Research conducted by civil engineering professors and students at the University of Minnesota shows fewer signs of physical aging and deformation in the I-35W St. Anthony Falls Bridge than the original design predicted. The bridge, which is just over five years old, was designed to last 100 years.
The researchers use nearly 500 sensors along the bridge to measure strain, load distribution, vibrations, thermal stress and movement. With the sensors, they found less creep and shrinkage, but slightly higher thermal stress than designers predicted.
With funding from the Minnesota DOT (MnDOT), the research team is also developing a prototype monitoring system that will alert MnDOT Metro Maintenance personnel of expansion joint problems. Once the monitoring system for expansion joints is finalized, MnDOT may utilize the system to evaluate other sensor data, develop a maintenance bridge tool and use the data to aid future bridge designers.