Truss Bridge Rehabilitation Using Steel Arches

There are many bridges in North America that are inadequate for modern traffic loads because of deterioration or insufficient original design strength, or both. Although many of these bridges do not meet the present standards for roadway width and other geometrical considerations, they are serving well, probably because of low traffic volumes on these bridges. Thus, rehabilitation and reinforcement, rather than replacement of these bridges, can be very cost‐effective. This paper describes a reinforcement system suitable for many through truss bridges, particularly those built around the turn of the century. The reinforcement system investigated consists of superimposed arches with additional hangers and additional floor beams. This reinforcement was implemented on a one‐seventh (1:7) scale model of a steel truss bridge. A series of static load tests was conducted on the reinforced model to determine the effectiveness of the reinforcement system. The test results indicate that the reinforcement system is very effective to the extent that the model was still stable even after severing the bottom chords in one panel of the bridge model.