Rushville US-22 Bridge

Information and Findings From Ohio's Historic Bridge Inventory

Setting/Context

The bridge carries a 2 lane road over a stream and the former New York Central RR in a rural setting between the villages of West Rushville and Rushville. The bridge was placed on a new alignment that bypasses the town centers of both villages.

Physical Description

The 3 span, 515'-long, riveted, continuous Pratt deck truss bridge with cantilevered arms is composed of 110' cantilever arms anchored by the 220' long main span with 36' long, simply supported rolled stringer end sections. The stringers at each end of the bridge bear on sliding plates atop the transverse beam connecting to end of the cantilevered chords and on rocker bearings atop stub abutments at the other end of stringer. There are deflection joints where the stringers meet the truss lines. This unusual design was driven by the substrate and the desire to construct the truss superstructure with no rock excavation and to found the east end of the bridge on sound shale. The truss lines are deepest at the pier bearings (a roller bearing exists on the west end and a bolster bearing on the east end), and the cantilevered arms have unsupported ends. Each truss panel is 22' long for 440' long truss lines. The truss members are riveted, built up box sections for the chords, and rolled sections for the diagonals and verticals. The west pier, adjacent to the railroad, is founded on steel piles (for scour protection) driven through silt and clay to refusal (rock) while the east pier footing is founded directly on rock. The original concrete base and tubular aluminum handrail railings have been removed and replaced with safety shape barriers. Otherwise, the bridge appears to be complete.

Summary of Significance

The design of the 1959, 3 span, continuous Pratt deck truss bridge with cantilevered end spans was developed in response to site conditions and the substrate. The decision was made to limit excavation of the rock slope on the east side and to bring the founding of the east end back to solid shale. This drove the design with the unusual 36' long stringer ends supported by the cantilevered arms and stub abutments. Use of the continuous deck truss design meant that the cantilevered truss arms did not have to be supported at the ends. The 36' long stringers are used to span the difference between the end of the cantilevered truss arms and the desired end of the span on the east, which was determined by the soundness of the substrate. The tapered shape of the cantilever arms corresponds to the original rock slope profile of the east side. The west side had no such rock slope, so a great deal of fill was used to match the elevation of the east end. Although the design is not common, it is not historically or technologically significant. It employs engineering principles that had been known for decades. The continuous design, where the trusses are deepest over the pier bearings, since the stresses are the greatest at those points, together with the tapered cantilevered ends is a more economical use of material. The bridge can be erected without false work and is rigid under traffic. Three span continuous designs, like the Little Rush Creek bridge, proved to be the most common arrangement as after three spans, joints to accommodate expansion and contraction are needed.

Bridge Considered Historic By Survey: No