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A summary of already-reported results of earlier tests on integral abutments supported by steel H-piles is provided, and a detailed description of further testing is given. The additional tests were performed on an abutment that was consistent with what was still in use by the Tennessee Department of Transportation (TDOT) and was 20% wider than the abutments in the earlier tests. The tests consisted of pulling horizontally a simulated abutment supported by a steel H-pile and restrained against free rotation at the top. Test results clearly showed that the wider abutment was capable of withstanding larger horizontal displacements than the abutments in the earlier tests, although the former performed adequately to satisfy TDOT criteria. In the tests reported here with the currently used abutment width, the abutment-pile was capable of withstanding horizontal displacements at the ground surface well beyond the 1-in. (25.4-mm) maximum displacement permitted by TDOT criteria.

An impact study on a long-span continuous highway steel girder bridge is described. Crawl and full-speed test data were analyzed to examine the influence of bridge approach, surface condition, and truck velocity on impact factors for fatigue-prone details in both main and secondary bridge members. The measured impact factors for fatigue stress categories A, B, E, and E’ details were compared with values obtained using the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications formula. For fatigue-prone details, the test results showed that surface roughness, truck velocity, and bridge approach affect the impact factor. Measured impact factors varied with the location of the detail. Also, the study showed that the AASHTO design impact factors were unconservative for details located in the bridge approach or end span.

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