Hundreds of millions of people cross bridges every day, and they trust those bridges with their lives. With this quick guide on structural health monitoring, you’ll see how organizations monitor those bridges for safety.

First, we’ll examine why people are monitoring bridge health.

Why Structural Health Monitoring Matters

According to CNN, well over 50,000 bridges in the United States are in less than perfect shape. It would cost over $100 billion to fix them all. Sadly, only about $8 billion was available for bridge maintenance in 2017.

Given the impossible cost of fixing everything, planners need to make decisions about which bridges to restore. Bridge health monitoring is an essential tool in the process of making those decisions.

What Is Structural Health Monitoring?

Structural health monitoring of bridges involves observing physical changes in bridges over time. To monitor these bridges, experts select many locations on that structure and apply sensors. These experts then decide how often data needs to be collected from the sensors to ensure the structure’s health and safety.

As time passes, a history of data from each sensor accumulates. That data is then analyzed so that experts can determine how well the bridge is holding up with use.

Sensor data is especially crucial after a severe storm, earthquake, or other potentially dangerous events. With a clear picture of how a bridge looked before the event, it is much easier to see if damage occurred.

So what type of sensors make sure bridges are structurally sound?

Force Sensors

Force sensors are a type of sensor that measures force acting on an object. Determining how much force acts on different points on a bridge is crucial to understanding how safe it is.

Strain-gauge sensors are a common type of force sensor used on bridges. Read more about force sensors on the Load Indicator website.


Strain-gauge Sensors

Strain-gage sensors often look like a tight zig-zag of lines on a flat piece of flexible material. This unique arrangement makes it so that when force is applied to the sensor, its resistance changes. Electronic devices can then translate that change in resistance to an amount of force.

These sensors will tell observers how much a bridge bends over time. A little bending is natural as bridges age, but these sensors are essential in determining when it affects safety.

A more common example of a strain-gauge sensor that you may have experienced is in electronic bodyweight scales. When you stand on it, the sensor detects your weight.

Monitoring the structural health of bridges ensures the safety of transportation networks around the globe. With the help of sensors, experts can make sure that bridges are as safe as possible.



Load Indicator AB


Address: Aröds Industriväg 58, Hisings Backa

Tel: +46 31 22 07 30

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