The ICC-ES AC358 is the definitive acceptance criteria for helical foundation systems, published by the International Code Council Evaluation Service. It establishes a rigorous framework and standardized methods for evaluating the structural adequacy, design capacity, and durability of helical piles.

This standard is critical for helical pier installation for several reasons:

• Building Code Compliance: Adherence to AC358 ensures that helical systems meet regulatory requirements and provides the third-party validation necessary for building code acceptance.
• Quality Assurance: It governs four essential performance categories: Design capacity verification (using test piles or empirical methods), corrosion protection (mandating specific steel thicknesses and coatings like hot-dip galvanizing), torque correlation (linking installation torque to actual load capacity), and material standards (ensuring steel quality per ASTM specifications).
• Reliability in Challenging Soils: For regions like the Colorado Front Range with expansive clay soils and freeze-thaw cycles, AC358-validated systems offer independent verification that the piers can withstand intense geotechnical stress.
• Standardized Testing: It specifies rigorous load testing and creep monitoring protocols, ensuring that results are comparable and that the piles will support intended structural loads safely over their service life.