Located only ½ mile from the Oklahoma border, K-23 provides the only state road crossing of the Cimarron River for nearly 20 miles in either direction. The existing concrete deck girder bridge measured nearly 1,400 feet long and had deteriorated to the point that the structure was continuously monitored with strain gauges. A hydraulic study was conducted for the new bridge, because the Cimarron River watershed extends into four states and is nearly 8,800 square miles. Years of aquifer use for irrigation and drinking water had lowered the water table in much of the watershed area. Following coordination with KDOT and multiple federal agencies, the final design for the new bridge was over 400 feet shorter than the existing structure.
At roughly 1,000 feet long, the new K-23 structure consists of 12 spans, each 84 feet long. The prestressed I-girder superstructure was broken into two units with a finger plate expansion joint in the center to provide room for thermal movement. With the sandy soil extending hundreds of feet before reaching bedrock, all substructure units are supported by friction H-piles. Three piers consisting of columns on spread pile footings provide stiffness for the two units, while concrete encased pile bents permit expansion and contraction.