Methods and apparatus for building expanded shaft augured foundation elements
An apparatus for building expanded shaft augured foundation elements, comprising: a dual-section drilling augur having a lower section and an upper section, wherein the lower section and the upper section are configured to rotate relative to each other.
1 . An apparatus for building expanded shaft augured foundation elements, comprising:
a dual-section augur having a lower section and an upper section, wherein the lower section and the upper section are configured to rotate relative to each other; and,
an augur conveyance restriction element disposed between the lower section and the upper section.
2 . The apparatus according to claim 1 , wherein the upper section rotates independently from the lower section.
3 . The apparatus according to claim 1 , wherein the upper section terminates in a flat, horizontal flange at a lower end of the upper section.
4 . The apparatus according to claim 3 , wherein the flange is a half-circle in profile when viewed from the bottom of the flange.
5 . The apparatus according to claim 3 , wherein the diameter of the flange is the same or less than the diameter of at least one flight of the augur.
6 . The apparatus according to claim 1 , wherein the lower section terminates in a flat, horizontal flange at an upper end of the lower section.
7 . The apparatus according to claim 6 , wherein the flange is a half-circle in profile when viewed from the bottom of the flange.
8 . The apparatus according to claim 6 , wherein the diameter of the flange is the same or less than the diameter of at least one flight of the augur.
9 . The apparatus according to claim 1 , wherein a lower portion of the upper section and an upper portion of the lower section form the augur conveyance restrictor element.
10 . The apparatus according to claim 9 , wherein the augur conveyance restrictor element is configured in an open configuration when the upper section is aligned coincident with the lower section.
11 . The apparatus according to claim 9 , wherein the augur conveyance restrictor element is configured in a closed configuration when the upper section is not aligned coincident with the lower section.
12 . The apparatus according to claim 1 , further comprising a hollow augur stem through which backfill material flows during operation.
13 . The apparatus according to claim 1 , further comprising a tip at a bottom end of the dual-section drilling augur through which backfill material flows during operation.
14 . A method for building expanded shaft augured foundation elements, comprising:
aligning a lower section and an upper section of a dual-section drilling augur to achieve an open configuration to allow for augur spoil conveyance.;
advancing the dual-section drilling augur in to a subsurface ground material, wherein as the dual-section drilling augur cuts into the subsurface material, cuttings are conveyed upwards on flights of the dual-section drilling augur, enabled by the open configuration;
placing backfill material into the dual-section drilling augur when design depth has been achieved;
raising the dual-section drilling augur to allow the flow of the backfill material out of the dual-section drilling augur at the design depth;
re-advancing the dual-section drilling augur downwardly into the backfill material until the backfill material forms cuttings on augur flights of the lower section;
reversing rotation direction of the dual-section drilling augur causing the upper section to swivel relative to the lower section and placing the dual-section drilling augur into a closed configuration which prohibits the upward conveyance of cuttings; and,
creating an expanded shaft, augured foundation element through a combination of downwardly movement and the reverse rotation of the dual-section drilling augur forcing the backfill material cuttings that are on the augur flights of the lower section to move down and outward relative to the dual-section drilling augur.
15 . The method according to claim 14 , wherein reversing rotation is rotating the dual-section drilling augur in a counter-clockwise direction.
16 . The method according to claim 14 , wherein backfill material is placed into a hollow augur stem of the dual-section drilling augur.
17 . The method according to claim 14 , wherein the backfill material flows out of the placing backfill material into the dual-section drilling augur from a tip at a bottom end of the dual-section drilling augur.
18 . The method according to claim 14 , wherein the expanded shaft is located at at least one of the bottom of the augured foundation element and at a distance above the bottom of the augured foundation element.
19 . The method according to claim 14 , further comprising continuing reverse rotation upwardly to extract the dual-section drilling augur to complete forming the augured foundation element.