Our Ground Screw Anchor foundation solution from Guojian factory effectively addresses many pain points of traditional concrete foundations, such as long construction period, significant disturbance to the soil and difficult site restoration. Each pile has stable compressive and uplift resistance performance and is suitable for various complex geological conditions such as clay, sandy soil and backfill. We provide comprehensive services including detailed engineering design, third-party inspection reports, phased delivery and on-site technical guidance to reduce the total life cycle cost of the project.
• Not a generic, standardized fitting: While screw piles on the market may look similar, their actual load-bearing capacities can vary several-fold depending on conditions such as backfill, mountainous slopes, or saline-alkali soil. Drawing on extensive experience with domestic renewable energy projects, we customize parameters—such as blade pitch, blade diameter, and pipe wall thickness—based on specific soil shear characteristics, rather than applying a "one-size-fits-all" specification to diverse geological conditions.
• Concrete-free, dry-installation method: Installed by mechanically screwing the pile into the ground, this method eliminates the need for excavation, formwork, concrete pouring, and curing. The pile can support the superstructure immediately upon installation, making it ideal for time-sensitive projects, such as photovoltaic (PV) installations requiring rapid grid connection.
• Versatile superstructure compatibility: Pile tops can be fitted with various connectors—such as flanges or connection plates—to interface directly with PV mounting systems, carport columns, energy storage unit bases, and lightweight steel fencing structures, enabling rapid assembly of the foundation and superstructure.
• Eco-friendly and recyclable: The process generates no solid concrete waste. During project modification, relocation, or decommissioning, the piles can be unscrewed and extracted intact, preserving the original surface landscape to the greatest extent possible; this makes them suitable for strictly regulated sites such as ecological reserves and mountainous forest areas.
• Proactive risk control: We offer sample testing and preliminary model selection based on client-provided geological survey reports, helping to prevent costly rework caused by issues like pile slippage or insufficient load-bearing capacity.
The load-bearing capacity of the screw pile relies on more than just the friction between the steel pipe wall and the soil; it functions through a synergistic three-part mechanism: shaft friction + end-bearing resistance of the helical blades + interlocking/locking force between the blades and the soil. 1. The drilling rig’s output torque drives the entire helical pile to screw into the ground at a constant speed; the helical blades cut into and compress the surrounding soil, creating compacted soil discs above and below the blades.
2. Vertical loads from above are supported by these compacted soil discs; under uplift conditions, the blades firmly anchor into the underlying soil, preventing the pile from being pulled directly out.
3. Horizontal wind loads are counteracted by the lateral restraint provided by the interaction between the pile shaft wall and the surrounding soil.
Practical Insight: The blade pitch must be matched to the drilling rig's torque. If the pitch is too large, low-torque equipment cannot drive the pile in; if the pitch is too small, installation is slow and the original soil layer is disturbed, which actually reduces the pile's load-bearing capacity—a detail often overlooked by low-cost helical piles on the market.
Ground Screw Anchor are concealed underground components that cannot be visually inspected after installation; therefore, quality control must be implemented during the production phase. Guojian employs a comprehensive, end-to-end quality control chain:
1. Incoming Material Verification: Material certificates are checked for every batch of steel pipe raw materials, and wall thickness and yield strength are spot-checked to prevent substandard or thin-walled pipes from entering production.
2. CNC Cutting and Straightening: Pipes are cut to fixed lengths and straightened; excessive curvature in the pile body would directly compromise verticality during installation.
3. Helical Blade Forming and Assembly Welding: Blades are rolled using specialized molds to ensure uniform pitch; continuous full welding is used instead of intermittent spot welding; welds are ground smooth to eliminate porosity and cold welds (cold welds are a frequent cause of pile failure under high-wind conditions).
4. Hot-Dip Galvanizing: Strict adherence to the GB/T 13912 standard, involving pickling, fluxing, immersion in zinc at 450–460°C, and passivation; the average zinc coating thickness is ≥85μm, with options for thicker coatings for saline-alkali or coastal environments.
5. Final Inspection and Dispatch: Visual appearance check, spot checks on zinc coating thickness, and re-measurement of critical dimensions; material reports and galvanizing inspection records can be provided upon request for bulk orders.
Pitfall Warning: Some low-priced products on the market use cold galvanizing or only partial galvanizing; these can rust within 2–5 years of underground installation, directly compromising the structural integrity of the foundation.
1. PV Mounting Foundations: Prioritize continuous helical blades; in backfilled areas, ensure the blades rest on a stable, compacted soil layer rather than loose fill.
2. PV Carport Foundations: Carports are subject to significant wind loads; prioritize large-diameter, thick-walled screw piles paired with reinforced flange connection plates, and avoid lightweight, small-specification piles. 3. Fencing/Guardrail Foundations: Primarily subject to lateral loads; focus on controlling embedment depth to enhance lateral stability; cost-effective specifications are suitable.
4. Coastal Saline-Alkali Zones: Standard cold-galvanized products are unsuitable; thickened hot-dip galvanized coatings are required to delay underground corrosion and degradation.
• Mountain-based Ground PV Project: Utilized 114mm diameter screw piles to replace traditional independent concrete foundations, significantly reducing earthwork excavation; the overall foundation construction period was shortened by 60%, meeting grid-connection deadlines.
• Factory PV Carport Project: Used customized, extended-height flanged screw piles; no on-site concrete pouring was required, as steel columns were directly bolted to the piles, shortening the on-site installation cycle.
• Ecological Control Zone Fencing Project: Upon completion, all screw piles were unscrewed and recovered, leaving no concrete residue on the surface and meeting site restoration acceptance standards.
A: Guojian (Tianjin) Steel operates its own processing lines and supports both small-batch sampling and large-scale project supply for screw piles; the MOQ is 30 tons.
A: Yes, samples are available; standard specifications ship within 3–5 days, while non-standard custom samples take 7–10 working days.
A: Standard market specifications are delivered within 3–7 days; non-standard customizations (involving pipe diameter, flighting, or connectors) take 7–12 working days; phased delivery can be negotiated for large orders.
A: For bulk orders, we provide steel pipe material certificates and galvanization test records for project documentation and acceptance.
A: Large, solid rock layers are unsuitable for direct installation; for weathered rock or gravel layers, reinforced piles may be used, subject to a feasibility assessment based on provided geological data.
A: Warranty covers raw materials and the welding/fabrication process; the service life regarding underground corrosion depends on the anti-corrosion treatment and local soil pH levels (upgrading to a thicker galvanized coating is recommended for coastal saline-alkali environments).
• Packaging: Bundled with steel strapping to prevent deformation from impact during transport; flanges and connecting plates are packaged separately.
• Shipping: Container loading available; packing lists provided.
• Technical Support: Written installation guidelines provided; for major projects, online technical briefings are available to explain pile-driving torque, verticality control, and acceptance criteria; assistance with coordinating construction resources is also available.
Address
No. 2, Expressway Auxiliary Road, South Area of High-tech Industrial Park, Zitai Economic and Technological Development Zone, Tianjin, China
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