Health Monitoring of a Lenticular Truss Bridge Using Wireless Strain Sensors and Finite Element Models: A Case Study

Abstract

An increasing number of new and old structures are instrumented with some sort of structural health monitoring (SHM) systems, which include a variety of sensors driven or governed by dedicated hardware and software. This paper presents the monitoring of the Smithfield Street Bridge, one of the oldest and most iconic bridges in the city of Pittsburgh (Pennsylvania). The bridge was instrumented with wireless strain, displacement, and rotation sensors by an independent party not involved with the research presented here. In order to interpret the sensors' data, a finite element model was developed, and a static analysis was performed to quantify the deformation at certain members of the bridge under known loading conditions. The results of the finite element analysis were then compared with the results of a test in which a truck of known weight crossed the bridge multiple times. Finally, the data from the strain sensors relative to three-years of uninterrupted monitoring were processed and analyzed to identify eventual anomalies.