From ODOT- The Arch Falsework comes down

Our contractor, Hamilton Construction, has spent more than nine months building the two graceful arched spans that will support the new southbound Interstate 5 bridge. As you travel past the construction project, you may have noticed the arches nearing completion.

Starting last April, crews built falsework to form the arches. They started by erecting steel supports on the work bridge and welding them into place. On top of the steel supports, the crews built a wooden deck and forms that outlined the curve of the arches. Inside the arch forms, they built a “skeleton” of reinforcing steel bars that gives each arch both strength and flexibility. Finally, crews filled the forms with concrete that protects the reinforcing steel and adds to overall strength.

Now that the arches can stand on their own, we have started dismantling the wooden forms and steel support system. Most all of the material will be saved and stored near the site and reused to build the arches for the northbound I-5 bridge.

With all the falsework now removed in span 2, the weight of the arches is fully supported on large concrete shafts that were constructed deep in the ground on either bank and in the middle of the river.

The graceful lines of the river crossing can now be seen.





Here are the arches under construction, with falsework in place.


Here are the span 2 arches standing free of falsework.