Extensible shells and related methods for constructing a ductile support pier

A method for constructing a ductile support pier in ground, the method qcomprising:

• positioning an extensible shell for driving into ground, the shell defining an interior for holding granular construction material and defining a first end having a first opening therethrough for receiving the granular construction material into the interior and an opposing second end having an end closed by a cap;
• inserting a driving mandrel into the shell, the driving mandrel further comprising a removable driving collar for using in driving the nested extensible shell, and a removable pin;
• driving the shell into the ground using the driving mandrel;
• removing the driving collar and continuing to drive the mandrel such that the shell cap is removed;
• filling the shell with granular construction material;
• compacting the granular construction material such that a bottom bulb is formed beneath the shell as driven into the ground;
• raising the mandrel out of the shell while simultaneously adding additional granular construction material to fill the shell and form a ductile pier.