Q355 Heavy-Duty Helical Pile Foundation System

Product Overview

When a project's structural design calls for foundation loads beyond the capacity of standard ground screws — whether due to high wind zones, heavy snow loads, deep frost lines, or large-span tracker rows — standard Ø76mm screws with 2.5mm wall thickness become the limiting factor in the structural chain.

The Q355 Heavy-Duty Helical Pile Foundation System is engineered for these high-load applications. Using Q355B high-strength steel with 3mm thick wall and an optimized helix geometry, this pile delivers:

50kN compression capacity — 67% higher than standard Q235 ground screws

40kN pull-out capacity — verified by ASTM D3689 full-scale load testing

Deeper embedment capable: Standard lengths to 2500mm; custom up to 4000mm with extension couplings for deep frost or soft soil conditions

Compatible with all mounting systems: The standard flanged head accepts posts, beams, and tracker bearing assemblies from any STLSUN ground-mount or tracking system

When to specify Q355 over standard Q235 screws: High-wind sites (40 m/s design), high-snow sites (3,000 Pa), tracker foundations with high overturning moment, soft soil requiring deeper embedment, and any project where the geotechnical report indicates soil bearing capacity below 150 kPa.

Technical Specifications

Applications

Tracker row foundations with high overturning moment

High-wind zone projects (40 m/s+ design wind)

Heavy snow load regions (3,000–5,400 Pa)

Deep frost-line locations (northern US, Canada, Scandinavia, Russia)

Soft soil conditions requiring deeper embedment

Solar carport foundations with high lateral wind load

Engineering Note: Why Wall Thickness Matters

For a helical pile, the relationship between wall thickness and bending capacity is cubic — a 20% increase in wall thickness (from 2.5mm to 3.0mm) increases the section modulus by approximately 44%. This is critical for tracker foundations where the pile is subjected to cyclic bending from daily tracking motion combined with wind gusts. The 3.0mm wall provides the fatigue resistance necessary for 25-year tracker life.

Image Placement

SEO Keywords

Primary: Q355 ground screw pile, heavy duty helical pile solar, 50kN solar foundation, high load ground screw

Secondary: utility scale solar pile foundation, Q355B helical anchor, solar tracker foundation pile, deep embedment ground screw