International Geotechnical Structural Laboratories Inc

The International Helical Piles are screw piles with shaft sizes ranging from 2 7/8'' to 10 3/4'' in diameter with varying wall thickness and combination of helix sizes. We service the tri-state area of NY, NJ, and CT. The helical piles with shaft diameters of 2 7/'', 3½'', and 4½'' are in stock and ready for delivery and installation. The higher capacity piles (up to 200 Tons) with shaft diameters 5½'' to 10¾'' will be ready for delivery and installation in timely manner upon special request of our client.

The table below lists the helical piles and the corresponding torsional and axial strengths.

OUTSIDE DIAMETER OF SHAFT	WALL THICKNESS	MAXIMUM TORSIONAL STRENGTH	ULTIMATE CAPACITY AXIAL COMPRESSION
2⁷/₈''	0.276"	8000 ft-lbs	80,000 lbs
3½''	0.30"	13,000 ft-lbs	110,000 lbs
4½''	0.337"	21,000 ft-lbs	160,000 lbs
5½''	0.258"	32,000 ft-lbs	150,000 lbs
6⁵/₈''	0.28"	51,000 ft-lbs	200,000 lbs
8⁵/₈''	0.322"	81,000 ft-lbs	300,000 lbs
10¾''	0.365"	Over 90,000 ft-lbs	420,000 lbs

The torsional strengths listed above are based on experience. The compressive strengths are based on the minimum specified yield stress of pile shaft material. The as-installed pile capacity in the field depends also on the soil condition. The interaction between the pile geometry and field soil properties (e.g. particle size, compactness, and moisture content) ultimately determines the maximum load that the pile can withstand. This should be demonstrated by testing a representative pile.

Disclaimer

The contents of the above table are suggested specifications of the helical piles to assist the engineer in designing and writing their own specifications. The final design of any helical pile system requires knowledge of the specific soil properties and the structural conditions of each project.
The design of any helical pile system is the full and complete responsibility of the design engineer.