Crews are working with steel and concrete to meet ODOT’s requirement of a 75-year design life.
Construction is well under way of a $12 million project to replace six downtown bridges connecting roadways to over-the-water pier structures by the Columbia River in the city of Astoria, Ore. All of the bridges have been restricted to three-ton weight limits — the lowest the Oregon Department of Transportation (ODOT) can go before having to close down the bridge.
The contractor, Legacy Contracting, Inc. began its work in late 2019.
The city refers to these six bridge structures as their waterfront bridges since they are located at the north ends of our streets along the waterfront, said Cindy Moore, assistant city engineer.
"The waterfront bridges are of utmost importance to the City as they provide access to a critical portion of our waterfront. They provide both pedestrian and vehicular access to many businesses and attractions. In addition, they provide very important emergency vehicle access to the waterfront."
Originally constructed of wood after a fire destroyed downtown Astoria in 1922 and maintained to varying degrees since, the new bridges are built on steel pilings with precast concrete piling caps and decks.
"The reason for going to steel and concrete is ODOT requires a 75-year design life and so modern materials were required for that," Moore said. "We couldn't replace with wood because it doesn't have that same design life."
The project is funded largely through a state bridge program, said ODOT spokesman Lou Torres.
"These are bridge dollars that can go to local bridges," Torres said. "They're very old bridges. They were load limited for a long time. They really needed to be replaced or the city would be making costly repairs every year."
The odd numbered street bridges — 7th, 9th and 11th — were rebuilt last winter during the months when in-water work can take place as permitted under the Threatened and Endangered Species Act. The ribbon cutting on those took place in August, but the completion was nearly three months overdue, Torres said.
"Two of the main reasons were we had weather delays. Not so much on location, but bringing in supplies from other parts of the country. There was a lot of flooding in the midwest, and they couldn't get steel and steel products out. The other reason, which is typical of old projects, when you start taking them apart and dismantling and rebuilding, you start to discover issues you didn't anticipate. That happens all the time. We call those surprises. We try to anticipate as much as we can."
Those "surprises" should make work easier on the next three bridges — 6th, 8th and 10th Streets — which began last fall.
"It should go smoother because the contractor was able to order material and supplies that were used on the first three," Torres said. "They've already got those stored and ready to use. You just learn things as you go along. In a multi-phase project, the first season is the roughest in terms of lessons learned.. As you go into the second and third phases, you're planning better."
One of the most critical components of the project was working with local businesses to make sure people knew how to reach them with the bridges closed.
"How do people get to the businesses if bridges were down? Another big challenge was enabling pedestrian access," Torres said. "ODOT and the city worked together to improve the signage around these bridges so the pedestrians could figure out how to get to the businesses on the other side of the bridge. We had to detour some pedestrian traffic. Signage really important. The message to people was that the businesses are open, but you can't get there the normal way. The business community was really concerned. They knew the bridges had to be replaced. The worst-case scenario was if bridges got closed in an emergency. It was not great, but the best we could do. ODOT tries to be as sympathetic as we can. The city was very aware of it, too. You try to do the best you can." CEG