Influence of daily and annual thermal variations on integral abutment bridge performance

The increased use of integral abutment bridges in recent decades has preceded fundamental understanding of system behavior and development of design methods that appropriately account for controlling parameters. Due to its integral design, the influence of factors such as thermal expansion/contraction must be revisited as they have a dominant role in behavior. This paper summarizes the soil-structure interaction aspects of the south abutment performance of a 270-ft three-span integral abutment bridge in central Massachusetts. Continuous performance monitoring with an instrumentation array of 85 sensors is ongoing. A site investigation of the abutment backfill was performed to estimate the lateral earth pressures. The influence of thermal effects on the south abutment performance over one 12-month cycle that included temperature variations between –18°C and 38°C is presented