By: Metal Culverts, Inc
Award-Winning Innovation: The Cost-Effective Power of Corrugated Metal Pipe Bridge Replacement, Guthrie County’s Triumph
Across the vast network of America’s secondary roads, county highways, and recreational trails, one inevitably encounters aging timber frame and steel bridges, many of which have surpassed their intended lifespan. Consequently, these structures impose significant financial burdens on counties, necessitating extensive maintenance and repairs to adhere to stringent state and federal bridge safety standards. While these bridges might not serve the high traffic volumes of urban infrastructure, their significance remains paramount. Indeed, billions of dollars in agricultural trade depend on a secure and reliable secondary road system, facilitating the efficient transportation of crops and livestock to market. Therefore, the strategic implementation of corrugated metal pipe bridge replacement, as exemplified by the award-winning Guthrie County project, becomes increasingly vital.
Guthrie County’s Strategic Shift: Embracing Modern Solutions, A Project of the Year
Guthrie County, Iowa, much like numerous other rural regions, grapples with the challenge of deteriorating bridge infrastructure. Specifically, this county alone harbors over 150 timber frame bridges slated for replacement. Consequently, in recent years, Guthrie County has proactively adopted large-diameter corrugated metal pipe (CMP) structures as a dependable and efficient alternative for replacing these outdated and hazardous bridges. Furthermore, by utilizing underground corrugated metal pipe bridge replacement structures, municipalities like Guthrie County can construct bridges that eliminate the need for guardrails, a particularly crucial factor in rural areas accommodating ever-larger farming equipment. Additionally, these structures negate the requirement for special load postings and minimize the frequency of inspections and maintenance. It is this forward thinking, and successful outcome, that led to the project being awarded Project of the Year.
Analyzing Replacement Options: The Triumph of CMP, A Proven Success
In a particular bridge replacement project, that would go on to win project of the year, Guthrie County replaced a 22-foot long by 16-foot wide timber bridge, whose installation date remained undocumented. Considering the drainage area and hydraulic requirements, the Guthrie County engineer evaluated three replacement options. First, a single 6-foot by 7-foot reinforced concrete box; second, a single 84-inch corrugated metal pipe; and third, a twin run of 60-inch corrugated metal pipes. Ultimately, after conducting a thorough cost analysis, the single 84-inch CMP emerged as the most economically viable choice for corrugated metal pipe bridge replacement, a decision that ultimately proved to be an award winning one.
Cost Savings and Efficiency: A Clear Advantage, Award Winning Results
Moreover, when comparing the single 84-inch, 10-gauge, 3×1 CMP option with the concrete box alternative, Guthrie County Assistant Engineer Ethan Shelter, who oversaw the project, observed a remarkable 57% reduction in installation costs and a nearly four-week decrease in installation time. Subsequently, these substantial savings highlight the efficiency and cost-effectiveness of corrugated metal pipe bridge replacement, and directly contributed to the project winning the prestigious award.
Enhanced Durability: The “Zebra Pipe” Innovation, A Choice That Paid Off
Additionally, the county considered Metal Culvert’s “Zebra Pipe” for this project. Consequently, this “hybrid” CMP product, featuring traditional galvanized steel on the upper half and polymer-coated steel on the lower half (invert), offered an economical solution. In essence, the “Zebra Pipe” provides superior protection at the pipe’s most corrosion-prone point. According to Mr. Shelter, given the pipe’s location, which included runoff from a large cattle feedlot and its position under a well-traveled road, selecting a product with polymer coating and a 100-year service life was a straightforward decision. Therefore, the implementation of such advanced materials further solidifies the long-term benefits of corrugated metal pipe bridge replacement, and solidified this project as an award winner.
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