamoush, an expert in civil infrastructure, and his colleagues Miguel Picornell and Won-Chang Choi used a technique called seismic analysis. They placed a small acoustic device against the side of the building. The device emits gentle ultrasound waves, which spread like ripples in a pond, and can be detected by receivers arrayed across the building’s surface. Based on the time it takes a wave to travel from source to each receiver, it’s possible to estimate the strength of the intervening construction material.

The team’s seismic analysis revealed unseen weak spots along the 25-foot towers that bookend the stadium’s arched facade, an indication that the facade’s top coating is peeling away from the underlying concrete. The reseachers also found vulnerable spots in the concrete slabs supporting two of the stadium’s bleacher sections.

The findings should aid the designers and engineers tasked with refurbishing the aging sports venue. For A&T’s baseball team, those renovations can’t come soon enough. The Aggies will surely look to pack the stands as they chase a fourth Mid-Eastern Athletic Conference title this year.