Patent ID: 9181673
Filing Date: 2015-11-10
Classification: E02D

Abstract:
1. A method of constructing large diameter underground piles, comprising the steps of: a) providing an underground, small diameter cylindrical pilot core made of mechanically erodible material extending along a central axis of a pile to be constructed; b) excavating the soil around the pilot core using the pilot core as a guide for a drilling tool, the tool comprising: a central, cylindrical guiding cavity adapted to fit around the core; first lower cutter elements for drilling the soil underneath the tool; and second inner cutter elements located above the cylindrical guiding cavity, for milling the top of the core as the tool moves downward guided along the same core; and c) milling the top of the core as the tool moves downward guided along the core and filling the borehole formed by the soil excavation with concrete.