Field Performance of an Integral Abutment Bridge

Project summary:

Integral abutment bridges are popular for several reasons including the elimination of expansion joints and the ability to drive a single line of piles for the abutment foundation. These features make the integral abutment system economically attractive. In addition, the elimination of the expansion joint reduces the need for bridge maintenance. This feature is particularly desirable for bridges on gravel roads where aggregate may become lodged in the expansion joint and consequently restricts its movement. Problems have been observed in the past with integral abutments regarding deterioration of the wing-walls and deformation incompatibility with the pavements and approach panels. Lack of knowledge concerning how the actual system performs versus assumed stress distributions currently limits the allowable length and skew of the system. The objective of this project is to gain a better understanding of the behavior of moderate-span integral abutment bridges. This will be accomplished by instrumenting a moderate-span integral abutment bridge and monitoring it over a period of three years. Information to be obtained includes: soil pressure distribution on integral abutments, plastification (if any) of piles at the abutments and piers, cyclic displacement history of the bridge, etc.