Structural engineering: application of structural reliability principles for the evaluation of a steel bridge, supported by monitoring and instrumentation

Abstract

This article presents a structural reliability evaluation of the main components of one of the most important steel bridges on Colombia’s National Road Network. The assessment, based on structural reliability techniques, was supported by both field and office activities, including geometric surveying, mechanical testing, traffic counting, load testing, structural model calibration, instrumentation, monitoring, and numerical simulation. For the monitoring process, an electronic data acquisition system was implemented using a multipoint master-slave network (RS-485), incorporating signals from ten (10) strain gauges installed on the main structural elements of the bridge over a fifteen-day period. The monitoring allowed for a detailed analysis of the actual stress demands generated by traffic on the main bridge elements, which were compared against the design load (C40-95) specified by the Colombian Seismic Bridge Design Code (CCDSP). Significant overloads were identified on certain elements, posing safety concerns that require immediate corrective actions. Additionally, failure probabilities were calculated for some structural components, revealing values outside acceptable safety thresholds, thus compromising their stability and increasing the associated risk.