A structurally unstable bridge oscillates under specific wind conditions. Which mechanism explains why adding more support columns linearly *doesn't* always proportionally increase the bridge's stability?

💡 Explanation

The bridge doesn't linearly increase in stability with more columns because eigenvalue excitation relates to the bridge's resonant frequency, and approaching this frequency dramatically reduces stability. Therefore, adding support isn't always effective, rather than columns inducing harmonic motion or soil liquefaction being the main factor.