Boundary Performance Enhancement Monitoring Based on Smart Bearing Service Performance Indicators

Abstract Boundary-condition anomalies in continuous girder bridges redistribute support reactions and internal forces, yet long-term reaction monitoring is seldom connected to field intervention and assessment. We developed a support-reaction monitoring workflow for force-measuring adjustable bearings. Here, smart refers to continuous sensing, remote transmission, and controllable in situ height adjustment rather than autonomous diagnosis or actuation. Three long-window indicators, normalized reaction time mean (NRTM), normalized reaction time variance (NRTV), and reaction time correlation coefficient (RTCC), were derived from statistically steady traffic windows to suppress individual-vehicle effects. Simulations of a 60-m + 80-m + 60-m variable-section girder showed convergence after 6 h, with NRTM, NRTV, and RTCC errors of 0.00%, 1.06%, and −1.34%, respectively. The indicators were only weakly affected by changes in traffic parameters, while NRTV and RTCC recovered stable values at signal-to-noise ratios of at least 30 dB. Up to 30°, a simplified skew influence-surface check yielded small NRTM, NRTV, and RTCC deviations of 0.18%, 0.87%, and −1.19%, respectively. This supports the use of resultant reactions within the tested skew range. Field implementation involved an in-service, skewed, variable-section, continuous steel box-girder bridge equipped with 12 force-measuring adjustable spherical bearings. Indicators were calculated using a 9-h sliding window with 10-min steps. Under open traffic conditions, the bearing height underwent four stages of adjustment (1–2 mm each), during which the monitored time series of indicators changed accordingly. The postadjustment shift toward finite-element targets provided a relative assessment of the intervention outcome. These results support the use of indicators with engineering records and finite-element analysis to assess boundary anomalies, staged adjustment, and relative postadjustment changes under routine traffic.