Mississippi County rates condition of bridges in spillway

Sunday, July 31, 2011

CHARLESTON, Mo. -- Four A's, a B, four C's, 2 D's and an F probably would be frowned upon as a student report card but Mississippi County's floodway bridges could have done a lot worse.

Dennis Cox, an engineer for Smith and Co. in Poplar Bluff, presented county commissioners with the inspection report on the 11 bridges in the spillway during their regular meeting Thursday.

Bridges were rated on an A to F scale, Cox said.

A and B bridges are in great condition while C means the bridge should be replaced within 10 years, according to Cox.

"Anything that is rated class D needs to be replaced now," he said, and F is "failed, fell down."

The bridge on County Road 310 was the only bridge inspected to receive an F. The cost estimate to restore that bridge is "to be determined," Cox said, because there is no bank on the east side of the ditch.

Costs for bridges of similar length can be used, he said, but officials must also consider the cost of the extensive roadwork -- maybe a half-mile -- that must be completed to get a road to the bridge.

Putting a bridge in like it was before the flood would place the bridge at an angle across the ditch and take a clear span of around 100 feet in length.

Cox estimated the cost could be around $400,000 for the bridge and another $100,000 or $200,000 for roadwork.

"I would suggest squaring it," he said, "but you would have to do more roadwork."

Placing the bridge at a right angle as suggested by Cox may get the length down to about 60 feet, but would require building up the roadway on the east side or relocating the road and bridge upstream.

Presiding Commissioner Carlin Bennett said the county could do roadwork as it would be credited toward the county's in-kind contributions.

Replacing the 51-foot bridge on County Road 312 with a new bridge would cost about $396,000, according to Cox.

The bridge was lowered from a 20-ton limit to 10 tons and was classified as class D.

Cox advised that to keep from losing Off-System Bridge Replacement Program funding, the bridge should not be removed and replaced with pipes on a temporary basis as discussed by commissioners.

He recommended putting in a temporary crossing with pipes downstream from the bridge.

Consolidated Drainage District officials are "probably not going to go for that," Bennett said, as it would restrict water flow in the ditch.

Cox said the bridge "has an exceptional amount of traffic" due in part to the bridge on the nearby County Road 310 being completely out.

The 112-foot truss bridge on County Road 521 over the Wilkerson Ditch, was rated a class D bridge, had its load limit reduced from 15 tons to 10 tons, Cox said, and would cost $648,000 to replace.

"This bridge was built in 1965," he said, and its piles are reaching the end of their life span. Replacing them would be "just about impossible," he said.

The 106-foot bridge on County Road 305 in the Brewer's Lake area was built in 1954 and would cost $167,000 to replace. It received a C grade.

The load limit on the truss bridge on County Road 319, built in 1965, was lowered from 20 tons to 18 tons. Its center pile needs attention but can be repaired, Cox said. He rated the bridge class C.

The 78-foot bridge on County Road 314's load limit remains at 18 tons also has a pile issue so is also rated class C.

Cox recommended maintenance to the steel for both the 314 and 319 bridges. Putting in new piles, however, could cost around $100,000 and would improve the load limits but would not increase the life span for either bridge.

The bridge on County Road 307, built in 1921, is rated for 16 tons and is rated class C.

The 30-foot bridge built in 1980 on County Road 329 received a class B grade and is rated for 20 tons.

"There's nothing that needs to be done to it," Cox said. "It's got quite a few years left in its life span."

Cox said the 40-foot bridge on County Road 301 was built in 1996, probably with Off-System Bridge Replacement Program funding, and is a class A bridge.

The 152-foot bridge on County Road 515 at Ten Mile Pond is also a grade A bridge. "It's in excellent condition," he said.

The 112-foot bridge at Four Mile Pond on County Road 518 also received a class A grade having been built in 2005.

Cox said that although the report lists cost estimates for replacement bridges, which include the costs of design, construction, inspection and minimal road work, those estimates are only a budgetary tool and may not reflect what actual construction costs would come to.

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