Diagnostics of Concrete Box Beam Bridges Using Wireless Sensors and Finite Element Analysis

Abstract

Three pretensioned adjacent concrete box beam bridges were studied with a structural health monitoring (SHM) paradigm based on strain measurements and finite element static analyses. An accurate model for one bridge and an approximate model for the other two were created using ansys software. The analyses were used to calculate the strains generated by six concentrated loads that mimic the presence of a truck. Pristine and damage scenarios were implemented, and the associated numerical strains were compared to the experimental strains measured with proprietary wireless sensors during a truck test. As the results from the approximate models deviated significantly from the field response of the bridge, the accurate model applied to one bridge was extended to the other two. The comparison between numerical and experimental results revealed the presence of noncritical anomalies related to strain distribution across adjacent beams. Such issues were confirmed with the examination of the historical strains streamed for several months to a repository, using simple data processing strategies. The intellectual contribution of the work resides in the combination of finite element analysis and SHM applied to three existing bridges with very similar structural characteristics. This combination revealed the presence of noncritical issues impossible to be diagnosed with conventional inspection.