In the past I was determined to design my bridges as safe, usable, appropriate, low cost structures. I felt that was my goal as the engineer of record. My feelings have shifted in this regard…still safe, usable but I am open to spending more money for a better design.
Partially because I believe that a low cost structure is not always the “right” structure for a location (if it is, use a low cost structure) and partially, and this seems bad, I see so much money wasted on other projects.
Typically a bridge type is chosen for a location and then the budget is determined by calculating what that bridge will cost.
How many times have you said to the person with the purse strings that you could improve the design and possibly lower the cost with some minor changes? Do you get to make the changes?
Probably not because that may mean a non-standard design. I have seen “standard” bridges built with five piers in a river where a change to a non-standard design would reduce the piers in the water with the added benefit of looking significantly better than the multi-span standard bridge
But you say, the standard bridge will be cheaper. The initial material cost may be cheaper but placing five piers in the river will involve multiple cofferdams and when you factor in the cost of building them you often find the larger span bridge with two piers will be cheaper.
In defense of the “right” structure for a location I ask engineers to look at their own neighborhoods. Would you want a number of square houses (easiest to design and build) next to your house? Simple boxes that all look the same? NIMBA!
I know this may be a poor analogy but anyone who has owned a house next to someone who never mows their lawn or paints their house understands my example.
Typically on a project that has/wants aesthetics in the design a percentage of the total cost will be set aside for the “added” features after a bridge type is chosen. Say a standard bridge will cost $1 million dollars, an additional 10% ($100,000 dollars) will be added to the final cost for the inclusion of decorations/improvements to the standard design.
What I think would be an better way to design a bridge, before picking a bridge type, is to first determine the budget. If you want a $10 million dollar bridge, I will show you what we have available for that price.
What I hate is picking the bridge type first and then determining the budget. This continues the practice of standard bridges and reduces everything to the lowest cost.
This post sort of got away from me but to sum up…..
If designers knew the budget up front, before choosing a bridge type, I believe engineers would be more willing to design non-standard structures because they will examine what can be built for the allotted money.
Instead of reaching for the low cost option first, we could look at what could be built for the money, which I believe would allow us to build more appropriate and interesting structures.
Updated: I don’t think this post makes sense? Oh well I have been working on artistic, sculpture bridges. So far this is all I have…