I hadn’t intended to write two back-to-back columns about infrastructure, but a confluence of events dictates otherwise.
The first of these is the recent passing of Louis Guy, a man I can easily describe as an “engineer’s engineer.” Louis was immensely respected in our region, not only for his engineering prowess, but for his love of local history and his passion for our region.
About three years ago, Louis had to drop something off at my home for a website I was working on. Over beverages, he listened while I pitched the idea I’ll describe in a minute. When I was done, he expressed genuine enthusiasm for it, which coming from a professional of his stature was huge to me.
At the time, decisions had already been made and this idea was no longer really viable, but recent events have made it worth considering once again, so I present it here:
The project is the extension of Nimmo Parkway in Virginia Beach to Sandbridge. A couple of recent accidents on Sandbridge Rd. – the current route – have highlighted how inadequate it is for the traffic it carries, leading to renewed discussions about the project.
The original plan died, and rightly so, over concerns about the amount of negative impact it would have on the environment – particularly sensitive wetlands.
Here, I need to provide a little background regarding my idea.
Back in 1997, I saw a Nova special on PBS called “Super Bridge.” It was about a project to build a replacement bridge for a critical route spanning the Mississippi River between Missouri and Illinois. It was fascinating to me, which I guess makes me into something of an engineering nerd, but whatever…
The special highlighted the advanced engineering of the bridge, which was designed by a company based in Florida known as the Figg Engineering Group. If an engineering company can have groupies, then I’ve become an unabashed Figg groupie.
You’ve seen many of their projects probably without realizing it. Locally, they designed and participated in building the beautiful new Jordan Bridge over the Elizabeth River. And if you’ve driven I-295 outside of Richmond, you’ve likely crossed the eye-popping Varina-Enon Bridge. Soon, construction will begin in Virginia Beach on a new Lesner Bridge – also of their design. Their slogan is “Creating Bridges as Art.”
Other notable bridges they’ve designed include the Sunshine Skyway Bridge from Tampa to St. Petersburg, and the Leonard P. Zakim Bridge in Boston – the last piece of the “Big Dig” project. There are dozens more.
But perhaps their most noteworthy achievement was the rebuilding of the I-35 bridge in Minneapolis after the tragic collapse in 2007 of the old bridge due to structural failure. 13 people lost their lives, and another 145 were injured.
Working with their construction partners, Figg designed, engineered and built one of the most advanced bridges in the country, and opened it a mere 13 months after the collapse.
Imagine that. We can barely get our potholes fixed in that timeframe.
Figg pioneered two specific construction methods that were revolutionary. The first is the cable-stay bridge, which was actually first used in post WW2 Europe as a fast, cost effective way to replace many critical spans that had been destroyed in the war. The Varina-Enon Bridge is a beautiful example of this.
This methodology was first brought to America, and subsequently refined by Eugene Figg, the company’s namesake, in the early 60s.
The other innovation, and the more important in many ways, was the development and refinement of the so-called “precast segmental concrete construction” method. In this system, sections of the bridge are precast on the ground, then assembled together in the air like a string of pearls, using pretensioned steel cable.
This is how the Jordan Bridge was built. You may recall a minor accident during the construction. It was, in fact, one of these segments which was dropped.
The new Lesner Bridge will also be constructed using this method.
This brings me to the Nimmo Parkway project. One of Figg’s more amazing projects was construction of the gorgeous Blue Ridge Parkway Viaduct in North Carolina – the last segment of the parkway to be completed because of the environmental challenges.
Using the precast segment method and some innovative machinery, Figg was able to design a roadway that would have almost no negative environmental impact – either in its construction or over the lifetime of the structure. It was this that got me thinking about Nimmo Parkway.
Suppose that instead of going into these wetlands and other environmentally sensitive areas and trying to build up a conventional roadbed, we were to use the precast segment method to build a viaduct over the sensitive areas?
The only impact would come from sinking the support pilings, which can be done (mostly) from the viaduct surface itself as the roadway grows segment by segment. By giving the viaduct just a few feet of elevation, it would be unaffected by tidal changes, as well as allowing for the passage of wildlife underneath.
As a bonus, these segments have an enclosed, trapezoidally shaped support area underneath the road surface which could be used to catch and pipe stormwater runoff from the road, as well as carrying major utility services like power and water lines.
Yes – such a construction method would surely cost more per mile than conventional roadway in suitable non-sensitive areas. But when you consider all the advantages (mitigation of most environmental impact – particularly zero loss of wetlands, easy routing of utilities, creation of a much more secure evacuation route from Sandbridge, virtually unaffected by flooding), how would using this method to span the areas of the Nimmo Parkway project that cause the most heartburn NOT be the most logical way to go.
This brings me back to Louis Guy. I’m not a trained engineer (although I took engineering in college and have done some informally). So, the night Louis dropped by and we had this conversation meant so much to me because, here was one of the most highly-respected engineers in our area, willing to listen to my idea, and then offering praise and encouragement for the concept.
At the time of our conversation, the Nimmo Parkway project was officially kaput. But with discussions now being reopened about how best to address the issue of access to Sandbridge, and in honor of a man who meant so much to our region, and who made me feel validated, I humbly offer this idea for the environmentally-responsible extension of that road, for the consideration of anyone interested.
I would also opt for naming it the “Louis Guy Causeway.”