Structural Health Monitoring (SHM)

Structural Health Monitoring

Structural Health Monitoring, or SHM, is a journey, and without establishing a clear destination and mapping out the route in advance, the trip will not be a success. Intelligent Infrastructure Systems believes that monitoring of infrastructure to track performance and mitigate risk is a design problem, requiring expertise in the arena of sensing technology, as well as bridge engineering experience and heuristics. A monitoring effort, without exception, must follow these rules:

  1. Crawl, walk, run – the success of a monitoring project is often determined in the initial phases.
  2. The simplest solution, is often the best solution – complexity is not equivalent to value.
  3. A goals-based targeted design generates performance information of higher value compared to systems with an overabundance of sensors and their inherent excessive costs and wasteful complexity.

Our approach to Structural Health Monitoring (SHM) always begins with a formal risk assessment which is carried out with the bridge owner’s participation to identify relevant hazards and vulnerabilities which are properly captured. A key feature of our SHM approach is our insistence on capturing both response metrics and associated demand indicators, which allows the full transfer function (i.e. input and output) of the bridge to be characterized. We use the risk assessment and analysis of response metrics to establish high level performance requirements of the SHM system. This represents a distinction from how SHM systems are commonly specified in RFPs – a table of desired sensors. Our approach forces engineers to plan out ahead of time, exactly how each sensor will be used resulting in efficient sensor counts and effective data collection.

Intelligent Infrastructure Systems maintains the in-house expertise to not only carry out this design, but also to execute the selection/design of sensors and hardware components, algorithms for data collection, zeroing, filtering, etc.; hardware watchdogs, data compression and storage algorithms, effective visualization approaches, and automated reporting and alerting.

As with detailed human health monitoring, SHM is not appropriate for most or all bridges. However, where the bridge is complex or is exposed to high-risk hazards or vulnerabilities, a monitoring system can provide great value to those who maintain and operate the structure by properly tracking and managing the risks of concern.

For more information about our Structural Health Monitoring services, please contact us at