Foundation members for reactive soils and methods and machines for installing same

A method of embedding a threaded foundation component in ground with a layer of reactive soil with a combined drilling and driving machine, the method comprising:

• with an automated controller executing a control program, controlling the machine to begin an automated embedment operation to drive a threaded foundation component into a reactive soil with a combination of torque and downforce;
• for a first portion of the embedment operation, with the automated controller, controlling the machine to advance a drill bit through the foundation component to extend out of an open lower end to cause sheering of the soil around the foundation component;
• and
• for a second portion of the embedment operation, with the automated controller, controlling the machine to retract the expanding drill bit back into the foundation component and to continue to embed the foundation component until a target embedment depth is reached.

A foundation component for use in ground with a layer of reactive soil comprising:

• an elongated hollow shaft;
• a driving coupler at a first end of the hollow shaft;
• an external thread form beginning proximate to a second end of the hollow shaft and extending along its length;
• and
• at least one shearing feature formed on an outer surface of the shaft between the thread form and the driving coupler.