CEDAR RAPIDS — When Joe Stanisz tapped a hammer against the underside of the 12th Avenue Bridge over the Cedar River, the concrete returned a hollow sound in one spot.
You’re looking for a solid thud, said Stanisz, a structural engineer for Shuck-Britson Inc. of Des Moines. Hollow means the concrete will eventually start to pop off, he said.
“But, it’s nothing critical because of where it’s at,” Stanisz said.
Stanisz will note the flaw in his inspection report, which city officials receive to help guide repair work. The report also is compiled into a federal database, which is another safeguard for deteriorating bridges.
Inspections are required on most bridges every two years by the Federal Highway Administration.
Shuck-Britson is inspecting all of the bridges that cross the Cedar River this week, which could mean some delays for motorists. A dozen lane closures will be scattered through the week, including locations along 2nd, 3rd, 8th, 12th, 16th, E, and F Avenues, and Edgewood Road.
The work is scheduled to wrap up on Thursday.
Doug Wilson, a project manager for Cedar Rapids Public Works, said local firm Anderson Bogart Engineers and Surveyors will inspect the other 67 bridges the city maintains this fall.
Wilson said the city spends approximately $96,000 for the biennial bridge inspections program and use of special equipment for the inspections.
Inspections for bridges over the Cedar River require a special vehicle called a “snooper truck,” which is why the Des Moines firm was hired, Wilson said.
The snooper truck parks on the bridge deck and three booms extend such that Stanisz can maneuver a basket into crevasses on the side and underside of the bridge.
In another area, Stanisz found concrete that has crumbled away to expose rebar. That’s likely caused from salt in water drainage slowly eating away at the bridge, he said.
Previous inspections help guide what Stanisz looks for as he works. The most recent federal data, shows the 12th Avenue Bridge, which was built in 1974, received a score of five (with one being worst and nine the best) for its substructure condition, a five for its deck condition and a six for its superstructure condition.
Those three categories are considered the most critical to the inspection, and a score of four or below in any of the categories can trigger a structurally deficient designation.
Cedar Rapids has managed to stay ahead of the curve on bridge conditions.
Even as the 12th Avenue Bridge was being inspected another crew was patching other spots on the bridge as part of a $2.4 million repair project that should be complete this fall, Wilson said.
“A lot of the really bad bridges are on rural roads,” Stanisz said. “There’s just so many of them that it’s hard for counties to keep up. The bigger cities have such a high volume of traffic they do a good job keeping up.”
While one in five bridges in Iowa are considered structurally deficient, which ranks as second worst in the nation, according to the federal database, Cedar Rapids only has one structurally deficient bridge, Wilson said.
That bridge is over McLoud Run. The city has financing in place to replace the bridge, but the work is pending acquisition of land, Wilson said.
“This is just the nature of the stuff we do every year,” Wilson said. “We are required to do it, plus it’s a good idea to take care of our bridges.”
Lane closures at the bridges include:
Monday, August 18
16th Avenue south lane from approximately 8:00 — 9:30 a.m.
12th Avenue south lane from approximately 9:30 — 11:30 a.m.
Second Avenue south lane from approximately 12:00 — 3:30 p.m.
12th Avenue north lane from approximately 3:30 — 5 p.m.
Tuesday, August 19
Third Avenue north lane from approximately 7:00 — 9:30 a.m.
Eighth Avenue south lane from approximately 9:30 a.m. — 12:30 p.m.
Eighth Avenue north lane from approximately 1:30 — 5 p.m.
Wednesday, August 20
Edgewood Road east lane from approximately 7:00 — 11:30 a.m.
Edgewood Road west lane from approximately 12:30 — 5 p.m.
Thursday, August 21
5-in-1 — E Avenue south lane from approximately 7:00 — 9 a.m.
5-in-1 — F Avenue north lane from approximately 9:00 — 11 a.m.
Third Avenue south lane from approximately 12:00 — 2 p.m.
For a list of road closures please check: http://bit.ly/cJupdw