Tests of Four Highway Bridges to Failure

Four deck-girder highway bridges, located in an area which has since been flooded as a part of a TVA reservoir, were tested to failure under static loading. A system of rock anchors was used to develop the necessary forces. The loads were applied to a bridge span at eight load points, simulating the rear wheels of two AASHO HS trucks, one truck in each traffic lane. Load-deflection curves for each bridge are presented. All of the bridges but one failed, as expected, in a flexural mode. Composite action was lost in the prestressed concrete bridge, and the two interior girders failed in shear. All of the bridges exhibited considerable ductility, with large deflections at failure. The failure load for each bridge, achieved at the expense of large deflections, was several times the design load for the bridge.