– First in a Series –
By Brad Mosher
New England has a bridge which may need to be closed for repairs in the near future.
The Main Street bridge which crosses the Cannonball River just north of Riverside Park is in serious need of repairs.
It isn’t the only one.
There are 16 bridges in Hettinger County labeled as structurally deficient by recent inspections from 2016 to 2018 and needed repair or corrective action.
Another 11 bridges were identified as meeting the minimum tolerable limits but still needed repairs.
Forty bridges are identified as being in good condition in Hettinger County.
After an inspection in Sept. 2017, the bridge made the list of the county’s structurally deficient bridges with a poor rating. It also had a sufficiency rating of 33.50.
By comparison, the nearby State Highway 22 bridge over the river has a good/fair overall status, with a sufficiency rating of 96.10 and in fair condition according to the NBI Bridge Condition standards.
According to the survey, the bridge met the minimum tolerable limits to be left in place as is.
The bridge also was given a rating of 2 for its deck geometry and declared that it was requiring a high priority for replacement.
The bridge was built in 1912 and has not been reconstructed, according to the information listed by Florida Today which covered all of the states including North Dakota.
According to the inspection in 2017, the deck is in poor condition with advanced section loss, deterioration, spalling or scour. Spalling is when concrete is breaking into smaller pieces. That can occur because of temperature, moisture, corrosion, weathering and mechanical pressures which stress concrete. Scour is when there is erosion around the foundation.
The superstructure and the substructure were also in the same poor condition, according to the last inspection.
In addition, the bank protection is being eroded, with river control devices and/or the embankment having major damage, the 2017 inspection cited.
The railings on the bridge had the lowest score – zero – and does not meet currently acceptable standards or have a required safety feature. The zero rating is for the bridge railings, the transitions, the approach guard rail and the approach guard rails ends.
The bridge itself is eligible for the National Register of Historic Places.
A nearby bridge over the Cannonball River on 60th Street W approximately a mile west of the city was rebuilt recently after an October 2016 inspection had given it a sufficiency rating of just 28.00 and was designated as structurally deficient. It had been built in 1944.
The bridge had been identified as scour critical with the bridge foundations determined to be unstable. After the inspection, the bridge was identified as needing replacement because of substandard load carrying capacity or substandard bridge roadway geometry.
One bridge closed
There is just one bridge in Hettinger County that has been closed.
It is located on 73rd St. SW along the eastern border of the county one mile south of Highway 21 over Thirty Mile Creek, 13 miles east of the county seat. The bridge, located east of Bentley Road, had been built in 1916 and not been reconstructed since. It had a sufficiency rating of 48, but had serious problems.
After the Sept. 2017 inspection, the deck of the bridge was described as being in “imminent” failure condition. The inspection also said there was major deterioration or section loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. The bridge is closed to traffic, but corrective action may put back in light service.
The inspection also reported that the bank and embankment protection at the location had been severely undermined, severe damage to river control devices and the presence of large deposits of debris.
As a state, North Dakota ranks tenth in the country with the percentage of structurally deficient bridges, according to the report issued by the American Road and Transportation Builders Association.
Of North Dakota’s 4,355 bridges, 469 are listed as structurally deficient or 10.8 percent. Of the bridges in North Dakota, the state’s Department of Transportation is responsible for about 1,100, with various counties being responsible for maintaining roadways and bridges.
The 469 total is lower than the 512 listed in 2014, but the method of identifying the structurally deficient structures has changed. In 2018
The state barely made the top 10 list by percentage, beating out Michigan (10.7 percent).
Rhode Island had the fewest bridges of any of the 50 states (780), but the highest percentage (23.1%) of deficient bridges when 180 of the bridges made the deficient listing.
West Virginia followed with 1,444 of its 7,269 were listed as structurally deficient. Iowa had the third highest percentage of deficient bridges while having the most bridges (24,123) on the top 10 listing.
New England bridge
In Hettinger County, the most traveled structurally deficient bridge was built in 1912 and has 500 daily crossings, according to the ARTBA report. That is on a county road over the Cannonball River just one mile south of New England.
The bridge has not gone through any reconstruction and is currently described as poor by the latest NBI evaluation. It was last inspected in September 2017 and has a suggested inspection frequency of every 18 months.
The weight limit for the bridge has been recently lowered.
Another bridge near the city was rebuilt recently. The bridge over 60th St. SW, one mile west of the city, was rebuild recently. The bridge had a lower sufficiency rating (28) than its neighbor south of the city (33.60) that connects to Highway 21.