Insights Gained from I-35W Saint Anthony Falls Bridge Long-Term Monitoring System

Abstract

The new I-35W Saint Anthony Falls Bridge in Minneapolis, MN was fit with a system over 500 sensors to investigate structural behavior, which has been collecting data since the bridge opening to traffic in 2008. This large dataset presents a unique opportunity to investigate the I-35W Bridge’s behavior over years, seasons, and conditions, with the underlying objective to develop structural health monitoring protocols with long-term data. Long-term structural health monitoring is one approach to assist in the maintenance and management of structural systems. The long-term monitoring strategy presented updates the previous monitoring framework in Hedegaard et al. 2017 to account for uncertainty in the time-dependent deflections when establishing the bounds on the predicted behavior of the bridge. Additionally, the long-term data set is leveraged to compare the behavior of the bridge under environmental loading to design assumptions allowing for evaluation of serviceability stresses due to maximum temperature gradients at the midspan of the bridge.