Crumbling underpass targeted for repairs

Fargo's 10th Street underpass beneath Main Avenue is due for a facelift, but first officials need to find out what's below the skin.

They began that process Wednesday, when a North Dakota Department of Transportation crew from Bismarck drilled about 100 feet beneath the pavement to learn more about the geology below.

The 70-year-old underpass is structurally solid but cosmetically challenged, Mayor Dennis Walaker said.

"The sidewalks, retaining walls have needed some major repairs for an awfully long time," he said.

The extent of the repairs will be determined by the ongoing study, a joint effort between the city and state, which owns the underpass.

"We're hoping that we can have a project ready in 2010," said Kevin Gorder, NDDOT assistant district engineer.

The boring samples will tell engineers more about the subsoil and water table to help them figure out how much support is needed for the new retaining walls, Gorder said. The existing retaining walls are leaning and separating from the sidewalk in some areas.

Officials also will look at redoing the sidewalks and the lighting, Gorder said. Two Fargo residents publicly criticized the underpass last summer, saying the dark corridor is a safety hazard.

Gorder said some burned-out lights were replaced in response to the criticism.

"Whether there has to be some wholesale improvements to the lighting so it's more reliable, I guess that's something we'll have to take a look at," he said.

Walaker said he would like to see the asphalt driving surface replaced with concrete to make it longer-lasting and more reflective to light. The narrow, three-lane road requires frequent repairs to its crumbling edges.

"It's a constant headache," he said.

Officials also plan to repair cracks and chips in the concrete girders, walls and supports to improve the look of the underpass.

Despite the concrete's outer appearance, Gorder said core samples taken from the underpass last year revealed that "the underlying concrete is still very sound."

During its most recent inspection, in August 2007, the underpass was classified as "functionally obsolete" because of its narrow driving lines and substandard height clearance.

The inspection report described the sidewalks as "faulted" and "deteriorated" and said the "entire substructure has varying degrees of deterioration - cracking spalling, exposed rebar."

The substructure received a rating of "fair," while the deck and superstructure were rated "satisfactory."

The last major repairs to the underpass were made in 1984, when crews rebuilt the deck and repaired and repainted 12 of 19 steel girders.

Walaker said funding has not been identified for a full-scale replacement of the underpass, which is likely several years away.

Readers can reach Forum reporter Mike Nowatzki at (701) 241-5528