Bridges

Cover of Structural and Risk Assessment of Steel and Concrete Bridges using Inservice Dynamic Response
Structural and Risk Assessment of Steel and Concrete Bridges using Inservice Dynamic Response
  • Publication no: ABC2017-059-17
  • Published: 21 April 2017

Mainmark are introducing the STRAAM system of full scale structural integrity assessment and continuous monitoring for Bridges into Australia and New Zealand. Advances in measuring extremely low amplitude vibrations combined with methods for extracting the unique dynamic signature have now enabled the rapid measurement of the response of steel and concrete bridge structures.

The STRAAM method utilizes the normal traffic conditions and wind loads on the bridge, without any lane closures, to measure the frequency response of the structure. This allows the quick calibration of Finite Element Models that can be used to accurately assess the strength of a bridge. Furthermore, this information allows bridge owners to efficiently track changes in the capacity of their bridges due to aging, impact, earthquake or flood activity through changes in the vibration of the bridge and associated natural frequencies, mode shapes and damping ratios.

Because of the sensitivity of the instrumentation and the novelty of the analysis techniques, the information available to bridge owners and assessors allows information-based decisions to be made in a way that optimizes the financial implications. In addition, the techniques are non-invasive and nondestructive and they give additional information about the connectivity of the bridge with the surrounding terrain, and whether that connectivity is compromised.

This paper discusses the results obtained from field measurements from bridges located in USA, South America and Asia.