In the last edition of TheBridgeGuy, we examined the role of the architect on building projects. Architects act as project managers, coordinating the various disciplines employed in the design of complex facilities like buildings. Modern buildings require electrical power, heating and cooling machinery, a stable foundation to stand on and a structural framework. Beyond the engineering, buildings also require finish carpentry, drywall, window installation, bricklayers, etc. Coordinating all of that, keeping the project on schedule, under budget and within scope is all the province of the architect.
Bridges are, well, a bit different. Why aren’t architects involved in bridge projects like they are with building projects? In this edition we will find out the answer to that question and more.
The primary reason why architects aren’t involved in bridge projects is they just aren’t that complicated. Now don’t get me wrong, bridges can be complex in their own right. But they aren’t “building” complex from the standpoint of requiring so many different disciplines.
Unless a bridge is movable, there really isn’t any machinery or moving parts involved in a bridge project that would require input from a mechanical engineer. Some otherwise simple bridges may have navigation lighting, interior lighting or other features requiring electrical power, however these are usually simple systems that can be installed by electricians and wouldn’t require an electrical engineer’s involvement.
The elimination of those two disciplines remove the bulk of an architect’s headaches. There is no need to coordinate the space for mechanical systems, like HVAC, in a bridge. There is no need to coordinate runs of electrical wire, coaxial cable, fiber or telephone wiring in a bridge.
For the typical roadway or multi-modal bridge, accessibility by vehicles, pedestrians and bicyclists fall under a completely different code than that of buildings. The Manual on Uniform Traffic Control Devices for Streets and Highways, the AASHTO Green Book and state or local transportation policy documents are primarily taught to engineers rather than architects. These codes, and the principles behind them, make up the basis for transportation engineering, one of the sub-specialties of civil engineering.
In short, an architect is focused on building design. This is why a structural engineer working on buildings will interface more during their career with an architect, as opposed to a bridge engineer, who might go their entire career and never work with an architect.
So if architects never get involved in a bridge project, who fills their role? Typically – the civil engineer. Not, as you might expect, the bridge engineer.
Why? Because the bridge is often part of a larger project that is primarily civil in nature. Bridges typically carry roadways. That roadway is designed by a transportation engineer. Bridges need foundations just like buildings and a lot of the design work there is done by geotechnical engineers. Not to mention hydraulics for water crossings, environmental and of course, construction.
A bridge project is a civil works project, often involving all of the disciplines that make up civil engineering. Another term for this type of work is heavy civil, probably because the components that make up a bridge are heavier (think prestressed concrete girders) than those used in buildings. You’re unlikely to ever see a building requiring a member to span 200 feet!
Now, can we really say that architects never get involved in a bridge project? Certainly not. Many state departments of transportation employ a State Bridge Architect. But if bridges don’t require the coordination of multiple disciplines beyond civil engineering and aren’t typically that complex, what does a bridge architect do?
That answer has more to do with aesthetics, how something looks, rather than the traditional role an architect would play. The line between public art and nice looking structures has often been debated and is beyond the scope of this article, but that really is the role of a bridge architect.
The role of bridge architect is a niche one, much like a golf course architect. Bridges, because they are in the realm of the engineer, are usually utilitarian in nature with little thought given to the way they look. But as pressure mounts from the public to make roadway infrastructure just a little less ugly, this is where the role of bridge architect comes into play.
Many roadway corridors around the country have defined themes. That theme may be related to the state or local culture, the historic nature of the location or the natural setting, just to name a few. Themes can involve specific architectural features – such as formliner features into concrete, slogans, barrier/railing types and colors. Even the shape of bridge columns may be defined by the theme. These themes are usually developed by bridge architects.
Early on in the design process, the bridge architect is consulted on the aesthetic treatments for a bridge. Things like railing, pigmentation and formliners are the three typical considerations, but it is not uncommon for large or more visible projects to have more complex architect involvement. As an extreme example, Santiago Calatrava is known for incorporating aesthetics into the very structure of a bridge.
Unlike the building architect however, the bridge architect’s role on a bridge project is fleeting. Once the scheme is decided upon, it is up to the engineers to make the architect’s vision a reality. The successful bridge architect understands the role bridges play in society and the limitations of the structural components. Different from a building architect, a bridge architect will often have a background in engineering or architectural engineering. Two of the bridge architects that I know personally started their careers as bridge engineers.
That’s all for this edition of TheBridgeGuy. As always, I’m on the lookout for cool bridges to write about. Stay tuned for upcoming articles on cool bridges from Hawaii, Australia and New Zealand!
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