Bearing Assessment with Periodic Temperature-Based Measurements

Bearing performance is closely tied to overall structural performance and serviceability issues and, as a result, demands considerable attention to condition assessment. That the life cycle of bearing systems is far less than that of bridges has been well documented. Eventually, the bearings break down, with resultant undesirable forces and deformations. Currently, visual inspection is the most common method used to assess bearings and other movement systems. The correlation is limited, however, between visual appearance and the functionality of movement systems. Thus visual inspection falls significantly short in such assessments; this situation necessitates the application of sensing technology for in-depth evaluations. This paper discusses a method, termed periodic temperature-based assessment (PTBA), which aimed to supplement visual inspection through measured input–output temperature responses without the use of a finite element model. A framework was developed for a general approach to PTBA. Strategies also were researched for the measurement of the input–output temperature relationship for bridge structures related to movement systems. In addition, the PTBA method was demonstrated on a long-span, steel, tied-arch bridge to evaluate its expansion bearings.