Displacement Monitoring of I35W Bridge with Current VibrationBased System

Principal Investigator(s):

Lauren Linderman, Associate Professor, Civil, Environmental and Geo-Engineering


  • Carol Shield, Professor, Civil, Environmental and Geo-Engineering

Project summary:

Vertical displacements, while informative for monitoring the long-term serviceability and short-term behavior of bridge structures, are traditionally challenging to measure without onsite surveying. This project is developing an advanced sensor system to estimate the long-term and dynamic vertical displacements without a reference or onsite surveying. The long-term vertical displacements reflect the serviceability of the bridge. Meanwhile, the dynamic displacements are used to augment the monitoring of the I35W bridge as a more robust indicator of stiffness, connection, and foundation degradation. Additionally, vertical deflection may offer a more direct comparison with design calculations and maintenance guidelines. Minnesota offers the unique opportunity to use the acceleration data from the I35W Saint Anthony Falls Bridge alongside the GPS correction service offered by MnDOT to implement a vertical deflection monitoring system. Based on the long-term fidelity of the acceleration data, the accelerometer data (accounting for temperature and time-dependent effects) are used in conjunction with a low-cost GPS sensor to estimate the vertical displacement of the bridge. Thus, no GPS base-station or fixed reference are required. If the technique is successful and inexpensive,the monitoring approach could be widely implemented to help MnDOT prioritize maintenance needs among bridges and could limit routine surveying requirements.

Project details:

  • Project number: 2017006
  • Start date: 06/2016
  • Project status: Completed
  • Research area: Infrastructure
  • Topics: Bridge design and sensing