Crews make last substantial pours on new northbound bridge arches

From ODOT-

Our team recently poured the top sections of the southernmost arch for the new northbound Whilamut Passage Bridge. These top portions are called crown arch rib sections and they will soon be joined together to complete the graceful arch that will support the deck to carry freeway traffic.

Crews poured approximately 100-foot segments on each side of the arch apex, starting at the peak and working down each side of the curved arch ribs to the previously-poured lower sections. As we’ve described before, the rebar framework of the bridge arches is surrounded by wooden falsework and formwork, creating a form that allows fresh concrete to cure in the desired shape and size.

Poured in a series, you can see the result of a previous arch pour in this photo. Notice that lower portions of the formwork were removed, but the crown arch rib section formwork remains intact.

What's next? The construction team will jack apart the arch sections located on the north bank next week, using large hydraulic ram jacks. Just after the New Year, crews will repeat the jacking process on teh recently poured arch sections of the southermost arch. Each arch will require a closure pour after being jacked apart completing the final arch shape. Our goal is to complete the first closure pour on the northernmost arch before Christmas.



Other than the minimal but critical closure pours, these crown arch rib sections are the last arch pours on this project the new northbound bridge is definitely taking shape.