Temperature Effects on a Box-Girder Integral-Abutment Bridge

As part of a study to quantify temperature effects on integral-abutment box-girder bridges, field instrumentation was monitored continuously for one year on a bridge near Sacramento, California. Thermocouples were installed throughout the deck as well as over the height of the superstructure. Temperature changes were used to obtain maximum and minimum average temperatures as well as positive and negative thermal gradients. These values were compared with recommended respective temperature ranges. Strain changes at various locations were obtained by driving trucks along five load paths. These data, along with strain changes resulting from daily temperature variations, were used to validate a finite-element model using solid elements for the superstructure and springs at the abutments, in order to replicate the partial fixity of the bridge. The validated finite-element model was used to evaluate the effects that the partial fixity and temperature gradients have on the temperature stress for a typical integral-abutment bridge.