Applicability and structural response for bearing system replacement in suspension bridge rehabilitation

Suitable maintenance, rehabilitation, and repair methods for long-span bridges should be decided based on their purposes as evaluated by carrying out close inspection and observation. This study deals with a rehabilitation method, its applicability to a long-span bridge with a fatigue crack in the stinger-bearing connection plate. Replacing line type contact bearing systems with pot bearings was proposed as the rehabilitation method to stop fatigue cracking, reduce local stress of the fatigue-cracked connection plates, and improve the structural behaviors of the main suspension bridge members. Thus, a stringer-bearing connection specimen was fabricated; then, gouging and bracket installation were simulated for replacing a deteriorated bearing system with a new bearing system. From the results of the gouging and bracket-installation test, the applicability of the rehabilitation method for change works was verified. In addition, the structural responses of the loading tests were compared with those of a finite element analysis in terms of changes in bearing conditions. The deformations of the stringer and the end-beam improved, and local stress and displacement in the fatigue-cracked connection plate were reduced owing to the bearing system replacement. Therefore, replacement of the bearing system can improve the stress level and stop further fatigue cracking in fatigue-cracked connection plates of suspension bridges. In addition, these results can provide basic information about the rehabilitation method involving replacing the bearing systems of bridges with line type contact bearings. •Propose the rehabilitation method for bearings of suspension bridge•Evaluate the structural responses depending on bearing conditions•Loading test of stringer-bearing connection specimen for rehabilitation method