MacArthur pile

A patented pile formed by driving a steel shell into the ground to the required depth, putting in small quantities of concrete, and hammering them down so as to force the concrete into the earth beyond the point of the shell; thus enlarging the end and greatly increasing the bearing area. The shell is afterward withdrawn gradually, as the hole that it made is filled with concrete. If the shell were left in, the method would be far more satisfactory; as the shaft of the pile is liable to be seriously imperfect. Same as pedestal pile.