The topic of integral abutment bridges has been of interest for the Iowa Department of Transportation for the past few decades. One specific bridge design implementing an integral abutment supported on HP-steel piles embedded in concrete drilled shafts was utilized on the 9th Street Bridge in Des Moines, Iowa and is the topic of this study. The primary objective of this study was to monitor the bridge behavior over a two year period in order to better understand the bridge behavior. In order to satisfy the objectives of this study, a literature review was performed, a monitoring system was developed and installed on the bridge, bimonthly surveying of the bridge occurred in order to track bridge movements, and data obtained during monitoring of the bridge was analyzed. From the results obtained from the bridge monitoring system and surveying, the following general conclusions were made: The bridge expanded and contracted around one point as expected with seasons, but did not appear to move in one specific direction; Surveying as a bridge monitoring technique was a comparable method to the more traditional method of displacement meters; The incremental axial strain in the steel piles showed a trend with temperature relative to pile location (i.e. internal versus external pile location) which was analyzed by modeling an abutment temperature gradient using a commercial software program; The equivalent cantilever method of steel pile analysis was verified by the steel pile incremental bending strains; The measured strains in the drilled shafts indicated no problems in the shafts; The south abutment wall appeared to tilt in a cycle related to bridge thermal movements, while the adjacent south abutment MSE wall rotated continually in the north direction (i.e. towards the road) with a superimposed cycle of tilt related to the bridge thermal movements.
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