An engineering firm hired by the village last spring to inspect the Brookfield Avenue bridge over Salt Creek says the span is in “poor” condition and in need of replacement.
As a result, the Brookfield Village Board on Oct. 13 gave Village Manager Keith Sbiral the go-ahead to select a firm to complete preliminary engineering for a new bridge, which could be under construction by the spring of 2017.
The Chicago-based engineering firm Ciorba Group, which completed the most recent inspection, estimated that the total cost for replacing the bridge would be in the vicinity of $1.5 million.
Salvatore DiBernardo, executive vice president of Ciorba Group, told the village board last week that the bridge was not a safety hazard for pedestrians or vehicles. However, he did note that the Illinois Department of Transportation had already limited loads on the bridge to 22 tons and deemed it a candidate for annual inspections. IDOT typically inspects bridges every two years, DiBernardo said.
Asked by Village President Kit Ketchmark if the bridge posed an immediate safety risk, DiBernardo said, “We don’t think so.”
DiBernardo in a separate interview with the Landmark took pains to explain that sufficiency ratings had to do more with the village’s ability to tap into certain types of funding for bridge replacement and less to do with making statements regarding “safety.”
Even a bridge with a low sufficiency rating “doesn’t translate into a safety risk,” said DiBernardo.
“If there was a safety issue, we would have to report that to the authorities and shut down the bridge right away,” he said. There are no safety concerns with respect to the Brookfield Avenue bridge, he added.
However, the bridge’s abutments are approaching 100 years old and the bridge deck and superstructure have shown signs of deterioration, suggesting that it is a candidate for replacement.
Ciorba engineers recommended to the Illinois Department of Transportation that the bridge deck and superstructure be downgraded from “fair” to “poor,” based on their observations during visits in April and May.
The firm also recommended downgrading the bridge’s substructure, which dates to 1916, to “poor” because of cracks that have begun to appear in a cantilevered section where the deck extends past the original bridge abutments. The deck was replaced in 1986 and widened northward to accommodate a sidewalk.
In early October, IDOT lowered the bridge’s rating to a level where Brookfield is eligible to apply for federal funding to replace the bridge. If the village obtains that funding, it would cover 80 percent of the cost of construction. Brookfield’s share of the bill would be around $310,000 if that happens.
Brookfield trustees agreed that it made more sense to replace the bridge with federal funding than rehabilitate the bridge at a cost of $260,000. While a rehab might extend the life of the bridge, it would not eliminate some of the issues described by Ciorba Group in its inspection report.
If the village opts for replacement, the century-old east and west abutments would be replaced, along with the deck. While it’s too early to say exactly what design the village may settle upon, Ciorba Group suggested that the village might be able to construct a single-span bridge over Salt Creek.
That would allow the removal of the central pier supporting the bridge. Eliminating the pier would prevent debris from building up at the bridge and improve stream flow under the bridge.
“Based on our preliminary observation and the required size of the bridge opening, a single-span concrete superstructure seems feasible,” the Ciorba report states.
Brookfield will also have to decide whether it wants to close the bridge during construction or stage construction so that a portion of the bridge is open at all times to at least one lane of traffic.
Staging construction will increase the cost and length of construction, although DiBernardo stated that, either way, construction could be completed within one year.
Sbiral and Village Engineer Derek Treichel will put together a request for proposals for the preliminary engineering work sometime this winter, Sbiral said. Whichever engineering firm is chosen will take the lead in applying for federal funding for the project.