Periodic Temperature-Based Bearing Assessment of a Steel Multigirder Bridge

This paper presents a case study that extends the periodic temperature-based assessment framework to the bearing evaluation of a steel multigirder bridge. The bearing investigation was prompted by the significant and consistently documented rocker bearing reversal at the bridge abutment. This malfunction, although historically identified in inspections, had not been investigated to determine its source nor its corresponding effects on the bridge. The improper function of longitudinal expansion mechanisms such as bearings can induce unintended demands that bridges are not designed to accommodate. A structural health monitoring system was designed and installed with the aim of identifying the root cause of the poor bearing performance and quantifying its effect on the multigirder bridge. As a result of this investigation, it was determined that the expansion bearings of the span were not performing at all and that axial forces were developing in the bridge because of temperature changes. This study also documented a three-dimensional planar relationship between strain, displacement, and temperature as evidence that the bridge was not able to fully expand and relieve the thermal forces.