Pyramidal or conical shaped tamper heads and method of use for making rammed aggregate piers
AssigneeGeopier Foundation Company, Inc.
InventorKord J. Wissmann
Life of this patent
Estimating the term…
Abstract
A tamper head having an elongated pyramidal or conical shape is used to construct rammed aggregate piers. The pyramidal or conical shape of the tamper head is more efficient at building up lateral earth pressure and provides for greater economy in the construction of the piers than available with existing methods that rely on tamper heads with flat bottoms and beveled sides.
Claims30
A method of constructing aggregate piers comprising the steps of:
- forming an elongated cavity in a ground surface, said cavity having a sidewall and a generally uniform cross-sectional area;
- placing a lift of aggregate into the cavity with a lift thickness approximately equal to a distance across the cavity;
- tamping the lift with a pyramidal or conically shaped tamper head having a substantially hollow portion and a top or base approximately equal to said cross-sectional area of the cavity, and a bottom or tip no more than about 20% of the area of the top or base, to increase the lateral stresses in the sidewall of the cavity, wherein the tamper head is sized and configured to connect to and be manipulated by a tamper rod, mandrel or shaft that connects to and communicates a mechanized force from a power source to the tamper head for delivery to the lift of aggregate;
- and
- repeating the placing and tamping steps with successive lifts.
An apparatus for forming an aggregate pier in a generally vertical cavity in a ground surface, said cavity having a generally circular cross-section, said apparatus comprising:
- a power source configured to generate a mechanized force;
- a tamper rod, mandrel or shaft in force communication with said power source and configured to move in response to the mechanized force;
- and
- a tamper head comprising a generally pyramidal or conical body tapering toward a point at its lower end and having a cross-section at its upper end which is at least about 90% of said cavity cross-section, said tamper head including a substantially hollow portion and being configured and sized to attach to and be manipulated by the tamper rod, mandrell or shaft, wherein said tamper head receives and delivers the mechanized force from said tamper rod, mandrel or shaft.
A tamper head for forming an aggregate pier in a generally vertical cavity in a ground surface, said cavity having a generally circular cross-section, said tamper head comprising a generally pyramidal or conical body tapering toward a point at its lower end no more than about 20% of a cross-section of an upper end of the body, said upper end cross-section being at least about 90% of said cavity cross-section, said tamper head including a substantially hollow portion and being configured to attach to a tamper rod, mandrel or shaft that communicates a mechanized force from a power source to the tamper head, and wherein the tamper head is sized to be manipulated by said tamper rod, mandrel or shaft.
Dependencies are inferred from the claim text.