Determining the lateral load capacity for ICC-ES compliance involves a multi-layered engineering approach that combines full-scale laboratory testing, shaft geometry analysis, and field validation.

To meet ICC-ES AC358 standards, the lateral capacity of our helical pier systems is determined through the following factors:

• Full-Scale Testing: Unlike simple design tables, AC358-compliant reports are based on physical testing in controlled environments. These tests evaluate the connection assemblies and their ability to transfer horizontal forces from the structure to the pile.
• Shaft Geometry and Stiffness: We evaluate the shaft diameter and wall thickness, as these are the primary drivers of lateral resistance. A larger diameter increases the moment of inertia (stiffness) and mobilizes more passive soil resistance, which is critical in the expansive soils found across the Denver metro area.
• Fixed-Head Connections: For maximum capacity, we often utilize fixed-head connections, such as reinforcing the pile within a concrete cap. This creates a moment-resisting joint that engages deeper soil layers, significantly improving performance compared to free-head connections.
• Field Verification via Torque: During installation, we record the torque-to-capacity correlation. While this is primarily an axial check, these records serve as the permanent Quality Assurance (QA/QC) link, demonstrating that the pile has engaged the soil sufficiently to meet the engineered design.
• Serviceability and Deflection: Under updated standards like ASCE 7-22, compliance is often determined by deflection limits. We ensure the system resists lateral movement (from wind or seismic loads) to prevent cracking in foundation walls or grade beams.

Because every site is unique, final lateral capacity must be verified by a licensed structural engineer through a site-specific geotechnical evaluation. Actual outcomes depend on local site conditions and inspections.

• Helical Pile Lateral Load Capacity: ICC-ES Standards Guide