Located in Nicolette County below Minnesota Highway 22 and three miles north of Saint Peter, a twin 10’ x 10’ concrete box culvert with structural cracks and deteriorated invert required rehabilitation. In order to reinforce the existing box culvert while maintaining the invert elevation of the structure, an open bottom reline product was needed. As the best solution, the Minnesota Department of Transportation (MNDOT) decided to utilize twin 9’-7” x 9’-4” steel, 2-flange Liner Plates, 96’ in length, from Contech Engineered Solutions.
Contech’s 2-flange Liner Plate offered the highest continuous ring stiffness and high compression joint strength. In fact, 2-flange Liner Plate has effective stiffness that is more than twice that of the same gage (thickness) of a 4-flange Liner Plate. The result is more effective corrugation performance for the highest stiffness and strength in the industry. 2-flange Liner Plate was the best choice because it allowed for construction of the arch to occur within the confines of the original, deteriorating concrete box culvert.
During construction, water was diverted into one side of the twin arch while installation and grouting occurred on the opposite side. Relining the structure, instead of total replacement, not only saved a substantial amount of tax dollars, but also prevented road closure. Both lanes of the highway remained open throughout the entire construction process, with no traffic detour required.