Method and apparatus for testing helical piles

1. An apparatus for testing the load capacity of a helical pile positioned in soil, the helical pile being operably connected to a reaction system having a cross beam and at least two reaction piles positioned in the soil adjacent to the helical pile, the apparatus comprising:

a bi-directional load-generating device, positioned above the surface of the soil, for simultaneously generating tensile and compressive load on the helical pile,

the helical pile, having a shaft with an upper end and a lower end,

at least one load-transferring pipe, positioned within the pile shaft, the load-transferring pipe having an upper end and a lower end,

the lower ends of the helical pile and the load-transferring pipe configured to provide a hub and Kelly-bar arrangement positioned below the surface of the soil,

wherein the tensile and compressive loads impart simultaneous upward forces to the pile and downward forces to the load-transferring pipe for determining the shaft resistance and end-bearing capacity of the pile.

2. The apparatus of claim 1 , wherein the bi-directional load-generating device is positioned within an adjustable housing operably connected to the reaction system.

3. The apparatus of claim 1 , wherein the hub is affixed to the helical pile.

4. The apparatus of claim 1 , wherein the Kelly-bar is connected to the load-transferring pipe.

5. The apparatus of claim 1 , wherein the helical pile comprises at least one helical plate.

6. The apparatus of claim 1 , wherein the helical pile comprises a plurality of helical plates positioned above, below, or above and below the Kelly-bar and hub arrangement.

7. The apparatus of claim 1 , wherein the lower end of the helical pile is conical.

8. The apparatus of claim 1 , wherein the load-generating device comprises a hydraulic jack and pressurized load cell.

9. A method, comprising:

using the apparatus of claim 1 for simultaneously measuring the shaft resistance and the end-bearing capacity of the helical pile.

10. A method of testing the load capacity of a helical pile positioned in the soil, the pile being operatively connected to a pile reaction system, the method comprising:

providing a helical pile, having at least one helical plate, the pile comprising an inner load-transferring pipe telescopically received within an outer pile shaft, the lower end of the load-transferring pipe and pile adapted to provide a Kelly-bar coupled to a tubular hub below the surface of the soil,

providing a load-generating device above the surface of the soil for producing a tensile load on the pile and a compressive load on the load-transferring pipe, and

measuring the pile resistance and end-bearing capacity of the pile.

11. The method of claim 10 , wherein the helical pile comprises at least two helical plates.

12. The method of claim 10 , wherein the helical pile comprises two or more helical plates.

13. The method of claim 10 , wherein the end-bearing capacity is detected by measuring the telescopic movement of the load-transferring pipe from the outer pile shaft.