Bridging the Modern World

Bridges are so integral to our society, most people think nothing of them. The only bridges that get attention are iconic ones, like the San Francisco Golden Gate Bridge, or the French Millau Viaduct

I don't work with anything half as iconic, but the impact my work represents would be much more far reaching. I study the dynamics of railway bridges, specifically how high speed railways are affecting existing, older bridges, and the best ways to retrofit those bridges so they can support the increased demand.

Below is an image of our bridge (just the end of it) pre-damper installation.

Now here is a photo post-damper installation

The dampers are meant to reduce the vibrations the bridge feels due to the increased demand of the high speed railway on the bridge. The high speed rail induces higher frequencies on the bridge, which if it ever reaches resonance, is a major issue. Resonance is when the forced vibrations due to external loads (like a train or an earthquake) match the internal or natural frequency of the bridge. The resonance would cause massive deformation, and would dislodge the ballast on the bridge (the ballast is what acts as a base for the track to lay on) and thereby cause a derailment of the bridge.