I stumbled on this reading about fast projects for bridge construction. It turns out, there's a lot of them. And the reason seems to be economics (no one has any money) driving fast (read: cost efficient) solutions, or perhaps solutions (read: new methods and technology) making it economical. I'll leave the chicken and egg argument for someone else.
Nevertheless, accelerated construction is a project phenomenon that is being moved along by these factors:
- A US federally funded Accelerating Construction Technology Transfer (ACTT) Program
- Pre-fabrication (nothing new, but part of the plan), and
- SPMTs (self-propelled modular transporters) which are multi-axle, computer-controlled platform vehicles that can move bridge systems weighing up to several thousand tons with precision to within a fraction of an inch. (Let's hear it for GPS!) The vehicles can move in any horizontal direction and also have vertical lift.
But, in the bridge business, having the right transporter technology is perhaps the one project tool above all others that makes the rapid schedules workable.
From the US Federal Highway Administration website, we learn a few case studies:
- Sam White Bridge over I-15 in American Fork, Utah - In March 2011, the Utah DOT (UDOT) used two sets of SPMTs to lift the Sam White Bridge across eight freeway lanes of I-15. This was the longest two-span bridge ever moved by SPMTs in the Western Hemisphere and was UDOT's 23rd use of the technology.
- Massachusetts FAST 14 Project - The use of accelerated bridge construction, prefabricated bridge elements and the design-build project delivery method enabled the Massachusetts DOT to shrink a four-year bridge replacement project to just one summer. The $98 million project, dubbed "Fast 14," involved the rapid replacement of 14 deteriorated bridge superstructures along I-93