Comparing surface areas of plates and cones
CALCULATIONS ON PLATE DIAMETER AREAS, CONE AREAS AND MULTITURN FLIGHT AREAS.
The Compression Load Bearing Area comparisons of a Round Single Plate Helix,,the area of Multiturn Flights and the Enlarged Cone Surface Area when the Multiturn “ Bulb Effect “ comes into play.Comparisons are for Typical Multiturn Helix commercially available at time of writing.
150mm MultiturnSurface area of 150mm Diameter Plate Helix = 0.0177 m 2Surface area of 150mm Multiturn Helix = 0.0327 m 2Surface area of 150mm Compacted Cone in Dense Material = 0.0699 m 2 200mm mk2 MultiturnSurface area of 200mm Diameter Plate Helix = 0.0314 m 2Surface area of 200mm Multiturn Helix = 0.065 m 2Surface area of 200mm Compacted Cone in Dense Material = 0.0848 m 2
300mm MultiturnSurface area of 300mm Diameter Plate Helix = 0.0707m 2Surface area of 300mm Multiturn Helix = 0.119 m 2Surface area of 300mm Compacted Cone in Dense Material = 0.194 m 2
350mm MultiturnSurface area of 350mm Diameter Plate Helix = 0.0962 m 2Surface area of 350mm Multiturn Helix= 0.195 m 2Surface area of 350mm Compacted Cone in Dense Material = 0.264 m 2
400mm MultiturnSurface area of 400mm Diameter Plate Helix = 0.1257 m 2Surface area of 400mm Multiturn Helix = 0.316 m 2Surface area of 400mm Compacted Cone in Dense Material = 0.4016 m 2
450mm MultiturnSurface area of 450mm Diameter Plate Helix = 0.1590 m 2Surface area of 450mm Multiturn Helix = 0.309 m 2Surface area of 450mm Compacted Cone in Dense Material = 0.4532 m 2
540mm MultiturnSurface area of 540mm Diameter Plate Helix = 0.229 m 2Surface area of 540mm Multiturn Helix = 0.492 m 2Surface area of 540mm Compacted Cone in Dense Material = 0.591 m 2
600mm MultiturnSurface area of 600mm Diameter Plate Helix = 0.283 m 2Surface area of 600mm Multiturn Helix = 0.614 m 2Surface area of 600mm Compacted Cone in Dense Material = 0.887 m 2
BY COMPARISON.
Surface area of 800mm Diameter Plate Helix = 0.5027 m 2Surface area of 900mm Diameter Plate Helix = 0.636 m 2Surface area of 1000mm Diameter Plate Helix = 0.7854 m 2Surface area of 1200mm Diameter Plate Helix = 1.131 m 2
From the above Relative Surface areas available for Load Bearing Transfer into Ground Material, even in poor ground conditions, all Multiturn Helix have a Greater Load Bearing area than the corresponding size Plate Helix, thus providing in all size helix a degree of better load capacity. In fact as the Multiturn Helix Diameter increases ( eg 540mm and 600mm above )its load bearing advantage over a similar size single Plate Helix is much greater than 100% additional capacity. This offers a much higher safety factor on higher load piles OR allows the Engineer to increase compression load capacity of the pile by up to 100 %.
When calculating the load capacity of the Multiturn helix using the surface area of the cone for each helix, allowance needs to be made for the compaction of the various ground types. For Dense Clays the load capacity should be reduced by 10 % and for Dense Sands the load can be increased by 10 % due to the differing performance of the materials
The Compression Load Bearing Area comparisons of a Round Single Plate Helix,,the area of Multiturn Flights and the Enlarged Cone Surface Area when the Multiturn “ Bulb Effect “ comes into play.Comparisons are for Typical Multiturn Helix commercially available at time of writing.
150mm MultiturnSurface area of 150mm Diameter Plate Helix = 0.0177 m 2Surface area of 150mm Multiturn Helix = 0.0327 m 2Surface area of 150mm Compacted Cone in Dense Material = 0.0699 m 2 200mm mk2 MultiturnSurface area of 200mm Diameter Plate Helix = 0.0314 m 2Surface area of 200mm Multiturn Helix = 0.065 m 2Surface area of 200mm Compacted Cone in Dense Material = 0.0848 m 2
300mm MultiturnSurface area of 300mm Diameter Plate Helix = 0.0707m 2Surface area of 300mm Multiturn Helix = 0.119 m 2Surface area of 300mm Compacted Cone in Dense Material = 0.194 m 2
350mm MultiturnSurface area of 350mm Diameter Plate Helix = 0.0962 m 2Surface area of 350mm Multiturn Helix= 0.195 m 2Surface area of 350mm Compacted Cone in Dense Material = 0.264 m 2
400mm MultiturnSurface area of 400mm Diameter Plate Helix = 0.1257 m 2Surface area of 400mm Multiturn Helix = 0.316 m 2Surface area of 400mm Compacted Cone in Dense Material = 0.4016 m 2
450mm MultiturnSurface area of 450mm Diameter Plate Helix = 0.1590 m 2Surface area of 450mm Multiturn Helix = 0.309 m 2Surface area of 450mm Compacted Cone in Dense Material = 0.4532 m 2
540mm MultiturnSurface area of 540mm Diameter Plate Helix = 0.229 m 2Surface area of 540mm Multiturn Helix = 0.492 m 2Surface area of 540mm Compacted Cone in Dense Material = 0.591 m 2
600mm MultiturnSurface area of 600mm Diameter Plate Helix = 0.283 m 2Surface area of 600mm Multiturn Helix = 0.614 m 2Surface area of 600mm Compacted Cone in Dense Material = 0.887 m 2
BY COMPARISON.
Surface area of 800mm Diameter Plate Helix = 0.5027 m 2Surface area of 900mm Diameter Plate Helix = 0.636 m 2Surface area of 1000mm Diameter Plate Helix = 0.7854 m 2Surface area of 1200mm Diameter Plate Helix = 1.131 m 2
From the above Relative Surface areas available for Load Bearing Transfer into Ground Material, even in poor ground conditions, all Multiturn Helix have a Greater Load Bearing area than the corresponding size Plate Helix, thus providing in all size helix a degree of better load capacity. In fact as the Multiturn Helix Diameter increases ( eg 540mm and 600mm above )its load bearing advantage over a similar size single Plate Helix is much greater than 100% additional capacity. This offers a much higher safety factor on higher load piles OR allows the Engineer to increase compression load capacity of the pile by up to 100 %.
When calculating the load capacity of the Multiturn helix using the surface area of the cone for each helix, allowance needs to be made for the compaction of the various ground types. For Dense Clays the load capacity should be reduced by 10 % and for Dense Sands the load can be increased by 10 % due to the differing performance of the materials