Inspectors OK bridge on U.S. 54 at Logan

By Chelle Delaney: Quay County Sun

State bridge inspectors gave the bridge on U.S. 54 near Logan passing marks on Thursday after spending several hours examining its structure.

The bridge is one of four steel-truss bridges in New Mexico that was ordered by Gov. Bill Richardson to undergo a comprehensive inspection last week. Richardon’s order was prompted by the deadly bridge failure in Minneapolis.

“It’ll be a five,” said Heather Sandoval, assistant district engineer and bridge engineer with New Mexico Department of Transportation.

A 5 rating means that the bridge is in “Fair condition – all primary structural elements are sound but may have minor loss, cracking, spalling or scour,” according to federal guidelines for bridge inspection.

“Spalling” or “scour” refers to defects in the concrete almost like a pothole or blister, said Sandoval.

Bridges are rated between nine, for excellent condition, and one, for “imminent” failure condition.

Next month, the bridge will have its annual inspection which is conducted by New Mexico State University at Las Cruces, Sandoval said.

At that time every rivet will be checked out, with a University crew that will use a bucket that is anchored atop the bridge, Sandoval said.
Thursday’s bridge inspection was visual with the use of binoculars.

If it needs further examination, a crew will come out with ladders, Sandoval said.

When a bridge reaches a rating of 2, it is immediately shut down and closed to all traffic, Sandoval said.

A 2 rating is described as a bridge in Critical condition – advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or sacour kmay have removed substructure support. Unless closely monitored it mkay be necessary to close the bridge until corrective action is taken.
The Logan Bridge was opened in June 1954.

Bridge Ratings
9: Excellent condition
8: Very good condition – no problems noted.
7: Good condition – some minor problems.
6: Satisfactory condition – structural elements show some minor deterioration.
5: Fair condition – all primary structural elements are sound but may have minor loss, cracking, spalling or scour.
4: Poor condition – advanced section loss, deterioration, spalling or scour.
3: Serious condition – loss of section, deterioration, spalling or scour have seriously affected primary structural components. Local failures are possible. Fatigue cracks in steel or shear cracks in concrete may be present.
2: Critical condition – advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or sacour kmay have removed substructure support. Unless closely monitored it mkay be necessary to close the bridge until corrective action is taken.
1: “Imminent” failure condition – major deterioration or section loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. BVridge is closed to traffic but corrective action may put back in light service.
0 Failed condition – out of service – beyond corrective action.