Sustainable Bridges for Every Bridge Engineer

Daniel Whittemore, AI Engineers, Inc., Middletown, CT

Introduction

As "green design" has become mainstream, examples of bridges with notable "green" features can now be found all over the world. . The Kurilpa Pedestrian Bridge in Brisbane, Australia, designed by Cox Architects, uses an array of 84 solar panels to power LED lights to illuminate its deck. In Ballybofey, Ireland, engineers have installed a water-powered light system powered by the currents of the river it crosses. And in San Diego, California, engineers have proposed a new structure that has an LED light show powered every night by 100% renewable sources including wind turbines. Do these stately, impressive crossings represent the leading edge of sustainable bridge design?

Before we can begin to answer that question, we need to first define the term "sustainable bridge." I suspect this term evokes images of structures like those listed above in the minds of many of my fellow bridge engineers when they hear that term. Or, perhaps they imagine picturesque glued-laminated wooden structures blending harmo- niously with their surroundings deep in a national park. Notably, the one common thread would be that these images would appear to have very little applicability to the real world, day-to-day problems faced by bridge owners or bridge professionals. Being pragmatic, many of us would then quickly dismiss the concept of a sustainable bridge as something impractical, or at best, of limited usefulness outside of the arena of green design.