Crew uses ‘rapid replacement’ to install new bridge

ELKTON — In a matter of hours, a nearly 80-year-old bridge between Elkton and Drain that crosses Elk Creek was demolished and replaced by a new structure that crews slid into its place.

The 225-foot-long bridge on the east side of the Elk Creek Tunnel on Highway 38 was demolished Friday night. Crews closed the highway Friday evening and reopened it Sunday evening, several hours ahead of schedule. In that time, excavators clawed away at the old bridge and, using hydraulic machinery, a replacement bridge was slid along tracks into the gaping hole.

The method, called rapid replacement, is “very unusual” and rarely used, said Steve Vestal, agency project manager for Oregon Bridge Delivery Partners, the group overseeing the project. In the past, when rapid replacement had been used, it was usually for smaller sections of a crossing, not for moving an entire bridge, he said.

“I think you can look at the history and say ‘We’ve done it before,’” project manager Larry Gescher said. “But not like this.”

Generally when replacing bridges, traffic detours are used on temporary bridges while the permanent structures are built. In order to use temporary bridges, though, at least 600 feet of roadway is needed on either side of the bridge to allow for traffic lanes to merge back to the roadway. The bridge at Elk Creek only had about 30 feet of pavement before meeting the tunnel, Vestal said.

“We had to figure out a different way to do it,” he said.

One contractor proposal required single-lane closures through the tunnel and use of a temporary bridge. The method would have meant installing stoplights and stop signs at both ends of the tunnel, and would have led to longer wait times for vehicles. The closures would have occurred around the clock for six months. The proposal was plausible, but would have required tricky maneuvering of vehicles, and would have tested the patience of drivers, Vestal said.

Slayden Construction Group, the Stayton-based company that was hired as lead contractor, proposed the rapid replacement method as a solution. A Netherlands-based, multinational firm called Mammoet Inc. was brought in to provide the hydraulic equipment for the replacement.

For the past several months, construction crews have been working to build the new structure and prepare the bridge for the move. Most of the new structure was built on temporary supports next to the old bridge. Hydraulic jacks were placed under the new crossing a couple of weeks ago, and crews recently built containment platforms to keep concrete from the demolished bridge from falling into the creek, Gescher said.

The process of removing the old bridge and sliding the new bridge along steel tracks into its place, took a few hours. Then, the 50 workers at the site worked around the clock the rest of the weekend, securing the bridge with precast wing walls and end panels and repaving the road and crossing, Vestal said. Sunday, the bridge became fully operational.

“The big thing about this project is keeping traffic going,” Vestal said.

The weekend closure marks the only time the highway was completely shut down. Brief hold-ups, restricted to a maximum of 20 minutes, have occurred off and on since Slayden Construction started work at the site last June, Gescher said.

Keeping the closure time to only a few days was important to Elkton Mayor Rebecca Swearingen, she said. The highway heading to the coast brings 3,500 drivers a day — usually recreational vehicles or folks towing quads — through the small city. A brief closure means travelers are still able to stop in the city on their way to the coast throughout the summer, Swearingen said.

The Elk Creek bridge replacement was one of five bridge projects taking place near the city. The bridge to the west of the tunnel is set to be replaced using the same method sometime in July or August, and work on the crossing over Hardscrabble Creek, a few miles west of Drain on Highway 38, will also start up in the coming months, Swearingen said. The five-bridge project is set to wrap up by December 2009.

“We’re working on a (city) beautification project, and (the bridge replacement) ties right in with it,” Swearingen said. “It’s just going to be so pretty.”



• You can reach reporter Marissa Harshman at 957-4202 or by e-mail at mharshman@newsreview.info.