International Concrete Abstracts Portal

Title: Monitoring and Assessment of a Prestressed Concrete Segmental Box Girder Bridge

Author(s): Marc Savard and Jean-François Laflamme

Publication: Symposium Paper

Volume: 342

Issue:

Appears on pages(s): 20-39

Keywords: data analysis, finite element analysis, load tests, modal analysis, prestressed concrete bridge, structural damage, structural health monitoring

DOI: 10.14359/51725935

Date: 6/1/2020

Abstract:
Several of the first prestressed concrete segmental bridges in North America were built in Quebec, Canada. The Rivière-aux-Mulets bridge was one of them. Built in the early 1960s, this bridge experienced several disorders due to inadequate design criteria enforced at that time. Despite a structural strengthening in the late 1980s, a bridge behavior follow-up has been required to ensure reliability. The structural health monitoring program implemented to track structural disorders, along with results from modal analysis and diagnostic load tests, is presented with a focus on the instrumentation and the data analysis. A three-dimensional finite element model was developed and calibrated using the frequencies and mode shapes detected under ambient traffic conditions. Data analyses showed that the expansion bearings were frozen, causing bending of the associated piers, which generated axial forces in the deck and decompression of concrete in the area surrounding active cracks. This process enables premature failure of prestressing tendons in the vicinity of these cracks, especially those located in the top flange, which is a corrosion-friendly environment. Development of cracks and associated prestress loss caused a reduction in the bridge load-carrying capacity. Analyses of health monitoring data led to acute assessment of the overall bridge structural performance.