Can Corrosion Cause a Helical Pier to Fail over Time?

Yes, corrosion is a critical factor that can cause helical piers to fail over time. It is an electrochemical reaction—primarily involving moisture and steel—that leads to progressive section loss of the pier shaft.

This process impacts structural integrity in several ways:

• Reduced Load Capacity: As the steel cross-section diminishes due to rust, the pier’s ability to support design loads decreases proportionally. This can lead to differential settlement or, in severe cases, cause the pier to buckle or fail entirely.
• Environmental Acceleration: Corrosion can be accelerated by soils with low electrical resistivity (high chloride, sulfate, or acid content), persistently high moisture levels, or stray DC currents from nearby utility lines and rail systems.
• Triggering Other Failures: A weakened shaft may become more susceptible to negative skin friction, where shifting surrounding soils grip the pier and exert downward pressure that the compromised steel can no longer withstand.

To mitigate these risks, it is essential to use products that meet ICC-ES AC358 standards, which require a minimum 0.002-inch hot-dip galvanized coating. In highly aggressive environments, additional protections like cathodic protection (using sacrificial anodes) may be necessary to ensure the pier’s long-term service life.