Semi-integral abutment bridges are one of the most common bridge types in the province of Ontario, Canada as well as in the rest of Canada and North America. The simple extension of the bridge deck horizontally over the abutment and then vertically downward (ballast wall) avoids the introduction of expansion joints within the superstructure. Hence, the benefits are much more valuable than just saving the cost of expansion joints. Leaking through expansion joints is a major source of deterioration of bridge decks, bearings and substructures. The repair cost and the associated traffic interruption are extremely high. Therefore, the present project introduces a semi-integral abutment bridge at a highway interchange. Two deck systems utilizing CPCI and Steel I girders were investigated in order to achieve an optimum bridge design. Further, one of the various design challenges was the significant skew angle of the bridge north abutment (30 degrees) to avoid an existing watermain. The design criterion focused not only on the initial cost of the investigated options but also on their durability, long-term maintenance as well as on their impact on the highway traffic and construction schedule.
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